COMPARISON OF COMMUNITY SCIENCE RAIN GAUGE MEASUREMENTS WITH SATELLITE PRECIPITATION DATA IN TUCSON, ARIZONA, USA

Abstract

The Sonora Environmental Research Institute, Inc. (SERI) is a non-profit organization in Tucson, Arizona, USA. With the help of community scientists, SERI installed 168 rain gauges for a precipitation study in central Tucson. One hundred twelve or 67% of the participants met the U.S. Department of Housing and Urban Development (HUD) criteria for being low income. Forty-three percent of the participants spoke Spanish as their primary language, and 60% of participants identified as Hispanic. We compared the rain gauge data to NASA's Global Precipitation Measurement Mission (GPM) Integrated Multi-satellitE Retrievals for Global Precipitation (IMERG). The overall chi-square is 7.0 mm, indicating there is significant disagreement between the GPM and rain gauge measurements. We calculated an overall bias of 6 mm and an RMSE of 13 mm. We found that Tucson precipitation is variable in intensity and through space and time. A significant portion of this variability is below the resolution of the 9x11 kilometer GPM IMERG pixel.