Capturing Effects of Crop Growth on the Atmosphere in the Southern Great Plains

Torn, M. S., Lawrence Berkeley National Laboratory

Surface Properties

Warm Boundary Layer Processes

Lu Y, I Williams, J Bagley, M Torn, and L Kueppers. 2017. "Representing winter wheat in the Community Land Model (version 4.5)." Geoscientific Model Development, 10(5), 10.5194/gmd-10-1873-2017.

Science

We implemented new algorithms and parameterizations in the Community Land Model (CLM) to capture the atmospheric influence of winter wheat, the dominant crop cover in the Southern Great Plains.

Impact

This new modeling capability that has been tested with ARM observations in the field enables Earth system models to more accurately represent the unique growth timing of winter wheat and therefore the role of vegetation in land-atmosphere coupling in wheat-growing regions.

Summary

We modified the winter wheat submodel in the Community Land Model (CLM) to better simulate winter wheat growth and yield. We calibrated three key parameters and modified the grain carbon allocation algorithm for simulations at the US Southern Great Plains ARM site, and we validated the model performance at eight additional sites across North America. The new winter wheat model improved the prediction of monthly variation in leaf area index, and reduced latent heat flux and net ecosystem exchange root mean square error (RMSE) by 41 and 35% during the spring growing season.