Partial ring current models for worldwide geomagnetic disturbances

Journal Article · Mon Jan 01 04:00:00 EST 1973 · Reviews of Geophysics (1985)

DOI:https://doi.org/10.1029/RG011i004p00795· OSTI ID:4322584

Fukushima, Naoshi; Kamide, Yohsuke

In recent years the longitudinal asymmetry of the ring current in the magnetosphere encircling the Earth has been advocated to explain the gemomagnetic field variation in middle and low latitudes. Direct observations of particles and magnetic field by means of satellites in the magnetosphere have given some supporting evidence for the existence of partial ring current in the magnetosphere. In this article a review is made of the analysis of lowlatitude geomagnetic variation during magnetic storms or substorms, and the contribution of the partial ring current system to low-latitude geomagnetic variations is discussed. After examining the magnetic effect of each part of the partial ring current system, i.e., (1) the equatorial ring current in a limited longitude range, (2) the Birkeland (field aligned) current in the magnetosphere connecting the equatorial plane and the ionosphere, and (3) the current in the ionosphere, including an electrojet along the auroral zone or oval, it is concluded that the main contribution to the longitudinal DELTA H asymmetry in middle and low latitudes (H is the horizontal component of the geomagnetic field) comes primarily from the Birkeland current and neither from the partial ring current in the equatorial plane nor from the auroral electrojet. Therefore the models of partial ring current need to be modified so as not to overemphasize the ring-form current closure in the equatorial plane. This article explains the reason for the above conclusions and gives some necessary considerations for interpreting the geomagnetic variations in low latitudes during magnetic storms and substorms and on quiet days. (auth)

• Research Organization: Tokyo Univ.
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-022153
• OSTI ID: 4322584
• Journal Information: Reviews of Geophysics (1985), Journal Name: Reviews of Geophysics (1985) Journal Issue: 4 Vol. 11; ISSN REGEEP; ISSN 8755-1209
• Publisher: American Geophysical Union (AGU)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*GEOMAGNETIC FIELD-- VARIATIONS
*MAGNETIC BAYS-- RING CURRENTS
*MAGNETIC STORMS-- RING CURRENTS
*RING CURRENTS-- REVIEWS
79 ASTRONOMY AND ASTROPHYSICS
ELECTROJETS
IONOSPHERE
LATITUDE EFFECT
MAGNETOSPHERE