Combined wind profiler-weather radar observations of orographic rainband around Kyushu, Japan in the Baiu season
A special observation campaign (X-BAIU), using various instruments (wind profilers, <i>C</i>-band weather radars, <i>X</i>-band Doppler radars, rawinsondes, etc.), was carried out in Kyushu (western Japan) during the Baiu season, from 1998 to 2002. In the X-BAIU-99 and -...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2004-11-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/22/3971/2004/angeo-22-3971-2004.pdf |
| _version_ | 1811268946670649344 |
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| author | Y. Umemoto M. Teshiba Y. Shibagaki H. Hashiguchi M. D. Yamanaka M. D. Yamanaka S. Fukao X-BAIU-99 X-BAIU-02 observational groups |
| author_facet | Y. Umemoto M. Teshiba Y. Shibagaki H. Hashiguchi M. D. Yamanaka M. D. Yamanaka S. Fukao X-BAIU-99 X-BAIU-02 observational groups |
| author_sort | Y. Umemoto |
| collection | DOAJ |
| description | A special observation campaign (X-BAIU), using various instruments
(wind profilers, <i>C</i>-band weather radars, <i>X</i>-band
Doppler radars, rawinsondes, etc.), was carried out in Kyushu
(western Japan) during the Baiu season, from 1998 to 2002.
In the X-BAIU-99 and -02 observations, a line-shaped orographic
rainband extending northeastward from the Koshikijima Islands
appeared in the low-level strong wind with warm-moist airs.
The weather radar observation indicated that the rainband
was maintained for 11h.
The maximum length and width of the rainband observed in 1999
was ~200km and ~20km, respectively.
The rainband observed in 2002 was not so developed compared with
the case in 1999.
The Froude number averaged
from sea level to the top of the Koshikijima Islands (~600m)
was large (>1), and the lifting condensation level was
below the tops of the Koshikijima Islands.
Thus, it is suggested that the
clouds organizing the rainband are formed by
the triggering of the mountains on the airflow passing over them.
The vertical profile of horizontal wind in/around the rainband
was investigated in the wind profiler observations.
In the downdraft region 60km from the Koshikijima Islands,
strong wind and its clockwise rotation with increasing
height was observed below 3km altitude.
In addition, a strong wind component perpendicular to the rainband
was observed when the rainband was well developed.
These wind behaviors were related to the evolution of
the rainband. |
| first_indexed | 2024-04-12T21:32:04Z |
| format | Article |
| id | doaj.art-1cd8e6d46483478d91eee3636ea300d3 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-12T21:32:04Z |
| publishDate | 2004-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-1cd8e6d46483478d91eee3636ea300d32022-12-22T03:16:00ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762004-11-01223971398210.5194/angeo-22-3971-2004Combined wind profiler-weather radar observations of orographic rainband around Kyushu, Japan in the Baiu seasonY. Umemoto0M. Teshiba1Y. Shibagaki2H. Hashiguchi3M. D. Yamanaka4M. D. Yamanaka5S. Fukao6X-BAIU-99X-BAIU-02 observational groups7Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto 611–0011, JapanResearch Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto 611–0011, JapanOsaka Electro-Communication University, Neyagawa, Osaka 572–8530, JapanResearch Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto 611–0011, JapanGraduate School of Science and Technology, Kobe University, Kobe 657–8501, JapanInst. of Observ. Res. for Global Change, Japan Agency for Marine-Earth Science and Techn., Yokohama 236–0001, JapanResearch Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto 611–0011, JapanMeteorological Research Institute, Japan Meteorological Agency, Tsukuba, Ibaraki 305–0052, JapanA special observation campaign (X-BAIU), using various instruments (wind profilers, <i>C</i>-band weather radars, <i>X</i>-band Doppler radars, rawinsondes, etc.), was carried out in Kyushu (western Japan) during the Baiu season, from 1998 to 2002. In the X-BAIU-99 and -02 observations, a line-shaped orographic rainband extending northeastward from the Koshikijima Islands appeared in the low-level strong wind with warm-moist airs. The weather radar observation indicated that the rainband was maintained for 11h. The maximum length and width of the rainband observed in 1999 was ~200km and ~20km, respectively. The rainband observed in 2002 was not so developed compared with the case in 1999. The Froude number averaged from sea level to the top of the Koshikijima Islands (~600m) was large (>1), and the lifting condensation level was below the tops of the Koshikijima Islands. Thus, it is suggested that the clouds organizing the rainband are formed by the triggering of the mountains on the airflow passing over them. The vertical profile of horizontal wind in/around the rainband was investigated in the wind profiler observations. In the downdraft region 60km from the Koshikijima Islands, strong wind and its clockwise rotation with increasing height was observed below 3km altitude. In addition, a strong wind component perpendicular to the rainband was observed when the rainband was well developed. These wind behaviors were related to the evolution of the rainband.https://www.ann-geophys.net/22/3971/2004/angeo-22-3971-2004.pdf |
| spellingShingle | Y. Umemoto M. Teshiba Y. Shibagaki H. Hashiguchi M. D. Yamanaka M. D. Yamanaka S. Fukao X-BAIU-99 X-BAIU-02 observational groups Combined wind profiler-weather radar observations of orographic rainband around Kyushu, Japan in the Baiu season Annales Geophysicae |
| title | Combined wind profiler-weather radar observations of orographic rainband around Kyushu, Japan in the Baiu season |
| title_full | Combined wind profiler-weather radar observations of orographic rainband around Kyushu, Japan in the Baiu season |
| title_fullStr | Combined wind profiler-weather radar observations of orographic rainband around Kyushu, Japan in the Baiu season |
| title_full_unstemmed | Combined wind profiler-weather radar observations of orographic rainband around Kyushu, Japan in the Baiu season |
| title_short | Combined wind profiler-weather radar observations of orographic rainband around Kyushu, Japan in the Baiu season |
| title_sort | combined wind profiler weather radar observations of orographic rainband around kyushu japan in the baiu season |
| url | https://www.ann-geophys.net/22/3971/2004/angeo-22-3971-2004.pdf |
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