资源环境科技发展态势分析平台

Prior work suggests drought exacerbates US air quality by increasing surface ozone concentrations. We analyze 2005‐2015 tropospheric column concentrations of two trace gases that serve as proxies for surface ozone precursors retrieved from the OMI/Aura satellite: nitrogen dioxide (ΩNO_2; NO_x proxy) and formaldehyde (ΩHCHO; VOC proxy). We find 3.5% and 7.7% summer drought enhancements (classified by SPEI) for ΩNO₂ and ΩHCHO, respectively, corroborating signals previously extracted from ground‐level observations. When we subset by land cover type (using MCD12Q1), the strongest ΩHCHO drought enhancement (10%) occurs in the woody savannas of the Southeast US. By isolating the influences of precipitation and temperature, we infer that enhanced biogenic VOC emissions in this region increase ΩHCHO independently with both high temperature and low precipitation during drought. The strongest ΩNO₂ drought enhancement (6.0%) occurs over Midwest US croplands and grasslands, which we infer to reflect the sensitivity of soil NO_x emissions to temperature.