Asymmetry in the Earth’s magnetotail neutral sheet rotation due to IMF By sign?
|Author:||Pitkänen, Timo1,2,3; Kullen, Anita4; Cai, Lei4;|
1Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, China
2Department of Physics, Umeå University, Umeå, Sweden
3Space Physics and Astronomy Research Unit, University of Oulu, Oulu, Finland
4Space and Plasma Physics, School of Electrical Engineering and Computer Science, Royal Institute of Technology, Stockholm, Sweden
|Online Access:||PDF Full Text (PDF, 3 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe202103298648
|Publish Date:|| 2021-03-29
Evidence suggests that a non-zero dawn–dusk interplanetary magnetic field (IMF By) can cause a rotation of the cross-tail current sheet/neutral sheet around its axis aligned with the Sun–Earth line in Earth’s magnetotail. We use Geotail, THEMIS and Cluster data to statistically investigate how the rotation of the neutral sheet depends on the sign and magnitude of IMF By. In our dataset, we find that in the tail range of −30< XGSM <−15 RE, the degree of the neutral sheet rotation is clearly smaller, there appears no significant rotation or even, the rotation is clearly to an unexpected direction for negative IMF By, compared to positive IMF By. Comparison to a model by Tsyganenko et al. (2015, doi:10.5194/angeo-33-1-2015) suggests that this asymmetry in the neutral sheet rotation between positive and negative IMF By conditions is too large to be explained only by the currently known factors. The possible cause of the asymmetry remains unclear.
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
115 Astronomy and space science
The work was supported by the Swedish National Space Agency (SNSA) Grants 118/17 (T.P. and A.K.), 105/14 (A.D.S.), 81/17 (G.S.C.) and 271/14 (M.H.), the National Natural Science Foundation of China (NSFC) Grants 41750110486 (T.P.) and 41850410495 (J.-S.P.) and the Academy of Finland Grant 314664 (H.V.).
|Academy of Finland Grant Number:||
314664 (Academy of Finland Funding decision)
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