Control parameters for polar ionospheric convection patterns during northward interplanetary magnetic field

Journal Article · Fri Mar 15 04:00:00 EST 1996 · Geophysical Research Letters

DOI:https://doi.org/10.1029/96GL00452· OSTI ID:245174

Taguchi, S; Hoffman, R A ^[1]

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1. NASA Goddard Space Flight Center, Greenbelt, MD (United States)

Using the DE 2 electric field data from 191 dawn-dusk passes, the authors have sought parameters that distinguish between the various polar ionospheric convection patterns for northward IMF. The passes were divided into the daytime and nightime sectors, and categorized the convection into three convection patterns for each sector by focusing on flow having a horizontal scale of > 150 km. The three daytime sector patterns are convection of reverse polarity, i.e., sunward at the highest latitudes and antisunward on both sides of the sunward flow region, irregular convection having a single antisunward flow region at the highest latitude, which is similiar to the pattern for southward IMF. The IMF clock (B{sub y}/B{sub z}) angle, the Earth`s dipole tilt angle, and the IMF B{sub x}/B{sub z} angle measured from the dipole axis are the patterns that cause the difference in the three convection pattern. In the nighttime sector three similar convection patterns are identified. The occurrence of these patterns is controlled by the IMF clock angle. Thus, the convection pattern for northward IMF is very sensitive to the direction of the IMF. The magnetospheric sources for the convection patterns are discussed. 18 refs., 5 fig.

• OSTI ID: 245174
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 6 Vol. 23; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ELECTRIC FIELDS
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
NATURAL CONVECTION
POLAR REGIONS