87th AMS Annual Meeting

Tuesday, 16 January 2007: 9:00 AM
Rain Gauge Measurements in Mid-Atlantic Region
207A (Henry B. Gonzalez Convention Center)
Ali Tokay, JCET/Univ. of Maryland Baltimore County, Greenbelt, MD; and P. G. Bashor and V. L. McDowell
As part of the NASA Tropical Rainfall Measuring Mission ground validation program, a mid-latitude coastal ground validation site has been operating in the Mid-Atlantic region for over two years. The network includes 23 tipping bucket rain gauge stations within 15-200 km of National Weather Service (NWS) S-band Doppler radar (KAKQ), located at Wakefield, Virginia. With the guidance of the NWS Wakefield Office, the gauge stations were collocated with seven Automated Surface Observing Systems (ASOS) and seven co-op sites. In addition, we had four gauge stations near state agency weather stations, four at Automated Weather Observing Systems (AWOS) sites, and one at Climate Reference Network (CRN) site. We deployed triple gauges at each site except at ASOS sites where dual gauge platforms were situated. Operational NWS and other agencies weather station gauges are often employed in validating radar rainfall estimation and hydrological studies. The accuracy of operational gauges was determined through an application of a statistical package to daily and monthly gauge rainfall records. Our results showed that co-op gauges have a high percent of error on both daily and monthly scale, while the error statistics of ASOS gauges had a wide range depending on the site. The gauges had the best agreement at CRN site, while the AWOS gauges had poorer performance than ASOS sites. The state agency gauges had reasonable performance most of the rainy days. An independent study of tipping bucket performance was conducted at NASA Wallops Island, Virginia where we operated dual tipping bucket gauges from three different vendors. The low cost and high performance of Met One gauges seems to be the best choice for long-term operation at remote sites.

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