Statistical Analysis of the Main Ionospheric Trough Using Swarm in Situ Measurements
Name
JGR Space Physics - 2020 - Aa - Statistical Analysis of the Main Ionospheric Trough Using Swarm in Situ Measurements.pdf
Description
Published version
Size
3.17 MB
Format
Adobe PDF
Checksum (MD5)
1afd9556bba47de61d253b5c1b28cd7d
Author(s)
Aa, Ercha
Zou, Shasha
Erickson, Philip J
Zhang, Shun‐Rong
Liu, Siqing
Date Issued
February 27, 2020
Journal
Journal of Geophysical Research: Space Physics
Publisher
American Geophysical Union
Citation
Aa, E., Zou, S., Erickson, P. J., Zhang, S.-R., & Liu, S. (2020). Statistical analysis of the main ionospheric trough using Swarm in situ measurements. Journal of Geophysical Research: Space Physics, 125, e2019JA027583.
Version
Final published version
Abstract
A statistical analysis of the topside main ionospheric trough is implemented by using the Swarm constellation in situ plasma density measurements from December 2013 to November 2019. The key features of the main trough, such as the occurrence rate, minimum position, width, and depth, are characterized and quantified. The distribution patterns of these parameters are investigated with respect to magnetic local time, season, longitude, solar activity, and geomagnetic activity levels, respectively. The main results are as follows: (1) The diurnal variation of the trough occurrence rate usually exhibits a primary peak in the early morning, a subsidiary peak in the late evening, and a slight reduction around midnight especially in the Northern Hemisphere. (2) The seasonal variation of the nighttime trough has maximum occurrence rates around equinoxes, higher than those in local winter. (3) The trough distribution has an evident hemispherical asymmetry. It is more pronounced in the Northern Hemisphere during the winter and equinoctial seasons, with its average nighttime occurrence rate being 20–30% higher than that in the Southern Hemisphere. The trough minimum position and the trough width also exhibit more significant fluctuation in the Northern Hemisphere. (4) The longitudinal pattern of the trough shows clear east‐west preferences, which has a higher occurrence rate in eastern (western) longitudes around the December (June) solstice. (5) Conditions for the trough occurrence are more favored in low solar activity and high geomagnetic activity periods.
MIT Department
Haystack Observatory
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1029/2019ja027583
