Comparing Temperature Data from USA Mesonet Stations, Cooperative Observer (COOP) Stations, and Automatic Surface Observing Stations across the Northern Gulf Coast

Even on a relatively small scale of several tens of km, temperatures can differ significantly. This can impact agriculture and the comfort level of humans and animals. Furthermore, the location of the weather station used can determine the climate for a specific region. Therefore, this study will attempt to quantify the differences in temperature across localized are.a

 Climatological data (temperature and rainfall) from different types of instrumentation and weather station networks are compared. Across much of the northern gulf coast region of the United States, two types of networks provide a wealth of real-time weather and climatological data to forecasters, researchers, and the public: Automatic Surface Observing Stations (ASOS), Cooperative Observer (COOP), and stations from the South Alabama Mesonet. A set of nine pairs of stations, each including a South Alabama Mesonet station and either an ASOS or COOP station, separated by less than 31 km, are utilized. Data from September 2009 to August 2015 are used to form a six-year data set with temperature data from each station of interest.

 Temperature data from all types of stations were quality-controlled to ensure that only real and correct data were utilized. Quality-control procedures varied by instrumentation system and included: a range test, step test, and like-sensor tests (Mesonet only). Data that failed the quality-control process was set to missing and not utilized in the study.

 Analysis of minute by minute data will be performed using SAS’s JMP statistical software package. Statistical properties of the minute-to-minute temperature difference (ASOS versus South Alabama Mesonet – minute data is not available for COOP data) will be discussed, including extreme values, medians, and means. The nature of the distributions of the temperature differences will be presented and discussed. The diurnal and monthly variations of the means and medians will be explored. Temperature differences will be explained in terms of 1) differences in instrumentation, 2) aspirated versus non-aspirated radiations shields, and 3) micro-climatological factors.

Next, daily data will be analyzed using JMP. Daily data from ASOS and Mesonet stations will be calculated from the available minute data to agree with the products provided by the COOP stations. Again statistical properties, distributions, and diurnal/seasonal variations will be investigated.