Friday, January 23, 2009
A little more on Wilkens. It is a broad area of fast sea conected to the peninsula. It's pretty young, apparently in place for several hundreds or thousands of years. Unlike the smaller Larsen B Ice Shelf whose breakup was very publicized in 2001-2002, Wilkens isn't holding back flowing glaciers so its collapse won't increase sea level. However, its breakup will mean huge habitat loss to krill and species that on them such as Adelie penguins.
Early on Larsen was identified as susceptible to breakup as temperatures increase. In 1993 Professor David Vaughan of the British Antarctic Survey predicted that the northern part of the floating plate of ice was likely to be lost within the next 30 years if climate warming continued on the peninsula at the same rate. Events on the ground have proceeded much faster than his predictions and last March disintegration began. After several events last summer, the remaining sheet of over 5000 square miles (about the size of Connecticut) is now being held to the peninsula bya bridge only 500m wide at its narrowest. Breakup of that bridge will almost certaibly happen in the next weeks or months.
Meanwhile, evidence for warming of the continent itself is also piling up and that's link 2. Although there is still disagreement, an article in Nature this week gives new evidence that Antarctica is warming in step with the rest of the planet, with rates ranging from +1.1 degrees F / decade on the body of the peninsula (where Palmer is located, and those are the rates we measure) to 0.2 degrees F / decade on the continent proper.
The difficulty in understanding whether Antarctica is warming and how fast is mostly due to the difficulty in installing weather stations in the interior of the continent. Also, Antarctica is a complex story with a huge forces such as the Antarctic Circumpolar Current (ACC), the seasonal antarctic stratospheric vortex and the ozone hole all playing major roles in the climate of the region. Please let me know if you would like to hear more about these topics and I'd be pleased to share what I am learning.
Thursday, January 22, 2009
Dec 28th: The chicks are essentially engaged in an eating contest. Before summer dwindles and the sea ice returns they must be big enough and fast enough to fend for themselves. Occasionally, the marathon-paced eating (they are gaining the equivalent of their hatch weight every day) overcomes a chick's ability to stand and it tumbles over, belly first onto its nest.
Even the bird researchers here admit it - at times the chicks appear to have silly grins on their faces.
Although most nests on the interior of the colonies still have two chicks, a few little birds are missing. Most of these have been victim to the South Polar Skua. A pair of Skua is nested close to the penguins on Torgerson and feed their own chicks on return from hunting. A small number of viable-looking and well-protected chicks have also died - apparently as confusingly to the parents as to us watchers.
Entry 2: Muddy and wet !
Jan 7: On this morning I can smell the colony long before I get to it. It's a fact that doesn't come across in television or movies - penguins stink ! Our bird researchers have their own tent to change clothes and shower in for a reason.
I land amid light rain and return to the five nests I am watching most closely. At all of them the chicks are incredibly mobile and active. They flap wet wings and pace on muddy feet. The chicks don't go far though - to do so is to risk ostracism and death. In time, a few more weeks, the chicks and parents will recognize each other by smell. This ability isn't developed yet and chicks who wander from their nest at this stage will be treated as intruders and pecked by any adult they approach.
At one of the five nests I always check out both chicks are missing. Have they gotten lost ? I guess that the one sad and bedraggled kiddo below belonged to the nest once. Its now shunned and pecked by the adults I watch.
Entry 3: Awkward adolescent
Jan 13th: The chicks are now a month old and some of their babyish ways are beginning to drop away. They still can't defend or feed themselves but are starting to adopt adult postures and vocalizations. The little chick bodies, all bulging stomach and floppy wings are being replaced with a straight spine and cartilage. The oldest ones are just beginning to molt. In adults the yearly molt is supposedly uncomfortable and the birds are irritable while they wait on land for the molt to complete. The chicks however seem oblivious to any itchiness. Maybe they're proud of this next step towards the sea.
Wednesday, January 21, 2009
Tuesday, January 20, 2009
While we are back at the station, our USAP research vessel LM Gould is out at sea on the annual Long Term Ecological Research cruise to collect environmental and climatological data. Today they made the news with their innaugural celebration. Let me know if you are interested and I'll talk more about what the LTER project is doing in future posts.
Antarctic Climate Researchers Hold Distant Inaugural Celebration
By Juliet Eilperin
In what may well be the furthest-flung celebration of Barack Obama's
inauguration, scientists aboard the U.S. research vessel Laurence M
Gould held a commemoration 10,000 miles from Washington D.C. off
The researchers, who are spending three days at sea examining signs of
climate change, decided to call the temporary study area they have
established "Ocean Station Obama."
Doug Martinson, an oceanographer at Columbia University's Lamont-Doherty
Earth Observatory and the cruise's chief scientist, said they named the
station after the 44th president and his incoming administration "to
recognize their vital interest in the problem of climate change."
"The setting of our study, in an area of rapidly changing climate and
ecology, is an appropriate spot and moment in our history to dedicate
this sampling station to the events taking place in Washington,"
Martinson said in a statement. "In doing so, we hope to bring ocean
sciences and climate change research to the public's attention."
The three-day cruise is a part of a seven-week oceanographic expedition
known as the Palmer, Antarctica Long-Term Ecological Research Project
(PAL-LTER), which has surveyed a section of the western Antarctic
Peninsula each year since 1993.
The peninsula has warmed nearly 11 degrees Fahrenheit since 1950,
leaving the area with 90 fewer days of sea ice cover compared to 1978.
The warming has particularly hurt an Adelie penguin colony near Palmer
Station, which has declined by 80 percent since 1975.