Dissecting soil moisture‐precipitation coupling

The ability of soil moisture to affect precipitation (SM‐P) can be dissected into the ability of soil moisture to affect evapotranspiration (ET; SM‐ET) and the ability of ET to affect precipitation (ET‐P). SM‐ET is a local process that is relatively easy to quantify, but ET‐P includes nonlocal atmospheric processes and is more complex. Here, ET‐P is quantified both locally and remotely with a back‐trajectory method for water vapor transport, using corrected reanalysis data. It is found that, for SM‐P and ET‐P, local impact is greater than that from remote for most land areas with significant local impacts. By examining the responses of the three metrics (SM‐ET, ET‐P, and SM‐P) to climate variations over different climate regimes, we show that SM‐ET is the principal factor that determines the spatial pattern and variation of SM‐P. For climatologically wet regions, SM‐ET and SM‐P are higher during dry periods, and vice versa for climatologically dry regions. All three metrics show highest values over the transitional zones.