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 sun synchronous circular orbit. AIM carries three instruments - a nadir imager, a solar occultation instrument and an in-situ cosmic dust detector - that were specifically selected because of their ability to provide key measurements needed to address the six AIM science objectives. Descriptions of the science, instruments and observation scenario will be presented along with science results from the first northern hemisphere season and preliminary results for the southern hemisphere.
The AIM mission has changed our view of noctilucent clouds after only one northern hemisphere season of observations. Initial results show: that the clouds are more variable and brighter than expected; the presence of a previously suspected but never before seen population of very small particles that, together with the main ice layer, form one continuous layer extending over a broad altitude range; and mesospheric cloud structures, resolved for the first time, that exhibit complex features present in normal tropospheric clouds.