How not to measure temperature, part 40

29 11 2007

Rounding out a review of California weather stations this week we visit Gilroy, CA, the garlic capital. This COOP station has an MMTS temperature sensor on a pole just a few feet from a concrete slab. We’ve seen a lot of that lately. But look closely – roasted garlic anyone?


Photo from NWS, San Franciso/Monterey CA

While it’s likely the BBQ grill is not used daily, one has to wonder just how much bias it’s proximity imparts into the temperature record. This station  COOP number is 04-3417 as is part of NOAA’s “A” network which reports climate to NCDC. It is located at the Fire station in Gilroy, seen below. Notice that is is also near a large parking lot and major intersection downtown. So much for NOAA’s 100 foot rule for station siting.

gilroy_firestation_aerial.jpg
Click on the picture for a larger interactive view

The recently released paper from LaDochy et al. showed that “urban” stations warmed at a rate of 0.20°C per decade while the “non-urban” stations warmed only 0.08°C per decade, with the lack of attention to the measuring environment such as we see here, is it any wonder?