Indian scientists in Antarctica discover ionospheric secrets; Can help satellite based navigation
The ionosphere is part of the Earth’s upper atmosphere, which is partially ionized and extends from 100 to 1000 kilometers.
Indian Antarctica Station Bharati: Antarctica’s cold, dark winters and sunny summers harbor a secret in the ionosphere that scientists have recently uncovered. The day-night ionospheric density varied regardless of 24 hours of sunlight in summer and complete darkness in winter.
Decade-long ionospheric observations at Bharati Station, Antarctica, found significant seasonal variation with maximum total electron number (TEC) in the equinoctial months, followed by summer and winter. Such long-term studies can help understand and mitigate the effects of the ionosphere on satellite-based navigation and communications systems.
The ionosphere is part of the Earth’s upper atmosphere, which is partially ionized and extends from 100 to 1000 kilometers. The ionosphere in the polar regions is highly dynamic and acts as an important energy sink for space weather events and related processes in magnetosphere-ionosphere systems, as the magnetic field lines in this region are vertical. The ionospheric observations in Antarctica are small compared to the Arctic due to geographical limitations and a limited number of stations.
A team of scientists from the Indian Institute of Geomagnetism (IIG), an autonomous body of the Department of Science and Technology (DST), examined the long-term seasonal ionospheric observations at India’s Bharati Antarctica station between 2010 and 2022, as well as the solar activity after the sun’s 11-year cycle.
It was observed that during the winter months (polar nights) at Bharati station there was no sunlight for the entire day; a diurnal pattern was observed with a peak in ionospheric density around local noon. The variations in the ionospheric density between day and night were observed regardless of 24 hours of sunlight in summer and complete darkness in winter. The scientists attributed the peak ionization to particle precipitation and transport of convective plasma from high latitudes. Also, the maximum ionospheric density in the summer months, where there is 24 hours of sunlight (polar days), was about twice that of polar nights in the Bharati region.
The study was published in the Journal of Polar Science. These types of long-term studies will help us understand and mitigate the effects of the ionosphere on satellite-based navigation and communications systems.