Ionospheric measurements during the CRISTA/MAHRSI campaign: their implications and comparison with previous campaigns
et al.. Ionospheric measurements during the CRISTA/MAHRSI campaign: their implications and comparison with previous campaigns. Abstract. The CRISTA/MAHRSI experiment on board a space shuttle was accompanied by a broad campaign of rocket, balloon and ground-based measurements. Supporting lower ionospheric ground-based measurements were run in Europe and Eastern Asia between 1 October±30 November, 1994. Results of comparisons with long ionospheric data series together with short-term comparisons
... t-term comparisons inside the interval Octo-ber±November, 1994, showed that the upper middle atmosphere (h = 80±100 km) at middle latitudes of the Northern Hemisphere in the interval of the CRISTA/ MAHRSI experiment (4±12 November, 1994) was very close to its expected climatological state. In other words, the average results of the experiment can be used as climatological data, at least for the given area/altitudes. The role of solar/geomagnetic and"meteorological" control of the lower ionosphere is investigated and compared with the results of MAP/WINE, MAC/SINE and DYANA campaigns. The eects of both solar/ geomagnetic and global meteorological factors on the lower ionosphere are found to be weak during autumn 1994 compared to those in MAP/WINE and DYANA winters, and they are even slightly weaker than those in MAP/SINE summer. The comparison of the four campaigns suggests the following overall pattern: in winter the lower ionosphere at northern middle latitudes appears to be fairly well"meteorologically" controlled with a very weak solar in¯uence. In summer, solar in¯uence is somewhat stronger and dominates the weak'm eteorological" in¯uence, but the overall solar/mete-orological control is weaker than in winter. In autumn we ®nd the weakest overall solar/meteorological control, local eects evidently dominate.