In our biosphere, where “everything flows, and nothing abides, everything gives way, and nothing stays fixed” (Heraclitus, ~500 BC), estimating evaporation accurately remains to be a major challenge for the hydrology and remote sensing communities (Fisher et al., 2017; Baldocchi, 2020). This issue is further exacerbated with advection, the horizontal transport of energy or moisture (Philip, 1959). Accurate estimates of evaporation are needed to optimize irrigation water use efficiency, and one of the ways to monitor on-farm evaporation is through eddy covariance (Alfieri et al., 2018), which assumes homogeneity and steady flow (Foken and Wichura, 1996). However, this assumption is violated under real atmospheric flow, where surface heterogeneity often occurs (Businger et al., 1971; Rao et al., 1974). For example, in the Central Valley, many irrigated agricultural fields (‘oases’) are often surrounded by dry fields, forming a chessboard pattern that is susceptible to higher water loss via the advection of sensible heat flux(Philip, 1959; Blad and Rosenberg, 1974; Rosenberg and Verma, 1978; Tolk et al., 2006).
