The spurious effects of splashing precipitation on droplet measurements and the lack of natural cloud droplets in a RICO rain shaft

During the Rain In Clouds over the Ocean (RICO) field project, the NCAR C-130 targeted precipitation shafts below cloud bases on several missions. This situation is ideal for studying the effects of precipitation splashing on various instruments.

Data from a new 2D probe, SPEC incorporated's 2D-S, allows discrimination between natural particles and spurious particles due to splashing. For a RICO rain shaft, it is found that there are no or only very few natural cloud droplet sized particles. This may be due to lack of production when raindrops break up or may be due to evaporation of those produced since the rain-shaft will be under-saturated when it is also a downdraft.

The FSSP and CPI probes measure significant numbers of droplets with realistic size distributions due to splashing of precipitation. The effects, however, are not overwhelming and reasonably well predicted from 2D-C and 2D-P measurements of the precipitation.