Westward Drift of Ionospheric Plasma Irregularities over a Low to Mid-latitude Transition Region in Indian Sector

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Aashiq Hussain Bhat
Bilal Ahmad Ganaie
T K Ramkumar
Manzoor A Malik
P Pavan Chaitanya

Abstract




We report the observation of plasma depletions/plumes in the F region ionosphere over a low to middle latitude transition region in the Indian sector. The observation of these plasma depletions is based on the data obtained in May 2019 through the all-sky airglow CCD imager installed in the campus of University of Kashmir, Srinagar (34.12 °N, 74.83 °E, magnetic latitude 25.91 °N). The depletions on the two consecutive nights of 05 and 06 May 2019 are aligned along the North-South (N-S) direction and drift westward. Several depletion bands along with some enhancement bands are seen in the 630-nm airglow images throughout the two nights. The observed structures show certain characteristics similar to Medium Scale Traveling Ionospheric Disturbances (MSTIDs) but these airglow features are not completely periodic. Further, in the observed depletion bands some East-West asymmetries are observed along with the structured tree-like branches of the airglow depletions. Some depletion bands even bifurcate leading to the inference that the structures are signatures of plasma irregularities rather than the usual MSTIDs observed in low-mid latitude transition region. The westward drift of the depletions especially during geomagnetic quiet times over this region makes this study significant since it offers a possible evidence that shows extension of spread F irregularities from the mid latitude region to the low-mid latitude transition region. In this paper, we point out some possible mechanisms related to the occurrence of plasma depletions at this region and their westward movement during geomagnetic quiet times.





 

Article Details

How to Cite
Bhat, A. H., Ganaie, B. A., Ramkumar, T. K., Malik, M. A. and Chaitanya, P. P. (2021) “Westward Drift of Ionospheric Plasma Irregularities over a Low to Mid-latitude Transition Region in Indian Sector”, Annals of Geophysics, 64(4), p. PA437. doi: 10.4401/ag-8510.
Section
Physics of the Atmosphere
Author Biographies

Aashiq Hussain Bhat, University of Kashmir, Hazratbal Srinagar, Jammu and Kashmir, India

Ph.D. Research Student in the department of Physics University of Kashmir, Srinagar.

Bilal Ahmad Ganaie, University of Kashmir, Hazratbal Srinagar Jammu and Kashmir, India

Ph.D. Research Student in  Department of Physics University of Kashmir, Srinagar, Jammu and Kashmir Srinagar

T K Ramkumar, National atmospheric Research Laboratory, Gadanki Andhra Pradesh India

Scientist at National Atmospheric Research Laboratory ,Gadanki Andhra Pradesh, India

Manzoor A Malik, University of Kashmir, Hazratbal Srinagar, Jammu and Kashmir India.

Professor in the department of Physics University of Kashmir.

P Pavan Chaitanya, National Atmospheric Research Laboratory ,Gadanki Andhra Pradesh, India

Scientist at National Atmospheric Research Laboratory ,Gadanki Andhra Pradesh, India