Speaker: Dr. Jia Hailing

Time: 10:00-11:00 p.m., March 29, 2023 (Wednesday)

Venue: S818, Mong Man Wai Technology Building, Tsinghua University

Tencent meeting ID: 618-838-616

Introduction to the Lecture:

Atmospheric aerosols can directly affect the concentration of cloud droplets as cloud condensation nuclei, and given constant cloud water content, they may cause the decrease of cloud droplet size/increase of albedo, that is, the first aerosol indirect effect (also known as cloud albedo effect /Twomey effect). The change of cloud droplet size affects the precipitation and entrainment mixing process, thus changing the cloud water content and cloud cover, that is, the second aerosol indirect effect (also known as the rapid adjustment of cloud). It is worth noting that the influence of aerosols on cloud droplet number concentration is the trigger link of the whole action chain, with its intensity directly determining the total radiative forcing. According to the latest IPCC report, the radiative forcing caused by aerosol-cloud interaction is still one of the most uncertain factors in climate change prediction, and credible satellite observation constraints are very important to reduce the uncertainty of climate models. With a focus on the limitations of satellite observation constraints, this report will discuss the influence of the following problems on cloud droplet sensitivity estimation, including: 1) sampling bias; 2) updraft intensity; 3) precipitation; 4) inversion bias; 5) relative position of aerosol-cloud; 6) nonlinear problem; and the feasible repair strategy. In addition, this report will also focus on how the nonlinear responses of clouds to aerosols affect the interdecadal prediction of cloud droplet number concentration and the first indirect radiative forcing in the context of global emission mitigation.

Profile of the Speaker:

Dr. Jia Hailing graduated from Nanjing University of Information Science and Technology in 2020 with her doctoral dissertation winning a prize of excellence from Jiangsu Province that year, worked as a postdoctoral researcher in Professor Johannes Quaas’ Research Group of the Department of Meteorology, the University of Leipzig, Germany, and will join the Netherlands Institute of Space Research (SRON) to start the Tenure-Track Group Leader position in August this year. In recent years, Dr. Jia has been using satellite observation combined with climate model to study aerosol-cloud-radiation-interaction/cloud process-climate feedback/global climate change, with a focus on the climate forcing caused by the first aerosol indirect effect.