Meiofauna hotspot in the Atacama Trench,eastern South Pacific Ocean

Meiofaunal assemblages were investigated (in terms of abundance, biomass, individual size and community structure) at bathyal and hadal depths (from 1050 to 7800 m) in the Atacama Trench in the upwelling sector of the eastern South Pacific Ocean, in relation to the distribution and availability of potential food sources (phytopigments, biochemical compounds and bacterial biomass) in this highly productive region. Meiofaunal density and biomass in the Atacama Trench were one to two orders of magnitude higher than values reported in other “oligotrophic” hadal systems. The Atacama Trench presented very high concentrations of nutritionally rich organic matter at 7800-m depth and displayed characteristics typical of eutrophic systems. Surprisingly, despite a decrease in chlorophyll-a and organic matter concentrations of about 50% from bathyal to hadal depths, meiofaunal abundance in hadal sediments was 10-fold higher than at bathyal depths. As indicated by the higher protein to carbohydrate ratio observed in trench sediments, the extraordinarily high meiofaunal density reported in the Atacama Trench was more dependent upon organic matter quality than on its quantity. The trophic richness of the system was reflected by a shift of the size structure of the benthic organisms. In contrast with typical trends of deep-sea systems, the ratio of bacterial to meiofaunal biomass decreased with increasing depth and, in the Atacama Trench, meiofaunal biomass largely dominated total benthic biomass. Nematodes at 7800-m depth accounted for more than 80% of total density and about 50% of total meiofaunal biomass. In hadal sediments a clear meiofaunal dwarfism was observed: the individual body size of nematodes and other taxa was reduced by 30–40% compared to individuals collected at bathyal depths. The peculiarity of this trophic-rich system allows rejection of previous hypotheses, which explained deep-sea dwarfism by the extremely oligotrophic conditions typical of deep-sea regions.     

Evidence for water exchange between the South China Sea and the Pacific Ocean through the Luzon Strait

An analysis of historical oxygen data provides evidence on the water exchange between theSouth China Sea (SCS) and the Pacific Ocean (PO). In the vicinity of the Luzon Strait (LS) , the dissolved oxygen concentration of sea water is found to be lower on the Pacific side than on the SCS side at depths between 700 and 1500 m (intermediate layer) , while the situation is reversed above 700 m (upper layer) and below 1 500 m (deep layer). The evidence suggests that water exits the SCS in the intermediate layer but enters it from the Pacific in both the upper and the deep layers, supporting the earlier speculation that the Luzon Strait transport has a sandwiched structure in the vertical. Within the SCS basin, the oxygen distribution indicates widespread vertical movement, including the upwelling in the intermediate layer and the downwelling in the deep layer.     

Helium and Oxygen isotopic evidence on exchange of waters between the western Pacific Ocean and the South China Sea

The composition and distribution of helium and oxygen isotopes in samples of seawater obtained at depths from surface to 300 m in the western Pacific(7°-26°N,122°-130°E) were discussed in detail.The results show that both δ¹⁸O and δ³He isoline extend eastward in the Pacific side of the Bashi Channel, which may suggest that the South China Sea water intrudes into the western Pacific by the Bashi Channel.     

南海北部潮汕坳陷海区海底地震仪调查实验

潮汕坳陷被认为是一个具有良好油气前景的中生代残留沉积坳陷,其中生代地层也被新近的钻井证实。为研究其盆地深部构造,“十五”863课题跨越该区进行了深地质调查。调查采用5台国产海底地震仪记录深部地震资料。处理结果显示本次调查清楚地记录到了来自地壳内部和Moho面的震相,这是国产海底地震仪在南海地区的首次成功实践。海底地震仪记录揭示沿测线的地壳在南海形成过程中减薄程度较低,中生代地层速度较高,代表致密的岩石,这些因素可能不利于油气的储集,需要在勘探中避开。     

