Changing ENSO-induced Rainfall Extremes under Global Warming
Abstract
Changes in the properties of extreme rainfall events are going to be one of the most impactful consequences of Global Warming. As the atmosphere warms up, the amount of water vapor available for rainfall increases. Therefore, it is expected that in the future, severe weather events will be characterized by stronger rainfall rates. These events could also become weaker or stronger depending on changes in atmospheric circulation. Changes in coupled modes of climate variability such as El Niño-Southern Oscillation (ENSO) phenomenon in the tropical Indo-Pacific could also alter atmospheric circulation, particularly in the tropics. Climate model simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5) show varying rates of change in the heaviest rain rates associated with the different phases of the El Niño Southern Oscillation (ENSO). This variation could be attributed to the difference in convective parameterization of these models. Higher rates are found during El Niño and La Niña relative to neutral ENSO states. For example, CCSM4, one of the models of CMIP5 shows 9.96% K-1 and 11.27% K-1 increases at the 99.99th percentile rain rate respectively during El Niño and La Niña. Whereas during neutral phase of ENSO, there is a 7.95% K-1 increase. The goal of this study is (i) to relate changes in rainfall extremes to changes in SST variability associated with ENSO and other coupled modes under Global Warming and (ii) to compare the results obtained using simulations of CMIP5 and CMIP6 models.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC42E..08T
- Keywords:
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- 1616 Climate variability;
- GLOBAL CHANGE;
- 1626 Global climate models;
- GLOBAL CHANGE;
- 1631 Land/atmosphere interactions;
- GLOBAL CHANGE;
- 1866 Soil moisture;
- HYDROLOGY