Future Multiyear Droughts in California and Implications of Vegetation Stress and Wildfire Risk
Abstract
The occurrence of 21st century droughts on timescales ranging from 12 to 60 months in California and their interplay with vegetation stress, tree mortality, and wildfire risk are examined in the Community Earth System Model Large Ensemble (CESM-LENS). Future droughts are placed in the context of the extreme 2011-2015 drought that California experienced. Multiple drought indices (SPEI, SPI, P-ET, CWD) show that droughts like the 2011-2015 event will shift from being extreme to regular in their occurrence, potentially becoming a "new normal" by the second half of the 21st century. The earliest emergence of this new normal for historically extreme droughts is found when focusing on PET-based drought indices. We further explore the future of California droughts using the P-ET metric, where ET is estimated either by empirical relationships land surface model outputs from CESM. Finally, we discuss limitations in CESM's land surface model and how future improvements to it may lead to better future simulations of drought over California.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B31I2498M
- Keywords:
-
- 0410 Biodiversity;
- BIOGEOSCIENCES;
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 1616 Climate variability;
- GLOBAL CHANGE