南海-印度洋海域海洋安全灾害评估与风险区划

针对南海-印度洋海域丰富的海洋资源、重要的战略地位以及该海域的自然灾害风险和海盗活动、恐怖袭击与军事冲突等人为灾害风险,基于风险评估理论从孕灾环境敏感性、致灾因子危险性和承灾体脆弱性等方面选取评价指标并建立评估模型,利用地理信息系统(GIS)平台得到了该区域的自然灾害风险、人为灾害风险和综合风险区划。结果表明,冬季(1月),综合风险最高的区域为亚丁湾、孟加拉湾湾顶、马六甲海峡附近以及越南东南部近海,其次为南海东北部海域、南沙群岛西部海域、巽他海峡、望加锡海峡、科摩林角附近海域、霍尔木兹海峡及索马里近海;夏季(7月),综合风险最高的区域为亚丁湾、孟加拉湾湾顶及马六甲海峡附近,其次为索马里东北部海域、阿拉伯海中西部、斯里兰卡西南近海、吕宋岛西部近海以及巴士海峡附近。     

Comparisons of surface Chl a and primary productivity along three transects of the southern South China Sea,northern Java Sea and eastern Indian Ocean in April 2011

Results are presented about the changes in chlorophyll a density, carbon fixation and nutrient levels in the surface waters of three transects of the southern South China Sea (SCS), northern Java Sea (...     

2021年西北太平洋和南海台风活动概述

利用中央气象台台风实时业务资料、自动气象站观测资料以及卫星云图等对2021年西北太平洋及南海台风活动的主要特征和影响我国台风的路径、强度及风雨影响进行分析和回顾。结果表明：2021年西北太平洋及南海台风生成个数偏少,生成源地整体偏西;台风强度偏弱,但有多个台风出现了快速增强,其中台风“烟花”“灿都”的24 h强度增幅达40 m·s^-1,为近30 a少见;2021年先后有5个台风登陆我国,另有2个台风影响我国。在登陆台风中,4个登陆华南的台风强度均弱于历史平均值。所有登陆台风在登陆后的维持时间都明显高于历史均值,特别是台风“烟花”为历史上登陆华东后维持时间最长的台风,给我国带来了严重的灾害影响。     

2022年西北太平洋和南海台风活动概述

利用中国气象局热带气旋最佳路径等资料,对2022年西北太平洋及南海台风活动的主要特征和影响我国台风的路径、强度及风雨影响进行分析和回顾。结果表明：2022年西北太平洋及南海台风生成个数与常年持平,台风总体强度偏弱,生成源地显著偏北;登陆台风个数偏少,登陆强度偏弱;有3个台风集中在广东西部登陆,另外强台风“梅花”是1949年以来首个4次登陆不同省份的台风。全年多台风事件频发,共存的台风共计有11组,历史罕见。2022年台风灾害影响较轻,夏台风偏少,秋台风活跃。     

2020年西北太平洋和南海台风活动概述

利用中央气象台台风实时业务定位资料和地面气象观测资料对2020年西北太平洋和南海的台风活动主要特征以及主要影响我国的台风路径、强度及风雨情况进行了统计分析.2020年西北太平洋和南海共有23个台风生成,较多年平均值(27.0个)偏少4.0个;有5个台风登陆我国,较多年平均值(7.0个)偏少2.0个.2020年台风活动的...     

2019年西北太平洋和南海台风活动概述

应用中央气象台业务实时资料和中国气象局台风最佳路径资料对2019年发生在西北太平洋和南海的台风活动主要特征以及主要影响我国的台风路径、强度及风雨情况进行了统计分析和论述。2019年西北太平洋和南海共有29个台风生成,较多年平均值偏多2个;秋季台风异常活跃,生成数较常年明显偏多;台风整体强度偏弱,超强台风数与常年持平;有5个台风登陆我国,较多年平均值略偏少;登陆台风平均强度较多年平均值明显偏弱,但台风“利奇马”登陆强度强、风雨影响重。     

MODIS月平均海面温度在太平洋的检验与在南海的应用

使用由我国投放的位于太平洋海域的ARGO浮标表屡温度数据,对相应时相和海区的MODIS月平均海洋表面温度(SST)产品进行检验,验证结果表明,MODIS月平均SST产品的均方根误差为0.78℃,平均偏差为-0.37 ℃,二者的相关系数为0.994 5,因此,使用MODIS月平均SST数据对我国南海表层水温年变化规律进行...     

