Impact of Network Design on Daily Temperature and Precipitation and their Application: USCRN and COOP

The Cooperative Observer Program (COOP) originated in the 1980s as a volunteer network whose purpose was to provide daily data to agricultural communities. Over time, the network grew from hundreds to thousands of stations nationwide, and slowly evolved into the backbone of the US climatology data set. Despite the historically rich data set, station observer, evolution, and instrumentation biases have been noted to affect temperature and precipitation observations.

As work to improve bias correction continues, NOAA's National Climatic Data Center established a climate focused observational network known as the US Climate Reference Network (USCRN). This relatively young climate network of 124 stations was designed to detect and attribute climate signals over the next 50 years without the need of bias corrections due to observation continuity over time from stable, open environments.

As the USCRN data record lengthens and becomes suitable for a variety of climate applications, differences between COOP and USCRN network design and the role of network architecture on observational differences will become increasingly relevant. The purpose of this study was to compare USCRN and COOP temperature and precipitation observations from closely (500 meters) collocated station pairs. Additionally, this study will explore the impact of network design on commonly used indexes such as the standard precipitation index (SPI), palmer drought index, and Keetch-Byram drought index to assess fire danger. It is anticipated here that network design will lead to some systematic biases between collocated station pairs and underscore the importance of sensor redundancy and instrumentation shielding on observations.