A Diagnostic Study of the Early Phases of Sixteen Western North-Pacific Cyclones

DOI NDL Digital Collections Web Site Web Site 20 References
  • Kelly Robert W. P.
    Department of Atmospheric and Oceanic Sciences, McGill University Current affiliation: United Kingdom Meteorological Office
  • Gyakum John R.
    Department of Atmospheric and Oceanic Sciences, McGill University
  • Zhang Da-Lin
    Department of Atmospheric and Oceanic Sciences, McGill University
  • Roebber Paul J.
    Department of Atmospheric and Oceanic Sciences, McGill University Current affiliation: Department of Atmospheric Science, State University of New York at Albany

Bibliographic Information

Other Title
  • 西北部太平洋における低気圧の発達初期の診断研究
  • 西北部太平洋における低気圧の発達初期の診断研究〔英文〕
  • セイホクブ タイヘイヨウ ニ オケル テイキアツ ノ ハッタツ ショキ ノ シ

Search this article

Description

We study the phenomenon of rapid cyclogenesis by examining the time evolution of the synoptic-scale environment for the 36-h period prior to most rapid intensification. We perform this study with the construction of composites for eight explosively-developing cyclones whose maximum intensification commences within a 5° latitude-longitude region in the vicinity of the Kuroshio Current. A comparison is made with corresponding composites of eight weakly-developing lows within the same region. The set of 16 cases is a comprehensive sample of events for nine cold seasons. Synoptic-scale features for the strong cases, distinct from those of the weaker cases, are detected throughout the 36-h dynamical conditioning period.<br>The stronger cases form to the south and west of Japan with antecedent propagation predominately over the maritime environment. The weaker systems, in contrast, either form in situ in our study region, or travel eastward from the Sea of Japan over the Island of Honshu. The unique thermodynamic precursors of the stronger systems include: a warm 1000-500hPa thickness anomaly that travels from the East China Sea northeastward into the Kuroshio region, and a cold thickness anomaly and thermal jet east of our study area. The dynamical consequence of the warm anomaly includes the development of an anomalous southwesterly thermal wind to the northwest where incipient surface development occurs.<br>We examine a representative strong case in which initial surface development occurs to the northwest of the warm anomaly in a zone of quasi-geostrophic forcing for ascent. The system subsequently propagates into a favorable location for further development downstream of a second 500hPa trough within the northwesterly polar jet. At the onset of explosive deepening, the cyclone is propagating towards a second region of anomalously cold air and strong baroclinity.

Journal

References(20)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top