Estimates of the sensible heat of rainfall in the tropics from reanalysis and observations

Precipitation cools the surface because the temperature of raindrops is typically lower than the temperature of the surface. This precipitation-induced sensible heat flux (Q_P) due to the temperature difference between the surface and raindrops is thought to be small and is typically ignored in weather and climate models. However, there are many instances in which instantaneous values in Q_P can be large, especially in extreme rainfall events. In this study, we provide a systematic estimate of Q_P over the tropics based on in-situ buoy observations, satellite data, and reanalysis. The results show that the highest climatological Q_P values (~2 to 3 W m⁻²) are found over the Intertropical Convergence Zone (ITCZ) and the South Pacific Convergence Zone (SPCZ), both associated with higher amount of precipitation. The Q_P over land, however, is not well correlated with precipitation due to a more complex relationship between the raindrops temperature and surface temperature. Estimation of Q_P based on in-situ buoy observations shows that Q_P can be large at shorter time scales, and can be higher than surface sensible heat flux due to air-sea temperature difference (Q_SH), and even surface latent heat flux (Q_LH), for heavy precipitating events. Implications of these results and possible future research avenues related to Q_P are discussed.