北部湾海雾气候特征及变化初步解释

利用广西北部湾典型地面气象观测站数据,全面分析广西北部湾地区轻雾、大雾的年际、年代际、逐月变化规律;并在此基础上利用气温和相对湿度多个气候因子分析北部湾海雾气候特征变化的可能原因。结果表明:广西北部湾地区多数站点轻雾发生频次呈增加趋势,其发生频次经过不同次数和幅度的波动。总体来说,多数站点轻雾20世纪70年代前为降低趋势,70年代后为增加趋势;各站点轻雾年代际变化规律波动较大。北部湾地区多数站点大雾发生频次呈减少趋势,较之于轻雾而言,其波动更频繁,周期更短。多数站点20世纪80年代前为增加趋势,80年代后为减少趋势;各站点大雾年代际变化规律波动也较大。各站点轻雾、大雾主要集中发生在每年在1~4月和12月,这5个月轻雾出现概率达53.9%~83.3%、大雾出现概率达80.1%~98.4%。北部湾地区温度的升高和大气湿度的降低是其轻雾日数增加和大雾日数减少的可能原因。

Climatic Characteristics of Beibuwan Sea Fog and a preliminaryexplanation for its change

In this paper, six typical ground meteorological observation stations" data of Guangxi Beibuwan zone are used to analyze sea fog"s inter-annual distinction, inter-decadal feature and monthly variation. Then, climate factors include temperature elements and relative humidity are utilized to explore the possible reasons for the change of sea fog. The results show that: The light fog occurrence frequency increases during the last 60 years for most sites with differentSfluctuationScycleSandSrange.n general, the light fog exhibits a reducing trend before the 1970 s then turns into a increasing trend. The heavy fog occurrence frequency decreases during the last 60 years for most sites with shorterSfluctuationScycleSand higherSrange compared to light fog. The heavy fog exhibits a increasing trend before the 1980 s then turns into a decreasing trend. The occurrence frequencies for both light and heavy fog are very high from January to April and December. SThe occurrence probability of light fog is 53.9 to 83.3% in these five months, meanwhile, for heavy fog, the probability is 80.1 to 98.4%. The rising temperature and reducing air humidity are the possible causes to explain the increasing trend of light fog and the decreasing trend of heavy fog.