However, a new challenge arises: At sub-hourly time scales, surface-atmosphere exchange is rarely resolved completely by the turbulent flux alone. Specifically in the case of taller towers, storage beneath the turbulent flux measurement height can comprise a substantial amount of the actual surface-atmosphere exchange. The companion paper by Metzger presents the methodological considerations for, and implications of, combining turbulent and storage flux into an ERF virtual control volume.
Here, we show the first practical application of this concept, and produce temporally resolved maps of heat, water and carbon net ecosystem exchange. For this purpose, eddy-covariance and profile observations in 2011 Aug from the 447 m tall AmeriFlux Park Falls WLEF tower in Wisconsin, USA are used. To construct the coupled ERF, eddy-covariance and profile observations are related to surface properties and meteorological forcings separately. In this study, turbulent flux, storage flux and surface-atmosphere exchange of sensible heat integrated over a 20×20 km2 target domain differ substantially from the tower observations in their monthly averaged value (+4.7 W/m2, +2.7 W/m2 and +7.3 W/m2) and diurnal cycle. Through superimposing storage and turbulent flux, we demonstrate an improved performance in mapping net ecosystem exchange. This bears the potential to diagnose advective contributions and surface-heterogeneity-related components of a frequently observed non-closed energy balance. These advances promise significant improvements for model-data comparison, assimilation and model building.