Tuesday, January 28, 2014

January State Record Temperature in Port Alsworth

Rick noted today that the Alaska January temperature record of 62°F was tied yesterday (1/27) at the CRN station in Port Alsworth. This is quite a fortuitous observation. The CRN network was established to create a baseline of data for future climate change studies. The sites were selected to represent a  variety of ecological settings without the urbanization, land use, and equipment changes that may affect long term temperature measurements. Highly reliable equipment is used at CRN stations.

Port Alsworth is located on the southeast shore of Lake Clark approximately 170 miles southwest of Anchorage. Looking at recent VIIRS and Modis imagery, there appears to be no snow cover in the vicinity of the station (see second image below). Also, there is a state airport weather station in Port Alsworth (PALJ) and a RAWS station. The chart below shows the 15-minute observations from the CRN station plus the few airport and more numerous RAWS observations. Quite clearly, the airport and RAWS data support the CRN data. Finally, since the 62°F reading was one of the 15-minute observations, there is a chance that a higher reading occurred between the 15-minute readings.


Fig 1. Temperature plot of CRN, airport, and RAWS temperatures on 1.17/14.


Fig 2. Suomi NPP Landcover image from 1/28/14 showing the lack of snow cover in the region. Cyan is snow and brown indicats no snow. White indicates clouds (not snow). Port Alsworth is at the lower left end of the yellow line. Anchorage is at the upper right end of the yellow line. Click on image for a closer look.

2 comments:

  1. The CRN site linked requires a login. I did look at some of the other nearby station data. It appears the winds were a brisk 30-40 easterly during the 27th.

    I've flown to Port Alsworth several times in early summer. It lies at the exit of a nearby mountain drainage, and of course along Lake Clark, itself a drainage.

    Might it have been downslope dry adiabatic heating similar to the recent Delta Jct warmth? Any idea what special events precipitated the record event?

    Gary

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    1. Gary, I found this page with all of the CRN datasets: http://www.ncdc.noaa.gov/crn/qcdatasets.html
      One of them is 5-minute temperatures. There is not a good readme.txt file so it takes a few minutes to orient yourself.

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