講演情報
[PEM18-12]日本経度帯のプラズマ圏密度季節変化：北半球、南半球各々でのMAGDAS磁場観測からの推定・比較
尾上 彩希子2、*河野 英昭1、魚住 禎司3、Shevtsov Boris4、Khomutov Sergey4、Poddelskiy Igor4、Marshall Richard5、吉川 顕正1、MAGDAS/CPMN group3 (1.九州大学大学院理学研究院地球惑星科学部門、2.九州大学理学部地球惑星科学科、3.九州大学国際宇宙天気科学・教育センター、4.IKIR FEB RAS, Russia、5.Space Weather Services section, Bureau of Meteorology, Australia)
In this paper we have applied the cross-phase method and the amplitude-ratio method to the MAGDAS/CPMN ground-magnetometer pairs MGD-PTK (Magadan and Paratunka, located in the Russian Far East) and CAN-HOB (Canberra and Hobart, located in eastern Australia), both along the 210MM (Magnetic Meridian), and identified FLR (field-line resonance) events.
MGD is located at (53.6, 219.1) magnetic latitude and longitude [deg], and PTK is located at (46.2, 226.2). Their L values are 2.9 and 2.1. CAN is located at (-45.7, 226.6), and HOB is located at (-54.2, 226.5). Their L values are 2.1 and 2.9. We have identified the FLR events by using both visual inspection and an automatic-identification computer code.
Although the MGD and PTK (CAN and HOB) are separated by about seven (nine) degrees in magnetic latitudes, which is larger than the typical separation (about 1-2 degrees) to which the cross-phase and amplitude-ratio methods are efficient, but we could identify more than a hundred FLR events a year from the both station pairs, and the FLR events had a fairly continuous coverage.
In this paper we estimate the plasmaspheric density from thus obtained FLR frequencies, and examine their seasonal dependence. The result suggests a weak, but marginally significant seasonal dependence with maxima in winter and minima in summer for the both hemispheres. More details will be discussed at the presentation.
MGD is located at (53.6, 219.1) magnetic latitude and longitude [deg], and PTK is located at (46.2, 226.2). Their L values are 2.9 and 2.1. CAN is located at (-45.7, 226.6), and HOB is located at (-54.2, 226.5). Their L values are 2.1 and 2.9. We have identified the FLR events by using both visual inspection and an automatic-identification computer code.
Although the MGD and PTK (CAN and HOB) are separated by about seven (nine) degrees in magnetic latitudes, which is larger than the typical separation (about 1-2 degrees) to which the cross-phase and amplitude-ratio methods are efficient, but we could identify more than a hundred FLR events a year from the both station pairs, and the FLR events had a fairly continuous coverage.
In this paper we estimate the plasmaspheric density from thus obtained FLR frequencies, and examine their seasonal dependence. The result suggests a weak, but marginally significant seasonal dependence with maxima in winter and minima in summer for the both hemispheres. More details will be discussed at the presentation.