Do local-generated convective cloud regimes have any preference over wet or dry soil moisture condition?

Description

Soil moisture, atmospheric boundary layer (ABL), clouds and precipitation are very important components of the climate system. However, the interactive processes between land surface and convection are poorly understood. Studies show that late-afternoon precipitation events over land may have preference over either wet or dry soil conditions (e.g. Findell et a.l, 2011, Taylor et al., 2012, Ford et al. 2015). In this study, we use ARM and OK mesonet ground-based observations to study the possible relationship that links soil wetness and spatial heterogeneity with different convection regimes, such as forced and active fair-weather shallow cumulus and late-afternoon deep convection (Zhang and Klein, 2010 and 2013). We statistically assess: 1) the differences in soil moisture and surface heterogeneity between different convective regimes; and 2) the variances of the associated effects on surface and boundary layer meteorological conditions inside each convective regime. A specific question will be: under different soil moisture conditions, e.g. wet/dry, which convective weather regime will be favored and how this is related to large-scale environmental factors, such as free-troposphere stability and humidity? The answer to this question will improve our understanding of how soil moisture impacts boundary layer turbulence and thermodynamics, and influences the convection triggering and maintenance and their feedbacks on soil moisture, thus establish a link between soil moisture and convection at the process level. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-681958