基于1979—2019年欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)ERA5逐月平均风速、有效波高,分析了风速和有效波高的时空变化特征。利用Mann-Kendall检验法分析其年际变化和经验正交函数分析方法(E...基于1979—2019年欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)ERA5逐月平均风速、有效波高,分析了风速和有效波高的时空变化特征。利用Mann-Kendall检验法分析其年际变化和经验正交函数分析方法(Empirical Orthogonal Function,EOF)研究空间分布特征。结果表明:(1)南大西洋风向以30°S,10°W为中心逆时针旋转,风速大值区以东南信风带和西风带控制区为主,低值区以副高和低压带控制区为主。冬季风速高于其他季节,且全年风速和风向分布天气系统的季节变化有关。(2)有效波高与风速之间有很强的相关性,且二者都呈纬向环状型空间分布特征。冬季有效波高整体最大,夏季整体偏小。(3)Mann-Kendall检验结果显示风速和有效波高年际变化均呈上升趋势,风速在2006和2009年附近出现突变,有效波高于1994年前后出现突变。(4)风速EOF第一模态显示,信风带-西风带与副高带-低压带反向型分布,前者风速呈显著上升趋势,后者呈下降趋势。有效波高EOF第一模态显示:60°S以北海域有效波高变率为正位相,以南为负位相,正位相区域有效波高增大趋势显著,负位相区域有效波高减小趋势显著。展开更多
利用欧洲中尺度天气预报中心(ECMWF——European Centre for Medium-Range Weather Forecasts)的1979年1月2014年12月逐6 h的ERA-Interim有效波高和10 m风场资料,分析了近36年期间北太平洋海域海浪场和风场的变化特征。结果表明:1)中低...利用欧洲中尺度天气预报中心(ECMWF——European Centre for Medium-Range Weather Forecasts)的1979年1月2014年12月逐6 h的ERA-Interim有效波高和10 m风场资料,分析了近36年期间北太平洋海域海浪场和风场的变化特征。结果表明:1)中低纬度的西北太平洋波高有逐年线性递增趋势,大约在0.2~0.6 cm/a,而低纬度的太平洋东北部海域则以-0.4^-0.2 cm/a的趋势减小。2)风速线性变化趋势显著的区域主要集中在太平洋东北部低纬度海域,约以1.0~2.0 cm/(s·a)的速度在增加。而日本岛四周、菲律宾半岛以南等海域大都以-1.0^-0.5 cm/(s·a)的速度减小。3)北太平洋海域波高和风速都具有明显的季节变化特征,两者具有很强的相关性。西风带内有一个个波高超过10 m的风暴圈,其波高受风浪和涌浪的双重作用。这可为航海、海洋工程设计、军事及海洋能开发与利用等方面提供科学依据。展开更多
By taking into consideration the effects of ocean surface wave-induced Stokes drift velocity Un, and current velocity Uc on the drag coefficient, the spatial distributions of drag coefficient and wind stress in 2004 a...By taking into consideration the effects of ocean surface wave-induced Stokes drift velocity Un, and current velocity Uc on the drag coefficient, the spatial distributions of drag coefficient and wind stress in 2004 are computed over the tropical and northern Pacific using an empirical drag coefficient parameterization formula based on wave steepness and wind speed. The global ocean current field is generated from the Hybrid Coordinate Ocean Model （HYCOM） and the wave data are generated from Wavewatch Ill （WW3）. The spatial variability of the drag coefficient and wind stress is analyzed. Preliminary results indicate that the ocean surface Stokes drift velocity and current velocity exert an important influence on the wind stress. The results also show that consideration of the effects of the ocean surface Stokes drift velocity and current velocity on the wind stress can significantly improve the modeling of ocean circulation and air-sea interaction processes.展开更多
The mass stream function of zonal mean meridional circulation is calculated in terms of NCEP/NCAR monthly meridional wind speed and vertical velocity, and the climatic and anomalous features of zonal mean SST and meri...The mass stream function of zonal mean meridional circulation is calculated in terms of NCEP/NCAR monthly meridional wind speed and vertical velocity, and the climatic and anomalous features of zonal mean SST and meridional circulation are investigated. Results show that (1) a joint ascending branch of Northern and Southern Hadley circulation is on the side of the summer hemisphere near the equator ,being well consistent with the extremum of[]SST,and a strong descending by the winter-hemispheric side.(2)El Ni駉-related][SSTin low latitudes is an important outer-forcing source for anomaly meridional circulation, which is affected by seasonal variation of basic airflow and[]SST, and interannual and interdecadal changes of []SST.展开更多
