In the Department of Atmospheric and Oceanic Sciences, the research focuses on key questions in atmospheric sciences, oceanic sciences, and ocean-atmosphere interactions. Our research covers key areas of atmospheric sciences and physical oceanography with no favor for a particular area. The philosophy is in line with our tradition with the vision of providing comprehensive education for young generations. At present, our department runs the Peking University Laboratory for Climate and Ocean-Atmosphere Studies and the Joint Research Center for Atmospheric Hydrological Cycle and Weather Modification of Peking University-Chinese Meteorological Administration. Our research areas include:
Climatology. Climate change is the hot topic in current climate research, and the key research question is the extent to which global climate change has been caused by human activities, e.g., the impacts of increasing greenhouse gases and decreasing stratospheric ozone on the global climate system. Focusing on this general question, we study the trends and variability of climate at a variety of temporal (from interannual to inter-decadal) and spatial (from regional to global) scales. We have also worked on paleoclimate, targeting on questions like climate change during the last 20,000 years and the snowball earth phenomena 600-700 million years ago. We have recently expanded our research to planetary sciences, focusing on the climate of Mars, Venus, and the recently discovered exoplanets. Our main research approaches are observational analyses and numerical simulations.
Related faculty members: HU Yongyun (professor), LIU Zhenyu (‘One Thoudsand Talents Plan’ professor), YANG Haijun (professor), QIAN Weihong (professor), WEI Jun (‘One Hundred Researchers Plan’ scholar), and WEN Xinyu (lecturer).
Atmospheric dynamics. We study the large-scale dynamics and basic characteristics of rotating fluids, the dynamic mechanisms of synoptic systems such as cyclones, and the dynamics of atmospheric circulation such as the Hadley Cell and Walker Circulation. The movement of the air is driven essentially by the pressure gradient force due to thermal contrast. The wave-like movement is driven by the pressure gradient force, gravity, and Coriolis force. It is often called ‘Rossby Wave’ with profound impacts on the synoptic and climate systems. The area of atmospheric dynamics studies the three-dimensional propagation of atmospheric waves, the dynamic interactions between the stratosphere and troposphere, and the impacts of atmospheric circulation on the regional climate. Our main research methods are observational analyses, numerical simulations, and theoretical derivations.
Related faculty members: TAN Benkui (professor), HU Yongyun (professor), FU Zuntao (professor), and ZHAO Qiang (associate professor).
Meso- and micro-scale weather simulation and forecast. We study the weather phenomena at the spatial scales of 10-1000 km, including convective weather systems (tornados, hails, thunderstorms, and squall lines), typhoons and cyclones. These phenomena are the main causes of the severe weather damage. We use as research tools satellite measurements, radar observations, regular meteorological measurements, and numerical simulations to study the physical mechanisms driving these phenomena. We also develop and employ the latest data assimilation techniques to improve weather forecast, especially severe weather forecast.
Related faculty members: ZHANG Qinghong (professor), WANG Hongqing (professor), MENG Zhiyong (‘One Hundred Researchers Plan’ scholar), and ZHANG Yan (senior engineer).
Physical Oceanography. We study the physical properties (temperature, salinity, etc.), physical processes and dynamics of the oceans as well as their impacts on the climate and ecology. Oceanic movements include the wind-driven movements of surface oceans and the slow oceanic circulations at the temporal scale of more than 1000 years driven by temperature and salinity differences. We also study near-shore oceanic movements and impacts on the coastal environment and ecology. We have a particular focus on ocean-atmosphere interactions, since oceans are a powerful reservoir and modulator of the coupled ocean-atmosphere climate system due to their significant thermal inertia.
Related faculty members: LIU Zhengyu (‘One Thousand Talents Plan’ professor), YANG Haijun (professor), WEI Jun (‘One Hundred Researchers Plan’ scholar), and HU Yongyun (professor).
Atmospheric radiation and remote sensing. Solar (shortwave) and terrestrial (longwave) radiation are absorbed and/or scattered by gaseous molecules and aerosols in the atmosphere. The absorption and scattering has large impacts on the radiation and energy balance of the Earth, and also on the climate system. Therefore the radiative transfer of solar and terrestrial radiation is an important research area in atmospheric sciences. Both ground- and space-based remote sensing take advantage of the absorption/scattering characteristics of gases and aerosols to retrieve a variety of key atmospheric properties such as air temperature and concentrations of gases and aerosols. Our research is focused on remote sensing of aerosols, water vapor, nitrogen dioxide, etc. With the advancement of remote sensing and retrieval techniques, satellite remote sensing has become a key player in studies of climate change and atmospheric pollution.
Related faculty members:ZHAO Bolin (CAS member and professor), LI Chengcai (associate professor), LI Wanbiao (associate professor), LIU Xiaoyang (associate professor) , and LIN Jintai (‘One Hundred Researchers Plan’ scholar).
Cloud physics and atmospheric chemistry. Originally, the area of cloud physics studied the microphysics of phase change of water in the atmosphere, that is, the transition from water vapor to cloud droplets, rain droplets or ice particles (through aggregation), and to precipitation. Currently, the study has evolved to emphasize the influence of anthropogenic aerosols on cloud formation and precipitation, particularly on the role of aerosols in the formation of cloud condensation nuclei and ice nuclei. The uncertainty in cloud radiative effect is a key factor affecting our capability in climate prediction. Aerosols and other atmospheric constituents undergo complex physical and chemical processes in the atmosphere, and are under the profound influences of human activities. With the economic and industrial development, nitrogen species, sulfur species, volatile organic compounds and other pollutants emitted from human activities affect tropospheric ozone and aerosols through complex chemical processes. The same chemical processes are responsible for the severe haze problem damaging the public health in China. Our studies include field measurements, pollution monitoring, pollution transport analyses, and cloud simulations.
Related faculty members: ZHAO Chunsheng (professor), XUE Huiwen (associate professor), FU Zongmei (‘One Hundred Researchers Plan’ scholar), LIN Jintai (One Hundred Researchers Plan’ scholar), and ZHANG Lin (‘One Thousand Young Talents Plan’ scholar).
Atmospheric boundary layer. Atmospheric boundary layer is the layer from surface to about 1.5 km, where the atmosphere is affected significantly by friction and turbulence at various scales, undergoing movements significantly different from the movements of the free atmosphere. The boundary layer is also where heat, water vapor and momentum are exchanged between atmosphere and terrestrial and between atmosphere and oceans. It is also where most air pollution is concentrated. We study turbulence in the boundary layer, terrestrial-atmosphere fluxes, spatiotemporal patterns of boundary-layer pollution, monitoring of dust events, and impacts of terrestrial ecology on the regional climate.
Related faculty members: LIU Shuhua (professor), ZHANG Hongsheng (professor), XIN Guojun (associate professor), LIANG Fuming (lecturer).
