2019年04月18日 作者: 颜开
报告题目： Observational Estimates of Convective Cloud Entrainment Rates
报告人： Michael P. Jensen, Brookhaven National Laboratory
主 持 人： 陆春松 教授
Dr. Jensen’s research focuses on a combination of observational and modeling studies to better understand the lifecycle of cloud systems and the role they play in the Earth’s energy balance. He has been actively involved with the Department of Energy’s Atmospheric Radiation Measurement Facility and the Atmospheric System Research Program since 1996 working on research projects studying the radiative impacts of deep convective clouds in the tropics, defining the characteristics of marine boundary layer clouds and the retrieval of cloud microphysical properties from remote sensing observations. He was the principal investigator for the Midlatitude Continental Convective Clouds Experiment (MC3E) in 2011 and will serve in the same role for the TRacking Aerosol Convection interactions Experiment (TRACER) in 2021. Recent research activities have also aimed at using radar observations and high-resolution weather modeling towards the prediction of utility outages.
摘要:The mixing of dry environmental air into rising convective parcels plays an important role in determining the depth and subsequent lifecycle of convective clouds. Despite its importance, the entrainment process remains poorly understood and its measurement and quantification are extremely difficult. Techniques for the estimation of convective cloud entrainment rates using a simple plume model constrained by vertically-pointing cloud radar observations are presented for several long-term datasets from the Department of Energy’s Atmospheric Radiation Measurement (ARM) Facility fixed sites in the Tropical Western Pacific and Southern Great Plains, and the ARM Mobil Facility Deployment in Manacapuru, Brazil. The evolution of these techniques, particularly the implications of the Eulerian reference frame of the ARM observations is considered as is the environmental controls on the estimate of entrainment rates with an eye towards parameterization development.