Breakdown in precipitation–temperature scaling over India predominantly explained by cloud-driven cooling
<p>Climate models predict an intensification of precipitation extremes as a result of a warmer and moister atmosphere at the rate of 7 % K<span class="inline-formula"><sup>−1</sup></span>. However, observations in tropical regions show contrastingly negative p...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-08-01
|
| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://hess.copernicus.org/articles/26/4431/2022/hess-26-4431-2022.pdf |
| Summary: | <p>Climate models predict an intensification of precipitation extremes as a result of a warmer and moister atmosphere at the rate of 7 % K<span class="inline-formula"><sup>−1</sup></span>. However, observations in tropical regions show contrastingly negative precipitation–temperature scaling at temperatures above 23–25 <span class="inline-formula"><sup>∘</sup></span>C. We use observations from India and show that this negative scaling can be explained by the radiative effects of clouds on surface temperatures. Cloud radiative cooling during precipitation
events make observed temperatures covary with precipitation, with wetter
periods and heavier precipitation having a stronger cooling effect. We
remove this confounding effect of clouds from temperatures using a surface
energy balance approach constrained by thermodynamics. We then find a
diametric change in precipitation scaling with rates becoming positive and
coming closer to the Clausius–Clapeyron (CC) scaling rate (7 % K<span class="inline-formula"><sup>−1</sup></span>). Our findings imply that the intensification of precipitation extremes with warmer temperatures expected with global warming is consistent with observations from tropical regions when the radiative effect of clouds on surface temperatures and the resulting covariation with precipitation is accounted for.</p> |
|---|---|
| ISSN: | 1027-5606 1607-7938 |