The action of wind on the sea surface plays an important role in the noise generation mechanism.Sea surface wind speed can be estimated accurately provided there is an accurate understanding of the relationship betwee...The action of wind on the sea surface plays an important role in the noise generation mechanism.Sea surface wind speed can be estimated accurately provided there is an accurate understanding of the relationship between the ocean ambient noise and wind speed.Many measurements and analyses of the wind dependence of ambient noise have been conducted.The approximate empirical rule given by Wenz[1]states that in the frequency band between 0.5and 5 kHz,the ambient sea-noise spectrum levels decrease展开更多
文摘基于1979—2019年欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)ERA5逐月平均风速、有效波高,分析了风速和有效波高的时空变化特征。利用Mann-Kendall检验法分析其年际变化和经验正交函数分析方法(Empirical Orthogonal Function,EOF)研究空间分布特征。结果表明:(1)南大西洋风向以30°S,10°W为中心逆时针旋转,风速大值区以东南信风带和西风带控制区为主,低值区以副高和低压带控制区为主。冬季风速高于其他季节,且全年风速和风向分布天气系统的季节变化有关。(2)有效波高与风速之间有很强的相关性,且二者都呈纬向环状型空间分布特征。冬季有效波高整体最大,夏季整体偏小。(3)Mann-Kendall检验结果显示风速和有效波高年际变化均呈上升趋势,风速在2006和2009年附近出现突变,有效波高于1994年前后出现突变。(4)风速EOF第一模态显示,信风带-西风带与副高带-低压带反向型分布,前者风速呈显著上升趋势,后者呈下降趋势。有效波高EOF第一模态显示:60°S以北海域有效波高变率为正位相,以南为负位相,正位相区域有效波高增大趋势显著,负位相区域有效波高减小趋势显著。
基金the National Basic Research Program of China (grant Nos2005CB422302, 2005CB422307 and 2007CB411806)Great Project of National Natural Science Foundation of China (No 40490263)the NOAA/NECP data server are appreciated
文摘By taking into consideration the effects of ocean surface wave-induced Stokes drift velocity Un, and current velocity Uc on the drag coefficient, the spatial distributions of drag coefficient and wind stress in 2004 are computed over the tropical and northern Pacific using an empirical drag coefficient parameterization formula based on wave steepness and wind speed. The global ocean current field is generated from the Hybrid Coordinate Ocean Model （HYCOM） and the wave data are generated from Wavewatch Ill （WW3）. The spatial variability of the drag coefficient and wind stress is analyzed. Preliminary results indicate that the ocean surface Stokes drift velocity and current velocity exert an important influence on the wind stress. The results also show that consideration of the effects of the ocean surface Stokes drift velocity and current velocity on the wind stress can significantly improve the modeling of ocean circulation and air-sea interaction processes.
文摘The mass stream function of zonal mean meridional circulation is calculated in terms of NCEP/NCAR monthly meridional wind speed and vertical velocity, and the climatic and anomalous features of zonal mean SST and meridional circulation are investigated. Results show that (1) a joint ascending branch of Northern and Southern Hadley circulation is on the side of the summer hemisphere near the equator ,being well consistent with the extremum of[]SST,and a strong descending by the winter-hemispheric side.(2)El Ni駉-related][SSTin low latitudes is an important outer-forcing source for anomaly meridional circulation, which is affected by seasonal variation of basic airflow and[]SST, and interannual and interdecadal changes of []SST.
基金supported by the National Natural Science Foundation of China(Grant Nos.11434012,41561144006,and 11404366)
文摘The action of wind on the sea surface plays an important role in the noise generation mechanism.Sea surface wind speed can be estimated accurately provided there is an accurate understanding of the relationship between the ocean ambient noise and wind speed.Many measurements and analyses of the wind dependence of ambient noise have been conducted.The approximate empirical rule given by Wenz[1]states that in the frequency band between 0.5and 5 kHz,the ambient sea-noise spectrum levels decrease
