JpGU-AGU Joint Meeting 2017

講演情報

[EE] ポスター発表

セッション記号 A (大気水圏科学) » A-AS 大気科学・気象学・大気環境

[A-AS09] [EE] 成層圏-対流圏相互作用 ―統一領域としての新しい視点―

2017年5月24日(水) 10:45 〜 12:15 ポスター会場 (国際展示場 7ホール)

コンビーナ:江口 菜穂(Kyushu University)、Rei Ueyama(NASA Ames Research Center)、Sean M Davis(NOAA Boulder)、Seok Woo Son(Seoul National University)

[AAS09-P06] A three-week total ozone reduction over Rio Gallegos in Argentina in November 2009 and its relation to blocking in the troposphere

*秋吉 英治1門脇 正尚2中村 東奈3,1杉田 考史1原田 やよい4廣岡 俊彦5水野 亮6 (1.国立環境研究所、2.日本原子力研究開発機構、3.富士通FIP、4.気象研究所、5.九州大学、6.名古屋大学宇宙地球環境研究所)

キーワード:ozone, polar vortex, South America, blocking, wave flux

A three-week total ozone reduction over the southern tip of South America in November 2009 was reported by de Laat et al. (2010). Such long lasting low total ozone is unusual for this region and season. Ozone vertical profile measurements at Rio Gallegos, Argentina (51°S, 69°W), by ozone LIDAR suggest that isentropic surfaces of 675K and 475K over Rio Gallegos were inside the Antarctic polar vortex around November 13-14 and 22-23, respectively (Wolfram et al., 2012); thus, the low total ozone lasted for three weeks. Analyses of the total ozone observed by OMI, and ERA-Interim and JRA-55 reanalysis data indicate that the low total ozone event was caused by a polar vortex migration toward the South American continent at the time of the vortex breakup, and that the migration is associated with an enhanced wave flux from the troposphere to the stratosphere at around 120-150°W and 50-60°S. In November, a large positive deviation of a 500 hPa geopotential height from the zonal-mean was evident. This large positive deviation was considered to be a blocking by diagnosing the geopotential height filed in accordance with the method of Mendes et al. (2012). These results suggest a relation between the long-term low total ozone event over Rio Gallegos and a blocking phenomenon in the troposphere of the Southern Hemisphere through wave propagation from the blocking region.