Tuesday, 24 January 2012: 3:30 PM
The NOAA/FAA/NCAR Winter Precipitation Test Bed: How Well Are We Measuring Snow?
Room 239 (New Orleans Convention Center )
Precipitation is one of the most important atmospheric variables for ecosystems, hydrologic systems, climate, and weather forecasting. Despite its importance, accurate measurement remains challenging, and the lack of recent and complete intercomparisons leads researchers to discount the importance and severity of measurement errors. These errors are exacerbated for the automated measurement of solid precipitation and underestimates of 20-50% are common. While solid precipitation measurements have been the subject of many studies, there have been only a limited number of coordinated assessments on the accuracy, reliability, and repeatability of automatic precipitation measurements. The most recent comprehensive study, the “WMO Solid Precipitation Measurement Intercomparison” concluded in 1998 (Goodison et al. 1998) focused on manual techniques of solid precipitation measurement. Precipitation gauge technology has changed considerably in the last 12 years and the focus has shifted to automated techniques. This talk will highlight recent efforts to understand the relative accuracies of different instrumentation, gauges and wind-shield configurations to measure snowfall at the NCAR Marshall Field test bed. This joint collaboration between NOAA, NCAR, NWS, and FAA involves testing new gauges and other solid precipitation measurement techniques in comparison to reference measurements from gauges with large wind shields. This assessment is critical for any ongoing studies and applications such as climate monitoring that rely on accurate and consistent precipitation measurements.