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-P02] A comparison of the momentum budget in reanalysis datasets during sudden stratospheric warming events

*Patrick Martineau1Seok-Woo Son2Masakazu Taguchi3Amy Butler4 (1.UCLA、2.Seoul National University、3.Aichi University of Education、4.NOAA/CIRES)

The agreement between reanalysis datasets is evaluated during sudden stratospheric warming (SSW) events using the zonal-mean momentum budget. Zonal-mean variables reveal a good agreement among datasets for the fast warming and weakening of the polar vortex in the lower stratosphere. Eddy fluxes and forcings for zonal-mean zonal wind acceleration are also relatively similar in the lower atmosphere. This agreement is, however, severely degraded in the mid-to-upper-stratosphere. Discrepancies among reanalyses are particularly large during the onset of SSW events, a period characterized by unusually strong fluxes of planetary-scale waves from the troposphere to the stratosphere, and are substantially smaller after the onset. The discrepancies are also typically larger for the most intense SSW events. While the largest uncertainty in the momentum budget originates from the Coriolis torque, momentum flux convergence also presents a non-negligible spread among the reanalyses. The uncertainty of all terms of the zonal-mean momentum equation among reanalyses is reduced in the latest reanalysis products.