【摘要】 给出了1991年以来甘肃省夏季降水的实况和预测评估,对甘肃省夏季降水的影响因子作了多方面的分析和思考,指出对甘肃省汛期预测影响较大的因子是北半球极涡活动、太平洋海温、西太平洋副热带高压、夏季登陆的热带风暴数、越赤道气流与季风、夏季东亚地区阻塞高压等;西太平洋副热带高压的影响,最重要的是其阶段性的综合演变特征;夏季高原高度场持续偏高的态势已经削弱了它的信号作用;太阳活动对甘肃省夏季旱涝的影响比较复杂,不能一概而论。更多还原

【Abstract】 After giving observational precipitation and forecasting evaluation in summer over Gansu province since 1991, the influencing factors on precipitation in summer were analyzed generally. Results show that the main influencing factors on summer precipitation are Northern Hemisphere polar vortex activity, sea surface temperature of Pacific Ocean, subtropical high over western Pacific Ocean, disembarking tropical storm number, the air current through equator and monsoon, blocking high in eastern Asia in summer. The stage developing characteristic is significant about influencing of subtropical high over western Pacific Ocean, and continue higher situation of the height field in summer has weakened its signal effect. The influence of the sun activity is more complicated.更多还原