Dispatch 07 - July 21, 2002
By C.A. Linder
Weather conditions: fog and haze, winds 20 knots from the NW, calm seas, air temperature 40° F.
Getting the Hang of It
Practice makes perfect. Undaunted by the harsh blowing mist and frigid temperatures this morning, Jim Johnson led two successful mooring deployments today. The constantly moving ice gave the mooring crew a few scares, though, as several small floes came close to the current meter dangling on the taut mooring line. Since the 1200 lb. anchor goes into the water first, the mooring line is under great tension. If a large ice floe hits this line, it can cut it or drag it along, possibly causing one of the deck lines to snap. The instruments, while robust enough to withstand being underwater for over a year, could be damaged by a sharp blow.
Luckily, the bridge was ready to respond by blowing out the ice in the wash of one of the propellers. In the span of a few short hours, the weather changed for the better; the fog blew off and left us basking in the suns warming rays. The next mooring was in the water in a half an hour, a testimony to the great teamwork between the Polar Stars crew and the science team. These moorings are located near the shelfbreak, where the bottom drops away steeply into the Canada Basin. They are designed to measure the water flowing off the Chukchi Sea shelf and into the Arctic Ocean throughout the next 14 months.
The CTD crew also honed their skills, finishing the west to east section in the early morning hours and starting into a south-north section on the outer Chukchi shelf. Tonight we discovered our first traces of warm Atlantic water (a balmy 32° F!) , which has traveled all the way across the Arctic Ocean from the Gulf Stream via the Fram Strait between Greenland and Iceland. We easily spotted it on our CTD trace since it is markedly warmer and saltier than the local waters of the Chukchi Sea lying above it.
You might be asking - how can the water get warmer as you go deeper? Well, remember that this water is saltier, and that salt makes the water more dense. After completing this section, we will turn back south for Barrow Canyon to deploy the fourth UW/UAF mooring.
We spotted another polar bear in the distance today, a slightly creamier-colored white spot moving amid the snow-white ice. Everyone on the ship is eager to see one of these awesome predators up close (yet from the safety of the ship). Given the prodigious size of the Polar Star, and the sound of her massive engines, if we meet any bears up close it will be on their terms.
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