How daily temperature and precipitation distributions evolve with surface temperature
Abstract
The day-to-day variability of temperature and precipitation is a key component of regional climate. As global mean surface temperature changes, so will the statistical distributions of daily weather - but how? Their means may change, as may their widths and shapes, or any combination of the three, and the total change will be a key component of experienced climate change.
Large Ensemble simulations allow us to investigate the probability density functions (PDFs) of daily temperature and precipitation, within the consistent framework of a single Earth System Model. Here, we use the CESM1 Large Ensemble to show how regionally and seasonally resolved PDFs evolve with surface temperature, under the anthropogenic influences assumed in RCP8.5. Using a specially derived set of indicators, we also estimate which regions most rapidly transition away from preindustrial conditions. As global temperature increases, Europe and the US are projected to see a rapid reduction in wintertime cold days, and East Asia to experience a strong increase in intense summertime precipitation. Southern Africa may see a shift to a more intrinsically variable climate, but with little change in mean properties. The sensitivities of Arctic and African intrinsic variability to surface temperature are found to be particularly high. Further, we use a set of 10-member ensemble simulations from CanESM5 to investigate the influence of different combinations of short-lived climate forcers (as assumed in the Shared Socioeconomic Pathways) on Southern and Eastern Asian daily climate. The results are compared to CESM1, and to ERA5 reanalysis, to provide a first indication of the reliability of the simulations. In summary, we show how Large Ensemble simulations provide a novel window on the evolution of daily, regional climate change - which, in turn, is a key aspect of comprehensive risk assessments.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC23D..03S
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 4805 Biogeochemical cycles;
- processes;
- and modeling;
- OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL;
- 4215 Climate and interannual variability;
- OCEANOGRAPHY: GENERAL