Soil Moisture Cloud Precipitation Feedback in the Lower Atmosphere from
Functional Decomposition of Satellite Observations
Abstract
The feedback of topsoil moisture (SM) content on convective clouds and
precipitation is not well understood and represented in the current
generation of coupled cloud physics and land-surface models. Here, we
use functional decomposition of satellite-derived SM (SMAP/L4) and cloud
vertical profiles (CVP: GPM/DPR/L2A) in the central US to quantify the
relationship between SM and the vertical distribution of cloud water.
High-dimensional model representation disentangles the contributions of
SM and other land-surface and atmospheric variables to the CVP. Results
show the sign and strength of this feedback varies with cloud height and
time lag and displays a large spatial variability. Positive anomalies in
the antecedent 7-hour SM and land-surface temperature can increase
reflectivity up to 4 dBZ in the lower atmosphere (1-3 km above the
surface). The presented approach brings new insights into observational
understanding of SM-precipitation feedback and possesses the potential
for diagnosing cloud models regarding land-atmosphere coupling
representation.