Amundsen Sea 2009

finally, pictures.

2009-06-28T07:29:00.002-04:00

A little late, but for those still interested, I've posted some pictures of this cruise on my web site:

http://www.princeton.edu/~cmlittle/Antarctica2009.html

30 miles and counting

2009-02-26T12:52:00.000-05:00

Well we have made it into protected seas about a day and a half
earlier than originally planned and should be in P.A. in 5 hours or
so. Hurray! I don't think anyone on the cruise is complaining. In
fact, there's a lot of smiles and more laughing at the lunch table
than there has been in a while. It has been a long transit. 12 days
since our last view of an ice shelf, probably 10 days since our last
view of sea ice. It reinforces how far away we actually were from
civilization.

I'm downloading pictures that other people have posted on the public
drive, trying to make sure that I have a record of all of the events
and people who were on the cruise. We did take a cruise photo on the
bow yesterday, but I'm trying to capture the day-to-day activities.
I find that it's not hard to remember the people and activities from
the 07 cruise, but who knows what happens after more time. Here's a
list (still no photos) for you and for me of some of the things that
I will remember from this cruise (in no particular order):

The Autosub's harrowing experiences but ultimate triumph
The PIG's southern notch -- caves, currents, and chaotic ice
Interacting with DT's class
Models and CTD observations that are not too different
Penguin and people party on the ice
Fishing boats against the Getz ice shelf
Receiving pictures of Liz's growing belly
When I decided I'd sample the water in insulated gloves instead of
barehanded
Naps on the partially full beanbag
Intense Scrabble matches
(I'm sure there are more...)

I had a "closing" interview with the videographer documenting the
cruise (Sarah) a few days ago. I spent a fair amount of time with her
and the other photographer on board talking about the ocean -- water
masses, heat transport, mixing, sub-ice circulation, etc. They
always said that I was generous with my time and explained these
concepts well. But I don't necessarily think that I explained them
better than others -- I'm sure there were a lot of unnecessary
detours -- I just have a compulsion for them to understand! Despite
the fact that it's shrouded in the guise of answering their
questions, I wonder if it's even for their benefit. I learn from
trying to explain; it helps me form connections between disparate
ideas. It also makes me feel like I've learned something over the
past 4.5 years in graduate school.

Anyway, in the interview Sarah asked a typical question -- open, more
philosophical than scientific, probably unanswerable -- about why I
want to be a scientist and why I choose to study Antarctica. And,
cognizant that it was a little cheesy, I said it was about learning
something new. The explaining (teaching, formally or informally) that
I get to do, along the way and afterward, is inseparable from the
learning. The blog is an attempt to do this in a different format.
So for those who've said thanks on the blog, it's really about me --
thank you for listening and your comments. If you enjoyed it let me
know why, where it was interesting, where it lagged. If and when
there is a next time, I hope there are even more questions from
shadow crew members, peanut galleries, friends, family, and anonymous
lurkers.

Stay tuned for links to pictures and feel free to continue to comment
on the blog -- they'll all be forwarded to me.

Chris

weather=better, but not good

2009-02-23T16:11:00.000-05:00

Meteorological Situation at 230900Z: A 942 mb dynamic low pressure
system is located near 63S 089W with an occluded frontal system
spiraling inwards to its center. Your track lies about 120 nm north
of the occlusion. This Low is moving southeast and is forecast to be
located near 65S 084W at 231800Z with a central pressure of 945 mb;
forecast to continue moving southeast and located near 66S 072WS at
241800Z with a central pressure of 954 mb. A trough upstream will
move east and over your track at 241200Z.

2. 24 Hour Forecast commencing 231800Z along estimated track from
58.5S 089.0W on a course of 325T/07.0kts as indicated reference A:
A. Sky/Weather: Mostly cloudy with few moderate rain showers,
becoming cloudy with scattered moderate rain showers at 241200Z.
B. Visibility (NM): Unrestricted, except 1-3 in periods of
precipitation.
C. Surface Wind (KT): WNW 45-55; decreasing to WNW 30-35 at 240000Z;
decreasing to WNW 25-30 at 240600Z.
D. Max/Min Temperature (C): 7/6.
E. Sea Surface Temperature (C): 4.7, increasing to 5.4 at 241800Z.
F. Combined Sea (FT): WNW 33-39; abating to WNW 18-24 at 240000Z;
further abating to WNW 13-17 at 240600Z; decreasing to WNW 12-15 at
241200Z.
G. Ice accretion (cm/hr): None.

3. Outlook to 48 hours: The trough over your track will pass to the
east by 250000Z; however, another trough, associated with a 981 mb
Low near 58S 087W at 251200Z, will begin affecting weather over your
track. Winds WNW 25-30 knots at 241800Z; veering to NW 25-30 knots at
250600Z; then backing to WNW 30-35 knots at 251200Z. Combined seas
WNW 12-15 feet at 241800Z; building to NW 15-18 feet at 251200Z.//

the southern ocean win(d)s

2009-02-23T09:33:00.000-05:00

Well you can't get too confident predicting an ETA back in port when
you have to cross 2000 miles of ocean. We're now heading northwest
(wrong direction) trying to hit the 40-50 foot oncoming waves in the
least destructive manner. Even so, most stuff that wasn't tied down
is on the floor. Over the course of the night, I was entertained by
the migration of my chair and everything else that was on the desk
across the room. At least it gave me something to do since I was
awake anyway. Everything eventually ended up in a pile near the door
which I needed to dig out of before stumbling to the mess this morning.

Word is it will calm down later today. Hope so!

the domain of the albatross

2009-02-22T17:54:00.000-05:00

We've crossed 60 south and have picked up a bunch of albatrosses
(albatri?) along the way. Truly magnificent -- they swoop down right
above the waves and seem to have no problem with 30 knot winds. In
fact some of the bigger ones apparently won't even fly until the
winds are strong. They'll just bob in the water. I guess it takes
way too much energy to flap their winds to make it worthwhile.

Most of the ones we're seeing ONLY have about a 6 or 8 foot wingspan.

We hit a period of 50 knot winds and rain earlier today and lost the
birds. But we are now suffering the aftereffects -- big waves, the
first to really move the ship up and down. Good timing for the
pingpong finale. But these guys are so good it didn't even seem to
affect their game.

It does affect my ability to stare at a computer screen though, so
excuse the brevity on this report. Finishing my sections of the
cruise report took away my energy for writing.

670 miles to the straits of magellan, then 20 hours to P.A. from
there. Yee-haw!

Thanks!

2009-02-21T19:35:00.000-05:00

to the shadow friends for their analysis and comparison of the
Antarctic data to that of the California Current...

You're right! The CTD profiles is confusing and a little weird.
Sea ice really does change the salinity of the top of the ocean. And
it can vary dramatically depending on what season and where you are.
Because we visit Antarctica in the summer, when sea ice is melting,
usually we see a really fresh layer of water near the surface.
Because that water is fresh, it is lighter, and it stays on top. I
think the experiments you have planned sound like a great idea! One
thing that's pretty cool to do is just to watch what happens to the
temperature of a glass of ice water if you pour some salt in it. Any
ideas?

You're also right that the temperature change is gradual compared
with California. But what's really interesting is that it gets
warmer the farther you go down towards the bottom. That's strange for
most people because usually warm water floats on top of cold. But in
Antarctica, especially the Amundsen Sea, the salt is more important
to the density than temperature. So warm water will sink below cold
water if it is salty enough.

For everyone else (?) reading, we've broken the 1000 mile to port
mark and continue forging on. Winds are picking up again after a
short period of blue sky yesterday afternoon. Drafts of the cruise
report sections are being reviewed, and I'm getting ready to settle
in to watch a movie. Unfortunately, I've been having trouble keeping
my eyes open whenever I sit down to watch a movie or read a book. I
guess a gentle rocking helps inspire sleep no matter how old you are...

1300 miles and counting

2009-02-20T14:31:00.000-05:00

Hi all,

We're slowly getting closer to P.A., but slowly is the operative
word. Our top speed is usually about 11 knots, but yesterday we
probably averaged more like 9 as the wind was blowing at 30-40 knots
all day. The ship was pretty stable in all of that but the views
were limited. Lots of spray and low clouds, mixed snow and rain.
It's calmer today -- we may have even seen a quick glimpse of sun.
We are still seeing icebergs fairly frequently, although they are way
smaller and more eroded. It doesn't take long once you get past the
continental shelf break for icebergs to take a beating by the seas
and (relatively) warm water.

Even though the waves are smaller today, there may be more movement
on the ship. The waves are hitting us on our port side as opposed to
head-on, illustrating the difference between pitch and roll. Where
it really makes a difference is the pingpong table, which is aligned
with the ship. Any type of lob moves a lot before you get a chance
to hit it.

I'm busy writing a section of the cruise report and editing some
others. Although we've still got 5-6 days before port, several
gentle reminders have been made prodding us to produce something
sooner rather than later. Yesterday I cleaned all of the oxygen
titration equipment and got the titrator to be broken down. Have to
admit, I'm not sorry to see that responsibility go away. It's
necessary, but a little anticlimactic. You spend a lot of time very
carefully making sure that you get values that have already been
determined by the sensors. Of course, if the sensors are wrong, it's
invaluable to have a double check, but still it's a lot more work
than reading a screen at the CTD console.

