Drought Variability over the Conterminous United States for the Past Century

Abstract We examine the drought variability over conterminous United States (CONUS) for 1915–2018 using Noah-MP land surface model. different model options on reconstruction, including optional representation of groundwater and dynamic vegetation phenology. Over our 104-yr reconstruction period, we identify 12 great droughts that each covered at least 36% CONUS lasted 5 months. The tend to have smaller areas when and/or are included in configuration. detect a small decreasing trend dry area coverage all configurations. 45 major baseline (with greater than 23.6% CONUS) are, average, somewhat less severe droughts. find tends increase duration both droughts, primarily by leading earlier onset (some due short-lived recovery from previous drought) or later demise (groundwater anomalies lag precipitation anomalies). In contrast, shorten duration, (closed stoma dead reduces ET loss during droughts). On regional basis, U.S. Southwest (Southeast) has longest (shortest) durations. Consistent with work, subregions except decreased. effects vary regionally differences depths (hence connectivity surface) types.