Spatial Variability of the Response of Land‐Atmosphere Coupling to Climate Warming in Northern China

Abstract Northern China is a global hotspot for intense land‐atmosphere coupling because its atmospheric and land‐surface features vary substantially, making the mutual feedbacks and linked responses between coupling variables more prominent. Based on Global Land Data Assimilation System (GLDAS) data, land grid data from ECMWF Re‐Analysis project data‐Interim (ERA‐Interim), ECMWF Scheme for Surface Exchanges over Land incorporating land surface hydrology (ERA5‐land) and Global Land Evaporation Amsterdam Model 4 (GLEAM4) global land flux network (FLUXNET) data and weather observation data, the variability of the response of land‐atmosphere coupling processes to climate warming with the spatial change of the climate background in northern China was analyzed. The response mechanisms of the coupling processes between land evapotranspiration and soil moisture, and between surface net radiation and soil moisture to the spatial change of precipitation climate space (defined by the annual mean value of a given physical quantity) were investigated. Additionally, the effect of climate space on land‐atmosphere coupling characteristics was investigated. Results indicate that there were significant spatial differences in the trends of temperature and precipitation variation in northern China, and the characteristics of land‐atmosphere coupling in response to climate change were strongly reliant on the energy and moisture constraints in climate space. The summer monsoon transitional region (SMTR) was found to be a climate‐sensitive zone with competition between moisture and energy, where the response of land‐surface physical quantities to climate change underwent a radical transformation, and land‐atmosphere coupling processes displayed both positive feedback (temperature increasing→soil moisture decreasing→net radiation decreasing→temperature increasing) and negative feedback (temperature increasing→soil moisture decreasing→net radiation increasing→temperature decreasing) to climate warming. These findings would improve the scientific understanding of the characteristics and mechanisms of land‐atmosphere coupling processes for a heterogeneous underlying surface, and may provide an important theoretical basis for climate prediction in northern China.