MAGNETIC RECONNECTION IN THE SOLAR WIND AT CURRENT SHEETS ASSOCIATED WITH EXTREMELY SMALL FIELD SHEAR ANGLES

Journal Article · Fri Feb 01 04:00:00 EST 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/763/2/L39· OSTI ID:22078302

Gosling, J T ^[1]

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1. Laboratory for Atmospheric and Space Physics, University of Colorado, 3665 Discovery Drive, Boulder, CO 80303 (United States)

Using Wind 3 s plasma and magnetic field data, we have identified nine reconnection exhausts within a solar wind disturbance on 1998 October 18-20 driven by a moderately fast interplanetary coronal mass ejection (ICME). Three of the exhausts within the ICME were associated with current sheets having local field shear angles, {theta}, ranging from 4 Degree-Sign to 9 Degree-Sign , the smallest reported values of {theta} yet associated with reconnection exhausts in a space plasma. They were observed in plasma characterized by extremely low (0.02-0.04) plasma {beta}, and very high (281-383 km s{sup -1}) Alfven speed, V{sub A}. Low {beta} allows reconnection to occur at small {theta} and high V{sub A} leads to exhaust jets that are fast enough relative to the surrounding solar wind to be readily identified. Very small-{theta} current sheets are common in the solar wind at 1 AU, but typically are not associated with particularly low plasma {beta} or high V{sub A}. On the other hand, small-{theta} current sheets should be common in the lower solar corona, a plasma regime of extremely low {beta} and extremely high V{sub A}. Our observations lend credence to models that predict that reconnection at small-{theta} current sheets is primarily responsible for coronal heating.

• OSTI ID: 22078302
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 763; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALFVEN WAVES
DISTURBANCES
HEATING
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MASS
PLASMA
SHEAR
SOLAR CORONA
SOLAR WIND