MGS Radio Science electron density profiles: Longitudinal characteristics
Abstract
Early analysis of the first few sets of electron density profiles returned by the radio science experiment aboard MGS spacecraft provided a strong evidence for planetocentric longitude dependence of the photochemical controlled E and F1 layers of the Martian ionosphere. This feature is not seen in the E and F1 layer of the Earth's ionosphere, which too are photochemical. In this study, with the availability of several MGS data sets containing a total of 5600 electron density profiles, we re-examine the longitude dependence of the observed peak parameters (viz. height and density) as well as of other derived parameters, like the electron content and the atmospheric scale height of the E and F1 layers. We find that though there is a lot of variability, the distribution with longitude for each of these parameters is nearly uniform most of time. However, exceptions are periods during late spring and early summer (northern latitudes) when the longitudinal variations indicate the presence of crests/troughs, in the observed as well as in the derived parameters, broadly spread around 0°, 70° and 140° E longitudes. On examining the characteristics of the electron density profiles located at these crests/troughs, we find a large difference between the two sets, with the peak height and peak density showing large excursions. Further, the peak density, electron content and atmospheric scale height show significant relationship with the excursions in peak height. These observations can be explained if there are rapid changes in Mars thermosphere.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E3466U