Numerical Investigation of Development Processes of Baiu Frontal Depressions Part I: Case Studies

• TOCHIMOTO Eigo

  Department of Earth and Planetary Sciences, Kyushu University, Kyushu, Japan

• KAWANO Tetsuya

  Department of Earth and Planetary Sciences, Kyushu University, Kyushu, Japan

Bibliographic Information

Other Title

• Numerical Investigation of Development Processes of Baiu Frontal Depressions(Part 1)Case Studies

Abstract

 This work investigates the development processes of Baiu frontal depressions (BFDs) using a numerical model. To investigate the effects of upper-level disturbances, latent heating, and baroclinicity on the development of BFDs, case-study numerical simulations are performed. In the present study, two typical cases were selected from BFDs that appeared in June and July, 2000-2007—a BFD that developed in the western part of the Baiu frontal zone (W-BFD) from 26 to 27 June, 2003, and a BFD that had formed in the eastern part of the Baiu frontal zone (E-BFD) from 1 to 3 July, 2003. An available potential energy diagnosis shows that the effect of latent heating is dominant during the W-BFD development, while baroclinicity as well as latent heating is important to the E-BFD development. A sensitivity experiment excluding upper-level potential vorticity (PV) anomalies shows that upper-level disturbances are important contributors to the development of E-BFDs.  The low-level PV and its production associated with latent heating suggest that the W-BFD has a development mechanism driven by latent heating. In the early developmental stage, PV near the W-BFD center is enhanced. This feature is consistent with the nonlinear conditional instability of the second kind mechanism. In the later developmental stage, PV is produced in front of the W-BFD center, in which low-level baroclinicity is large. This process is consistent with a diabatic Rossby vortex. In contrast, the E-BFD develops through a baroclinic instability-like mechanism in the moist atmosphere.

Journal

• Journal of the Meteorological Society of Japan. Ser. II

  Journal of the Meteorological Society of Japan. Ser. II 95 (2), 91-109, 2017

  Meteorological Society of Japan

Keywords

• Baiu
• depression
• extratropical depression

Details

• CRID: 1390001206504202496
• NII Article ID: 130005450162
• NII Book ID: AA00702524
• DOI: 10.2151/jmsj.2017-005
• ISSN: 21869057
• ISSN: 00261165
• NDL BIB ID: 028137264
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I028137264
• Web Site: https://www.jstage.jst.go.jp/article/jmsj/95/2/95_2017-005/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed