题    目：Planetary Atmospheres: From Here to Light Years Away

　　报 告 人：张曦（Faculty at University of California, Santa Cruz) 

　　摘    要：An atmosphere is the outer skin of a planet. Besides the accessibility of information and the richness of phenomena, this tiny fraction justifies its significance in several other ways. It connects the surface or interior of a planet to the outer space, and tells us about the material from which the planet formed and perhaps how it formed, and stores information about the evolution history of the planet, and may be the key for the planet to harbor life. In this presentation I will guide a sweeping tour of diverse atmospheres from Earth to the planets thousands of light years away from us. We will see atmospheres very thick and very thin, very heavy and very light, very hot and very cold, very quiet and very violent, very dry and very wet, and their amazing behaviors that continue to surprise us. In the last decades, a spectacular series of space-borne and ground-based observational breakthroughs has led to a number of striking discoveries in planetary atmospheres. In parallel, planetary scientists are looking for fundamental principles underlying those mysterious worlds, which govern the relative abundance of the atmospheric composition, sources of different kinds of energy and their inter-conversion, movement of mass in local and global scales. I will target some specific examples including large moons, earth-size planets, and giant planets to illustrate how those discoveries were made and how the basic principles in physics and chemistry shape the weather and climate in different atmospheres and the planetary evolution. Several intriguing problems and possible solutions are discussed. The slides will be in English, but the talk will be given in Chinese.

　　时    间：7月1日（周二）上午10：00

　　地    点：苏富特一楼会议室

欢迎大家积极参加！

                                            　　紫金山天文台学术委员会