I'm also getting prepared to send some O-18 samples home (did I ever
talk about O-18? should I?) and have scored an ideal box on board the
ship. So I'm amassing all of the packing materials and making sure
they don't break on the long journey back to the states.

So between the cruise report, emails, thesis writing, and the blog,
I'll be doing some writing over the next week or so. Yet another
reason to hope for calm weather. Gets a little old to be rocking
back and forth while staring at a screen...

1800 miles to go...

2009-02-18T22:35:00.000-05:00

according to the TV screen (which, if updated, gives our waypoints
and ETA) until we return to dry land. We're following a "great
circle" (extra credit?) back to P.A and the straits of Magellan. At
about 10 knots, we should be in sometime on the 26th. A little ahead
of schedule, but there's a lot of ocean and potential weather delays
until we get there. As of right now, it's smooth sailing though.

I'll probably write some reflections on the trip over the next week
or so, as I work on putting some of the data together for the final
cruise report. But if anyone has suggestions, or questions that have
have been left unasked, let me know (write a comment!).

I'm trying to switch back to a more traditional schedule, so I've got
to get to bed now -- before I get hungry, since I skipped midrats.
The rocking motion seems to help...

Fwd: 0901.6

2009-02-17T00:04:00.000-05:00

And, speaking of sea ice, the (final?) weekly report!!!!!!

Back in the 1970s, NASA investigators divided the circumpolar
Southern Ocean sea ice pie into 5 pieces and began to monitor their
sea ice extents and concentrations. The overall ice extent has
increased since then, mainly due to changes in the Ross sector, in
contrast to the widely publicized declines in the Arctic summer ice
minimum. However, the Amundsen and Bellingshausen sector has bucked
the Antarctic trend, with the length of its sea ice season declining
by more than two months. This is comparable to Arctic changes over
the same period and, along the west side of the Antarctic Peninsula,
has been associated with one of the largest rates of regional surface
warming on the planet.

The Amundsen Sea differs from its Ross and Bellingshausen neighbors
by harboring broad, quasi-permanent areas of fast ice, held in place
by myriads of large, grounded icebergs. It experiences prevailing E/
SE winds, less conducive to ice export than the Ross Sea southerlies.
Since the melting point of ice in seawater decreases as pressure
increases, upwelling beneath its deep-rooted ice shelves will be
stronger than in the Bellingshausen Sea, where the ice shelves are
thinner. But like the Bellingshausen, its precipitation is relatively
high, leading to 'snow ice' formation. This occurs when seawater
floods ice floes with negative freeboards, sunk by their snow loads,
with the ocean to atmosphere heat flux essentailly making an end run
around the tattered sea ice blanket.

Is the Amundsen sea ice thinner now in response to increased
upwelling of deep water that has not lost all its heat to melting
glacial ice? Is its snow cover thicker due to increased precipitation
in an enhanced hydrological cycle? Are there more icebergs to ground
the fast ice and also drive cooling and upwelling, now that the
glaciers are moving/calving faster? Is sea ice production and melting
higher or lower because wind strength and directions have changed due
to the deepening of atmospheric lows along the continental margin? We
don't yet know the answers to these and similar questions, in part
because few sea ice measurements have been made prior to NBP09-01
over the large but remote Amundsen continental shelf.

In this context, the sea ice component of O-274 has occupied 20 ice
stations and bagged 90+ m of ice core along N-S and E-W transects,
noting that the amount retrieved for structural analyses is a record
compared to the 3.6 m length of the sea ice team. Their work has been
reliably supported by the RPS MTs and others, and extensively
photographed and videotaped, including provocative pictures of the
bottoms of sea ice floes. Along with visual and camera logging of
surface conditions underway, the sea ice measuring, sampling and
subsequent modeling will be compared with satellite records of the
sea ice cover, and with data from three deployed ice mass balance
buoys currently reporting to collaborators on the home front. When
all is said and done, we should have a much better understanding of
the role of sea ice in the Amundsen Sea's deep water heat sink.

Macrophotographs of snowflakes were taken during 8 of the 12 short
snow showers that punctuated the otherwise sunny summer weather
during the first 6 weeks of the cruise. These photographs are being
analyzed to determine the size distribution and crystal habits of
falling snow, to complement records of the timing and intensity of
snowfall events measured with photoelectric particle counters mounted
on the ship's ice tower. The timing and relative intensity of
snowfall measured on the ship during cruises NBP07-02 and NBP07-09
are well correlated with the timing and relative intensity of
precipitation forecast by the ECMWF and some other weather models. To
correlate the absolute magnitude of documented precipitation events
with forecasts and reanalyses, one must know the size distribution
and water equivalent mass contained in the falling crystals. Most
snow observed during the warm summer snowstorms consisted of rimed
dendrites, with more plates, sector plates and rare hollow columns
closer to the continent, and one snowfall event composed entirely of
ice needles up to 3.5 mm in length.

Work on the continental shelf concluded near the end of this week,
and for mile after mile on and north of the shelf we weaved our way
through what may be the largest iceberg graveyard in the Southern
Ocean. Their common presence in this deep region suggests a large
area of weak or waffling currents. The varied features on overturned
bergs provided a crash course on what the bottom surfaces of melting
ice shelves probably look like.

2009-02-16T23:59:00.000-05:00

Hi everyone.

Feeling a little brain dead after a long quiet day as we transit to a
site in the middle of the southern ocean, so I can't think of
anything exciting to write about. I did get a question from DT's
class though so I think I'll just go with that.

The question was: is old sea ice denser than new sea ice?

That's a great question, but it's a very tough one to answer. My
guess is there is no simple rule relating density to age. Ice will
in general grow over time (as long as it's below freezing and the
water is cold), so we can generally say that old ice is thicker. But
the mass of the same size block of new and old ice is not as simple.
First of all, there are many types of sea ice (each of which has a
great name -- frazil, shuga, nilas, etc.), and each of which one of
which forms under different environments. The formation determines
the crystal structure which governs how tightly packed the ice is.
This crystal structure will change as the ice evolves and is heated
and cooled from above (by the atmosphere) and below (by the ocean).
Also involved in the aging is a very gradual moving around of salt,
which tends to form channels through the ice. Then snow (which is in
generally lighter than ice) falls on top of the sea ice and may or
may not be incorporated into the ice itself. All of these processes
(and I probably missed others) changes the density of sea ice (as
well as the characteristics that govern its effects on climate),
which make it difficult to generalize.

So if any of the students who asked this wants to consider pursuing
research, this question will probably still be around in some form
when they consider graduate studies.

Good Luck!

Re: batten the hatches: NBP returns to open ocean

2009-02-14T15:36:00.000-05:00

sorry for the forwards, but thought this was worth relaying. I'll
try to take some pictures of the crossing. Could get exciting!

On Feb 14, 2009, at 4:42 PM, NBP, MPC wrote:

Hello all,

Just a quick note to remind you that we will be departing the smooth
existence of ice protected sailing sometime tomorrow, Feb 15 and will
again be subject to the large swells of the southern ocean. So if
you value what you have sitting on your desk, tie it down. If you
need assistance with any tie downs, please feel free to consult with
any of the RPSC techs. Please doublecheck any liquids and things in
hoods and fridges.

We should finish with CTD/mooring/ice coring in the morning tomorrow
and will then head north and west to the site for the big mooring, at
roughly 66 S, 129 W.

Cheers and Happy Valentines Day!

Fwd: Welcome back to the Dead Zone

2009-02-14T13:34:00.000-05:00

Hi all,

This blog has at times suffered from out-of-date transmissions. We've
moved back into the "dead zone" over the past few days, so I expect
some slow responses and posting. Stick with us. Once we get back to
the Alive Zone (INMARSAT), I should be in 3x/day email communication
from here on out.

It's been nice to see the comments recently. I'm hoping to see more
when email kicks in again (no pressure, though)!

Begin forwarded message:

From: NBP System Administrator <admin@nbp.usap.gov>
Date: February 14, 2009 3:08:41 PM GMT-03:00
To: all_on_nbp@nbp.usap.gov
Subject: Welcome back to the Dead Zone

Please note we're once again out of INMARSAT range. Our last
successful email run was Friday, Feb 13 ~13:00 ship's time. Because
we are planning to be here for a rather short duration, we are
queueu'ing mail normally and we will wait until we are back in
INMARSAT range to send and receive mail from the ship. Looking at the
current plan, I expect we should start to see a signal again sometime
in the next 12-24 hours.

If you have urgent needs for off ship email before then, please
contact me.

For those of you who have not already sent that romantic missive to
that special someone for Valentine's Day (or made other
arrangements), may I suggest that nothing says I love you better than
a satellite phone call from the Amundsen.

(C.L.) Note on this last part -- romance comes in 7 minute increments
on the satphone, and is shared with the rest of the e-lab. Not
ideal. Sorry Liz.

carbon pumps and other assorted goodies

2009-02-13T16:38:00.000-05:00

Hi all,

First, seems like my entry on my talk a few days ago sounded a little
downbeat. It wasn't meant to be -- just trying to reflect on how to
do it better next time -- all the feedback I've gotten since then
suggests that people were involved and are excited about it.

Next, weather. Calm as possible today. Very glassy water, scattered
with just very small chunks of sea ice and cluttered with medium and
large tabular icebergs. Can't really remember a day like this on the
two Antarctic cruises I've been on now. Very cool for photos: all
the ice reflects in the water below, you can see ledges beneath bergs
deep underwater, and there is just a very thin layer of forming sea
ice at the surface. The wake from the ship is really the only
disturbance to what would be a totally tranquil scene. Unfortunately
we wouldn't be able to experience it without a 300 foot ship tearing
up the picture.

