NASA/UAH Earth and Atmospheric Science Seminars
Tuesday, May 12, 2015
11:00 am; Room 4078
Atmospheric Science Assistant to Associate Professor Candidate Dr. Jiwen Fan
Senior Research Scientist
Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory
Aerosol- Deep Convective Cloud (DCC) Interactions: from Process-level Understanding to Parameterization
Deep convective clouds (DCCs) play a crucial role in the general circulation, energy, and hydrological cycle of our climate system. Anthropogenic and natural aerosol particles may influence DCCs through changes in cloud properties, precipitation regimes, and radiation balance. In this talk, I will present (1) the important factors regulating aerosol impacts on DCCs; (2) the significance of aerosols modifications to convective intensity and cloud anvil properties by acting as cloud condensation nuclei (CCN) and ice nuclei (IN); and (3) a new mechanism for explaining ubiquitously-observed cloud invigoration phenomena, from our process-level studies through these years. Furthermore, I will talk about improving bulk microphysical parameterizations and parameterizing aerosol-cumulus interactions in regional and global climate models. At the regional scale, aerosol impacts through DCCs are significant in (1) producing a strong surface cooling in daytime and warming at night, and (2) redistributing precipitation pattern and occurrence frequencies of light and heavy rain. Those effects are missing from current large-scale models. Further directions in this field will be discussed.