Mechanisms of Meridional Teleconnection Observed between a Summer Monsoon System and a Subtropical Anticyclone. Part I: The Pacific–Japan Pattern

DOI PDF 被引用文献29件 参考文献45件 オープンアクセス
  • Yu Kosaka
    Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan
  • Hisashi Nakamura
    Department of Earth and Planetary Science, The University of Tokyo, Tokyo, and Research Institute for Global Change, JAMSTEC, Yokohama, Japan

書誌事項

公開日
2010-10-01
資源種別
journal article
DOI
  • 10.1175/2010jcli3413.1
公開者
American Meteorological Society

この論文をさがす

説明

<jats:title>Abstract</jats:title> <jats:p>Summertime atmospheric circulation over the midlatitude western North Pacific (WNP) is influenced by anomalous convective activity near the Philippines. This meridional teleconnection, observed in monthly anomalies and known as the Pacific–Japan (PJ) pattern, is characterized by zonally elongated cyclonic and anticyclonic anomalies around the enhanced convection center and to its northeast, respectively, in the lower troposphere, with an apparent poleward phase tilt with height. The authors’ idealized two-layer linear model, whose basic state consists of a zonal subtropical jet and a pair of a monsoon system and a subtropical anticyclone, can simulate a PJ-like response against diabatic heating located between the pair. Each of the observed and simulated patterns can gain energy through barotropic and baroclinic conversions from the zonally varying baroclinic mean flow, in an efficiency comparable with that of energy generation due to the anomalous diabatic heating, indicating a characteristic of the pattern as a dry dynamical mode. In fact, the conversion efficiency is sensitive to the location of the anomaly pattern relative to the climatological-mean flow. Furthermore, the second-least damped mode identified in the idealized model bears certain resemblance with the observed PJ pattern, indicating its modal characteristics as well as a critical importance of these features in the mean field for the pattern. In addition to the PJ pattern, another meridional teleconnection pattern with high efficiency for its energy conversion is identified observationally in association with anomalous convection near the Bonin Islands.</jats:p> <jats:p>The anomalous circulation of the PJ pattern, in turn, can intensify the anomalous convective activity near the Philippines through enhancing evaporation and moisture convergence and dynamically inducing anomalous ascent. It is thus hypothesized that the PJ pattern can be regarded as a moist dynamical mode that sustains itself both via dry energy conversion and interaction with moist processes.</jats:p>

収録刊行物

  • Journal of Climate

    Journal of Climate 23 (19), 5085-5108, 2010-10-01

    American Meteorological Society

被引用文献 (29)*注記

もっと見る

参考文献 (45)*注記

もっと見る

関連プロジェクト

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