By using the routine weather data and the numerical value forecast products,applying the weather analysis and diagnostic analysis methods,the cold wave weather which happened in the south area of Dalian was analyzed o...By using the routine weather data and the numerical value forecast products,applying the weather analysis and diagnostic analysis methods,the cold wave weather which happened in the south area of Dalian was analyzed on December 29-30,2009.The results showed that based on the temperature rise in prior period,the strong cold air accumulated in Mongolia and passed Ulan Bator,Erenhot to invade Dalian area.In the cold wave process,the circulation situations in the middle and high latitudes were the 'one ridge and one trough' pattern in Asia.The dynamic mechanisms were the rotary low-pressure trough in high altitude and the strong frontal zone,and the flow field which induced the cold wave to break out was the 'low trough rotation pattern'.After the cold air broke out,Dalian area was controlled by the strong cold advection.The cold high-pressure on the ground entered into the key zone and reached the intensity of cold wave.However,the circulation of cold wave occurrence was southerly,and the shifts of cold air and influence system were quicker.Therefore,the cold wave appeared in Dalian's south areas which included Lvshun,Dalian and Jinzhou.On this basis,the key point of cold wave weather forecast in Dalian area was summarized.展开更多
针对2018年1月21—22日张家口出现的寒潮天气过程,详细分析了前期气候背景和天气演变过程中500 h Pa与850 h Pa形势变化,以及地面冷高压变化。结果表明:该次寒潮过程属于横槽转竖型;降温过程48 h的日平均气温降幅大于日最低气温的降幅,...针对2018年1月21—22日张家口出现的寒潮天气过程,详细分析了前期气候背景和天气演变过程中500 h Pa与850 h Pa形势变化,以及地面冷高压变化。结果表明:该次寒潮过程属于横槽转竖型;降温过程48 h的日平均气温降幅大于日最低气温的降幅,根本原因是降水造成下垫面相对湿度大以及夜间较多云量影响了辐射降温,从而减小了最低气温的降幅;700 h Pa垂直速度的大值下沉区加速了地面气温的急剧下降,是该次寒潮天气的关键所在。另外,本地经验指标的应用,再次证明了局地经验指标的可行性。展开更多
文摘By using the routine weather data and the numerical value forecast products,applying the weather analysis and diagnostic analysis methods,the cold wave weather which happened in the south area of Dalian was analyzed on December 29-30,2009.The results showed that based on the temperature rise in prior period,the strong cold air accumulated in Mongolia and passed Ulan Bator,Erenhot to invade Dalian area.In the cold wave process,the circulation situations in the middle and high latitudes were the 'one ridge and one trough' pattern in Asia.The dynamic mechanisms were the rotary low-pressure trough in high altitude and the strong frontal zone,and the flow field which induced the cold wave to break out was the 'low trough rotation pattern'.After the cold air broke out,Dalian area was controlled by the strong cold advection.The cold high-pressure on the ground entered into the key zone and reached the intensity of cold wave.However,the circulation of cold wave occurrence was southerly,and the shifts of cold air and influence system were quicker.Therefore,the cold wave appeared in Dalian's south areas which included Lvshun,Dalian and Jinzhou.On this basis,the key point of cold wave weather forecast in Dalian area was summarized.
文摘针对2018年1月21—22日张家口出现的寒潮天气过程,详细分析了前期气候背景和天气演变过程中500 h Pa与850 h Pa形势变化,以及地面冷高压变化。结果表明:该次寒潮过程属于横槽转竖型;降温过程48 h的日平均气温降幅大于日最低气温的降幅,根本原因是降水造成下垫面相对湿度大以及夜间较多云量影响了辐射降温,从而减小了最低气温的降幅;700 h Pa垂直速度的大值下沉区加速了地面气温的急剧下降,是该次寒潮天气的关键所在。另外,本地经验指标的应用,再次证明了局地经验指标的可行性。