Now, the plan. Exciting news this morning. Because of the light sea
ice, we're able to head back to the Getz ice shelf, which we had to
pass by a few weeks ago due to stormy seas, as referred to in the
weekly report. So Southward we steam! Still competing in the
pingpong tournament, but working my way through the losers' bracket.
It's a long way to the title from where I stand.

Finally, the carbon stuff. Got an interesting comment a while ago
from Roy aka Dad about how the oceans work with respect to Carbon
Dioxide.
"One highlighted the fact that the deep ocean is kind of a kidney for
CO2 (absorbs it and flushes it out of the atmosphere), but with a
super-long cycle it just can't keep up."

This is true, but it's really only one part of the story. I'll
elaborate in a very brief way here which doesn't do this topic
justice. But I'm not a very fast typer, so:

Oceans can be looked at as having two parts -- the surface, which is
exposed to the atmosphere and which can exchange gases, heat, and
freshwater (through evaporation and precipitation), and the deep,
which only very slowly exchanges with the surface. Deep oceans
"sequester" carbon because they hold way more than they would if they
were in equilibrium with the atmosphere. The only way for this to
happen is for carbon to move from parts of the ocean that have less
to those that have more. In order to make this work, we need "pumps"
-- processes which allow us to move carbon in the opposite direction
as the difference between the surface and deep (like moving water
uphill!) The two most important are referred to as the solubility
and biological pump. The solubility pump is put into action by the
sinking of cold water near the poles. Since CO2 is more soluble in
cold water than warm, and these cold water fill most of the ocean's
volume, more CO2 is locked up at depth than at the surface. The
biological pump works because phytoplankton use CO2 near the surface
of the ocean to grow (photosynthesis). They die/are eaten/decompose
and eventually sink. But as they sink, they are "remineralized" into
forms of dissolved CO2 by bacteria and other organisms. If they
break down below the level where the atmosphere interacts, the carbon
is trapped in the deeper water. Over the 1000's of years it takes
for some parts of the ocean to get back to the surface, accumulated
dead stuff can take a lot of carbon out of the air.

So the net effect of these pumps is to remove CO2 and they WILL
operate to bring down concentrations of CO2 in the atmosphere if
given enough time (1000's of years). But if we make our model a
little more complicated and look at what happens in different places
near the poles, we see both sources and sinks of carbon. In fact,
where we're traveling, there is a significant amount of upwelling
water (this is the "warm" stuff, CDW) which vents a large amount of
CO2 to the surface. Like a malfunctioning kidney (a very apt
metaphor, coming from me), the ocean may shift it's absorbtion/
venting balance if it is perturbed. More "stuff" may be left in the
bloodstream. Since the amount of CO2 in the atmosphere is so small
relative to the amount in the ocean, even a small change in these
pumps (e.g. changes in the temperature of the water, changes in
locations and strength of winds, dominant phytoplankton species) may
exert a strong (positive or negative) effect on atmospheric CO2.

Enough science for now. Will you be my valentine?

Chris

science talks and new ice.

2009-02-11T15:15:00.000-05:00

Hola everyone,

I have strongly mixed feelings about giving "talks" about my work.
First of all there's a little nervousness and public speaking
anxiety. But I think one of the main problems I have is the lack of
interaction with the audience. Especially when the audience is mixed
-- some get bored while others are working hard to follow along. In
these situations, I feel like I drag trying to explain everything on
the slides. Talks are much different than teaching in this respect.
Even if I'm lecturing, my goal is to make sure students understand.
In research talks, I should relax that objective a little in order to
keep the pace (in fact I've received this advice before but I'm
trying to internalize it now). I felt a little let down after my
talk today, which tried to accomplish an overview of ocean modeling,
some thesis-related stuff, and some more cruise-related work.
Fortunately, I've gotten a huge amount of informative and
encouragement from the audience since finishing -- restoring faith
that the message got across and that the preparation was worth it.

In order to have really productive, brainstormy type talks on an
individual level, it's important to lay it out there in any form
(maybe unpolished) for people to digest as much as they can. This
may not be a revelation, but for me, it's important to realize that a
talk is really a stepping stone and not an endpoint.

Anyway, enough philosophizing. An exciting development over the past
few days, as we traverse areas of relatively thick sea ice on the
continental shelf break, is the appearance of "new ice". It's been
cold and relatively calm out and sea ice is starting to form (maybe
the summer is coming to a close already?). Though we've been off and
on in heavy "first-year" ice up to 2 or 3 meters thick, new sea ice
is much more exciting. Right when it forms, even when it's very
thin, the waves change and you only see the longer wavelengths. Then
you start to get "fingering nilas" -- which tends to break up and
fracture into thin interlocking segments. For some reason the process
is really exciting for me to watch. I'm hoping this will keep up
over the next few days, before we leave the ice for good. I expect
'll be spending some quality time on the bow if it does.

Weekly Report Time!

2009-02-09T22:40:00.000-05:00

Hi everyone,

Cranking out oxygens today and working hard on my talk (in four
minute intervals between samples), so it's fortunate that it;s weekly
report time -- means I have less writing to do (wouldn't want to
overwhelm my readership...).

One quick note though -- first sunrise/sunset in over a month last
night. Down around 3, up at 5 or so. We've been heading north as
the days have been getting shorter. Supposedly the night shift got
quite a visual treat. I saw some orange, but had to head to bed
after. I'll try to stay up for some of the excitement tonight but
cloudy skies may dull the glow.

The report follows, with only minor edits:

Fifteen years ago next to nothing was known about the bathymetry and
ocean circulation on the Amundsen Sea continental shelf, a nearly
inaccessible backwater presumed to have little relevance to such
weightier topics as Antarctic Bottom Water formation and biological
productivity, much less to ice shelf dynamics. However, unimagined
and highly relevant sea floor topography and oceanographic processes
have since been found lurking beneath its nearly perennial sea ice
cover. The deep troughs cut by larger ice streams during past glacial
epochs are now being filled by 'warm' deep water, speeding wastage of
the glaciers that carved them. Melt-driven upwelling of water
enriched in glacial flour drives persistent algal blooms, at odds
with conventional boom and bust cycles of macro/micro-nutrient
limited regions. Downwelling doesn't much matter here, but the
upwelling transports ocean heat to the floating and thinning parts of
the West Antarctic Ice Sheet.

Recent Amundsen expeditions, initially on the NB Palmer and
subsequently on Polarstern and JC Ross, have defined the late summer
water properties on the Amundsen continental shelf and provided
indications of their interannual variability. But longer and more
continuous records are needed to determine how this regional sea is
responding to seasonal and other atmospheric cycles, and causing the
increased melting of continental ice. That work began modestly 3
years ago with the setting of several simple near-bottom instrument
packages, some showing expected and others unexpected results when
recovered a year later. As this IPY draws to a close, we are setting
out more heavily instrumented moorings for longer periods and over a
broader area. The focus is on temperature, the primary gauge of
subsurface change, and on deep water inflow at depths >400 m,
lessening the risks posed by hundreds of large icebergs that infest
the eastern Amundsen. Nine bottom-anchored moorings have been
deployed to date on 0901, and another five should be added to the
array during the next week.

Those moorings must be recovered to retrieve the recorded data, but
we have also set out, on fast ice east of Bear Peninsula, an Ice
Tethered Profiler that knows how (if not when) to call home and
report its measurements. A joint effort with Woods Hole investigators
Toole & Timmermans, this is the first ITP deployment in the
Antarctic, following ~30 that have been placed on drifting pack ice
in the Arctic. The fast ice is thinner than we would have liked, with
seal holes nearby and a sporadic break-out record. But ice options
were slim this year, and with a bit of luck it will remain fast until
a daily 750 meter-depth record of temperature and salinity can be
generated over several seasons.

Shortly after leaving the idyllic conditions of Pine Island Bay,
progress was hampered by fog and ice, then high winds, confused seas
and cruise time contraints led to the cancellation of CTD profiling
transects near two ice shelf fronts. A 15-hour round trip back to the
fast edge turned into a wild goose chase, but a large raft of
penguins (>75) were observed there, all in Emperor's formal dress. A
non-functional sea ice buoy on one ice floe replaced a curious piece
of rubber flotsam from another. Fisherfolk were encountered occupying
a planned station site, and other fishing boats called to alert us
that they were (temporarily?) beset nearby. All are believed to be
longlining for toothfish (Chilean Sea Bass to your local
restauranteur), at depths below that of our bottom-moored instrument
arrays.

Amid these and other distractions, a fair amount of useful work was
accomplished. Accounting during the past week included 21 CTDO/LADCP/
rosette stations, 8 TMC casts, 6 ice sampling stations, 4 moorings
set and 1584 km of ship track swath-mapped. Phaeocystis was found to
dominate the high biomass in the Amundsen Polynya, but DMS was lower
there than in PIB and dissolved iron was low except below 100 m near
the ice shelves. A CRREL Ice Mass Balance buoy was installed near the
ITP, and is now reporting local surface conditions, according to
Lamont weatherman Richard Cullather.

