Tropical storms and drought amelioration in the CONUS

Abstract:

Droughts and tropical storms (TSs) are associated with water deficit and surplus, respectively. Soil moisture is a key component in the hydrological cycle that plays an important role in monitoring drought and reflects the infiltrated or stored water due to TS rainfall. Therefore, soil moisture information can be used for the assessment of whether TS events can ameliorate severe drought conditions. Here, we use downscaled 1 km Soil Moisture Active Passive (SMAP) dataset generated at the Center for Complex Hydrosystems Research (CCHR) at the University of Alabama, and HURricane DATabase 2^nd generation (HURDAT2) to examine the coincidence of extreme events between agricultural droughts and Atlantic TSs in the Contiguous US (CONUS) from 2015 to 2019. CDF matching approach was employed in order to correct the bias using the root zone soil moisture data provided by the North America Land Data Assimilation System Phase 2 (NLDAS-2) Noah model, and weekly Standardized Soil Moisture Index (SSI) was calculated for characterization of agricultural drought. As a result, we assess the frequency of TS impacted regions in the US, the frequency of drought events ameliorated by TSs, and the regions where TSs highly exacerbated drought. Our findings indicate detailed spatial information of the offset of drought conditions based on a high resolution dataset and provides potential information in terms of mitigating drought and TS for the future.