Sparge On!, December 14, 2005 Options

[Dena_Rosenberger]

Sparge On!
14 December, 2005

For those interested in things Antarctic, check out the weekly Antarctic newspaper at http://AntarcticSun.usap.gov

Hello from the Ice!
For additional Antarctic pics, check out the Gallery.

Where’s Rosenberger?
McMurdo Station and Scott Base, Ross Island, Antarctica

So all this week I have been sparging. What, you might ask, is sparging? Well, from Answers.com online encyclopedia, the definition is as follows:

sparge

1) sprinkle, bespatter; esp. spray
2) to agitate (a liquid) by means of compressed air or gas via a pipe
3) to wash out all soluble products from beer mash prior to boiling

Definition #1 is not what I have been doing in the lab. In fact, I have been trying NOT to bespatter or spray. Definitely not Definition #3 (although you never know what goes on in Antarctica). So it must be Definition #2.

As I have said previously, this week we have been analyzing the water from last year’s samples of Pony Lake by doing a photolysis (sunlight) experiment on the roof of the lab. We want to see how the sunlight, specifically the UV portion of the light, is affecting the molecules of Dissolved Organic Matter, or DOM, in the lake water. One of the things we must be careful about after it has been exposed to the sunlight is that we don’t want it to react with any oxygen before we can test it. So as I transfer the water from the test tubes that we put out into the sunlight into brown bottles that we keep in a dark refrigerator and then transfer to a small clear vial for the fluorescence test, I must keep them from reacting with the air, which contains oxygen.

The way we do this is to keep a syringe in all of the bottles that blows out argon gas continuously as we do the transfers. The syringe is hooked to a large tank of argon that supplies the gas. Now, I know that my chemistry students are wondering, “Why argon?” The reason is that, as my chem students know, argon is a noble gas, which means it is very non-reactive. It is also more dense than oxygen, so it essentially fills up the bottle with this heavy, non-reactive gas so that the air (oxygen) is forced to leave. Then, when I put in the lake water sample using a pipette, it goes right to the bottom of the bottle without being exposed to air. I then cap the bottle very tightly until it is ready to be tested.
> Sparging Set-up:


> The syringes connected with clear tubing to the wall are delivering the argon gas into the small vials:


Scott Base is the New Zealand Research Station and is about a one and a half mile walk along a road from McMurdo. Scott Base is much smaller than McMurdo and has only about 70 people. Their buildings and vehicles are all painted a nice bright green color. Only 19 people stayed there over the 6 month long winter!


This Base is right at the junction where the 20 foot thick sea ice of McMurdo Sound meets the 200-300 foot thick Ross Ice Shelf of permanent ice. Where these two types of ice meet, huge forces are at work. The moving and flexible sea ice pushes up against the immovable ice shelf and gets thrust up into fantastical shapes as high as 20-25 feet! In this photo, the sea ice is between the green building and the ridges, and the permanent ice is behind the ridges:


You can walk over there and around the base anytime, but to enter the buildings you must be invited. Thursday nights are “American Night” at Scott Base and you can go there then. They also have a store/gift shop that Americans can go to.

Did you know?
Antarctica supports a huge variety of plant species, but they are very small and inconspicuous compared to what we see most of in the United States. There are approximately 350 species of lichen, 100 species of mosses, and hundreds of species of algae, some of which are snow algae that turn areas of permanent snow into a patchwork of pink, red, yellow, and green. Some lichen and algae even live between the individual grains in the rocks and ice!

Current Conditions at McMurdo Station
A weak low pressure area to the east is supporting a northwest flow down McMurdo Sound, bringing low clouds and fog (and hampering both airplane and helicopter flights)

Right now:
Winds from the north at 7 knots
Pressure: 29.405 inHg
Temperature: 30 oF/-1 oC with wind chill: 19 F/ -7 C
Sunset: February 20 at 1:38 am