An assessment of storage terms in the surface energy balance of maize and soybean

Discrepancies in closure of the surface energy balance is often an issue for many land surface types. The role of canopy storage terms from canopy water content and photosynthesis is usually neglected in the surface energy balance of crops. Data from a research flux tower in central Illinois were used to evaluate these storage terms and their impact on the closure of the surface energy balance. When considered separately, the storage terms are generally a small fraction (<5%) of the net radiation. However, the combination of soil and canopy heat storage and the stored energy in the carbohydrate bonds from photosynthesis are shown to comprise roughly 15% of the total net radiation for maize and 7% for soybean during the morning hours from 06:00 to 12:00 h when the canopy is fully developed. When all of the storage terms were considered, the slopes of the 1:1 line between net radiation and the partitioned fluxes (latent, sensible, ground, and storage) increased by 10% and the scatter about the 1:1 line decreased for both maize and soybean with the r2 increasing by 0.05.