Science Seminars

4/23/2009 – The Aeronomy of Ice in the Mesosphere Mission: Science Results after four PMC seasons

Speaker: Scott Bailey, Jim Russell
Date: Thursday, Apr 23, 2009
Time: 4:00pm
Location: LSTB

Seminar Abstract:

The Aeronomy of Ice in the Mesosphere (AIM) mission was launched from Vandenberg Air Force Base in California at 1:26:03 PDT on April 25, 2007 becoming the first satellite mission dedicated to the study of noctilucent clouds. A Pegasus XL rocket launched the satellite into a near perfect 600 km, noon – midnight, sun synchronous orbit. AIM carries three instruments – a nadir imager, a solar occultation instrument and an in-situ cosmic dust detector. This paper will provide a brief mission overview, instrument descriptions and scientific findings. Results from the first two years of AIM observations show that the NLC season turns on and off like a “geophysical light bulb” transitioning at the season start from no clouds to 100% occurrence frequency in days and vice versa at the season end. Data show that temperature change is a dominant factor in controlling season onset, variability during the season and season end.  Rising water vapor levels at the beginning and falling values at the end also play a key role in season initiation and cessation. Structures seen in the clouds look very much like complex features seen in tropospheric clouds including large regions of near circular ice voids. This paper will also describe the first satellite observations of cosmic smoke input to the atmosphere measured by the SOFIE instrument. AIM is approved to operate through September 30, 2012.