Evidence of Global Mean Increases in the Frequency of Daily and Sub-daily Heavy Precipitation
Abstract
In a warming climate and assuming moisture availability, heavy precipitation is expected to increase at approximately 7% per degree of warming according to the Clausius-Clapeyron relationship, whereas total global precipitation is capped at ~2% K-1 by atmospheric energy balance constraints. Such disproportionality suggests that extreme events increase at the expense of moderate and light events. Here we present what is, to our knowledge, the first global analysis of frequency changes in hourly and daily heavy precipitation by exploiting the 1/4° spatial resolution of the latest ERA5 reanalysis. Our robust metric captures local changes across both wet and dry regions, and avoids several known statistical biases. We report that during 1989—2018, the event that occurred one hour per year in 1979—1988 increased in frequency by 71 [53—93, 2σ range] %, while the one day per year extreme event frequency increased by 44 [37—54] %. Our results replicate prior findings that relative frequency increases are larger for increasingly rare events and for the first time we quantify that the mean frequency increase is substantially greater over the global ocean than over global land. Finally, we also address questions about the fidelity and applicability of our results due to our choice of using a reanalysis product rather than instrumental observations.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA162...03C
- Keywords:
-
- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3354 Precipitation;
- ATMOSPHERIC PROCESSES;
- 1854 Precipitation;
- HYDROLOGY;
- 4313 Extreme events;
- NATURAL HAZARDS