Temporal Changes in Land-Surface Coupling Strength: an Example in a Semi-Arid Region of Australia

Abstract:

Land surface models provide the boundary conditions for the land-atmosphere interaction in the global climate models; hence, the mechanisms whereby water transport influences terrestrial water storage might impact the climate. The high spatial and temporal variability in soil water storage over Australia plays an essential role in affecting the variability of land-surface coupling strength. While previous studies focused more on the spatial variations of land-atmosphere interaction and resulting hotspots, in this study, we attempt to explore temporal variations of the land-surface coupling strength in the semi-arid regions. Preliminary results show high temporal variability of the coupling strength across the seasons. The land-surface coupling strength usually increases with soil moisture in the semi-arid climate. However, during the flood events, the coupling strength decreases when the evaporation approaches to the potential evaporation. After recovering from the floods, the coupling strength increases again during the recessing phase of soil water. Such temporal variations of the land-surface coupling strength have important implications to land-atmosphere interactions and climate predictions, and warrant further investigations using observational datasets.