Microwave observations of the giant planets - Cassini/Radar and Juno/MWR 

时间：2019年4月25日（星期四）上午10:00—11:00 

地点：三楼中会议室 

报告人：Dr. Cheng Li （李成）, JUNO Team, NASA JPL, Caltech 

摘要： 

The thermal emission of a giant planet’s atmosphere in the microwave region reveals the thermal structure and composition of the atmosphere below the clouds. During the last decade, the Cassini/Radar instrument mapped Saturn’s global thermal radiation at 2.2 cm wavelength. Particularly, in the year 2010, the planet-encircling giant storm on Saturn appeared 16 K brighter than average, revealing desiccation of ammonia gas due to convection and atmospheric dynamics. More recently at Jupiter, the Juno spacecraft has completed a dozen orbits around the planet, making detailed observations of Jupiter’s troposphere from north to south and down to pressures of about 200 bars. The results are both astonishing and stimulating. Jupiter’s equatorial zone appears cold in all six channels of Juno/MWR, which range from 1.2 – 50 cm, whereas the other latitudes are significantly warmer than what was predicted by an adiabatic model. The internal structure of the GRS has also been mapped during orbit 7th close approach. Yet, the interpretation is partly confounded by the inhomogeneous distribution of ammonia gas. We will give an overview of the previous findings, current challenges, and future opportunities of microwave sounding of the giant planets. 

Dr. Cheng Li （李成） 

JUNO Team, NASA JPL, Caltech 

EDUCATION 

Ph.D. Planetary Science, California Institute of Technology 2016 

B.S. Atmospheric Physics, Peking University 2011 

RESEARCH POSITIONS 

California Institute of Technology, Juno mission team member, 2017 – 2019 

Jet Propulsion Laboratory, NASA Postdoc Program fellow, 2016 – 2017 

AWARDS 

51 Pegasi b Fellowship (Heising-Simons Foundation) 2019 

NASA Postdoc Program Fellowship (NPP) 2016 

NASA Earth and Space Science Fellowship 2015 

RESEARCHES 

Photochemical modeling of Titan’s atmosphere, discovering a stable layer near 500 km above surface 

Modeling moist convection in hydrogen atmospheres, explaining the periodicity of Saturn’s Giant storms. 

Mapping the global distribution of ammonia gas in Jupiter’s atmosphere using the observations from the Juno microwave radiometer. 

Theoretical calculation on the moist thermodynamics of an atmospheric laden with multiple condensing species 

Development of a new three-dimensional Global Cloud Resolving Model (GCRM) for planetary atmospheres.