New Year at -40°

Stars of Orion and the city lights of Fairbanks, Alaska on New Years Eve 2009 with fireworks seen on the left. You can see two plums of ‘smoke’ rising up out of the ice fog in the distance from the two power plants in the city, with both plumes being swept off to the right. As noted by the photographer “The temperature was -40F and -40C, that single temperature where Centigrade and Fahrenheit coincide. The city was buried in ice fog that evening, fog that is generated by heat sources that contain moisture in any form. It is the same effect as the contrails from high flying jets, as they leave a frozen vapor trail across the sky. That trail they leave is just a trail of ice fog left from their warm moist exhaust, just as the ice fog covering our city is generated from the warm exhaust of all the sources of heat. And the coldest air is the heaviest air, so the low lying countryside ‘fills’ with the heavy cold air, and the cold air fills with fog from the city itself. So going up a hillside not only brings a few degrees warmer air, but it brings you above the ice fog as well. Even a herd of caribou in the wilderness can have its own small cloud of ice fog just from their breath. Breathe outside on a cold day, and the breath you can see is ice fog. And when it is really cold, it just stays.”