A Seasonal to Subseasonal Examination of Synoptic and Local Drivers of Flash Drought

Abstract

Flash drought is the rapid intensification of drought like conditions. Initiated by meteorological processes that quickly desiccate soil they can be devastating to agriculture and local ecosystems. Flash droughts are driven by a complex interaction of many terrestrial and atmospheric processes making prediction challenging. The prediction of future flash drought events will require a better understanding of these complex interactions. In particular, synoptic scale processes that lead to changes in evaporative stress are poorly understood, and little is known as to how they impact the local processes. To better predict flash drought both remote teleconnections and the effects of evaporative stress on local terrestrial conditions must be identified. Additionally, the temporal lag from remote drivers to flash drought development needs to be quantified. Using current datasets, multiple methods focusing on synoptic and local spatial scales from seasonal to sub seasonal temporal scales were used to increase our understanding of conditions that drive flash drought. Seasonal atmospheric variables were used to identify areas in Europe primed for agricultural flash drought development in a later season. Additionally, sea surface teleconnections and synoptic scale atmospheric processes were examined before and during flash drought development to identify remote drivers. Lastly, the identified remote drivers were mathematically and statistically assessed for both their covariance with evaporative stress and their correlation with changes in evaporative stress in the Central US.