The Aeronomy of Ice in the Mesosphere (AIM) mission will provide the first detailed exploration of Earth's unique and elusive noctilucent or night shining clouds that are found literally on the "edge of space". Located near the top of the Earth's mesosphere (the region just above the stratosphere), very little is known about how these polar mesospheric clouds form or why they vary. They are being seen at lower latitudes than ever before and have been growing brighter and more frequent, leading some scientists to suggest that this recent increase may be the direct result of human-induced climate change. The mission is led by Dr. James Russell of the Center for Atmospheric Sciences at Hampton University.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 22.214.171.124.0