Land-Atmosphere Interactions: Observations and Large Eddy Simulations over an Irrigation Gradient

In the spring and summer of 2018, two intensive observation periods were conducted in Southeastern Nebraska by the National Center for Atmospheric Research Earth Observing Laboratory (EOL) and the Center for Sever Weather Research (CSWR), NASA's Hydrological Sciences Laboratory and a group of research universities. The objective of the experiment was to obtain an expansive observational data set to investigate the impact of irrigation on land-atmosphere coupling, particularly the diurnal planetary boundary layer evolution, thermal circulation development, outflow boundary evolution, and cloud and precipitation processes. Southeastern Nebraska was chosen for its sharp gradient in applied irrigation across the Big Blue River region. The domain is one of the most heavily irrigated regions of the world thanks to the Ogallala Aquifer. The authors will present an overview of the experiment, observational results, and LES examination of boundary layer evolution over heterogenous land cover.