ionospheric-irregularities-that-influence-communication-navigation-systems-summary

Context: 

  • A multi-instrument based ionospheric study of space weather storms over India have found that the occurrence of equatorial spread F (ESF) irregularities and GPS scintillations are significantly affected by the geomagnetic storms. 
  • The Equatorial Spread-F (ESF) phenomenon is recorded in ionograms as a hierarchy of plasma instabilities in the F-layer of the equatorial ionosphere.

More on the news: 

  • The study included scientists from the Indian Institute of Geomagnetism (IIG), an autonomous institute under the Department of Science & Technology (DST). 

About plasma irregularities:

  • The Earth's magnetic field lines are nearly horizontal over the magnetic equator due to which equatorial ionosphere is a bed for a variety of plasma instabilities to cause plasma disturbances and plasma irregularities. 
  • The plasma irregularities is a complex phenomenon encompassing a wide range of scale sizes of irregularities in electron and ion densities as well as in electric fields. 
    • They also produce ionospheric scintillations in GPS receivers when radio waves traverse through the ionosphere.
    • Ionospheric scintillation is a rapid fluctuation of radio-frequency signal phase and/or amplitude, generated as a signal passes through the ionosphere.

Significance:

  • Understanding the thermosphere‐ionosphere-magnetosphere interactions: That control the electrodynamics behind dynamical evolution of ionospheric irregularities is most important in developing and maintaining communication and navigation systems.
    • As plasma irregularities pose severe problems to the communication and navigation systems and interfere with surveillance operations as well as disruption in detection and tracking of aircraft, missiles, and satellites.

The ionosphere

Source: Wikipedia

  • The ionosphere is the ionized part of Earth's upper atmosphere, from about 60 km to 1,000 km altitude, a region that includes the thermosphere and parts of the mesosphere and exosphere. 
  • The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. 
  • It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
  • The region below the ionosphere is called neutral atmosphere, or neutrosphere.

Source: https://pib.gov.in/PressReleasePage.aspx?PRID=1633389