1961—2010年平潭大雾的年际特征及雾季环流分析  

Interannaul variation of fog in Pintang island and the analysis of spring circulation in 1961—2010

作　　者：翁国玲[1,2] 黄志刚[3] 陈宏[2] 唐寒秋[2] 

机构地区：[1]南京大学大气科学系,江苏南京210032 [2]福建船政交通职业学院,福建福州350007 [3]福建省气象台,福建福州350001

出　　处：《海洋预报》2015年第1期79-86,共8页Marine Forecasts

基　　金：福建省教育厅A类课题(JA135755)

摘　　要：利用平潭气象站1961—2010年地面观测月报资料,使用小波分析雾日年际特征,结果表明:在1965—1975年和1985—1990年有准3年左右的显著周期,并通过显著性检验;同时经过九点平滑发现年雾日呈波动下降,趋势系数为-0.26天/年;2月为全年唯一雾日和持续时间双增加的月份,4、5月雾日减少明显但持续时间也显著上升。利用NCEP\NCAR资料进行平潭春季多雾年份和少雾年份合成分析,表明春季多雾年的特征为:台湾海峡海表温度偏低,为平流雾的生成提供冷水面,而赤道太平洋地区海温却是明显升高;500 h Pa副高偏强偏西,东亚大槽偏南,利于经向环流输送;沿(115°E,20°N)至(125°E,30°N)垂直流场剖面图表明平潭地区低空盛行下沉气流,利于层结稳定;同时水汽来源于南海和孟加拉湾且在850 h Pa表现最为明显。而春季少雾年的特征却刚好相反,台湾海峡海表温度偏高,赤道太平洋地区海温却是明显下降;500 h Pa副高偏弱偏南,不利于暖空气往北输送;沿(115°E,20°N)至(125°E,30°N)垂直流场剖面图表明平潭地区低空盛行上升气流,利于成云不利成雾;水汽输送仅来自孟加拉湾,低空850 h Pa水汽输送明显减少。With method of wavelet analysis, characteristics of fog-day change in Pingtan Island in the past 50 years has been studied according to the monthly data measured from 1961-2010. The results indicate that it is quasi-triennial period with 1961-1975 and 1985-1990 through significance test. The days of fog descend with undulation by nine-point moving average, and the rate of descend is-0.26 d/a. The fog-day and fog-duration only increase simultaneously in February, while fog-day decreases and fog-duration increases in April and May. Based on NCEP／NCAR reanalysis data, the variation characteristics of fog-day in spring is analyzed. The results shows that in spring with more fog, the sea surface temperature at the TAIWAN STRAIT is lower, while the temperature at the equatorial pacific is warmer obviously, and Western Pacific Subtropical High is enhanced and the East Asia trough moves more southerly, which benefits meridian circulation. Furthermore, the profiles of vertical circulation along 115° E, 20° N to 125° E, 30° N illustrate that there exists distinct sinking motion on the ground layer for more stratification stability during the spring of more fog. Finally, the vertically integrated moisture flux shows that water vapor comes from the South China Sea and the Bay of Bengal especially on the level of 850 h Pa during the spring of more fog. But the characters during the spring of less fog, such as sea surface temperature,the intensity and location of Western Pacific Subtropical High, vertical circulation, moisture flux, are opposite to during the spring of more fog.

关 键 词：平潭 平流雾 年际特征 气候条件 

分 类 号：P732[天文地球—海洋科学]