Effects of Land Management Strategies on Northern Plains Energy Balance Climatology

Regional temperature changes often exceed the magnitude of global anthropogenic temperature change, leading to areas with warming rates much larger or lower than the global average. Here, we investigated the role of land management strategies on components of the regional energy balance - an important part of regional climate – in the North American Northern Great Plains of the U.S. and Canada. Nearly 10 million acres of land once held in fallow during summer to conserve water for subsequent crops in this region are now planted. Cultivation increases evapotranspiration, which provides boundary layer moisture and enhances convective available potential energy. In consequence, the reduction of fallow may be responsible for increased convective precipitation.  Corresponding increases in latent heat flux are thought to contribute to increased cloudiness and the 6 W m^-2 summer cooling trend that has been observed across parts of this region. The area that has experienced this cooling trend and its persistence in the future are uncertain and must be quantified to understand interactions between land management and regional climate. Here, we analyze regional climate data to define – with uncertainty – the area of the North American Northern Great Plains that has experienced summertime cooling. We synthesize existing eddy covariance and atmospheric profile data to estimate changes in atmospheric boundary layer and lifted condensation level heights. The results of this work are part of a larger study using boundary layer and climate models to investigate how land management and regional climate interact and to forecast the dynamics of this interaction into the future.