Monday, January 7, 2013

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.

4 comments:

  1. How about comparing cloud cover and/or wind velocity with the RIS?

    Seems like a correlation may exist at both locations. I wonder how they may differ?

    Gary

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    Replies
    1. Gary,

      A good idea, except winds at the airport are too light most of the time and cloud cover data is not robust enough.

      Rick

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    2. Maybe we need one of these gizmos at the Airport to detect and quantify cloud cover:

      http://www2.gi.alaska.edu/splidar/

      Gary

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  2. Instead of the above, I really should have linked the current ceilometer used at FAI/PAFA. A former neighbor ran the LIDAR setup, so I picked that one in haste.

    I heard at one point they were having calibration issues with the CL-31 ceilometer upgrade and ops. I have no idea what's in place today.

    Rick, what's your take on the AWOS/ASOS systems we have, and is their cloud reporting somewhat...non-robust?

    Gary

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