Relative Inversion Strength

It seems like for the past couple weeks inversions have been mostly pretty strong in Fairbanks-land, stronger than normal anyway. So I've been toying with an easy way to quantify that.

Here's an attempt that uses the daily difference in standardized mean daily temperature anomaly for Fairbanks International Airport and Keystone Ridge. This accounts for the "normal inversion" as reflected in the daily means and adjusts for variance (the standardized part) that differs between hills and valleys (valleys have significantly larger variations in temperature). This differences is the relative inversion strength (RIS). I've plotted the daily anomalies for both sites in the background for reference.

The purple line is constructed so the positive values reflect stronger inversions than average, zero would be average and negative RIS are weaker than average. Positive RIS has indeed been the rule since late November, with the only extended exception the snowy week in mid-December.