Tuesday, November 29, 2011

Solar Heating or Lack Thereof

Here's a plot of the daily duration of solar heating at 65N (latitude of Fairbanks), defined as the duration the sun is 5° or more above the horizon. Note the plot extends for 15 months so to show the winter minimum. We are a week into the two months with no significant solar heating. Changes in surfaces temperatures during this time are modulated by horizontal movement of air (advection), vertical mixing (mostly wind) and presence of absence of clouds significant to reduce the continuous cooling of the top of the snow pack (long wave radiation).


  1. thanks for this interesting graph. I wonder how they came up with measurements for this type of thing.

  2. Trung,

    These are calculated times from when the solar elevations is 5 degrees above the horizon. I went through and found the "rising" time (when the sun reach 5 degrees in the AM) and the "setting" time (when the sun reached 5 degrees in the PM) for each day of the year and then plotted the duration.