Chapter 15 - Space Weather Phenomenon of Polar Ionosphere Over the Arctic Region

Abstract

Sun is the primary source of all natural phenomena, and space weather disturbances can cause severe fluctuations in the Earth’s electrical and magnetic fields. Several types of storms and their effects are observing various geostationary satellites, and these storms are a significant source of disturbances in the space plasma. The space weather causes mainly two types of effects—(1) induced effect of charged particle and (2) electrodynamical effects that are involved to change magnetic and electric fields of magnetosphere. During disturb days, space weather condition can change composition of thermosphere (95- to 500-km altitude) and also the composition of the upper atmosphere. It alters the recombination rate of the ion and electron of ionosphere (60- to beyond 1000-km altitude) and can change the electron density drastically in the polar ionosphere. Estimation rate of electron density would be allowing Global Positioning System (GPS) to correct the errors in signal propagation. During disturb days, space weather condition can also change the ionospheric F-region and perturb critical frequency (foF2) of F2 layer. Many ionospheric parameters are governed and controlled by solar geophysical conditions and it is partially affected by geomagnetic storms in the high-latitude region. Diurnal and seasonal variations study of total electron content (TEC) for space weather effect observation near the Earth magnetosphere plays a vital role to understand the dynamics of polar ionosphere. Sometimes, space weather forecasting comprises long- and short-term predicting capability under various conditions like solar wind interaction with the magnetosphere, ring current interaction with the ionosphere, and energetic charged particles. Observations of L1 and L2 signals of GPS satellites at time intervals of 30seconds by using dual-frequency receivers have been widely used for the study of polar ionospheric irregularities at high-latitudes region. Many GPS-based studies have been carried out to analyze the effects of geomagnetic storms and solar flares by measurement of slant total electron content value at high-latitude region. Effects of magnetic storm at equatorial latitudes by using GPS signal reported that the measurements at Fortaleza (dip latitude=4.5 degrees) show a precipitous fall in polar ionospheric TEC value. Basic characteristics of nighttime enhancement phenomena of TEC value have been already studied and concluded that solar and magnetic disturbances generate high latitudinal variation. During the winter season, TEC variations have been observed at low solar activity in the conjugate hemisphere stations.