Syed Aftab Haider | Physical Research Laboratory - India

Abstract

The proposed visit to INPE by Prof. S. A. Haider from the Physical Research Laboratory, Ahmedabad, India, has the objective to conduct investigation on the upper ionosphere of the planet Mars in comparison with the earth’s ionosphere, focusing on the dynamics and chemistry that control the ionospheres and the space weather and climatic effects on the two planets. The upper ionosphere of Mars has been explored during the encounters of Mariner 6, 7 and 9, Mars 2, 3, 4, 6 and 7, Viking 1 and 2 and recently by Mars Global Surveyor (MGS) (Acuna et al., 1998; Ness et al., 2000). The daytime ionosphere models, which consider ionization by solar radiation (Winchester and Rees, 1995), explain the total electron concentration obtained by the radio occultation experiments. The night side ionospheric models considering the precipitation of solar wind electrons agree with the Viking radio observations rather than other models (Haider et al, 2002). In spite of the relatively large number of measurements and models the effect of Coronal Mass Ejection (CME), magnetic storms and solar flares are not understood in the ionosphere of Mars. The magnetic storms occur on earth as a result of an unusually intense interaction between solar wind and magnetosphere (Abdu et al, 1990; Fejer and Scherliess, 1997). CME also plays an important role for sudden commencement type of magnetic storms on earth. Mars has no significant magnetic field. The solar wind interacts directly with the upper ionosphere of Mars. MGS has observed direction of interplanetary magnetic field in the Martian ionosphere. The study of CME, magnetic storms and solar flares and their influences on the Martian ionosphere would be a great achievement. We have a fairly good base of understanding of physical and chemical processes of these events in the earth's ionosphere. It is an appropriate time to analyze the available data of Mars and compare them with the earth's ionosphere to see whether the processes operating in earth's atmosphere hold good or they need scaling up or scaling down or search for new processes to explain the observed sudden commencement/change in the upper ionosphere of Mars. Radio occultation experiment onboard MGS has observed the electron density profiles at different latitudes, longitudes and seasons. More extensive observations are in progress from the experiment onboard Mars Express (ME) mission. These data is publicly available from planetary data centre. We shall use these data in the proposed study.The work plan for Prof Haider';s visit foresees the following activities: (1)- Development of a model based on the dynamical and chemical processes to calculate the vertical distribution of electron density in the Martian ionosphere whose result will be evaluated with the help of satellite data available on internet and through collaborations with international scientific groups; (2)- Analysis of Martian and Terrestrial ionospheric data obtained from different satellites and from ground based observational networks; (3)- Change of item 1 model for the Earth ionosphere conditions. (4)- Use of the ionospheric models already implemented by the ionospheric research group at INPE to calculate the electron density distribution to be compared with the results from the Item 1; (5)- Identification/selection of the Solar Flares, and CME (Coronal Mass Ejection) events and the associated magnetic storm events to be analyzed together with the ionospheric data from Mars and Earth with the objective to identify and evaluate the observed effects and response features, and to understand the physical processes that are complementary, in the ionospheres of the two planets; (6)- Interaction with the researchers of the INPE's Aeronomy Division and with the post-graduate students of the Space Geophysics area, by means of seminars and discussion sessions. (AU)