高级检索

崇左和防城港两地的台风韦帕(201907)降雨雨滴谱对比分析

Comparative Analysis of Rainfall Droplet Spectra of Typhoon Wipha (201907) in Chongzuo and Fangchenggang, China

  • 摘要: 利用崇左国家气象观测站、防城国家基准气候站的雨滴谱观测数据,结合观测站雨量数据及雷达观测资料,分析2019年8月2~3日台风“韦帕”影响期间内陆背风侧(LSI)、近海岸迎风侧(WSC)不同降水阶段的雨滴谱结构特征及其差异。结果显示,台风“韦帕”降雨以中、小雨滴贡献为主,尤其中雨滴贡献率稳定在70%以上。LSI处以层状云降水为主,雨强相对平缓,WSC处表现为积层混合云降水,雨强较大且波动剧烈。因强烈的对流上升运动导致WSC的雨滴数浓度、雨滴直径明显大于LSI。LSI处在台风登陆后雨势增强的最主要因素是雨滴直径增大,WSC处由台风眼墙转变为强对流螺旋雨带影响后其雨势增强则主要是由于雨滴数浓度增加。台风“韦帕”对流降水的质量加权平均直径均值为1.85 mm,对数标准化数浓度均值为3.95 mm−1 m−3;LSI处对流降水位于海洋性对流区域内,而WSC处则介于海洋性和大陆性对流之间。

     

    Abstract: We analyzed the structural characteristics and differences in raindrop spectrum at different precipitation stages on the inland leeward side (LSI) and near-coast windward side (WSC) during the impact of typhoon Wipha from August 2 to 3, 2019. We used the raindrop spectrum observation data from Chongzuo National Meteorological Observatory and Fangcheng National Reference Climate Station, combined with rainfall data and radar observation data for the analysis. The results show that typhoon Wipha’s rainfall is mainly contributed by medium and small raindrops, with the proportion of medium raindrops consistently exceeding 70%. The rainfall at LSI is dominated by stratiform clouds with relatively gentle rain intensity, while the rainfall at WSC is characterized by mixed cumulus clouds with considerable rain intensity and severe fluctuations. Raindrop concentration and diameter are significantly larger at WSC than at LSI due to the considerable convective activity and upward velocity. The main factor for the increase in rain intensity at LSI after typhoon landfall is an increase in raindrop diameter. Meanwhile, the increase in rain intensity at WSC after the change from typhoon eye wall to a strong convective spiral rain band is mainly due to an increase in raindrop number concentration. The average mass-weighted mean diameter of typhoon Wipha’s convective precipitation is 1.85 mm, with a logarithmic normalized intercept of 3.95 mm−1 m−3. Convective precipitation occurs in the maritime convective region at LSI, while it occurs between maritime and continental convection at WSC.

     

/

返回文章
返回