JaLCDOI 10.18926/ESR/47748
Title Alternative Characteristics of typhoon tracks and large-scale atmospheric fields associated with the typhoon approach to the Japan Islands in early summer
FullText URL esr_018_1_011_018.pdf
Author Hamamoto, Natsumi| Kato, Kuranoshin| Nakayama, Yuuki| Tsukamoto, Osamu|
Abstract The number of typhoons approaching the Japan Islands is much smaller in May and June than in August to September. However, some typhoons abnormally approach to the Japan Islands in May or June as in 2004. The present study investigated the characteristics of the typhoon tracks and the large-scale fields in May and June associated with the approach of typhoons to the Japan Islands. Climatologically speaking, typhoons are generally formed in the lower latitude in May and early June, and tend to turn to ENE-ward before they reach ~ 20N in May by the upper- and middle-level westerly wind. In June, the upper-level easterly wind associated with the Tibetan high seems to prevent typhoons from approaching to the Japan Islands. However, when the cell-type subtropical high and the deep westerly trough in its western side are formed with the SW-ly from the lower to the middle latitude, a favorable situation for the northward invasion of the typhoon can be realized in May. On the other hand, the formation of the barotropic-like subtropical high to the southeast of the Japan Islands seems to enable a typhoon to approach to the Japan Islands by the S-ly wind around the subtropical high.
Keywords typhoon tracks in early summer large-scale atmospheric fields in early summer
Publication Title Okayama University Earth Science Report
Published Date 2011-12-26
Volume volume18
Issue issue1
Start Page 11
End Page 18
ISSN 1340-7414
language 日本語
Copyright Holders © 2011 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved
File Version publisher
NAID 120003796476
JaLCDOI 10.18926/ESR/13848
Title Alternative Eastward extension of the Baiu Front on the surface weather maps in ralation to zonal scale of the area with strong low-level southerly wind toward the front
FullText URL EAR_13_1_19.pdf
Author Nakayama, Yuuki| Owada, Michio| Ikeda, shoichiro| Kato, Kuranoshin|
Abstract Eastward extension of the Baiu front in relation to zonal scale of the area with strong low-level southerly wind toward the front was examined based on the operational surface weather maps and the NCEP/NCAR re-analysis data mainly for the mature Baiu period (15 June to 31 July) from 1991 to 2000. During that period, the Baiu front on the surface weather maps appeared from the Changjiang River Basim to the east of the Japan Islands accompanied by the strong low-level southerly wind toward it in a wide zonal scala(~3500km), in many cases. However, the situations when the appesrance of the Baiu front was limited to the western part of the Japan Islands or limited to its eastern part are sometimes found with relatively narrow zonal acale of the strong low-level southerly wind toward the front, although the appearance frequency of such cases was not so high. As such the present results illustrate the importance of the zonal scale of the subtropical high for the spatial activity of the Baiu front.
Keywords variation of the Baiu front southerly wind in the subtropical high area zonal extension of the Baiu front
Publication Title Okayama University Earth Science Report
Published Date 2006-03-31
Volume volume13
Issue issue1
Start Page 19
End Page 25
ISSN 1340-7414
language 日本語
Copyright Holders 岡山大学地球科学研究報告編集委員会
File Version publisher
NAID 120006211873