RPS and ECO support has been exemplary, along with that of our
mooring maestros..

the ice tower

2009-02-08T21:01:00.000-05:00

is located above the bridge on the NBP, up three ladders. It is by
far my favorite place to spend some time for work or reflection, and
it is where I'm sitting now working on a "science" talk for the ship
that I just found out I'm giving in a day or a half. I'm about 75
feet or so above the water, and taking in a spectacular 270 degree
vista of water and ice. (Couple of emperors hanging out on a floe to
the port side.) It gets a little shaky and tippy up here in ice and
high seas, but it's worth it. Also it affords some privacy
sometimes, which is hard to come by on a 300 foot ship with 50 or so
people on it.

We're heading Northeast now toward where we entered the Amundsen Sea,
which has inspired a sense of the cruise drawing to a close, even
though we still have about 3 weeks left before we return to PA.
Also, most of the activity over the next few weeks will be focused
around moorings and sea ice. So in a way it's an ideal opportunity
for me to reflect on the new information and ideas I've seen on the
ship and integrate them into my thesis -- or at least plan for how I
can use them in future research. Hopefully the presentation will
help me with that as well!

(Couple more emporers swimming to port -- much cooler than seeing
them on ice -- they "porpoise", jumping out of the water just like
dolphins)

Anyway, I've found it hard to focus on my thesis work up to this
point with all the more pressing activities -- and the hope of using
my ocean model for a worthwhile porpoise while on the ship. Despite
the fact that I have less to do around the ship, today has been a
positive sign that I'm still able and motivated to continue the work
I left behind...

Ice adventure

2009-02-07T09:26:00.003-05:00

Since Chris can't send pictures to his blog from the ship (but was able to send this small one in an email), I'm posting it for him to share with everyone. A friend of mine said this picture looks like a Mexican stand-off, man vs. penguin. The penguins don't look to worried to me! The "baby" penguin on the right is actually a stuffed animal.
Liz Little

Emperors and the ITP

2009-02-06T21:29:00.000-05:00

We've deployed nine moorings so far on the cruise. Each one has been
sent over the side of the ship with a large concrete block connected
to a series of CTD-type devices via a rope and some floats. The
instruments are fixed at specific depths in the water column to
capture features of interest -- in the case of those deployed near
ice shelves, where models and observations imply that most of the
heat flows under the ice and meltwater flows out.

These will provide a long and continuous time-series of data that
will help us interpret tides, seasonal variations in flow and water
properties, and longer-term trends. However, the two biggest
downfalls about moorings is that information that they provide is
limited to specific depths and the data is not available until they
are successfully recovered. Given the obstacles to successful
mooring recoveries here (sea ice, bad weather, moving ice shelves,
etc), it is a huge benefit to be able to see the data in real time.

Enter the ice-tethered profiler...

which sits on top of the ice with a wire dangling below. Once a day,
a CTD device runs up to the just below the ice and down to the
maximum wire depth, giving a complete picture of the "water column
structure". When it reaches the surface, it sends a satellite signal
with the data it has collected that day. Up to this point these have
only been used in the arctic, where ice sticks around for longer.
However, some sea ice in the Amundsen is "fast ice" -- meaning it is
connected to the land (or ice on the continent). Because it is not
subject to waves and crashing into other floes, it may stay in one
frozen piece for many years. Yesterday several brave souls took a 3
mile ski-doo from the fast ice edge into a suitable site and
assembled the device between two ice shelves (the Thwaites and the
Crosson). A long day for those involved.

For those who weren't, the gangway was rolled out onto the ice and we
played with penguins. Actually the rules of the Antarctic and the
USAP do not allow us to play. It's more a game of mutual checking
out and bemusement. They chuckle at us in our matching orange float
coats and clumsy boots, and us at them in their bottom heaviness and
incredibly flexible necks. Emperors this time -- flashes of orange
and yellow tastefully integrated into the more traditional black tie.

still waiting

2009-02-05T13:29:00.000-05:00

(15 minutes or so) to get on the ice. But, in the meantime, I got
word from the chief scientist that it's OK for DT and class to use
those two CTD profiles from NBP0702 for your IPY activities. We'd be
interested in hearing what you're up to and how you use them. Also
I'd be interested if you and your class have any comments or insight
on the profiles. e.g. How do they differ from the California
Current? Where is most of the heat that can melt ice? But any
thoughts you have would be interesting.

exciting times

2009-02-05T11:36:00.000-05:00

One of our projects out here is to place an "Ice tethered profiler"
on a relatively stationary ice floe. It's deployment will involve a
fair number of people, ski-doos, a winch, and assorted other heavy
equipment. The powers that be have decided there may be enough time
for everyone to get of the boat if they so choose. Everyone on board
is excited; both the day and night shifts are awaiting the OK from
the powers that be. I'll give a report on the events tomorrow, but
in the meantime, I'm going to watch some "backing and ramming" as we
get the ship into position, but first some quick answers:

Did you see your shadow?

It's been overcast, foggy and snowing, so I did not see my shadow.
But since it's summer here when it's winter in the US, the shorter my
summer, the shorter your winter. What happened in Pennsylvania? I'm
hoping that it will be spring when I return in March.

How much more winter do we expect? (Yes, I know the hemisphere's are
reversed, but the kids wanted me to ask.)

If I remember correctly, you and your class are located in the
southwest...Is there really even a winter there?

They also wanted to know, if you are sleeping when a calving occurs,
can you hear it through the hull or do the engines make too much noise?

If I was a lighter sleeper, I might be able to hear one, but I could
sleep through a collision with an iceberg.

Calving, though, doesn't happen very often (at least big calving
events). We're in front of an ice shelf now (the Dotson) which
hasn't calved in at least 3 years or so. Some of the bigger ice
shelves break off in huge chunks only every few decades.

Chris

weekly update

2009-02-03T16:32:00.000-05:00

Hi all, more progress has been made in the past week, and since I'm
too lazy to report on all of it in my own words, here are some
excerpts from the weekly report. Ask questions on any part that's
unclear and I'll try to give a decent explanation:

In certain parts of North America, February 2nd is when a furry
creature is said to emerge from its burrow and, depending on shadows
seen, there could be several more weeks of winter. Here in the
Amundsen, a furry creature emerged from the sea early today to
inspect a ongoing ice buoy deployment, and the weather turned from
fair to foggy. Whether or not any shadows were cast, forward progress
has been slowed somewhat by the elements as we enter late summer and
the second half of NBP09-01.

Autosub prep work and forays under the PIG kept the ship within a
half day of the ice front for most of the week, resulting in fairly
comprehensive coverage of the inner Pine Island Bay (PIB), as another
1522 km of seafloor were swath-mapped. Twenty four CTD - LADCP -
rosette stations were occupied, bringing the total for that activity
to 111, and documenting upwelling near the center of a clockwise gyre
in the bay. Temporal and spatial water column variability is
relatively high in the upper 400 m, but with coherent extrema in
meltwater content, light scattering and other parameters. XBT casts
were made along the ice front, during which the height of the
'barrier' was calculated at regular intervals using radar range and a
ship's sextant, while its its draft was estimated from multibean side-
echoes.

[The sea ice team] sampled fast ice southeast of the Thwaites Glacier
Tongue and near the northern end of its sea ice extension, and
deployed two GPS ice motion transmitters on mobile pack north of the
fast ice to monitor drift and deformation. To date they have occupied
8 sites, obtaining 46.5 meters of ice core, from which 331 sections
have been sampled for salinity and d18O, and 163 for chl-a. Mean ice
core thickness is 160 cm, but has ranged from 47 to 469 cm.
Structural analysis of 12 cores includes 137 thin sections revealing
large amounts of complex granular ice and a wide range of crystal
sizes. In addition, meteoric ice appears to comprise a substantial
fraction of the ice in some cores, mainly snow ice from seawater
flooding, with thin layers of superimposed ice from refrozen snow
melt perched above in most cores.

Eleven TMC [trace metal clean] casts were completed this past week to
sample for Fe, organic ligands and phytoplankton parameters and 2 for
large-volume surface water experiments. Six were taken while
transiting a persistent (6 week) area of high phytoplankton biomass
shown by satellite ocean color (chlorophyll) imagery. The responsible
agent is Phaeocystis antarctica, and the high productivity was
accompanied by extremely low surface values of pCO2.

[The photographers] have been busy documenting operations by still
camera and video, some from the zodiac during Asub retrievals, along
with sea ice coring, CTD/rosette work and upwelling near the PIG. Ice
crystals have been photographed under polarized light, the bottom of
the sea ice via a camera lowered through an ice hole, and icebergs
and ice fronts captured in all their revealing detail. They have also
interviewed science personnel, some more willing than others, and are
grateful for the access and cooperation provided.

morale support

2009-02-03T11:59:00.000-05:00

Thanks to those who answered by plea for a response. It's nice to
hear from you. I'll assume there's a few more out there who are
listening as well and so I will continue to ramble.

We've got a little bit of a storm rolling the ship around today.
It's been a while since we've been able to detect motion! It adds a
little bit of excitement to mooring deployments, CTD's, and ping
pong. We're on our way to the Getz ice shelf, a curious and complex
shelf with multiple outlets to the ocean. It seems to be thinning
along with the other, more notorious ice shelves in the Amundsen, but
is exposed to comparatively cold water (only around 0.6C, as opposed
to the balmy 1.2C in Pine Island Bay). From there, we will track
towards the East along the ice shelf fronts of the Getz and Dotson
ice shelves, and will get as close as we can to the Thwaites Glacier.

