The Response of Precipitation Extremes to the Twentieth- and Twenty-First-Century Global Temperature Change in a Comprehensive Suite of CESM1 Large Ensemble Simulation: Revisiting the Role of Forcing Agents Vs. the Role of Forcing Magnitudes
[1];
[2];
[3];
[6]
- Texas A & M University, College Station, TX (United States); Texas A&M University
- Sun Yat-Sen University, Guangzhou (China)
- Texas A & M University, College Station, TX (United States)
- Chinese Academy of Meteorological Sciences, Beijing (China)
- National Center for Atmospheric Research (NCAR), Boulder, CO (United States)
- National Center for Atmospheric Research (NCAR), Boulder, CO (United States); Monash University, Melbourne, VIC (Australia)
The response of precipitation extremes (PEs) to global warming is found to be nonlinear in Community Earth System Model version 1 (CESM1) and other global climate models (Pendergrass et al., 2019), which led to the concern that it is not accurate to approximate the response of PE to a single forcing as the difference between simulations with all forcing agents and those that exclude one specific forcing. This calls into question previous model-based results that the sensitivity of PE with warming due to aerosol forcing is significantly larger than that due to greenhouse gases (GHGs). We reevaluate the PE sensitivity to GHGs and aerosols using available CESM1 ensemble simulations. We show that although the PE response to warming is nonlinear in CESM1, especially for the high warming projected in the twenty-first-century, PE sensitivity to aerosols is still significantly stronger than that due to GHGs when the comparison is made within similar warming regimes to avoid the bias induced by the nonlinear behavior. But the difference is smaller than previously estimated. We also conclude that the additivity assumption is largely valid to isolate the PE response due to aerosol forcing from the paired simulations including the “all forcing” experiment when the warming regime is small (e.g., 1°C–2°C in the next few decades when aerosol forcing is projected to decline and becomes a major source of uncertainty for model projection).
- Research Organization:
- Texas A & M University, College Station, TX (United States); University of California, Oakland, CA (United States)
- Sponsoring Organization:
- Australian Research Council; National Center for Atmospheric Research (NCAR); National Natural Science Foundation of China; National Science Foundation (NSF); USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- AC02-05CH11231; SC0022070
- OSTI ID:
- 1978505
- Journal Information:
- Earth and Space Science, Journal Name: Earth and Space Science Journal Issue: 1 Vol. 9; ISSN 2333-5084
- Publisher:
- American Geophysical Union (AGU)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Climate Change Projections in CESM1(CAM5) Compared to CCSM4
Nonlinear Climate Responses to Increasing CO2 and Anthropogenic Aerosols Simulated by CESM1