Mesoscale Variability of Land–Atmosphere Coupling Across the Southern Great Plains in the North American Regional Reanalysis

The purpose of this study was to investigate the seasonal to interannual variability of the temporal and spatial distributions of land–atmosphere coupling (LAC) at the mesoscale within the Southern Great Plains (SGP) of the United States. The North American Regional Reanalysis data set from 1979 to 2014 was used to complete this study. To further expand the relationship between soil moisture and precipitation, LAC was examined for the effects of soil moisture variability on latent heat flux (SM-E) and the impact of latent heat flux variability on precipitation (E-P). Results revealed that within the SGP there is a temporal and spatial seasonal evolution of the SM-E relationship and dry boreal summer month (June, July and August, JJA) periods exhibit a stronger E-P relationship relative to pluvial boreal summer month periods. Further, the variability of coupling was large both within-season (i.e. JJA) as well as at the interannual scale while the interannual spatial and temporal coherence was such that no specific locations showed consistent coupling within the domain. Thus, the results indicate that while the SGP domain is sensitive to coupling, the location of preferred coupling is likely due to non-local factors at the mesoscale embedded within synoptic conditions as well as the regional climate.