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SUMMARY:Improved Understanding of Thermosphere-Mesosphere-Stratosphere-Tro
 posphere Coupling Using Lidar Measurements
DTSTART:20140916T161500
DTEND:20140916T171500
DTSTAMP:20260406T050655Z
UID:8109453d7266087c46f6e8d30b35c475497b01eddb67151f19f2fc29
CATEGORIES:Conferences - Seminars
DESCRIPTION:Dr Robert Sica\, Department of Physics and Astronomy\, The Uni
 versity of Western Ontario\, London (CA) - currently visiting professor @ 
 EFLUM\nAbstract:\nSolar-terrestrial relations is the study of how solar ra
 diation and particles enter and interact with Earth's atmosphere-ionospher
 e-magnetosphere system. The atmospheric component of solar-terrestrial rel
 ations traditionally emphasizes the interaction of solar energy with the m
 iddle and upper atmosphere. Over the last 20 years it has been realized th
 at the coupling of the lower atmosphere with the upper atmosphere is criti
 cal to understanding climate and weather on the surface. Thus\, simultaneo
 us measurements over a wide range of heights are necessary to provide the 
 inputs needed to understand coupling processes between atmospheric regions
 .\nActive sensing techniques such as radar and lidar (laser radar) allow t
 his coupling to be investigated over a wide range of heights. My group's p
 rimary research tool is the Purple Crow Lidar (PCL)\, which measures atmos
 pheric composition and temperature from near the surface to the lower ther
 mosphere (altitudes above 100 km). The PCL uses a 2.6 m diameter liquid mi
 rror telescope coupled with a high-power laser transmitter to measure temp
 erature\, density and water vapour mixing ratio. Due to its large power-ap
 erture product\, several of its measurement capabilities are unique\, such
  as the ability to resolve individual gravity waves and measure water vapo
 ur in the upper troposphere and lower stratosphere. In addition to the PCL
 \, my group actively collaborates with two other lidar systems located in 
 the high Arctic as part of the Canadian Network for the Detection of Atmos
 pheric Change (CANDAC). Comparison of these measurements with the PCL cont
 ributes to understanding teleconnections between high and low latitudes.\n
 The role of small scale waves on the atmospheric system will be discussed 
 and examples will be shown of measurements we have made that demonstrate a
 tmospheric coupling\, as well as the transport of atmospheric constituents
  such as ozone and pollutants between the troposphere and stratosphere. Ex
 amples will also be shown of a new retrieval technique for temperature fro
 m these measurements\, which will improve our ability to use these measure
 ments to search for temperature change.
LOCATION:GR A3 31 http://plan.epfl.ch/?room=GR%20A3%2031
STATUS:CONFIRMED
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