Global Wet/Dry Patterns and Mechanisms Since the Last Glacial Maximum: A Key to Future Projection

Abstract

Abstract Investigating the response mechanisms of long‐term global wet/dry pattern changes to cold/warm periods and climate forcings can provide scientific supports for the projection of future wet/dry patterns in the context of global warming. Here we present a systematic assessment into the response of global wet/dry patterns to cold/warm periods since the Last Glacial Maximum, and test the triggers for global wet/dry status change. Then we conduct an assessment of future global wet/dry patterns based on a thorough analysis of modern observations, paleoclimate simulations and records. Results show that regions following the hypothesis of “wet gets wetter, dry gets drier” (WWDD) account for 22.81% of the world's land area except Antarctica in the future. Regions complied with future “DD” pattern mostly concentrate in the parts of southwestern North America, southwestern South America, Mediterranean, northern Africa, southern Africa and Asia, covering 18.21% of the modern dry regions. Regions complied with future “WW” pattern occupy 25.41% of the modern wet regions, mainly distributing around the parts of northeastern South America, central Africa, western Russia, eastern Asia and northeastern Australia. Besides we investigate global wet/dry patterns during the abrupt climate change and find that global wet/dry patterns generally have the opposite status between abrupt warm and cold periods. If an abrupt cold event appears in the near warm future, it is likely that some parts of southwestern North America and Mediterranean in modern dry regions will be getting wet.

Keywords

• wet/dry status
• the Last Glacial Maximum
• paleoclimate records
• simulations
• future projections