Posts Tagged ‘LTER’

Sea Ice

Thursday, December 10th, 2009

1-2/10thsSomething I have learned during my time here in Antarctica is that sea ice takes glider piloting to a whole new level. It can be an unpredictable moving obstacle that can mean danger for a glider. So in order to have a better understanding of this obstacle I spent some time learning about the different categories of sea ice and learning how to read sea ice coverage maps. Tom Holden is the Special Support Coordinator at NIC the National Ice Center and each morning his team sends the LTER scientists a sea ice image for the Anvers Island area. We then use these images to monitor the area and decide whether or not it is safe to fly the gliders.

Dec 3rdTypically, my image categorizes the Anvers Island area sea ice into four categories (see image Dec. 3rd). On the December 3rd image you can see an example of the sea ice being broken down into A, B, C and D. Level A ice is classified as 1-2/1oths, Level B is 3-4/10ths, Level C is 5-6/10ths and D is 7-9/10ths. The classification of sea ice is actually based on a percentage, so Level A ice in an area actually means the area is about 10-20% sea ice compared to that of Level D which means an area is about 70-90% sea ice. To go even more in depth Tom sent me the following description which explains how the age of the ice also plays a role in how they analyze the images and than categorize.

The A, B, C and D that you see on the charts, are used to designate attributes to each individual area.  Each area you see is analyzed, based upon the ice type (classification) AND the concentration.  Ice types are based upon thickness and age of the ice.  The purpose for this, is generally, older ice, is harder and thicker. The reason it is harder, is that gravity pulls on the brine content and it drains its way through, leaving nearly pure frozen water behind. New, Young ice is easily broken and Multi-year and glacial is the hardest to break.

Leopard SealUnfortunately, even with all this information the bottom line is still the more sea ice in an area, the more tightly it will be packed together, making it more difficult for a glider to surface. Comparing the various types and actually seeing them in real time and seeing the consistency of the ice allowed me to determine that a glider should be able to surface in Level A ice without problems. However, level B, C and D are a different story and therefore we avoid those areas.

5/10th'sHowever, aside from the fact that sea ice can be a nuisance and prohibit us from taking zodiacs out or potentially cause a glider to not surface it serves many useful purposes. Various species in both the Antarctic and Arctic use sea ice as a means of hunting, breeding, feeding and even resting. Down here in Antarctica we have seen numerous leopard seals hauled out on large chunks of sea ice napping. The same also goes for the various avian species such as the Adelie penguin.

A Visit from Neil Armstrong!

Monday, November 23rd, 2009
Neil Armstrong with B-019

Brian, Tina, Alex, Neil Armstrong, and Carol

This past weekend Palmer Station had a very exciting visitor, NASA Astronaut Neil Armstrong and his wife Carol. They were aboard one of the National Geographic cruises that stops by Palmer. Neil and Carol got a full tour of the station and then we got to spend some time with him and talk to him about gliders. He was very interested and even started testing the flexibility of our glider wings which made us all a tad nervous. After his visit on station, the National Geographic Crew invited us aboard their boat to watch Neil give a talk later that evening. It was quite the opportunity and we were all very appreciative of the offer.

Deep Glider Deployment!

Monday, November 16th, 2009

DeployedWednesday November 11th marked the first glider deployment for this years Antarctic field season. We couldn't of asked for better weather, it was a balmy 30 degrees, clear sunny skies and flat calm seas. We journeyed out to Station E and after surveying the water depth in the area, we decided it was a good spot to splash RU25. After she completed a few short missions it was time for her journey to begin. The main mission is to obtain a battery curve for this glider in preparation for her flight to Rothera later in the season. However, we will also be running the CTD and optics puck and collecting some science. Enjoy the photos!

Passing a Bergimg_6319

Meet Bruiser!

Wednesday, October 28th, 2009

BruiserYesterday (Tuesday) was our first sampling day here at station. We would have gone Monday but if the wind is blowing over 20 knots they don't want us out on the water. Which is fine by us, no one wants to feed the fishy! So since the winds had laid down it was time to head out on our trusty zodiac 'Bruiser'. As you can see Bruiser is kind of a beast! The good news is that since it's such a heavy boat it would take an Orca to flip it, so hopefully I will have better luck here than I did in the Azores! Anyway back to the science, we have two main goals while sampling, first is the lowering of our bio-optics cage and second is collecting seawater samples. Yesterday we lowered our optics cage to 60m and collected water in Niskin bottles at 50, 25 and 10m and then two surface samples. Once we have what we need it's time to head back to the lab and filter the samples. As you can see we have a lovely filtration system setup. Filtration SystemWe use 25mm filters and filter the seawater in incriminates of 100ml until we see pigment on the filters. Right now since the water is so clear there is not a lot of activity so we have to filter more water. This will change as the weather warms and the water livens up as we head deeper into the Antarctic summer. We follow this process twice, once for chlorophyll samples and a second time for HPLC samples. Once we have the filters we store them in either the deep freeze or in liquid nitrogen. And that's a wrap!

The Season Begins!

Monday, October 26th, 2009

Palmer Station and the GouldGreetings from Palmer Station Antarctica. This year Alex (veteran from last year), Brian, and myself (Tina) are here for the LTER summer season. Some changes this year are the addition of a third person and a third glider to our group which will hopefully allow us to get even more accomplished. We will be working very closely with Maggie and Dan who are from Hugh Ducklow's group  since we are all sampling the same water and at the same depths. We will also be working closely with Kristen and Jenn who are the Penguin girls from Bill Fraser's group. Together the seven of us form the LTER science group! We have been spending the past week finding all our gear and setting up our respective labs. Today we are hoping will be our first sampling day however we are faced with a very high tide and 20 knot winds. Neither of which yields to successful boating. So instead we play it by ear and hope for a break in the weather.

Adelie Colony on Torgersen Island

It hasn't all been hard labor though... we were all lucky enough to go to Torgersen Island which has a couple Adelie penguin colonies on it. It was a beautiful day and quite the experience.