Latitude: 74.09 S Longitude: 112.43 W Temperature: -3.4 degrees Wind chill: -14.2 degrees
Well, so much for the warming trend we saw yesterday! Today we awoke to more snow and much colder weather, thanks to those Antarctic winds! We are near the Dotson Ice shelf and have seen some incredible ice floes and icebergs. I even spotted a penguin on one of the floes. You may be wondering why we are not seeing more penguins, seals, etc. It has to do with the ice. They need ice to come up on! Here in the polynya there is more open water with considerably less ice. So perhaps in the next couple of days as we begin our transect to the Ross Sea we will find more large biology.
The biology we have found includes diatoms and a type of algae called phaeocystis which is a dominant group here. Phaeocystis produces DMS- dimethyl sulfide. According to Dave Hutchins, when DMS leaves the sea surface it goes into the atmosphere as aerosol particles. These particles act like a nucleus around which raindrops can form, making clouds. Clouds block the sun and reflect heat away from it, cooling the earth. This also slows down the growth of algae, which means less DMS, and fewer clouds. With fewer clouds...the cycle repeats -it's a self-regulated system!
Phaeocystis
This bucket of brown, smelly water is full of Phaeocystis!*
Erik Mattsson and Daniel Barrdahl are studying halocarbon production of the algae in the Antarctic Seas for PI Katarina Abrahamson, Gothenburg University and Chalmers University of Technology. The project focuses on the relationship between current climate change, the rising CO2 levels and halocarbon production in the sea and its release into the atmosphere. Halocarbons are volatile organic compounds with a halo gene (like flourine, bromine, iodine and chlorine) attached to it. Halocarbons are released into the atmosphere which can affect the ozone layer that covers and shields our earth from dangerous ultraviolet radiation from the sun. While the natural production of halocarbons by algae has always occurred, human production through the use of Freon, industrial by-products, and in the 70's by dry cleaning has contributed to the increased concentration of halocarbons in the atmosphere and the sea. The percentage of the human production of halocarbons is less now, but they are still found and are damaging the ozone layer.
Using samples of sea water from the bottom to the surface they analyze the distribution patterns of the halocarbons. Samples from snow, ice and brine allow them to study organisms from different environments to see how much and what type of halocarbons are produced by each. The method for analyzing the halocarbons is by using a purge and trap system connected to a gas chromatograph (GC) with an electron capture detector ( ECD). The purge and trap system uses nitrogen gas to bubble out the halocarbons from the sea water sample. The gas which carries the halocarbons then goes into a cold trap where they get stuck on an absorbent surface. Heating of the trap releases the halocarbons into the GC where they are separated according to their specific boiling points .When they finally pass through the ECD, each specific halocarbon can be detected by its electronegative characteristics.
Halo Studies
Erik and Daniel explain the Electron Capture Detector.*
Another scientist interested in the microbiology of this area is Janos Hajdu, Professor at Stanford University and Uppsala University in Sweden. Janos is looking for the smallest living creatures capable of self-replication without a host. The smallest known so far are mycoplasmas and picoplankton. He is looking for photosynthetic picoplankton that measure from 300 nanometers - 1 micrometer. Janos explained that we know that life fits within a sphere of 300 nanometers, but we don't know what he smallest possible size could be to permit independent life. He is interested in getting a very high resolution picture of the molecular details of the structure of picoplankton. While he is here, he will be capturing and culturing samples taken from the first 200 M of the water column and take them back to his lab where he will analyze them with x-ray free electron lasers. Grad student Marvin Seibert is assisting Janos with his work. They are using a high speed cell sorter with four lasers onboard the Oden to sort and select picoplankton cells. Janos and Marvin are also looking at life(small cells) in the atmosphere carried by the sea spray and aerosols using specialized equipment from the Lawrence Livermore National Laboratory to monitor and collect aerosols from the Antarctic area. This is the first time he has done this study here in Antarctica.
Janos in his Lab
Janos explains how the high speed cell sorter works.*
Marvin Seibert
Marvin explains how cells are sorted by size.*
There were some interesting ice floes at this station that seemed to come out of nowhere. Look at these images - can you tell how these tracks were made??
Ice Prints
Who's been walking on this ice????*
Penguin Tracks
Where there one or two visitors to this ice floe?*
All for now! Lollie