ASPIRE: The Amundsen Sea Polynya International Research Expedition

1. Adélie penguins (Pygoscelis adeliae) are the most commonly seen penguin in the Amundsen Sea
region. They feed on the krill associated with the sea ice. Here, we encountered a group of
them as we were breaking through the sea ice pack near the Thwaites Iceberg Tongue on
December 31 (Photo credit: P. Yager)

2. Amundsen Sea Polynya: This image was taken from the pack ice as we first approached the
open waters of the Amundsen Sea Polynya. Polynyas are recurring areas of open water
surrounded by sea ice. (Photo credit: P. Yager)

3. Calm Amundsen Sea: When the wind stops blowing, which happens only occasionally in the
austral summer, the polynya surface can become like glass. Here, you can see how, no longer
pushed around the wind, the sea ice can then spread out. The golden brown color in the ice floe
is ice algae, typically diatoms which have golden brown pigments in addition to chlorophyll. If
you look carefully in the dark areas of the photo, you can see "grease ice," which is the first
steps of new sea ice formation. Air temperatures are still below freezing at this time of year, so
when it gets calm, new sea ice crystals can form. (Photo credit: P. Yager)

4. Sea Ice in the Amundsen: Phytoplankton are very abundant in the surface waters of the central
polynya. Here, a large floe of sea ice was blown into the otherwise open region, providing a nice
backdrop for seeing the green color of the water. (Photo credit: D. Munroe).

5. Amundsen Sea Wildlife: Adélie penguins and a crabeater seal on the sea ice floes near the open
polynya waters and Thwaites Iceberg Tongue in the distance. (Photo credit: P. Yager)

6. Collecting Sea Ice Algae: The marginal ice zone, on the edges of the polynya, is a very productive
part of the polar ecosystem because of the sea ice algae there. Here, postdoctoral fellows, Tara
Connelly (left front) and Rachel Sipler (right front), Emily Rogalsky (back right), and Sandy
Aylesworth (standing back left), are collecting organic-rich nutrients from the slushy sea ice flow
near the ship. The ice was too thin to stand on, so the Palmer crew used a crane to lower them
over the side of the ship in what is usually called the "man basket." We renamed it the "woman
basket" that day. (Photo credit: P. Yager)

7. The Conductivity-Temperature-Depth sensor (CTD) with its "rosette" of 24 10-liter Niskin bottles,
is one of the main oceanographic instruments for studying the open waters of the polynya. As
the ship holds position on station, it is lowered by a winch slowly through the entire water
column and then returned to the surface. The CTD sends data back to the ship in real time, and
the Niskin bottles (which go into the water open) are closed at points of interest on the way up
to collect water samples.(Photo credit: K. Esswein)

8. Floating Sediment Trap Array: One of the questions of ASPIRE had to do with the fate of the
very high algal productivity in the surface waters of the polynya. To capture particles sinking to
the deep, a floating sediment trap array, pictured here, set free from the ship while attached to
a buoy with a locating transmitter, was deployed to depths of 60, 150, and 300 m for several
days. When brought back to the surface, we could see that a great deal of material was indeed
sinking below the polynya surface, likely providing food to deep dwelling zooplankton and
benthic organisms. (Photo credit: P. Yager)

9. Fish Larva: Onboard ASPIRE, a Multiple Opening / Closing Net and Environmental Sensing
System (or "MOCNESS") was deployed to collect zooplankton in the waters of the polynya. Some
of the animals it collected were fish larvae, as shown here. (Photo credit: S. Kjellerup).

