Folks have been complaining that last month (December has 2012) was one of the worst in memory. Dark, wet, and dark again. But was this our imagination? Let us cast light on this darkness!
Let's begin by examining a plot of cumulative solar radiation on my department's roof since the beginning of December through the end of the month (the numbers on the bottom are the number of hours into the month). This is a measure of the total solar radiation you could have soaked up at any point in the month. The black line is for December 2012 and red is normal (past 13 year average). For the first few days we were getting normal sun, but then we started falling behind more and more. Yes my friends it was darker much than normal.
A good way to start the New Year. And a happy new year to all of you!