Apparently, we ran into two fishing boats last night looking for
toothfish (aka Patagonian toothfish, aka Chilean Sea Bass). They were
fishing right over our planned CTD station. I don't know the details
of the encounter and communication, but I'll look into it. The
suggestion was made that we storm their boat to look for fresh
veggies. But my guess is they'd be limited there as well. At least
their fish is fresh!

If I were awake, it would have been strange to see another ship.

Nate + MC, I had heard from someone else on the ship that Google
Earth was planning to do something with the oceans. What do they
include/what can you map? Sea surface height/temperature/bathymetry?
Any information about the interior of the ocean (CTD records/etc?)
And I'll put brewing on the calendar for the spring. Start thinking
about recipes!

Thanks also to everyone for the suggestions on smelly laundry!
Vinegar or baking soda -- interesting. What happens if you use both
at once?

Chris

lurkers unite! make your voice heard!

2009-02-01T01:08:00.000-05:00

Happy February!

I understand lurking -- I would be reluctant to write comments if I
were in your position too. But it really is nice for me to see that
people are interested, and if you're not, let me know what you think
might be worth writing about. Since we've gotten most of the basics
of the science objectives and techniques out of the way, I can
digress or dive in more detail. Your call...

We're approaching hump day on the cruise -- and transitioning
activities to other parts of the Amundsen Sea. Autosub went under
the ice 6 times for up to 24 hours at a time and we spent more time
in front of and around PIG than any other cruise (possibly all put
together) up to this point. In the next few days, we should be back
in the sea ice and placing "drifters" to track the motion of some of
the thicker ice floes. More moorings, including an ice-tethered
profiler, will be deployed. Our general movement will be northwest,
where the water is cooler (but still warm by antarctic standards).
We'd like to understand why.

It looks like email service will continue to be iffy for the next few
weeks of the cruise track so stick with me despite irregular
updates. I'll try to make them count.

Friday night midnight movie last night: Man on Wire. Next Friday
word has it that it will be Encounters at the Edge of the World,
another documentary, this time about Antarctica, and starring one of
the IT techs, a former McMurdo resident. No football here tomorrow,
but I heard a rumor there might be some liquid Nitrogen ice cream.

Hope to hear from you soon!

Chris

smelly laundry, pingpong, and the NBP triathlon

2009-01-29T17:35:00.000-05:00

We're approaching the midway point of this cruise, and though the
focus will shift to other projects in the next few weeks, life has
settled into a quasi-regular rhythm. Up at 11 am or so, lunch for
breakfast, monitor CTD's, run oxygen samples every other day or so,
transition shifts around midnight, then to the gym, sauna, or just
goof around until bedtime. Tonight, I'm running some oxygen samples
while waiting for my laundry upstairs to complete. It's a big
decision whether to do laundry or not and you have to time it because
the ship's water supply is derived from the seawater (via reverse
osmosis) in which the ship is traveling. That means that, not unlike
water at home (but maybe more so), what's living is the water affects
its taste and smell. Up until now I was clueless about the rhyme or
reason behind smelly laundry (and toothbrushing water), but have been
illuminated by the biological oceanographers aboard that this is due
to Phaeocystis, a slime forming and smell-producing algae that blooms
here. I think I timed my laundry poorly today and have potentially
more smelly clothes -- and sheets! -- than I did beforehand. We'll
see -- I'm trying to cover it up with dryer sheets right now. Next
time I'll wait till the diatoms are blooming.

The pingpong season has also started in earnest. We play on a
slightly smaller than regulation piece of wood held up by to
sawhorses in the noisy and probably dangerous cargo hold on a rocking
ship. It's fun, I promise. On a previous cruise one of my fellow
crew managed to develop a double elimination pingpong championship
where you played doubles with a new partner each time. This time, he
and another mastermind have devised a triathlon -- pingpong,
foosball, and pool. Not sure about a lot of details or how pool on a
ship works (is it simple a game of chance?) but I will keep you
updated as these things develop. My chances of winning have
diminished greatly with the addition of foosball.

excerpts from weekly report 3

2009-01-27T16:56:00.000-05:00

Hi all, another edition of the NBP0901 weekly science report is
available below:

Before that, an answer for D. Tortise.
I'm going to have to ask the chief scientist on board if it's OK to
use the CTD profiles. I'll get back to you.

And thanks to those (two) who participated in the "name the sea
iceketeers" contest. It's a tie between the core convicts and the
ice ice babies.

As promised, the weekly report
The Antarctic ice sheet, which appears to have been losing mass at an
accelerating rate over recent decades, is potentially the largest
contributor to future sea level rise. Current ice loss is focused in key
drainage basins where dynamical changes in outlet glaciers have led to
increased discharge, most significantly along the Amundsen Sea coast.
The
apparently synchronous response of independent glaciers that thin most
rapidly over their ice shelf extensions is generally assumed to be
ocean-driven change, but the actual mechanisms are speculative.
Flooding of
the deeper parts of the continental shelf by 'warm' deep water (CDW)
causes
rapid melting of floating ice, but we need to understand better the
processes that control CDW inflow variability and interactions with that
ice in order to quantify past, present and possible future oceanic
forcing
of the glaciers. CTD profiles and moored instruments on the continental
shelf provide pictures of the spatial and temporal variability of CDW
inflows, while an AUV can do the same in the ocean cavity beneath an ice
shelf. Although the technology is relatively new and its use beneath
ice is
rare, the UK/NERC Autosub-III was specifically designed with a deep
under-ice capability. On this second Autosub expedition into the
Amundsen
Sea, unusually light ice conditions have allowed much of the past
week to
be devoted to a study of the 'black box' under the Pine Island Glacier
(PIG) ice shelf.

Autosub is 7 meters long, powered by 5000 D cells, and can range to
400 km
and to depths of 1600 m. On 0901 it is fitted with a CTD system that
includes a dissolved oxygen sensor and transmissometer, upward- and
downward-looking Acoustic Doppler Current Profilers and a multi-beam
echo-sounder that can be pointed up or down. An extendable gantry
mounted
on the main deck lifts Autosub from its protective container and
lowers it
over the stern of the ship. Once sent on its way, the sub runs for
10-15 km in open water before passing under the ice
front, returning 15 to 30 hours later. Four successful missions this
week, including one that penetrated nearly 60
km to the region of the grounding line, have yielded a wealth of data on
the cavity shape and its seawater properties.

The DynaLiFe project sampled 6 trace metal clean stations near
the PIG, four profiling surface waters down to 300m for Fe, ligands and
other parameters, and two catching large volumes of surface water to
start
new experiments. High Fe concentrations and low biological activity
occurred at sites characterized by melt-driven upwelling of CDW from
beneath the PIG, and biological activity was patchy at the other sites.
Dissolved Fe concentrations in the upper 100m were low, yet no
indications
of Fe limitation of phytoplankton were observed, in contrast to
conditions
seen at earlier stations in the middle of the polynya. Experiments
examined
the accessibility of organically bound iron to phytoplankton and
successfully measured the effects of Fe limitation on its
susceptibility to
photoinhibition. In some cases Fe bound to ligands appears accessible to
the phytoplankton. The experiments clearly showed that Fe limitation
increases susceptibility of phytoplankton to photodamage by high light
conditions experienced near the surface. These findings will help to
explain the observed distribution of phytoplankton primary
productivity in
the Amundsen Sea and other Antarctic polynyas.

Two bottom-moored instrument arrays measuring deep temperature,
salinity,
pressure and ocean currents were deployed in the PIG/Thwaites Trough for
later (2011) recovery. Fifty-four CTD/rosette/LADCP profiles were
made of
temperature, salinity, oxygen, ocean current, light transmission, PAR
and
fluorescence, many at a time-series station for tidal analyses. Water
samples were drawn and processed aboard or stored for
later analyses. The water column profiling reveals such features as
layers
high in meltwater, surface and bottom boundary layers, levels of
stronger
and weaker currents, and the top of the CDW reservoir. Along with active
upwelling near an ice front, we have observed remarkable melt-generated
thermohaline staircases, both previously reported on smaller scales in
laboratory experiments.

confirmation

2009-01-26T12:47:00.000-05:00

According to a recent McMurdo resident, Tennyson is still engraved on
the cross atop Ob Hill.

saturday night yo-yo contest

2009-01-24T22:15:00.000-05:00

One of my fellow crewmembers jokingly asked yesterday what we should
do on friday night. I think you have to tone down your expectations
when you're aboard a 300 foot ship at 75S. Luckily I don't need too
much stimulation. I relaxed and watched my first movie of the trip.

Tonight's crazy saturday night activity consists of watching the CTD
monitor for 8 hours in a row. We're on a 24 hour "yo-yo" near the
ice front while the autosub is off exploring the depths of PIG.
Spending so much time in front of one ice shelf has left most people
feeling a little stir crazy. But because it's so difficult to get
here on a normal year and because there is a long wait for the sub to
get back from a 60 km trip under into the ice, we're sampling the
"temporal" variability in addition to the spatial variability.

In general, the problem with observations is that they are few and
far between in both space and time. When I use a model to describe
the ocean, I can show some of this variability, but it's difficult to
verify its accuracy. When we take observations, the data is real,
but we are limited in our capability to describe everything that's
happening in the ocean. Autosub is getting spatial coverage (where
we have no previous observations). The yo-yo is watching to see how
tides, winds, sunlight, and heat over the course of a day change the
flow in a critical part of the ocean.

