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On Estimation of Daytime Equatorial Vertical (E × B) Plasma Drifts Using Optical Neutral Dayglow Emission Measurements
Author(s) -
Karan Deepak K.,
Pallamraju Duggirala
Publication year - 2020
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2019ja026775
Subject(s) - daytime , equatorial electrojet , atmospheric sciences , airglow , noon , equator , latitude , physics , thermosphere , f region , ionosphere , local time , earth's magnetic field , environmental science , computational physics , geophysics , magnetic field , astronomy , quantum mechanics , statistics , mathematics
Vertical drift (E × B) over the geomagnetic equator of the Earth is one of the fundamental parameters that governs the equatorial electrodynamics, which is responsible for the formation of large‐scale phenomena in low and equatorial latitudes. We present a novel approach using ground‐based optical neutral oxygen dayglow emission intensity measurements to estimate the daytime equatorial vertical drifts. The diurnal patterns of the dayglow emission intensities at OI 557.7, 630.0, and 777.4 nm wavelengths obtained from a low‐latitude location, Hyderabad (78.4 ° E, 17.5 ° N; 8.9 ° N MLAT), India, are observed to be symmetric with respect to local noon on some days and asymmetric on some other. The extent of asymmetric nature is characterized by a parameter called Asymmetricity in Time (AT), which shows similar variations with the integrated Equatorial Electrojet (EEJ) strength. AT values obtained from the dayglow measurements are used to infer the vertical drifts. Vertical drifts derived by this method match well with the global climatological model estimates and with radar measurements. This new approach provides an alternative method for obtaining vertical drifts to enable systematic investigations of equatorial electrodynamics.