JpGU-AGU Joint Meeting 2017

講演情報

[EE] ポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM12] [EE] Space Weather, Space Climate, VarSITI

2017年5月23日(火) 15:30 〜 17:00 ポスター会場 (国際展示場 7ホール)

コンビーナ:片岡 龍峰(国立極地研究所)、Antti A Pulkkinen(NASA Goddard Space Flight Center)、草野 完也(名古屋大学宇宙地球環境研究所)、塩川 和夫(名古屋大学宇宙地球環境研究所)

[PEM12-P18] Identification of Active Longitude from the Solar Magnetograms

*近藤 克哉1今田 晋亮1藤山 雅士1町田 忍1 (1.名古屋大学宇宙地球科学研究所)

キーワード:Active Longitude, Sunspot

It is well known that the sun has the cycle of 11 years for its activity. In the active time, we can see lots of sunspots on the solar surface and sometime it cause large flares which largely affect the Earth’s environments. For example, the release of large-scale plasma called Coronal Mass Ejection (CME) hits the Earth’s magnetosphere and causes some effects, e.g. the Earth’s magnetic field fluctuation or trouble of the satellite. The appearance of sunspots has several characteristics. For example, sunspots appear around in the higher latitudes at the beginning of the cycle and in the lower latitudes at the end of the cycle on the sun. However, recent studies have shown that the appearances of sunspots also depend on longitudinal direction. The solar longitude where the sunspots are frequently observed is called Active Longitude (AL). The presence of active longitude has been discussed long time. But it is still not clear whether there is an AL or not. In this study, we identified AL using magnetic field observation on the solar surface, not sunspots data. As a result, we can study AL for the magnetic bipoles which do not develop to sunspots. The results show that the phase of AL in the northern hemisphere and the southern hemisphere are different in cycles 23 and 24. Further, we found that there is clear AL in the strong magnetic field data(|B|>500G), although there is no clear AL in the weak magnetic field data(|B|<40G).