Watts Up With That?

NOAA has put together a new series of surface stations called the Climate Reference Network (CRN) As a specialist in the technology of meteorology, I like this program a lot. It takes great care to place emphasis on accuracy, repeatability, linearity. and calibration of instruments. The best feature, as far as I'm concerned is the use of three simultaneous aspirated and calibrated air temperature probes, so that there is redundancy. And if one sensor starts drifting it will show up against the data from the other two. Dr. Tom Karl from NCDC deserves credit for bringing this project to implementation.

While this new instrumentation will ensure far more accurate in situ measurements in the future, it will do little to help the disarray seen in the surface temperature record of the past.

Here is the manual for it:

NOAA/NESDIS NOAA-CRN/OSD-2002-0002ROUD0
CRN Series December 10, 2002
X030 DCN 06
http://www1.ncdc.noaa.gov/pub/data/uscrn/documentation/program/X030FullDocumentD0.pdf

I want to bring attention to the way in which they rate weather station locations, because it is very germane to the argument that some of the existing USHCN and COOP stations have micro-site issues. As far as I know, no database exists of the ratings below applied to the existing network of weather stations.

From the USHCRN manual:

The USCRN will use the classification scheme below to document the "meteorological measurements representativity" at each site.

This scheme, described by Michel Leroy (1998), is being used by Meteo-France to classify their network of approximately 550 stations. The classification ranges from 1 to 5 for each measured parameter. The errors for the different classes are estimated values.

• Class 1 - Flat and horizontal ground surrounded by a clear surface with a slope below 1/3 (<19deg). Grass/low vegetation ground cover <10 centimeters high. Sensors located at least 100 meters from artificial heating or reflecting surfaces, such as buildings, concrete surfaces, and parking lots. Far from large bodies of water, except if it is representative of the area, and then located at least 100 meters away. No shading when the sun elevation >3 degrees.
   
• Class 2 - Same as Class 1 with the following differences. Surrounding Vegetation <25 centimeters. Artificial heating sources within 30m. No shading for a sun elevation >5deg.
   
• Class 3 (error 1C) - Same as Class 2, except no artificial heating sources within 10 meters.


• Class 4 (error >= 2C) - Artificial heating sources <10 meters.
   
• Class 5 (error >= 5C) - Temperature sensor located next to/above an artificial heating source, such a building, roof top, parking lot, or concrete surface."

One of the goals of the www.surfacestations.org project, will be to apply this site classification standard set forth by NOAA for the USCRN to the existing network of surface stations so that the problems associated with some sites can be quantified, and the good sites can be clearly defined as well. This will help scientists whom use the surface temperature data do more accurate analyses.