English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The present study examines the morning-afternoon asymmetry of the geosynchronous magnetic field strength on the\uddayside (magnetic local time [MLT] = 06:00~18:00) using observations by the Geostationary Operational Environmental\udSatellites (GOES) over a period of 9 years from February 1998 to January 2007. During geomagnetically quiet time (Kp <\ud3), we observed that a peak of the magnetic field strength is skewed toward the earlier local times (11:07~11:37 MLT) with\udrespect to local noon and that the geosynchronous field strength is larger in the morning sector than in the afternoon\udsector. That is, there is the morning-afternoon asymmetry of the geosynchronous magnetic field strength. Using solar\udwind data, it is confirmed that the morning-afternoon asymmetry is not associated with the aberration effect due to the\udorbital motion of the Earth about the Sun. We found that the peak location of the magnetic field strength is shifted toward\udthe earlier local times as the ratio of the magnetic field strength at MLT = 18 (B-dusk) to the magnetic field strength\udat MLT = 06 (B-dawn) is decreasing. It is also found that the dawn-dusk magnetic field median ratio, B-dusk/B-dawn, is\uddecreasing as the solar wind dynamic pressure is increasing. The morning-afternoon asymmetry of the magnetic field\udstrength appears in Tsyganenko geomagnetic field model (TS-04 model) when the partial ring current is included in TS-\ud04 model. Unlike our observations, however, TS-04 model shows that the peak location of the magnetic field strength\udis shifted toward local noon as the solar wind dynamic pressure grows in magnitude. This may be due to that the symmetric\udmagnetic field associated with the magnetopause current, strongly affected by the solar wind dynamic pressure,\udincreases. However, the partial ring current is not affected as much as the magnetopause current by the solar wind\uddynamic pressure in TS-04 model. Thus, our observations suggest that the contribution of the partial ring current at\udgeosynchronous orbit is much larger than that expected from TS-04 model as the solar wind dynamic pressure increases

Geosynchronous Magnetic Field Response to Solar Wind Dynamic Pressure