Observing the Diurnal Cycle of Coastal Rainfall over Western Puerto Rico in Collaboration with University of Puerto Rico Students

The diurnal cycle of coastal rainfall over western Puerto Rico was studied with high-frequency radiosondes launched by undergraduate students at the University of Puerto Rico at Mayaguez (UPRM). Thirty radiosondes were launched during a 3-week period as part of NASA's Convective Processes Experiment-Aerosols and Winds (CPEX-AW) field project. The objective of the radiosonde launches over Puerto Rico was to understand the evolution of coastal convective systems that are often challenging to predict. Four different events were sampled: 1) a short-lived rainfall event during a Saharan air dust outbreak, 2) a 2-day period of limited rainfall activity under northeasterly wind conditions, 3) a 2-day period of heavy rainfall over land, and 4) a 2-day period of long-lived rainfall events that initiated over land and propagated offshore during the evening hours. The radiosondes captured the sea-breeze onset during the midmorning hours, an erosion of lower-tropospheric inversions, and substantial differences in column humidity between the four events. All radiosondes were launched by volunteer undergraduate students who were able to participate in person, while the coordination was done virtually with lead scientists located in Puerto Rico, Oklahoma, and Saint Croix. Overall, this initiative highlighted the importance of student-scientist collaboration in collecting critical observations to better understand complex atmospheric processes.