1. 学术报告：Long-term cooling in the upper atmosphere as seen with Millstone Hill incoherent scatter radar 时  间：2011年11月7日上午9：30 地  点：教学行政楼1514会议室 报告人:张顺荣博士 单  位：麻省理工大学Millstone Hill观象台 题  目：Long-term cooling in the upper atmosphere as seen with Millstone Hill incoherent scatter radar 摘  要：More and more evidence from recent studies  shows that the earth’s upper atmosphere is falling during the recent a few decades.  The falling, a clear indication of global climate change, is due to the cooling trend in the upper atmospheric temperature.  Upper atmospheric cooling can cause a decrease in neutral density such that satellite orbits and lifetime are modified due to decreased air drag. It can also alter neutral composition such that radio propagation is affected due to changes in the ionospheric electron density. Climate changes in the upper atmosphere have the potential to affect our increasing activity in space.  This presentation will provide an incoherent scatter radar perspective that has to do with an important height dependency within 100-500 km for a comprehensive set of upper atmospheric parameters, in particular temperatures. Dr. Zhang will also provide an overview of the MIT Haystack Observatory upper atmospheric research facilities. [1] [2] [3] Download images (local images only) as a tar.gz pack: Full Size Small Size

李勤秀 Posted at 2011-10-28 15:47 CST Last modified at 2011-11-07 11:03 CST Link to this poster Top