SA13C-04
The Statistics of Neutral Density Maxima
Monday, 14 December 2015: 14:25
2016 (Moscone West)
Louise C Gentile1, Cheryl Y Huang1, Yanshi Huang2, Yi-Jiun Su3 and Eric K Sutton4, (1)Air Force Research Laboratory, Kirtland AFB, NM, United States, (2)University of New Mexico Main Campus, Albuquerque, NM, United States, (3)Air Force Research Laboratory Albuquerque, Albuquerque, NM, United States, (4)Kirtland Air Force Base, Kirtland AFB, NM, United States
Abstract:
We have analyzed neutral density observations from the CHAMP and GRACE spacecraft over the interval from launch in 2001 and 2002, respectively, to 2010 (CHAMP) and 2012 (GRACE). We extract maxima which are 30% above the ambient mean values as indications of localized Joule heating. Our analysis of these maxima shows that they occur predominantly at very high latitudes, with a mean of -74⁰ Magnetic Latitude (MLat) in the Southern Hemisphere, and 78⁰ MLat in the Northern Hemisphere. There is a maximum at 11.5-12 Magnetic Local Time (MLT) but the distribution is widely spread across all MLTs. The frequency of occurrence is correlated with the Interplanetary Magnetic Field (IMF) and with the SymH index. The implications of these results will be discussed in the context of coupling of the thermosphere to the magnetosphere and ionosphere.