Though we get to enjoy more varied sights and cover more ground when
we move more often, the yo-yo is giving us a new perspective on the
melting and circulation underneath the ice shelf. That said, I'm more
than happy to hand over control of the operation to my night shift
colleagues.

hot off the press

2009-01-22T15:12:00.000-05:00

Hi everyone!

I got permission form the chief scientist on board today to relay a
weekly update he prepares for interested parties. It's a nice summary
of the past weeks activity and the cruise as a whole and it relieves
me of some writing if I post it. Also there is often humor scattered
in. So here it is, only slightly edited. Feel free to ask ?'s if it's
unclear.

A primary science objective of NBP09-01 is to investigate why ice
shelves fringing the Antarctic coastline in the Amundsen Sea are
rapidly melting. Ice shelves form when glaciers flow off the land and
float in the sea, and range from ~100-2000 meters thick. Most
Amundsen ice shelves are small but deep at their grounding lines in
glacially cut troughs. Melting at their undersides can average 100
times faster than beneath the Texas-sized ice shelves in the Ross and
Weddell Seas. Those giants melt slowly and grow basal ice in some
areas, in part because they float in seawater that is cooled in
winter and made saltier (denser) by sea ice formation and export.
Amundsen ice shelves float in 3-4 degrees (C) warmer seawater, which
has upwelled from the Circumpolar Deep Water and flowed into the
continental shelf depressions. Their high basal melt rates may also
be increasing, thinning the shelf ice and allowing its incoming
glaciers to move more rapidly into the sea. That will contribute to
an increase in the rate of sea level rise, and to ocean freshening
when the ice melts.

In pursuit of that objectve during cruise week #2, we have profiled,
sampled and deployed instruments along a traverse extending from the
continental slope in the NE Amundsen to the front of the Pine Island
Glacier ice shelf (PIG), with additional transects along the ice
front and around its southern corner. The work included 31 CTD/
rosette casts, 4 moorings anchored to the sea floor and a full-depth
test run of the UK Autosub. Mild weather and a relatively low sea ice
cover for the region at this time of year facilitated progress, and
our first access to the PIG calving front since 1994. Preliminary
results revealed deep water properties in the main trough within the
ranges previously measured, and concentrated areas of outflow along
the PIG front. Retreat at the front of the northern lobe has left a
former pinning point exposed as an ice-domed feature, tentatively
named Capt Mike Is.

Swath mapping of the sea floor covered ~1220 km during the week and
focused on filling gaps between existing tracks. One of those tracks
may set the southern limit of the deepest depression on the outer
shelf, directly west of Thurston Island and the Abbot Ice Shelf. The
atypical lack of any sea ice in Pine Island Bay provided the
opportunity to better map the PIG trough seaward of its snout.

Chris Little (woo-hoo!) has been running numerical simulations of
ocean circulation within the PIG ice shelf cavity, using a Hallberg/
GFDL model modified for ice shelf-ocean interactions. Updated with
0901 CTD and multibeam bathymetry, preliminary results show areas of
inflow and outflow in general agreement with our CTD observations,
while providing some guidance for sampling strategy. In turn, the
ongoing observations should help to constrain model mixing
parameterizations. Model output depends on assumptions about cavity
shape, e.g., but suggests that the southern side lobe of the PIG is
actively involved in the circulation and upwelling.

Sea ice studies began with hourly underway sea ice observations
(ASPeCT protocol) on 11 Jan near 68 37 S, 99 35 W and ended on 16 Jan
at 73 36S, 106 45W near the southern ice edge. The transit work
included an automated camera system, and sampling of 6 floes ~30 nm
apart, 5 of which coincided with CTD casts. Snow and ice properties
were examined at the coring sites, and ten cores sectioned on the ice
for salinity, d18O and chl-a, with an additional 15 for structural
analysis. Predominant ice types were thick multiyear (>2m), thick
first year (1-2m) and thinner first year ice (0.5-1m). Snow cover was
generally heavy, sea surface and sea ice temperatures were above
freezing and flooding was pervasive, leading to highly porous ice
with multiple gap layers that appeared favorable for ice algal
communities.

Anne Alderkamp's group sampled at 9 stations for the DynaLiFe
project, on 2 of which the Trace Metal Clean (TMC) frame obtained 80L
of surface waters to start two different ligand experiments. Surface
water profiles down to 300m were obtained on the other 7 casts, with
TMC Goflo bottles on the TMC cable, to determine dissolved iron (Fe)
concentrations and biological parameters. On two of these stations,
samples of different depths were filtered in different size fractions
to obtain characteristics of the Fe-binding ligands that are
naturally present. Surface water was obtained from the CTD/rosette on
6 stations to determine carbon uptake kinetics, CO2/HCO3
disequilibrium uptake and the activity of carbonic anhydrase.
Preliminary results indicate low Fe concentrations in the partially
sea ice covered waters north of the Pine Island Polynya, and in
highly productive areas within the polynya, where signs of Fe
limitation of biological production were observed in the biological
experiments. Waters near the PIG contained higher Fe values, and no
signs of Fe limitation of the phytoplankton.

question

2009-01-22T13:55:00.000-05:00

Hi everyone,

Still search for audience participation so I thought I solicit some
non-science opinions. I need to come up with a nickname for some lab
mates who work on sea ice and spend most of their day in a freezer
cutting ice. They wear these bright orange full body jumpsuits
around the ship. I have a mental picture of a rap duo and the best I
can come up with is the Freez R Boyz. But since one is a woman this
is not really fair. I'm looking for something better unless you think
this is OK.

Any ideas?

miscellaneous items

2009-01-20T07:48:00.000-05:00

Hi all -- Looks like email difficulties will plague the NBP for at
least the next week or so as we are going to be at the PIG ice front
and sending Autosub under the ice repeatedly over the next few days.
Yesterday's test mission successful, it is, as we speak, motoring
around underneath (30km in) the ice shelf. Cross your fingers that
all goes well.

In the meantime, I have been titrating and analyzing some model
simulations which ma give some insight into the flow in and around
the ice shelf. Despite the fact that oxygen calibration is necessary
(we corrected a sensor on the CTD that was not reading right
yeterday), it feels good to be contributing something (with the
model) that is unique. It's been a hard few days though as I've been
working the full 12 hours plus to get everything done. Oh yeah and
no weekends either.

A beautiful slideshow by Maria Stenzel, the photographer on the
cruise with us, tonight to break up the batch of samples. She has
done a tremendous amount of work photographic the Antarctic with
scientists. I think a bunch of her photos are online at National
Geographic -- I had seen many of them before both in NG as well as on
the walls of the NBP.

And in response to:

>>desert tortise has left a new comment on your post "oxygen pt 2
and PENGUINS!!!":
>>How does churning from berg movement and storms work with DO levels?

This is a great question -- off the top of my head, I can think of
two opposing effects. Wind-generated waves will break and entrain/
engulf bubbles -- this will raise DO levels (this is exactly what
we're trying to avoid when sampling). But my guess is that the
bigger effect of winds/berg movement is that they will mix water from
below the surface with a much lower dissolved oxygen. Icebergs will
have the additional effect of melting into the ocean. Since this
will make the ocean near the iceberg lighter and water will rise
along the base of the berg, this may also lower DO levels without
really "churning".

This is exactly the type of question that we ask when looking at the
data -- which effect is bigger? And which process -- bergs, winds,
sea ice, etc. -- are causing the mixing? And it's why having more
than one "tracer" helps distinguish what's really happening.

Keep sending questions and thoughts -- it I don't reply it's probably
because we're struggling to find the satellite and I haven't read it
yet!

patience is a virtue

2009-01-18T21:26:00.000-05:00

for all those who are waiting with bated breath for the next entry,
it will likely be delayed. we are in an email dead zone, and may be
for quite some time. I will do my best to update as soon and as
regularly as I can. but it will depend upon whether and how long we
can keep a satellite connection. much email is backlogged. stay tuned.

Chris

it's a beautiful day at the PIG

2009-01-17T13:39:00.000-05:00

We arrived last night at the ice shelf front of Pine Island Glacier.
The front of PIG moves at ~3 km/year and is approximately half a
kilometer thick. On the edges of the fast moving ice, the glacier is
jumbled into ridges of jagged blocks. Amazing.

The weather was stellar and continues to be beautiful today. The
ocean is glass. The autosub is somewhere running a test mission
until later tonight. We are bobbing around waiting for it and
processing data and writing emails.

After a CTD cast to get a sense of the hydrography, we mapped
previously unsurveyed ocean floor in front of the ice. Along the way
we saw many minke whales, adelie penguins and at least one orca.
Needless to say, I stayed up way past my bedtime and missed my
morning workout in the gym this morning. Well worth it though.

I suppose that I should take this chance to mention we've got a
photographer and videographer on board with us documenting the
science as well as the scenery along the way. They were busy last
night. I feel a little outmatched with my point and shoot camera
which only 2 years ago I was so proud of.

It's been both fun and difficult at times to relay the scientific
mission and techniques to the photography team, even though they're
very quick to pick up on the details. It's also difficult to speak
into the camera/microphone about climate change and what's going to
happen with the ice sheets while trying to titrate dissolved oxygen.
They say I'll get used to it and I hope so.

