Vertical Dependence of Horizontal Variation of Cloud Microphysics: Observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models
In the current global climate models (GCM), the nonlinearity effect of subgrid cloud variations on the parameterization of warm rain process, e.g., the autoconversion rate, is often treated by multiplying the resolved-scale warm ran process rates by a so-called enhancement factor (EF). In this study, we investigate the subgrid-scale horizontal variations and covariation of cloud water content (????) and cloud droplet number concentration (????) in marine boundary layer (MBL) clouds based on the in-situ measurements from a recent field campaign, and study the implications for the autoconversion rate EF in GCMs. Based on a few carefully selected cases from the field campaign, we found that in contrast to the enhancing effect of ???? and ???? variations that tends to make EF>1, the strong positive correlation between ???? and ???? results in a suppressing effect that makes tends to make EF
Published: March 13, 2021
Citation
Zhang Z., Q. Song, D. Mechem, V.E. Larson, J. Wang, Y. Liu, and M.K. Witte, et al. 2021.Vertical Dependence of Horizontal Variation of Cloud Microphysics: Observations from the ACE-ENA field campaign and implications for warm-rain simulation in climate models.Atmospheric Chemistry and Physics 21, no. 4:3103–3121.PNNL-SA-155438.doi:10.5194/acp-21-3103-2021