Compound Heat Wave, Drought, and Dust Events in California

Abstract California is one of the nation’s top agriculture producers and vulnerable to extreme events such as droughts heat waves. Concurrent may further stress water energy resources, exerting greater adverse socioeconomic, environmental, health impacts than individual events. Here we examine features compound drought, wave, dust in during spring summer. From 2003 2020, 16 are found warm seasons, with a mean duration ∼4 days. Compound characterized by enhanced surface temperature up 4.5°C over northern western California, reduced soil moisture vegetation density, an increase optical depth (DOD) 0.05–0.1 central southern California. The DOD largely associated severe dieback that favors emissions southeasterly wind anomalies support northward transport from source regions Surface fine PM 2.5 concentrations also more 0.5 5 μ g m −3 , respectively, both relatively stable atmosphere traps pollutants. development related anomalous high west coast lower middle troposphere, which pattern favoring sinking motion dry conditions embedded wave train develops 7 days before In comparison extremes alone, show significantly higher density droughts.