Abrupt Change of the Generalized Complementary Relationship of Evaporation Over Irrigated Double Cropping North China Plain With East Asian Monsoon

Abstract

The complementary principle (Bouchet, 1963) results a relationship between the actual evaporation (E) from a landscape under natural condition, the apparent potential evaporation ( 𝐴𝐴 𝐴𝐴pa ) of a small saturated surface inside the natural landscape and the potential evaporation ( 𝐴𝐴 𝐴𝐴po ) that occurs from the landscape when it is well watered (Brutsaert, 2015). The complementary relationship (CR) arises from the land-atmosphere coupling via landscape evaporation and atmospheric evaporative demand, and offers the advantages of estimating the actual evaporation using routinely measured meteorological variables only (Brutsaert, 2005;. The atmospheric evaporative demand 𝐴𝐴 𝐴𝐴pa can be measured by means of standard evaporation pans or calculated by Penman ( 1948)'s open water evaporation, while 𝐴𝐴 𝐴𝐴po is thought to be limited by the available energy (Brutsaert & Stricker, 1979;Morton, 1983). The CR was originally referred to that E and 𝐴𝐴 𝐴𝐴pa deviate from 𝐴𝐴 𝐴𝐴po with equal but opposite changes along with the drying of the landscape (Bouchet, 1963), and is supported by the opposite changes in the actual and pan evaporations with the progressive expansion of irrigated land as a "natural" experiment (Han et al., 2014;Ozdogan & Salvucci, 2004;Roderick et al., 2009). The original symmetric CR was extended to an asymmetric linear relationship representing opposite changes of E and 𝐴𝐴 𝐴𝐴pa (Brutsaert & Parlange, 1998), and has evolved to generalized nonlinear functions (

Contrasting Land and Atmospheric Controls on the Generalized Complementary Relationship of Evaporation Over Grasslands and Forests

“…However, $$\frac{{E}_{eq}}{{E}_{Pen}}$$ is also affected by processes admixing outside air with different humidity and temperature into the atmosphere boundary layer, such as large‐scale changes in atmospheric circulation (Shuttleworth et al., 2009). Thus, the land surface controls on evaporation ($$\frac{E}{{E}_{Pen}}$$) could not be completely represented by $$\frac{{E}_{eq}}{{E}_{Pen}}$$ at landscapes located in different climate regions, or at the same landscape during periods with different atmospheric circulations (Han et al., 2023). Then, the generalized CR would be varying, as shown in Figure 4a, and needs to be described with the help of land surface wetness.…”

“…This advection effects related to horizontal water vapor transport or the large‐scale atmospheric process were thought to be negligible or changeless in the CR (Brutsaert & Stricker, 1979; Morton, 1983) by supposing fully or fixed land‐atmosphere coupling (Han & Tian, 2018b). But the land–atmosphere coupling would be disrupted by advected atmosphere moisture (McNaughton & Jarvis, 1983), which substantially affects the evaporation process (Han et al., 2023; Szilagyi et al., 2022). The arguments on parameterizations and the substantial biases of the CR equations with fixed parameters under conditions with varying land–atmosphere coupling (Han et al., 2023; Ma et al., 2021; Zhu et al., 2016) indicates that the land/atmospheric controls on CR need to be reexamined by considering the land–atmosphere coupling strength, especially the advection effects.…”