Temperature Inversion

The Fairbanks News-Miner had a couple of interesting articles on the effect of the super cold temperatures at the start of the race: Jeff Richardson’s Yukon’s extreme cold takes toll on people, dogs and John Schandelmeier’s
Why so many dropped dogs? Deep cold, risky strategy.

Jeff King’s scratch at Pelly Crossing highlights another issue – appetite. Jeff has been competing in 1000 mile races for decades, and certainly knows how to pack a sled for a run, but he was blind-sided by the change due to the cold. In a normal race each dog consumes about 25,000 calories per day and mushers load their sleds with that much plus a reserve. If you drop a dog, you have to leave at least 4 pounds of food per day for the dog to eat when it isn’t working.

Jeff left Pelly Crossing and got to the Scroggie Creek Dog Drop and saw that the dogs were eating much more than normal. At the stop he concluded he didn’t have enough food packed to ensure they were fed all the way to Dawson, so he returned to Pelly Crossing. There was no way for him to obtain the extra food he felt he would need for the trail to Dawson, so he scratched.

Temperature inversion is the name given to the phenomenon seen in valleys in the North in the winter. Because the cold air is dense it sinks to the bottom and the valleys are filled with the coldest air around. Climbing up a couple of hundred feet produces a notable temperature rise. Unfortunately the sled dogs trails are forced to the bottom, stuck in the river of frigid air.

It could also describe the current conditions in Alaska and New York. When I checked the weather this afternoon, it was 8°F in Fairbanks, Alaska with no windchill, and -1°F in Fairport, New York with a windchill of -17°F. The forecast calls for Fairbanks to have highs a few days this week in the 30s, while the low 20s is the most Fairport can hope for.