Mechanisms for the maintenance of the wintertime basin-scale atmospheric response to decadal SST variability in the North Pacific subarctic frontal zone

Satoru Okajima, Hisashi Nakamura, Kazuaki Nishii, Takafumi Miyasaka, Akira Kuwano-Yoshida, Bunmei Taguchi, Masato Mori, Yu Kosakaa

研究成果: Contribution to journalArticle査読

7 被引用数 (Scopus)

抄録

Mechanisms for the maintenance of a large-scale wintertime atmospheric response to warm sea surface temperature (SST) anomalies associated with decadal-scale poleward displacement of the North Pacific subarctic frontal zone (SAFZ) are investigated through the following two ensemble experiments with an atmospheric general circulation model (AGCM): one with climatological-mean SST and the other with positive SST anomalies along the SAFZ prescribed on top of the climatological-mean SST. As actually observed, the simulated January ensemble response over the North Pacific is anticyclonic throughout the depth of the troposphere, although its amplitude is smaller. This response is maintained through energy conversion from the ensemble climatological-mean circulation realized under the climatological SST as well as feedback from anomalous transient eddy activity, suggesting that the response may have characteristics as a preferred mode of variability (or "dynamical mode"). Conversions of both available potential energy and kinetic energy from the climatological-mean state are important for the observed anomaly, while the latter is less pronounced for the model response. Net transient feedback forcing is also important for both the observed anomaly and simulated response. These results imply that a moderate-resolution (~1°) AGCM may be able to simulate a basin-scale atmospheric response to the SAFZ SST anomaly through synoptic- and basin-scale dynamical processes. Weaker PNA-like internal variability in the model may lead to the weaker response, suggesting that misrepresentation of intrinsic atmospheric variability can affect the model response to the SST anomaly.

本文言語英語
ページ(範囲)297-315
ページ数19
ジャーナルJournal of Climate
31
1
DOI
出版ステータス出版済み - 1 1 2018
外部発表はい

All Science Journal Classification (ASJC) codes

  • Atmospheric Science

フィンガープリント 「Mechanisms for the maintenance of the wintertime basin-scale atmospheric response to decadal SST variability in the North Pacific subarctic frontal zone」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル