Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2010, Vol. 7, No. 3, pp. 120-127
Researching the influence of tropical cyclones on variations
of ionospheric parameters in the Asian region of Russia
M.A. Chernigovskaya
1, V.I. Kurkin
1, I.I. Orlov
1, E.A. Sharkov
2, I.V. Pokrovskaya
21 Institute of Solar-Terrestrial Physics SB RAS, Irkutsk
2 Space Research Institute RAS, Moscow
This article continues the researching of short-period variations of maximum observed frequencies (MOF) of oblique
sounding (OS) signals along the Norilsk-Irkutsk, Magadan-Irkutsk, and Khabarovsk-Irkutsk paths in East Siberia
and the Far East obtained at equinoxes (March, September) in 2008-2009. A frequency analysis has revealed
time intervals with enhanced intensity of short-period oscillations which may be interpreted as manifestations of
large-scale traveling ionospheric disturbances (TIDs) whose sources were internal gravity waves (IGWs) with periods
of 1-5 hours. The question concerning localization of possible sources of revealed disturbances is discussed.
Troposphere meteorological disturbances giant in their energy (tropical cyclones, typhoon) are considered as potential
sources of observable TIDs. A considerable increase in the energy of short-period wave disturbances was observed
along the OS paths during active tropical cyclogenesis in September 2008-2009. The intensity of the observed
TIDs decreased as the midpoints of the OS paths moved westward away from the potential IGW sources.
Ionospheric responses to wave disturbance propagation from the same IGW sources differ in the OS paths under
analysis. The wave disturbance propagation velocities were estimated from the delay in TID passage in the regions
of the midpoints of the spaced-apart OS paths. Short-period TIDs can also be observed at the spring equinox in
March 2008-2009 under quiet helio-geomagnetic conditions and in the absence of active tropical cyclones in the
north-west Pacific, but their energy is much lower than during the autumns of various years.
Keywords: upper and middle atmosphere, ionosphere, coupling of the atmospheric layers, wave disturbances, tropical cyclones
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