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オゴハラ カズノリ
OGOHARA Kazunori
小郷原 一智 所属 京都産業大学 理学部 宇宙物理・気象学科 職種 准教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2017/09 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki |
| 執筆形態 | その他 |
| 掲載誌名 | NATURE GEOSCIENCE |
| 出版社・発行元 | NATURE PUBLISHING GROUP |
| 巻・号・頁 | 10(9),pp.646-+ |
| 著者・共著者 | Takeshi Horinouchi,Shin-ya Murakami,Takehiko Satoh,Javier Peralta,Kazunori Ogohara,Toru Kouyama,Takeshi Imamura,Hiroki Kashimura,Sanjay S. Limaye,Kevin McGouldrick,Masato Nakamura,Takao M. Sato,Ko-ichiro Sugiyama,Masahiro Takagi,Shigeto Watanabe,Manabu Yamada,Atsushi Yamazaki,Eliot F. Young |
| 概要 | The Venusian atmosphere is in a state of superrotation where prevailing westward winds move much faster than the planet's rotation. Venus is covered with thick clouds that extend from about 45 to 70 km altitude, but thermal radiation emitted from the lower atmosphere and the surface on the planet's nightside escapes to space at narrow spectral windows of the near-infrared. The radiation can be used to estimate winds by tracking the silhouettes of clouds in the lower and middle cloud regions below about 57 km in altitude. Estimates of wind speeds have ranged from 50 to 70ms 1 at low to mid-latitudes, either nearly constant across latitudes or with winds peaking at mid-latitudes. Here we report the detection of winds at low latitude exceeding 80 m s(-1) using IR2 camera images from the Akatsuki orbiter taken during July and August 2016. The angular speed around the planetary rotation axis peaks near the equator, which we suggest is consistent with an equatorial jet, a feature that has not been observed previously in the Venusian atmosphere. The mechanism producing the jet remains unclear. Our observations reveal variability in the zonal flow in the lower and middle cloud region that may provide clues to the dynamics of Venus's atmospheric superrotation. |
| DOI | 10.1038/NGEO3016 |
| ISSN | 1752-0894/1752-0908 |
| Put Code(ORCID) | 52340108 |
| PermalinkURL | http://orcid.org/0000-0001-7666-4442 |