嘉兴地区大风气候特征分析

Analysis on Climatic Characteristics of Gale in Jiaxing Region

利用1981—2013年嘉兴地区6个地面观测站大风资料,分析嘉兴地区8级以上大风的分布规律。结果表明,嘉兴地区冬夏季风交替显著,大风的季风特征明显,冬半年大风多为冷空气大风,春季及初夏的大风多为低压、倒槽引起。夏季的大风主要是受热带气旋及副高边沿影响产生的。受地理位置影响,平湖的大风日数远远多于其他几个县。嘉兴地区平均大风日数总体呈线性递减趋势,平湖市的递减趋势尤为显著。运用Morlet小波分析方法分析嘉兴地区大风日数的年际变化,结果表明大风日数具有明显的周期变化规律特征,存在12年的短周期和32年的长周期,目前处于大风日数偏少期。

According to wind data of six meteorological stations in Jiaxing area from 1981 to 2013 ,the distribution of over 8-level wind in Jiaxing area was analyzed.The results showed that the alternation of winter and summer winds was significant in Jiaxing area with obvious monsoon features.The wind in the winter half year was mainly cold winds ,and wind in spring and early summer was mainly caused by depression and inverted trough. The wind in summer was mainly affected by tropical cyclones and subtropical high edge. Influenced by location ,the windy days in Pinghu was much more than other counties. The average windy days in Jiaxing area was linear decreasing trend with significant decreasing trend in Pinghu City. Using Morlet wavelet analysis method ,the annual variation of windy days in Jiaxing area was analyzed ,resulting that windy days has obvious characteristics of periodic variation ,existing 12-year short cycle and 32-year long cycle. At present ,it is in the period of short windy days.