Effects of Turbulent Entrainment-Mixing on Cloud Properties and Solar irradiance in WRF-Solar Simulations
Abstract
Accurately forecasting solar radiation in cloudy conditions remains a major challenge due to the highly variable nature of clouds and our limited understanding of microphysical processes. In this study we focus on the turbulent entrainment-mixing processes which are not well represented in most of the microphysical schemes. New microphysical parameterizations considering the effects of turbulence and entrainment mixing are implemented into the state of art Weather Research and Forecast model designed for solar radiation simulations and forecasting (WRF-Solar). The new schemes are evaluated against the measurements in different cloud regimes (shallow cumulus v.s. stratocumulus) collected at the DOEs ARM SGP site. In addition, we examine different treatments of energy dissipation rates and entrained dry air relative humidity within the entrainment-mixing process and compared the new schemes to Thompson aerosol aware scheme as the baseline. The results show significant sensitivities of cloud properties and solar irradiance, esp., cloud structure, to the entrainment-mixing, with details depending on cloud regimes. Furthermore, the dependence of entrainment-mixing effect on the cumulus parameterization will be explored. These results will improve our understanding of the causes of the resulted solar irradiance in WRF-Solar and provide physical insight into further improving solar irradiance forecast in cloud conditions.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMGC42C..03Z