Utility of a Shipborne Disdrometer and Marine Navigation Radar during Convective and Stratiform Rain

This study seeks to understand the capabilities of both a shipborne optical disdrometer and an X-band marine navigation radar to quantify convective and stratiform rain. Optical disdrometers are commonly used on land but are not routinely mounted on moving ocean-going platforms. It is not yet clear how platform motion affects disdrometer performance. Similarly, marine navigation radars have much different scanning strategies and performance than weather radars typically used to measure rain. However, navigation radars are widely-available, compact, and are standard equipment on research vessels. To assess the utility of these ship-based systems, this study analyzes observations of stratiform and convective rain events using a marine navigation radar, ship-based disdrometer, and ship-based rain gauge. Results from these instruments are compared to observations collected in similar rain regimes by research radars, parsivel optical disdrometers, and 2D video disdrometers. This comparison covers two different rain regimes: warm tropical oceans (SPURS-2 and DYNAMO experiments) and the temperate northeast Pacific Ocean (OLYMPEX field campaign). Using these datasets, we compare key parameters of the raindrop size distribution, rain rate time series, and spatial variability of radar echoes to understand the sampling limitations and strengths of shipborne disdrometer and marine navigation radars during convective and stratiform rain.