The rating system for site quality was borrowed verbatim from the new Climate Reference Network being put into operation by NCDC and NOAA to ensure quality data. Their siting criteria can be found here.
I welcome input on this work in progress. The site rating will now be a running total in the spreadsheet and always available online as new stations are added to the survey. What is important to note is that the majority of stations that have a rating of 4 are MMTS/Nimbus equipped stations, which according to NCDC’s MMS equipment lists, make up 71% of the USHCN network. It appears that cable issues with the electronic sensors have forced them closer to buildings, roads, etc because NOAA COOP managers don’t often have the budget, time, or tools to trench under roads, sidewalks etc to reach the site where Stevenson Screens once stood. While this isn’t always the case, a pattern is emerging.
For background, see this first: Conference presentation given at CIRES/UCAR on 8/29/07 describing this project and the methods used to assign station site quality ratings, along with examples of many site issues seen thus far.
Immediately after the conference, a senior official at NCDC requested a copy of the above slide show, which I provided to him on CDROM. After receiving it, in a follow up email he inquired as to distribution rights which I granted within NCDC and NOAA for the purpose of review. That was last week. Thus far no issues have been raised with the presentation content. Since no issues were raised at the conference or in the two weeks afterwards (two weeks as of today) I have decided to release it publicly.
Note that of the 33% surveyed, only 13% meet the CRN site criteria (Rating of 1 and 2)for an acceptable location to accurately measure long term climate change free of localized influences.
Climate Reference Network Rating Guide – Class 1 and 2 are considered best, 5 is the worst.
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. No 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.”