There have been some good questions about dissolved oxygen -- I'll
try to address some of these in the context of some of the analysis
we're doing at PIG in the next entry. Till then...

oxygen part 3: the sublime and the mundane

2009-01-15T18:52:00.000-05:00

So I've discussed all of the amazing things that you can learn from
dissolved oxygen, now I'll tell you what it means to actually be in
charge of it -- probably a little bit of a let down. When the
rosette/CTD arrives on deck, we sample the (-2 to 2 degree celsius)
water into flasks, being extremely careful not to trap air in it. If
we trap air, we have to do it again. We put a few chemicals in it to
stabilize the oxygen immediately, then store the flasks until I run
the "titrator" -- which is a technique to determine the amount of a
chemical in a solution. In this case we're looking for oxygen and we
use the current running through electrodes submerged in the solution
to determine the concentration of a chemical (which contains
oxygen). From the we determine the amount of O2 that was dissolved
as a gas in the solution. Each titration takes ~5 minutes, but
there's some prep work before and after involving a lot of dishwashing.

A few days ago, I calibrated the machine. The calibration of the
instrument involves running standard after blank after standard
through the machine until you get repeatable results. This took
approximately one 12 hour shift.

We sample 4-10 individual "Niskin" bottles (extra credit for the
origin) per CTD cast and we can have up to 4 CTD casts per day, so
there's always a line of samples waiting to be processed. It reminds
me of Newman's answer to Jerry when he asked him why post office
employees "go postal". Newman went into a long rant with the message
being that the mail never stops coming. Analyzing data on a ship is
like that. As soon as you complete one batch of samples, another few
appear. This is going to go on for another two months. I _think_ I
can keep sane for that long.

A research cruise to the Antarctic entails a mixture of beautiful,
otherworldly scenery and the prospect of answering important, unknown
questions while performing some incredible repetitive but precision-
demanding tasks for hours in a row.

I'm done with the titrator for the night and am going to seek some
inspiration outside as soon as I collect some more water. We'll
worry about analyzing it tomorrow.

penguin funniness

2009-01-15T09:28:00.000-05:00

My guess is they're funny because they're bottom-heavy.

But seriously one of the cool things that I saw when watching them is
that they can move from lying on their bellies to standing up with
virtually no effort or push from their wings (flippers). They just
sort of lean back and boom they're standing...

oxygen pt 2 and PENGUINS!!!

2009-01-14T00:17:00.000-05:00

Well I know you're itching to hear more about dissolved oxygen and
what it means to me. Because DO content reflects where the water has
been and what's happened to it, we can learn about the circulation
from it -- especially when we have complementary "tracers" which tell
the same story, or can differentiate processes which may lead to the
same effect on DO. We're particularly interesting in the flow of
"old", subsurface water, its access to ice shelves, and the flow of
meltwater away from these ice shelves. In this context, "old" means
it's been a long time since the water has been at the surface, where
it can equilibrate with the atmosphere (for those interested, its DO
content is ~4mL/L). Over time, biological detritus (poop) sinks and
microorganisms eat it, using oxygen in the water in the process.
This deep water is upwelled (rises) when it gets into contact with
ice and freshwater mixes with it. Since the DO content is lower in
the old water/ice shelf water mix than it water that's recently been
at the surface (~8mL/L), we can identify it, even if it is the same
density, salinity, or temperature as the water around it.

Penguins are becoming more frequent as we move south through the ice.
Though I've heard one report of an isolated emperor, all I've seen so
far are adelies -- which are my favorite anyway. I was fortunate to
get off the ship and get lowered onto the sea ice to help out with
some ice coring and related analysis (see pictures on my web site if
you're interested in seeing how this works...). It was a brilliant
day -- bright and right about freezing. We had two Adelies pay a
visit almost immediately, and they hung out with the two groups of
people that were coring two different areas on the ice floe. One was
extremely interested in our ice corer and was almost sticking his
head inside. We tried to act serious but it's very hard with
penguins watching.

Oh, and land ho! Thurston Island is visible to our East as we near
Pine Island Bay.

2:30 am and still titrating oxygen, I remain,
Chris

Oxygen, pt.1

2009-01-12T16:56:00.000-05:00

One of my main duties aboard seems to be taking shape. I'll be
responsible not only for sampling water from the rosette, but for
analyzing the dissolved oxygen (DO) content of the seawater we bring
up from below. There are actually two sensors on the CTD which can
read the DO content -- however, these need to be calibrated to values
which we determine through a titration on board.

Most people have heard about scientitsts in the Antarctic who study
ice cores and the gasses trapped in them -- when we study DO we are
doing roughly the same thing except there are things living in the
water and the water can move around faster than ice.

Three processes that we're interested in can change the dissolved
oxygen content of seawater -- equlibration with the atmosphere when
the ocean "touches" it at the surface, biological use as
phytoplankton/fish/etc are broken down by bacteria and/or other
creatures, and interaction with glacial ice. Can anyone come up with
reasons how these processes might affect the oxygen content? Given
that info, can you think of ways we can use it to study circulation
around Antarctica?

Barney's class was looking at dissolved of in a freshwater system.
I'm interested what sort of concentrations they got?. How and why
does oxygen in freshwater change? What would happen if you kept
putting salmon in the same water? Maybe we can compare what's
happening to their water with what's happening here...

Life is going well here but the workload has increased due to a lot
of tests on the titrator and on our sampling technique. Mexican
night last night; that's a highlight for me so far. Lots of
crabeater seals out on the ice but fewer penguins so far!

in the ice

2009-01-11T21:49:00.000-05:00

Hi everyone,

Round midnight, I'm coming to the end of my shift running blanks for
the dissolved oxygen calibration and we've ground ourselves into the
ice for some coring. At least four people are running around on the
ice (with a THICK layer of snow on top). I'm going to go check it
out and grab a snack at midrats (fruit -- watching out for scurvy) on
the way. More on oxygen and ping editing tomorrow.

Chris

into the antarctic

2009-01-11T09:36:00.000-05:00

Last night we crossed the antarctic circle and have pretty much lost
all hope of darkness for the next month and a half. The ocean is
full of icebergs and relatively flat, and I woke up this morning to a
light snowfall and winds from the northeast. We're hoping to hit the
sea ice edge at some point later today, and the sea ice scientists
are starting to get antsy...

Not much CTD activity today, it looks like we'll have one at 11pm,
near the end of my shift. In general, for jobs aboard the ship where
work may need to be done 24 hours a day (like CTD casts), two people
are assigned with 12 hour shifts. On NBP0901, I'm working the 12pm
to 12 am CTD shift. Over the past week, I've been retooling my
schedule to fit the meals and sleeping patterns to that shift. It
hasn't been a lot of work. It was harder on 0702, where I worked
from 3am to 3pm. With the 24 hour sunlight, it was easier than if I
was, but waking up was never easy. Actually waking up is never easy
for me. I slept in today.

Change in the weather

2009-01-10T09:11:00.000-05:00

After many days of pitching and rolling, the seas have finally
relaxed a little. Along with the winds and waves, there's been a
change in the temperature of both the surface of the ocean and air as
well. Ocean temp is now about 0.3C, air just around freezing as
well. From this point on, even as we get closer to the continent,
the air temperature won't change very much. Neither will the surface
ocean temperature. Even though on the continent it's well below
zero! Anyone have an idea why?

We've got a test CTD to work out kinks in the equipment and crew
today coming up at 1 pm. I'll send an update on the bloopers later
today and a little bit on my duties w/r/t the instrument.

Liz, nice question re: the freshies. For those who don't know, she's
talking about the fresh veggies and fruit, which have a habit of
running out after a week or two at sea. In answer, they're still
there but getting less frequent and less appetizing. In an attempt
to maximize my intake of these, I've been eating a LOT of salads. I
note that leaving from Chile in summer has it's advantages as far as
freshies (think AVOCADOS!!!). Avocados compliment virtually everything.

First berg

2009-01-09T10:56:00.000-05:00

quick update: we saw our first two icebergs today after crossing the
polar front last night. At 62S, the air and water temp are now both
around 2C.

cruise objectives, part two

2009-01-08T17:54:00.000-05:00

Drilling down a little on the broader goals -- which I now know were
posted -- we've got three distict groups of scientists on board. Even
though to an extent we are all driving at the same questions, the
methods and instruments we're using and the (small?) picture goals
differ. The physical oceanographers on board are most interested in
the heat and currents in the subsurface ocean (below 200m or so). To
learn more about these, we use everything we can; there are at least
5 instruments on board -- a CTD/Rosette, ocean floor moorings, an ice-
tethered profiler, multibeam swath sonar of the ocean floor, and an
AUV (autonomous underwater vehicle) which can travel ~10 hours on its
own collecting data (see link to the Autosub on the right). The CTD
measures temperature and salinity as it is lowered to the ocean
floor; the rosette collects water in 24 bottles from different depths
(more in previous blog from 2007). Moorings record temperature,
salinity, and currents for long after we leave, but they have to be
retrieved by other ships to see the data which they collect. The
"ITP" is like a mooring except it is attached to ice and can move up
and down on its own in the ocean beneath the ice. Since the ocean
floor is important to the control of currents, recording the
bathymetry (wikipedia?) is helpful for understanding why we see what
we see. On this cruise, I am monitoring and analyzing some of the
data and samples from the CTD, so will probably spend more time on
the details relating to that work.

