Temporal and Spatial Variability of Tropical Rain Rates over Kwajalein Atoll

Precipitation extremes and how they may change in a future climate have potentially large regional impacts. The Intertropical Convergence Zone (ITCZ) produces a large amount of the rainfall in the tropics (and the globe). Located in the Pacific ITCZ and approximately nine degrees above the equator, Kwajalein Atoll was the base for NASA's ground validation of the Tropical Rainfall Measuring Mission (TRMM) satellite. Observations from the Kwajalein radar were manipulated using interface description language (IDL). The results highlight how topical precipitation extremes vary based on spatial resolution ranging from 2 km to 128 km, temporal resolution ranging from 10 minutes to 1 day, and rain type (i.e., convective vs. stratiform). The importance of stratiform rain (i.e., aged convection that is more horizontally homogeneous and with weaker rain rates than active convection) in the tropics is often not resolved by satellites and global climate models. The Kwajalein radar rain rate statistics are compared to TRMM precipitation radar (PR) retrievals to test the accuracy of the satellite rain rate distributions and are further separated by daily sea surface temperature (SST) and large-scale vertical motion at 500 hPa (i.e., the middle troposphere) to see how sensitive rain rates and precipitation extremes are to environmental parameters.