Polar lows, its structure and mechanism of cyclogenesis.

极地低气压、其结构和气旋发生机制。

• 批准号: 06640556
• 负责人: TSUBOKI Kazuhisa
• 金额: $ 1.28万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640556/
• 关键词: polar low; mesoscale low; cold vortex; Hokkaido polar low; convergence line; CAPS II; numerieal modeling; band cloud; 小低気圧; メソスケール; 数値モデル; CASP II; コールドロウ

A polar low over the Labrador Sea was observed on 14-15 February 1992. Satellite images obtained from the AVHRR showed the cyclogenesis and development of the polar low. The cloud streaks over the Labrador sea suggested that a convergence formed between the westerly from Eastern Canada and the northeasterly from Greenland before when the polar low developed. A vortex formed along the convergence zone and developed into the polar low of which the horizontal diameter was about 500 km.On the basis of the JMA global objective analysis (GANAL), an intense upper cold vortex was located over the Labrador sea when the polar low occurred. The GANAL data showed a dry and cold westerly was prevailing over the Labrador sea and that the convergence occurred between the westerly from Eastern Canada and the northeasterly from Greenland. The polar low formed along the convergence zone. The polar low was shallow disturbance which was confined to below 700 hPa.In order to clarify the detailed structure and the processes of cyclogenesis and development of the polar low, we made numerical simulation experiments using the Japan Spectral Model. JSM simulated well the development of the Labrador polar low. First, a convergence occurred between the westerly from Eastern Canada and the northeasterly from Greenland. Then, the polar low developed along the convergence zone. There was a strong stable layer above 700 hPa and the disturbance of the polar low was confined to below 700 hPa.As far as this case of the Labrador polar low, we could infer that the convergence was important for the cyclogenesis and that the latent and sensible heat fluxes were important for the development. It is not clear presently the role of the upper cold vortex in the cyclogenesis of the polar low.

1992年2月14日至15日观察到拉布拉多海上的极低。拉布拉多海上的云条纹表明，在极低低点发展之前，从加拿大东部和东北的西北形成了融合。沿收敛区形成的涡流，并发展成为极低的极低，水平直径约为500 km。在JMA全球客观分析（Ganal）的基础上，当极低的低点发生时，强烈的上冷涡流位于拉布拉多海上。 Ganal数据显示，在拉布拉多海上盛行了干燥和寒冷的西风，并且这种收敛发生在加拿大东部和格陵兰岛的西北地区之间发生的融合。沿收敛带形成的极低。极低为浅扰动，仅限于700 hpa。 JSM很好地模拟了拉布拉多极低的发展。首先，从加拿大东部和格陵兰岛的西北地区发生了融合。然后，极低沿收敛区发展。高于700 hPa的稳定层强，极低的干扰仅限于700 hpa。就拉布拉多极低的这种情况而言，我们可以推断，收敛对环生成很重要，并且潜在且明智的热量对于开发很重要。目前尚不清楚上冷涡在极低的循环发生中的作用。

项目成果

Kazuhisa Tsuboki and Gorow Wakahama: "Mesoscale cyclogenesis in winter monsoon air streams : Quasi-geostrophic baroclinic instability as a mechanism of the cyclogenesis off the west coast of Hokkaido Island, Japan." J.Meteor.Soc.Japan. 70. 77-93 (1992)

Kazuhisa Tsuboki 和 Gorow Wakahama：“冬季季风气流中的中尺度气旋发生：准地转斜压不稳定性是日本北海道岛西海岸气旋发生的机制。”

Y.Fujiyoshi, Y.Kodama, K.Tsuboki, K.Nishimura and N.Ono: "Structures of cold air during the development of a broad band cloud and a meso-beta-scale vortex : Simultaneous two-point radiosonde observations." J.Meteor.Soc.Japan. 74. 281-297 (1996)

Y.Fujiyoshi、Y.Kodama、K.Tsuboki、K.Nishimura 和 N.Ono：“宽带云和中观 β 尺度涡旋发展过程中的冷空气结构：同时两点无线电探空仪观测。”

坪木和久: "冬季日本海上に発生するメソスケール低気圧の数値実験" 月刊海洋. 5. 125-133 (1993)

Kazuhisa Tsuboki：“冬季日本海上空发生的中尺度气旋的数值实验”月刊Kaiyo。5. 125-133（1993）

Yoshimitsu Ogura, Kazuhisa Tsuboki, Hisao Ohno, Kenichi Kusunoki and Hiroshi Nirasawa: "A Case Study of the Formation of an Embedded-Areal-Type Cloud Band over Kanto Plain." J.Meteor.Soc.Japan. 73. 857-872 (1995)

Yoshimitsu Ogura、Kazuhisa Tsuboki、Hisao Ohno、Kenichi Kusunoki 和 Hiroshi Nirasawa：“关东平原嵌入式区域型云带形成的案例研究”。

坪木和久: "温帯低気圧に伴う波状の降水エコー(Wave-like Bands Associated with Extratropical cyclone)." 天気. 42(color page). (1995)

Kazuhisa Tsuboki：“与温带气旋相关的波状带。”（彩页）。