NSF Award
0003684
Abstract ATM-0003684<br/>PI: Dr. M. J. Taylor<br/><br/>A SGER exploratory investigation of the occurrence and characteristics of noctilucent clouds (NLC) at mid-latitudes will be carried out to investigate the unususal occurrences of these events at mid-latitudes during the summer. These clouds are more typically observed at polar latitudes (> 55 N) and the detection of NLCs during the 99 summer at Logan Utah on the two dates of 22/23 and 23/24 of June was by happenstance. These two events may have been simply a rare occurrence with a low probability of re-occurrence. However, increases in NLC occurrence frequency and/or changes in their latitudinal extent have been linked to potentially serious changes taking place in the upper mesospheric climate. This award will support a systematic series of optical observations with high resolution digital photography to determine the properties of these clouds were they to re-occur. This work will be carried out over the summers of the next two years. If the occurrence of mid-latitude NLC displays is indeed established and if they are found to be on the increase, then this study could have a profound influence on future NSF sponsored research efforts as such results may well portend major, long-term, global changes taking place in the upper atmosphere.