10. The Thwaites Iceberg Tongue (in the distance) sits on the eastern edge of the Amundsen Sea
Polynya, separating it from the Pine Island Polynya (PIP). It is an important part of the ice-ocean
interactions that impact the Amundsen Sea Polynya formation. The productive marginal ice zone
on the eastern edge of the polynya is shown here in the foreground (Photo credit: P. Yager)

11. Ice algae, typically golden-brown diatoms, are very important to the Amundsen Sea ecosystem.
They are the base of the sea ice food web, which includes krill, Adelie penguins, crabeater seals,
minke whales, and orca whales, and are also an important component of the carbon cycle in the
region, helping to draw down CO2 from the surface waters before the sea ice melts. (Photo
credit: P. Yager)

12. Pack Ice North of Amundsen Sea Polynya: The large region of sea ice north of the Amundsen
Sea polynya hosts a productive food web based on ice algae, typically golden brown diatoms,
that provide food for the ice-associated krill. While not thought to be as productive as the open
waters of the polynya, this system is hard to characterize over large areas since satellites cannot
see the algae so easily as in open water (Photo credit: P. Yager)

13. Icebergs are pieces of the ice sheet that have broken off and are adrift in the polynya waters.
They can be over 100 feet (30 m) tall and reach down into the ocean several hundred meters,
providing a "stirring" mechanism for the upper surface waters as they drift northward. Much
thinner sea ice (1-3 m) can freeze around them as shown here. (Photo credit: K. Lowry)

14. The bridge of the U.S. Research Icebreaker Nathaniel B. Palmer looks out over a serene evening
view of the ice floes of the Amundsen Sea. (Photo credit: K. Esswein)

15. Nathaniel B. Palmer (NBP): Fondly called the "NBP," the U.S. Research Icebreaker Nathaniel B.
Palmer was built in 1992 to be capable of breaking 1 m of ice at 3 kts. It continues to be the
premier ocean-going platform for the US Antarctic Research Program. (Photo credit: P. Yager)

16. The Thwaites Iceberg Tongue is a nearly impenetrable section of ice sheet that separates the
Amundsen Sea Polynya from the Pine Island Polynya. ASPIRE wanted to collect some moorings
in the PIP for Stan Jacobs' team, so we had to try to cross through the Thwaites; we tried several
times and were not successful. Some years, it is more impenetrable than others. (Photo credit: P.
Yager)

17. U.S. Research Icebreaker Nathaniel B. Palmer Meeting Swedish Icebreaker Oden: As part of the
two-boat operation in the Amundsen Sea, the U.S. Research Icebreaker Nathaniel B. Palmer met
up with the Swedish Icebreaker Oden on December 21, 2010. Here, as seen from the bridge of
the NBP, the Oden parked itself against the sea ice, and then shortly thereafter, the NBP nudged
over closer and tied up to the Oden so that we could exchange personnel and some equipment.
Fortunately, it was a beautiful, calm evening, making the exchange smooth and successful.
(Photo credit: P. Abrahamsen)

18. The Dotson Ice Shelf, about 30 miles (50 km) wide, is located in the southeast corner of the
Amundsen Sea Polynya between the Martin and Bear Peninsulas. It was a focus of the ASPIRE
project that we called "the iron curtain" because we were testing the hypothesis that some of
the iron supply to the productive polynya comes from the melting ice sheet. (Photo credit: P.
Yager)

19. Sediment Trap Buoy: In the very productive central open water polynya, we deployed the
floating sediment trap array (see other photo above) for three days to collect particles sinking to
depth. On Day 2, we could tell from the transmitter that the buoy was behaving strangely, so we
went to retrieve it earlier than planned. When we located it, the buoy had been caught up in a
drifting ice floe. The white sea ice and the orange buoy provided the perfect color contrast to
the immense bloom of phytoplankton going on there. (Photo credit: D. Munroe)

20. The Amundsen Sea Polynya International Research Expedition (ASPIRE) team onboard the RVIB
Nathaniel B. Palmer included Captain Yuri Magrabe (front left) and his crew, Raytheon Polar
Services Marine Specialists and Technicians, and scientists from around the world. Collaboration
among all the team members was really exceptional, contributing significantly to the great
success of ASPIRE. (Photo credit: D. Munroe)