Study on the diversity in the structure of the Meiyu front and the distribution of rainfall and cloud

梅雨锋结构多样性及雨云分布研究

• 批准号: 09680172
• 负责人: TAKAHASHI Hideo
• 金额: $ 1.6万
• 依托单位: Tokyo Gakugei University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680172/
• 关键词: Meiyu front; Chine; Tibetan Plateau; disturbance; teleconnection; daily rainfall; convective rainfall; 中国大陸; ロスビー波列; 熱帯降雨観測衛星; 寒帯前線; 陰性・陽性梅雨; 華南・華中; 降水帯; 相対渦度場; 因子分析; 循環場; 梅雨; 前線構造; 降水分布; 雲分布; 対流雲

1. The formation process of the Meiyu frontal disturbance over China is different corresponding to its initial appearance location. That is, the meso-α-scale disturbance that formed in the eastern foot of the Tibetan Plateau causes heavy rainfall zone over the Yangtze River basin, while the cold northeasterly wind activates the Meiyu front over South China through the increase in temperature gradient.2. Though the distributions of height anomaly for the cases of both continuous southward migrating and stationary heavy rainfall zone over China indicate EU pattern-like teleconnection, the location of positive and negative anomaly is different between respective case. As for the former case, negative height anomaly locates in the East China Sea, which causes the southeastward retreat of the Subtropical High and the incursion of cold airmass into the Yangtze River basin from the Japan Sea. Airmass to the north of the Meiyu front of this case is rather cold and the frontal system indicates vertically higher structure. Concerning the latter case, height field over Southern China dose not decrease and the Subtropical ridge remains there. Since the cold northeasterly is restricted to the northern Japan Sea, negative temperature anomaly around the Meiyu front is not observed except in the lower layer.3. The structure of rain-producing cloud (convective/stratiform cloud) in the Baiu front around Japan could vary according to the characteristics of the frontal zone. In case the Baiu front corresponds to the Eurasian Polar frontal zone., rainfall from the stratifrom clouds preveils. On the contrary, convective rainfall prevails under the Baiu front that prolonged from China with cold airmass to the north of the front4. Contribution of daily rainfall amount to total rainfall amount during the Baiu season is investigated to clarify the geographical and year-to-year difference in the statistical feature of rainfall intensity over Japan.

1.我国梅雨锋扰动的形成过程与其初始出现的位置不同。也就是说，青藏高原东麓形成的中α尺度扰动导致长江流域强降水带的形成，而东北冷风通过温度梯度的增加激活了华南地区的梅雨锋.我国暴雨持续南移和静止过程的高度距平分布虽然都表现为EU型遥相关，但正负距平的位置不同。在前一种情况下，东海上空出现负高度距平，导致副高东移，日本海冷空气入侵长江流域。梅雨锋北侧的气团较冷，锋面系统表现出较高的垂直结构。在后一种情况下，华南地区的高度场没有减少，副热带高压脊仍然存在。由于东北冷气流仅限于北方日本海，所以梅雨锋附近除低层外，没有出现温度负距平.在日本附近的Baiu锋面上，产雨云（对流/层状云）的结构可以根据锋面区的特征而变化。如果Baiu锋对应于欧亚极地锋带，云层中的降雨开始出现。相反，从中国延伸到冷锋以北的冷空气团，在其下方对流性降水占优势。通过分析日本白鸥季日降雨量对总降雨量的贡献，探讨了日本降雨强度统计特征的地理差异和年际差异。

项目成果

Takahashi, H.: "Initial evolution process of the Mei-yu frontal disturbance in the eastern foot of the Tibetan Plateau - A case analysis for late June of 1992-"Preliminary research report on Japanese GAME/HUBEX" GAME Publication. No. 9. 126-140 (1998)

高桥H.：青藏高原东麓梅雨锋锋扰动的初始演化过程——以1992年6月下旬为例分析——《日本GAME/HUBEX初步研究报告》GAME刊第9期

Takahashi, H.: "Statistical relationships between synoptic feature over Asia and the activity of Meiyu over China based on principal component analysis of twice a day relative vorticity field at 850hPa level for six Meiyu seasons"Proceedings of the Second

Takahashi, H.：“基于 6 个梅雨季每天两次 850hPa 相对涡度场主成分分析的亚洲天气特征与中国梅雨活动的统计关系”第二届会议论文集

高橋日出男: "気象衛星ひまわりによる雲画像マイクロフィルムを用いた雲分布解析"学芸地理. 53. 14-23 (1998)

Hideo Takahashi：“利用向日葵气象卫星的云图像缩微胶卷进行云分布分析”Gakugei Geography 53. 14-23 (1998)。

高橋日出男: "気象衛星ひまわりによる雲画像マイクロフィルムを用いた雲分布解析" 学芸地理. 53. 14-23 (1998)

Hideo Takahashi：“利用向日葵气象卫星的云图像缩微胶卷进行云分布分析”Gakugei Geography 53. 14-23 (1998)。

高橋日出男: "北日本の太平洋・オホーツク海沿岸における梅雨季の低温出現とユーラシア大陸上の循環場の時間推移" 東京学芸大学紀要3部門. 49. 129-139 (1998)

高桥英夫：《日本北部太平洋和鄂霍次克海沿岸雨季低温的出现和欧亚大陆上空环流场的时间变化》东京学艺大学学报第3.49期129-139（1998）