近45 年南海-北印度洋波浪能资源评估

利用 ERA-40海表10 m 风场驱动第三代海浪数值模式(WAVEWATCH-,Ⅲ简称 WW3),得到南海–北印度洋1957年9月~2002年8月的海浪资料,计算该海域的波浪能,分析波浪能流密度的四季分布特征、不同能级出现的频率及波浪能流密度的稳定性,为海浪发电、海水淡化等选址提供依据.研究发现,南海–北印度洋海域蕴藏着较为丰富的波浪能:(1)南海–北印度洋大部分海域的年平均波浪能流密度在2 kW/m 以上,大值区位于南海、孟加拉湾、索马里附近海域.(2)南海–北印度洋海域波浪能流密度大于2 kW/m 和大于4 kW/m 出现的频率都较高.(3)南海–北印度洋的波浪能流密度具有较好的稳定性,春季、秋季、冬季的稳定性好于夏季,南海的稳定性好于北印度洋     

太平洋-印度洋贯穿流南海分支在卡里马塔海峡的十年观测回顾

除印度尼西亚贯穿流之外,南海贯穿流也是太平洋向印度洋输送海水的重要分支。尽管基于数值模拟等方法的研究早已指出,南海分支在太平洋-印度洋洋际交换中有重要作用,但是直到2007年之前,南海分支在卡里马塔海峡处的观测几乎是空白。本文回顾了自2007年起,通过中印尼合作项目"南海-印度尼西亚海水交换及对鱼类季节性洄游的影响（SITE）"在卡里马塔海峡开展的近十年观测,以及在此基础上进一步开展的"印度尼西亚贯穿流海域水交换、内波和混合观测及其生态效应（TIMIT）"观测项目,并对SITE和TIMIT观测取得的成果进行了总结。     

Variability of sea surface temperature and warm pool area in the South China Sea and its relationship to the western Pacific warm pool

Sea surface temperature (SST) data derived from satellite and in situ measurements are used to study the thermal variability in the South China Sea (SCS). Time–frequency–energy distributions, periods of variability, and trends are computed by the Hilbert–Huang transform method. The SST trend from 1982 to 2005 is 0.276°C per decade in the SCS which is higher than 0.144°C per decade in the western Pacific warm pool (WPWP). The warm pool (SST ≥ 28°C) area in the SCS has increased by 0.20 × 10⁶ km² per decade. The SST and area of the warm pool in the SCS are strongly correlated, respectively, with the SST and area of the WPWP with a time lag of 1 month, suggestive of a strong connection between these two warm pools. Once the annual cycle is eliminated, decadal oscillations dominate the variability of SST and warm pool area in the SCS.     

用小波变换研究赤道西太平洋温度细结构

使用小波变换分析了赤道西太平洋暖池区的CTD资料的温度序列,表明垂向温度细结构具有自相似特征,有可能使用分数维模型来描述.计算了温度序列的奇异性指数及其概率分布,发现此分布具有近似普适的形式.非零概率的负指数意味着温度剖面可能存在奇异点.对经小波变换后的序列的周期性统计表明周期△和尺度α遵从幂律标度△～αβ,β≈1.这提示着细结构背后可能存在简单的二分串级机制.小波变换的振幅反映了温度脉动的强弱.据此可以确定脉动能量的垂向分布和能谱密度,和传统方法的比较表明小波能谱较为光滑,有利于精确测定谱斜率.     

