Climatology of the equatorial thermospheric mass density anomaly

Details Climatology of the equatorial thermospheric mass density anomaly Climatology of the equatorial thermospheric mass density anomaly

May 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007jgra..11205305l&link_type=abstract

Journal of Geophysical Research, Volume 112, Issue A5, CiteID A05305

Physics

32

Atmospheric Composition And Structure: Pressure, Density, And Temperature, Atmospheric Composition And Structure: Thermosphere: Energy Deposition (3369), Atmospheric Composition And Structure: Ion Chemistry Of The Atmosphere (2419, 2427), Ionosphere: Equatorial Ionosphere

Scientific paper

The equatorial anomaly is an interesting and important feature of the Earth's thermosphere-ionosphere coupling in tropical regions. It is an anomalous latitudinal distribution found in both the ionized and unionized part of the atmosphere. Its equinox configuration consists of a minimum near the dip equator flanked by two maxima on both sides. The ionospheric side of this anomaly, often referred to as the equatorial ionization anomaly (EIA), has long been recognized since the 1930s. However, its thermospheric counterpart was only to be glimpsed by the Dynamic Explorer 2 satellite in the 1970s. A global picture of it has been rather recently revealed by the CHAMP satellite in 2005. In this paper we complement previous studies by investigating the climatology of the equatorial mass anomaly (EMA) in the thermosphere using 4 years of CHAMP measurements. Our analysis has revealed strong variation of the EMA with season and solar flux level. The EMA structure is most prominent around equinox, with a crest-to-trough ratio about 1.05 for F10.7 = 150. Near solstices, it is asymmetric about the dip equator. The density crest attains maximum 1-2 hours earlier and reaches higher values in the summer hemisphere than in the winter hemisphere. The density in EMA regions varies semiannually, with maxima near equinoxes. The latitudinal locations of the EMA crests undergo a seasonal variation, obviously following the movement of the subsolar point. The EMA structure has also been found to become more pronounced at higher solar flux levels. Both the location and magnitude of the EMA crests closely follow those of the EIA in corresponding seasons and solar flux levels, hence demonstrating strong plasma-neutral interaction. Furthermore, two seasonal asymmetries clearly present in the globally averaged density, with the density in March/December being ~15-20% higher than that in September/June.

Affiliated with

Also associated with

No associations

Rating

Climatology of the equatorial thermospheric mass density anomaly does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Climatology of the equatorial thermospheric mass density anomaly, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Climatology of the equatorial thermospheric mass density anomaly will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-770660