Lunar‐solar interactions in the equatorial electrojet. Issue 9 (6th May 2014)

• Record Type: Journal Article
• Authors: Gasperini, F.; Forbes, J. M.
• Is Part Of: Geophysical research letters. Volume 41:Issue 9(2014:May)
• Page Start: 3026
• Page End: 3031
• Publication Date: 2014-05-06
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2014GL059294
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main" id="grl51457-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p id="grl51457-para-0001">To first order the ground magnetic signature of the equatorial electrojet (EEJ) reflects the height integral of <italic>J</italic> = <italic>σ</italic><italic>E</italic>, where <italic>σ</italic>is a conductivity and <italic>E</italic> represents some combination of the global dynamo‐generated electric field and the electric field due to local winds. Day‐to‐day variations in the conductivity are strongly controlled by the solar flux, while <italic>E</italic> depends on solar and lunar tides, planetary waves, and the disturbance dynamo. In this study we demonstrate how complexity is introduced into the EEJ due to the interaction between lunar tide variability in the equatorial electric field and solar‐driven variability in the <italic>E</italic> region conductivity. Toward this end, we analyze magnetometer data from the Huancayo observatory both in the time and frequency domain. We present results for the year 1990, and we show that 86% of the variance in the EEJ is due to the lunar‐solar interaction.</p> </abstract>