摘要
利用台湾海峡ASCAT海面风场数据和气象观测资料,通过EOF和统计方法综合分析台湾海峡海面风场2007-2017年10年的时空模态变化特征,使用Mann-Kendall法和滑动t-检验法对10年间海面风速进行突变检验,对台湾海峡海面风场季节变化时空特征进行分析研究。(1)"狭管效应"在台湾海峡海面风场上呈现明显的季节性特征,其中春季、秋季和冬季海面风场季节性特征显著,夏季表现不明显。受台湾岛地形和季风环流影响,台湾岛南北两端海面易出现风速增强的角流区,岛中央山脉背风区易出现低风速尾流区。(2)10年间台湾海峡海面月平均风场EOF空间模态受台湾岛地形影响显著,台湾海峡海域为异常值偏差中心,易发生风速突然增幅和风向改变。时间模态大体表现为季节性振荡型变化,振幅在10年中表现为不活跃,呈逐年递减趋势。(3)Mann-Kendall法和滑动t-检验法等方法的突变检验结果表明风速并未发生显著性突变,10年间台湾海峡海面风速特征表现为从正相位向负相位的改变,且随着趋势持续加大,将可能发生风速突变。
Using the empirical orthogonal function(EOF)and the statistical analysis method,the ASCAT satellite data and meteorological data were collected to explore the temporal mode characteristics and spatial modes of the sea wind field in the Taiwan Strait from 2007 to 2017.The Mann-Kendall method and the sliding t-test method were used to test the abrupt change of sea surface wind speed.Moreover,the change of seasonal variation of wind field and the possible mechanism in the Taiwan Strait were analyzed and discussed.The main conclusions were as followed.(1)There were"narrow valley effect"in the middle of the straits in spring,autumn and winter except for summer.Terrain had prominent effects on the formation of wind field features,which caused a"corner flow"on the north and south ends of the sea and"wake area"downstream of the central mountain of the island.(2)The EOF spatial pattern of the sea surface wind field in the Taiwan Strait was dominated by the north-south pattern and the center of the anomaly deviation of EOF lay in the narrow strait of sea field as it was affected by the island terrain,which often caused the wind speed to increase.The EOF time mode was the winter-summer monsoon oscillation type,which was affected by the island topography and monsoon.It was noteworthy that the amplitude was decreasing in the past 10 years.(3)Results of comprehensive analysis of Mann-Kendall method and sliding t-test method showed that the wind speed characteristics of the Taiwan Strait had no significant mutation from 2007 to2017,but changed from positive phase to negative phase.If the trend continued to increase,a sudden change in wind speed might occur as a result of the island terrain and monsoon circulation in the Taiwan Strait.
作者
潘卫华
林毅
PAN Wei-hua;LIN Yi(Fujian Meteorological Institute of Science,Fuzhou 350001,China;Fujian Meteorological Observatory,Fuzhou 350001,China)
出处
《热带气象学报》
CSCD
北大核心
2019年第3期296-303,共8页
Journal of Tropical Meteorology
基金
公益性行业(气象)科研专项(GYHY201406014)
福建省科技计划重点项目(2014Y0041)
福建省自然科学基金项目(2013J01152)
华东区域气象科技协同创新基金合作项目(QYHZ201811)共同资助
关键词
海面风场
ASCAT
时空特征
EOF
台湾海峡
sea wind field
ASCAT
spatial and temporal characteristics
empirical orthogonal function
Taiwan strait
作者简介
通讯作者:潘卫华,男,江西省人,高级工程师,主要从事卫星遥感气象应用研究。E-mail:panwh@tom.com.
