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Winds carry soil particles onto the glaciers dirtying the surface, explains glaciologist and meteorological station operator Thomas Nylen of Portland State University. This decreases the glacier's albedo, that is the amount of light reflected by the glaciers and allows melting to occur, even when temperatures don't quite make it above freezing. Glacial meltwater is the principal source of water for the babbling brooks and rambling creeks close to the Stream Team's heart. The streams in turn are the main contributor of water and nutrients to Dry Valleys' lakes.

But even as winds help generate liquid water, they also carry some fraction of it away as water vapor by increasing evaporation.

Winds are generated by the sun's heat. Solar radiation warms an air mass, causing it to rise and creating an area of low pressure.

Commonwealth Glacier, Von Guerard Stream,
Lake Fryxell

As the air mass rises it cools and spreads. Once cooled it starts to sink back to earth making an area of high pressure. The movement of air from high to low pressure areas creates wind.

The normally elongated and cylindrical nematodes aren't so elongated and cylindrical when being blown around. Instead, says Jeb, they look uncannily like little cheerios. That's because they're in their anhydrobiotic or freeze-dried state. Anhydrobiosis is a process in which microscopic organisms lose 99% of their body water, leaving only the water bound to cell membranes. Dry Valleys' nematodes start the process as soon as they sense a loss of relative humidity in the soils. In addition to losing water, they change "their metabolic pathway to produce an anti-freeze, change their morphology to that of a cheerio, which reduces their surface area, and then go into a non-metabolic state," explains principal investigator Dr. Diana Wall of Colorado State University.

Diana works with nematodes in the lab
Photo by: Louise Huffman

Diana has shown that anhydrobiosis is the main way that the nematodes survive the harsh Antarctic winters. By minimizing the amount of water in their bodies and by producing antifreeze, the organisms prevent sharp ice crystals from forming that could rip cell walls and cause serious damage, a phenomenon we experience as frostbite.

Winds are a fact of life in the Valleys. You quickly learn to tie down or put rocks on everything otherwise you'll end up chasing wayward bags, papers, and cardboard boxes to the chagrin of the environmental folks back in McMurdo and to the amusement of your teammates. It is the wind that will suck the heat from your body and chill you to the bone. It is the wind that will rub your face raw and make you feel like you have been burned. And it is the wind that helps shape the valleys and make them what they are.

Water vapor and specks of dirt aren't all that's airborne in the valleys. Two-feet high sediment traps that look suspiciously like upside down bundt cake pans have revealed that microscopic nematodes are blowing around as well, says Dartmouth soil ecologist Dr. Jeb Barrett. These worms are among the most highly evolved animal life in the valleys, and winds seem to be an important means for their dispersal.

In Taylor Valley where we spend most of our time, typical winds have speeds of between five and ten miles per hour. Katabatic winds like the ones that put two of our tents out of commission can reach speeds of 90 miles per hour. Such katabatics can have a dramatic effect on local air temperatures, one that you might not expect. As the winds plunge some 6000 to 12,000 feet off the polar plateau and descend into the valleys because of gravity, they are subject to an atmospheric pressure that is greater closer to sea level, explains Thomas.

Jeb by a bundt cake pan sediment trap
This rise in pressure causes the temperature of the air mass to increase adiabatically, without input from an external source of heat. During the winter when the strongest katabatics occur, the winds can increase local air temperatures by as much as 30 degrees Celsius.

Thomas by the Explorer's
Cove Meteorological Station

Thomas points to the station's anemometer, an instrument that measures wind speed
and direction.