Abstract
Climate models show a conspicuous summer warm and dry bias over the central United States. Using results from 19 climate models in the Coupled Model Intercomparison Project Phase 5 (CMIP5), we report a persistent dependence of warm bias on dry bias with the precipitation deficit leading the warm bias over this region. The precipitation deficit is associated with the widespread failure of models in capturing strong rainfall events in summer over the central U.S. A robust linear relationship between the projected warming and the present-day warm bias enables us to empirically correct future temperature projections. By the end of the 21st century under the RCP8.5 scenario, the corrections substantially narrow the intermodel spread of the projections and reduce the projected temperature by 2.5 K, resulting mainly from the removal of the warm bias. Instead of a sharp decrease, after this correction the projected precipitation is nearly neutral for all scenarios.
Highlights
Climate models show a conspicuous summer warm and dry bias over the central United States
One of the most conspicuous is the warm and dry bias over the central U.S (CUS) in the summer (June–August) that has persisted in many generations of regional and global climate models[1, 3, 4]
We identify that the warm and dry bias over the CUS in GCMs is likely triggered by the precipitation deficit arising from the model’s failure in capturing the large precipitation events, followed by land–atmosphere feedbacks
Summary
Climate models show a conspicuous summer warm and dry bias over the central United States. Identifying the origins of these systematic biases and determining their potential impacts on future climate changes are immensely important and crucial for adaptation guidance and policy making. This topic is currently the subject of intense research in the climate community. Soil moisture deficit and the resultant underestimated shallow cumulus can lead to an excess of surface temperature and, reduce the formation of precipitation Though these feedbacks have been extensively discussed, the origins of the model biases are still unclear. Results show that current GCMs are likely overestimating future warming and drying over the CUS
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