The multifractal characters of temperature finestructures in the equatorial western Pacific Ocean

INTRODUCFIONTheknowledgeoffinestructureandmicrostructureplaysamajorroleintheresearchofoceanicdiapycnalmixing.Sofarastheliteratureisconcerned,finestructuresareroughlydefinedassmallstructuresdistributedonverticalscalesfromImto100m(Munk,1981),whereasmicrostructureshavesmallerscales.Forsimplicity,thesetwofeatureswillbecalledfinestructures ThestudywassupportedbytheNationalNaturalaudienceFoundationofChinaundercontractsNo.49376257,No.4950/6071andNo.49676275,andtheResearchFundfortutorialPngr…     

1957～2002年南海—北印度洋海浪场波候特征分析

利用ERA-40海表10 m风场驱动第三代海浪数值模式WAVEWATCH-Ⅲ,得到南海—北印度洋1957年9月至2002年8月的海浪场,并分析其波候(风候)特征.研究发现如下主要特征:(1)该海域的波高波向、风速风向受季风影响显著;(2)北印度洋大部分海域的海表风速呈显著性逐年线性递增趋势,大约0.01～0.02 m/(s·a),南海线性递增的区域则较少,有效波高呈显著性逐年线性递增的区域主要集中在低纬度中东印度洋(约0.003～0.006 m/a)、索马里附近海域(大约0.002～0.005 m/a)、南海大部分海域(约0.002～0.004 m/a),线性递减的区域主要集中在孟加拉湾海域(约-0.002 m/a);(3)Nino3指数与南海—北印度洋的海表风场、浪场存在密切的关系;(4)南海—北印度洋的海表风速与有效波高存在5.2a左右的共同周期,南海的海表风速、有效波高还存在2.0a左右的共同周期,北印度洋的海表风速、有效波高还存在26.0a的长周期震荡.     

南印度洋海浪场时空特征分析

根据 1950 —1995 年共 46 a 的南印度洋船舶气象报资料，按 5°×　5°网格统计的海浪要素进行分析研究。通过分析每月各要素的等值线分布图，得出南印度洋海浪场季节变化特点不如北半球各大洋显著，但仍有较明显的季节变化，只是季节性差异较小，冬季比夏季海浪强盛，相应的平均波高、大浪大涌频率也较大；盛行风浪传播方向、涌浪传播方向基本一致，10°S 以北为季风气候区，而其它海域则信风区常年盛行 SE 向浪，40°S 以南盛行偏 W 向浪。本文提供了南印度洋海域较为翔实的海浪场资料及变化规律。     

南海东部中尺度涡生成机制

利用高度计海面高度异常数据和非线性1½层约化重力模式研究了南海东部中尺度涡的生成机制。模式结果表明,南海内区风场是南海东部中尺度涡生成的主要驱动力,且南海内区高频风场能解释约54%的南海东部中尺度涡。从西太平洋传来的信号同样有十分重要的作用,由西太区域高频风场大致能解释南海东部40%的中尺度涡。风驱动的赤道附近的海面异常信号能经过锡布图通道和民都洛海峡传播到吕宋岛西海岸,其中有部分能量会以罗斯贝波的形式往西传播。这种信号在西传的过程中会发生不稳定,可能形成孤立的涡旋。     

Deep-Water Bottom Current Research in the Northern South China Sea

This article discusses an effective way to study deep-water current activity with the sedimentary features of seabed sediments. In the paper, we have processed a seismic survey line crossing the Northwest sub-basin of the South China Sea (SCS). In the seismic profile, we can clearly distinguish the contourite sediment waves and find the erosion scope formed by the deep-water bottom current. Combining the analytic result of piston cores sediments in the research area, we can conclude that the deep-water current is the contour current. It enters the SCS through the narrow Bashi Channel and then it flows to the southwest direction along the isobaths of Dongsha uplift and Southern uplift, but there isn't direct evidence to explain that bottom current flows to the direction of the deep-sea basin. The conclusion confirms former speculation about the passage of deep-water current and provides an important foundation to construct the whole structure of deep-water circulation for the SCS.