Why people are participating in citizen science . . . a CoCoRaHS fifteen year perspective from our volunteer rainfall network

What motivates a typical volunteer observer to buy a rain gauge, take daily observations and report those on an interactive website each day? Many seasoned volunteers have been doing this for the CoCoRaHS network for over ten years with some still participating since our inception in 1998. We will look at why this long lived network has been successful, why observers are participating in our network and why our retention rate remains much higher (60%) than we would have assumed.

CoCoRaHS (The Community Collaborative Rain, Hail and Snow Network) a simple, low-cost national volunteer precipitation monitoring network, now in it's fifteenth year is the largest single source of daily precipitation measurements in the country. Each day citizens from all fifty states and parts of Canada take backyard observations of precipitation and report them via the CoCoRaHS web site. With over 19,000 volunteers this high quality data set is used by hundreds of organizations from the National Weather Service to local county stormwater entities. CoCoRaHS's high resolution monitoring helps better capture and document the frequency, timing and geographic distribution of extreme events -- an interesting consideration in climate change research and discussions. During the past several years many observers have filed reports of drought impacts. These reports contribute to the US Drought Monitor, which plays a role influencing policy and decision making. Finally, the 'up' side of the water cycle is being reported by numerous CoCoRaHS volunteers. Reference evapotranspiration, which paints a picture of a community's water balance, is now being reported along with daily precipitation observations.