Examining Discrepancies Between Reported Tropical Cyclone Precipitation Trends

Modeling studies suggest that the Tropical Cyclone (TC) rain rates should reach a 7% increase per one Celsius degree of sea surface temperature warming, as given by the Clausius-Clapeyron relation (CCR). However, this statement entails general assumptions that could underestimate the precipitation changes, particularly at the scale of depth convective systems with high release of latent heat and intense upward motions. Recent observational investigations have found a regular increase in the TC rain rates exceeding the CCR scaling. The reported increases are mainly controlled by a reduction in the inner core and a significant increase in the rainband regions.

Although all the observational studies agreed on the increasing trends, there are discrepancies in the order of magnitude and statistical significance. Therefore, this research closely analyzes the precipitation retrieval differences between two well-known TRMM/GPM products (3B42 and IMERG) for TC rainfall analyses. In addition, remote sensing technologies at infrared wavelengths are employed to verify the reported trends over longer time series and to provide clues about the right order of magnitude in the TC precipitation increase.