I am less clear on the goals fo the other two groups, studying sea
ice and surface biology. Some of these scientists will give talks
about their work over the next few weeks and I will know more soon.
Briefly, the sea ice crew is going to core ice floes to analyze their
composition and thickness. They will also deploy "drifters" to
measure location, snowfall and meteorological conditions as the ice
floats around. One of their activities -- that everyone is
participating in -- is hourly observations of the types,
concentrations, and thicknesses of sea ice that we pass through on
the ship (not happening yet!). The biologists are most interested in
the nutrient concentrations and type and distribution of
phytoplankton, and will collect, filter, and analyze these on board.

Right now we are cruising on a straight line (actually a "great
circle" -- extra credit!) towards the nothern portion of the amundsen
sea. We have, as I write, over 1200 kilometers to go. At a speed of
18 km/hr or so, weather permitting, we'll make it within 3 days. For
those who were curious, I'm not sure whether we will dawdle there.
Since there is sea ice around there as well as potential sites for
mooring deployment, there may be a reason to stay and work. However,
there's no guarantee that the Pine Island Ice Shelf -- our end goal
500 km further south and where much of the work will take place --
will remain ice free.

More about the plan of action when I learn it (sorry Rich, I'll know
soon...). We've got at least 3 days of wavy ocean to consider it.

There is a sextant on board, although I had to ask -- I didn't know
we had one, much less know how to use one. I've been reassured that
it's part of the licensing process for captaining one of these ships,
so rest assured, tortoise and class, there are still people who know
how to use these if we lose our other equipment. What they're
learning in school IS useful.

And erika, you get the extra credit for figuring out what a nunatak
is (and for spelling it right). The extra credit is ... maybe I let
you win at scrabble next time we play.

argh

2009-01-07T21:40:00.000-05:00

well i wrote a really nice blog entry tonight describing the overall
objectives of the cruise and how all the different parts fit together
but something broke in my email and it vanished. i'm not going to
write it again tonight, and i hope it appears somewhere. if not,
i'll try again tomorrow.

Cruise objectives

2009-01-07T21:15:00.000-05:00

I've talked about the weather enough (p.s. not looking good for
tomorrow...ugh), I'm going to start to address what we are doing here
and how we are doing it. As of this point, I only know some of the
cruise's objectives: there are many scientists on board, all of whom
have individual goals and plans -- I'll try to address the common,
big-picture ones. It is an art for the science team, and the chief
scientist in particular, to orchestrate where and how we will
allocate time to each one. Particularly when the weather is fickle,
instruments malfunction, and time is limited. More on that later.

A common theme of the research we're doing is a desire to understand
how the oceanic environment around Antarctica interacts with the
global climate. My guess is that most of us on board think that this
region of the ocean (which is, area and volume-wise, very small) has
a disproportionate impact on the climate and the carbon cycle.
Understanding the key processes involved here will better allow an
assessment of their sensitivity to change. In my case, I'd like to
understand how changes in the ocean may affect the Antarctic ice
sheet, which may in turn influence the global sea level. I'd also
like to know if there are ways or locations where we can monitor
change. Others on board are trying to determine how productive the
coastal ocean in the Amundsen Sea is and what causes the biological
activity (or lack therof). Biology (phytoplankton, bugs, fish)
removes carbon from the atmosphere and places it in the ocean. We
don't know whether this compensates for other parts of the antarctic
where the carbon goes from the ocean to the atmosphere. Other
scientists want to know what happens to sea ice (ice that forms at
the surface) as it floats on top of the ocean. When and why does it
melt? Where does ice formed in one place drift ?

We can lump the science into what we're studying -- subsurface ocean
currents, sea ice, and phytoplankton, but all of these overlap.
Biologists studying phytoplankton need to know where the water in a
location is coming from, physical oceanographers need to use
chemicals which are taken up by phytoplankton in order to know where
the water is coming from.

A key tool for all of the scientists is the CTD/rosette (good
wikipedia opportunity), which allows us to understand what's
happening below the surface of the ocean, where satellites can't see.
Water collected at different depths gives clues as to where the water
originates from, what's happened to it on the way, and what's lived
in it. Since I'm working on monitoring and sampling from this tool,
it may get disproportionate focus here. More on the CTD soon.

It's somewhat less quiet around the ship today, I think most people
are beginning to acclimate to the motion of the ocean. Both air and
sea temperatures are around 6 degrees, winds slightly weaker today at
20-25 knots. Hope it stays that way.

quiet day

2009-01-06T17:21:00.000-05:00

when the sea acts up, especially in the first few days of a cruise,
it can get pretty quiet on the ship. part of coping with seasickness
seems to be persistence, and part seems to be finding your miracle
cure. in the first few days, many people have to figure (or wait) it
out. i'm lucky in that seasickness doesn't hit me too hard, but i've
steered away from reading much today and resorted to a post-breakfast
nap.

i'm just guessing here, but I bet most research ships bound for the
antarctic are characterized by a quiet period at the beginning.
traveling from south america requires a crossing of the drake passage
and the southern ocean, renowned for large swells and nasty storms
(extra credit if someone can explain why...). right now we've got
6.6 degrees celcius air temperature, 7.2 degrees water temperature,
steady 35-40 knot (40-45 mph) winds from the west, and a moderate
swell from the west. it's not great, but it's far from the worst
that people have seen. only 3 or so more days to go until we get to
(relatively) protected waters near antarctica.

thanks for all the questions earlier today, i'll keep thinking about
cape horn and how explorers could figure out iits shape well enough
to name it. my guess is they mapped what they saw as they sailed
around the continent, using the sun as a guide. we have it a little
easier these days.

we're still finalizing the cruise plan but it is unlikely we'll get
started in earnest until later tomorrow. i'll update then with some
more details on the plan for the next week.

NBP0901 is underway

2009-01-05T20:25:00.000-05:00

Hullo All,

We are steaming through the straits of Magellan, so named for the
explorer. It's not the only thing named for this guy around here.

Tonight will most likely be be our last glimpse of land (aside from
the occasional nunatuk -- look it up and post the answer for extra
credit!!) for the next two months. Desert tortoise and friends, I
don't know if I'll be able to take a picture of cape horn, as we will
head southeast out of the straits of magellan into the open ocean
tonight! There are some pictures of the Straits, which are
spectacularly scenic, on my website under Antarctic photos. I'll try
to take some more, weather dependent, later tonight. I'm hoping for
some wildlife -- dolphins, magellanic penguins, albatrosses, a whale?...

It's likely that the next week will be spent in transit across the
Drake Passage. Depending on the sea state, we will be working hard
making sure that all of the instruments will work as we get closer to
the "ice". Tonight I'm making and bottling some chemicals which we
will use to analyze dissolved oxygen in water that we collect from
below the surface. More important is to make sure belongings and
gear are secured so they don't fly around in rough waters. I have to
brush up on my knots, which I was never very good at to begin with.

Tonight we had a brief meeting to discuss the science objectives of
the cruise. Since there will be more talking than doing over the
next few days, I'll plan to describe them as I learn more.

Please feel free to post questions in the form of comments, otherwise
you'll just have to live with what I'm thinking when I sit down to
write.

Thanks for reading...

Finis Terrae

2009-01-04T07:41:00.002-05:00

literally, the end of the earth. Also, my hotel in Punta Arenas, the southernmost city in the world. I´m writing this email with the last gasps of high(er) speed internet. Off to the warehouse at 12 today for ECW (extreme cold weather) gear and then an all-hands meeting at 2pm. Moving in tonight for good and assuming all goes well, setting sail tomorrow for the Straits of Magellan and the Southern Ocean beyond.

Long way to go

2009-01-02T14:23:00.002-05:00

Since I'm bored and waiting for my ride to the airport (thanks Liz!), I wanted to see if I could use the last bits of real internet I have access to and find a cool way to show where I'm going. Apparently you need to buy an expensive edition of google earth if you want to make movies. But if you have google earth on your computer (well worth it) you can open this file and follow my air travels (6000 miles, 24 hours), then the cruise track to get to the front of Pine Island Ice Shelf (1700 miles, 1 week?).

Also, I spent some time today playing around on a website that has a ton of great graphics and detail about Antarctic weather if you're interested:

http://www.mmm.ucar.edu/rt/wrf/amps/index.html

See you in PA!

Prognosis positive

2008-12-29T10:38:00.005-05:00

One of the major hurdles in studying ice shelves is actually getting there. In the Amundsen, the continental shelf is often covered with sea ice late in summer. Since this cruise is relatively early-season, there is some worry about where we'll be able to go.

Here's a satellite photo of Pine Island Bay and satellite derived sea ice concentration around Antarctica on 12/27/2009. Pine island ice shelf (streaked area in lower right corner) is not blocked by fast ice (as it was in 2007), and it looks like the sea ice near Thwaites glacier tongue will allow passage into PI Bay. That's not to say things can't change between now and then but it's good news.

New and better (?) for 2009

2008-12-29T10:24:00.005-05:00

Hi friends, family, and other interested parties,

This is a new blog which I will update from the NBP , as I did on a previous research cruise in 2007. As of now, the plan is to touch on both the science and daily life on board. Likely changes include:

1. Less frequent updates -- I've got to write a thesis in the next year or so, so I have a target of updating every other day...
2. Interactivity -- unless the email burden becomes too great, comments will be forwarded to my email on board. I'm hoping everyone will contribute (short) thoughts and/or questions which will direct future posts.
3. Newslinks and a slideshow from 2007 -- taking advantage of new blogger features!
4. (Hopefully) real-time interaction with high schoolers -- if I can get a plan together in the next week or so.

Looking forward to hearing from you!

Chris