夏季南海西部中尺度物理过程对营养盐和叶绿素a分布特征的影响

通过对2014年8月31日-9月26日国家自然科学基金委南海西部综合航次的调查结果分析,发现在中南半岛沿岸海域存在具有低温高盐的冷涡和位于其东南部海域具有高温低盐的暖涡。相对于暖涡和其他海域,冷涡水团含有更高的营养盐,并在50 m、75 m和100 m层增加明显,DIP分别高0.21 μmol/L、0.39 μmol/L和0.23 μmol/L,DIN分别高4.94 μmol/L、7.56 μmol/L和3.76 μmol/L,DSi分别高2.55 μmol/L、5.25 μmol/L和3.46 μmol/L,说明冷涡对提高初级生产力具有明显的营养优势条件和巨大潜力;叶绿素a最大值均出现在50 m层,其中以海南岛近岸海域最大,冷涡在25 m层提高初级生产力明显,主要是受营养盐影响显著;而在75 m、100 m层可能受到冷涡带来的低温环境而导致叶绿素a含量不高。     

春季浙江南部海区溶解氧、pH值和营养盐分布特征及相互关系研究

浙江南部近海位于暖温带海区,受长江、钱塘江径流为主的浙江沿岸流影响,并提供丰富的营养盐类.台湾暖流在不同时期的盛衰对该海区亦有较大影响.适宜的海区温度,丰富的营养盐类使浮游生物大量生长,因此是我国重要渔场之一.     

红海湾水域溶解氧、pH值、盐度和营养盐分布特征及相互关系研究

通过１９９８年６月对广东省红海湾海水养殖水域环境因子的调查,阐述了海水中溶解氧、盐度、ｐＨ值和营养盐的分布特征及其变化规律,并讨论了它们之间的相互关系,结果表明,溶解氧及海水ｐＨ值随温度由北（除１５￣１７号站）向南（除６号站）增高而增高。同时证实了光合作用是导致溶解氧含量和ｐＨ值增高的主要原因。而营养盐与盐度呈密度的负相关,浮游植物总量随营养盐由北向南降低而明显增高。     

渤海冬夏季营养盐和叶绿素a的分布特征

在2000年8月和2001年1月对渤海进行的两个航次的调查取样的基础上,分析渤海营养盐和叶绿素a的分布特征,各海区营养盐的结构以及营养盐和叶绿素a的关系。结果表明,冬季营养盐的浓度高于夏季,硅酸盐有明显的垂向结构,40多年来渤海中部硝酸盐呈现增加趋势;莱州湾浮游植物生长处于磷限制,其它海区处于氮限制;冬季叶绿素a的浓度也高于夏季,叶绿素a的季节差异可能与夏季浮游动物对浮游植物的大量摄食有关。     

南海北部夏季叶绿素a分布规律及影响因素

采用2002—2016年6—9月Aqua/MODIS叶绿素a产品分析珠江冲淡水在南海北部生态效应的季节及年际变化特征。6月来自陆源的营养物质在西南季风作用下向河口以东陆架区输运, 浮游植物增殖, 叶绿素a含量增大; 7月河口以东高浓度叶绿素a覆盖面积达到最大; 8月在减弱的珠江径流和环境风场共同影响下, 口门外海高浓度叶绿素a覆盖面积明显减小; 9月北部陆架区处于东北季风影响之下, 河口以西覆盖面积逐渐增大。通过线性回归分析可知, 珠江径流量是口门外海高浓度叶绿素a覆盖面积的主要影响因素, 且这种影响有一个月左右的滞后效应。显著大于(小于)多年平均的珠江径流量和环境风场等因素共同作用, 导致2008(2004)年表现为高浓度叶绿素a覆盖面积的极大值(极小值)年份。叶绿素a在南海北部陆架区的时空变化特征主要受冲淡水过程影响, 订正过的卫星叶绿素a产品可以用来讨论珠江冲淡水的季节及年际变化。     

南海北部海域叶绿素a浓度时空特征遥感分析

利用2007-2010年MODIS的L2级叶绿素a浓度产品作为数据基础, 对叶绿素a浓度年平均和月平均数据进行分级分区处理, 研究南海北部海域叶绿素a浓度时空分布特征及其与海洋环境因素的关系。初步研究结果表明:2007-2010年在南海北部海域叶绿素a浓度的高值区(>5.0 mg/m3)主要分布在广东省沿岸河流的入海口, 分布范围在夏季最大, 在春秋次之, 在冬季最小;叶绿素a浓度的次高值区(1.0～5.0 mg/m3)主要分布在海岸线到50 m等深线之间的海域, 分布范围夏冬较大, 能扩展到50 m等深线附近, 而春秋较小, 会退缩到50 m等深线以内;叶绿素a浓度的中值区(0.3～1.0 mg/m3)主要分布在50 m到100 m等深线之间的海域, 时空变化复杂;叶绿素a浓度的低值区(<0.3 mg/m3)主要分布在100 m等深线以外的海域, 其区域平均值夏季最低, 春秋次之, 冬季最高, 同时该区域叶绿素a浓度在春夏秋三季空间分布较均匀, 而冬季受季风和黑潮入侵影响空间分布较为复杂。南海北部海域海表叶绿素a浓度的时空变化特征与季风、沿岸河流、海流、海表温度等海洋环境因素的变化有关。     

大亚湾生态系秋季叶绿素a和营养盐分布的分区研究初探

根据１９９８年１０月和１１月大亚湾进行的海洋生物－化学要素的调查资料,分析了大亚湾秋季叶绿素ａ和营养盐的分布特征,讨论了影响大亚为季叶绿素ａ和营养盐分布的主要因素,初步得出了大亚秋季叶绿素ａ和营养盐分布有分区特征,将大亚湾划分为五个各具特点亚区的结论。     

小清河口的叶绿素a及理化环境因子的分布特征和统计分析

根据2002年6月对小清河口及毗邻海域进行的一次大面调查资料,对叶绿素a、营养盐、溶解氧、化学耗氧量等环境因子的空间分布特征进行了研究,分析了各环境参数之间的相关性。结果表明,研究区域没有明显的层化现象,各参数的垂直分布都比较均匀。各环境参数在河口内外的分布情况具有显著差异。河口内为高温、低盐、高营养盐、低溶解氧、高化...     

基于遥感数据对比南海和阿拉伯海夏季叶绿素a浓度

The South China Sea(SCS) and the Arabian Sea(AS) are both located roughly in the north tropical zone with a range of similar latitude(0°–24°N). Monsoon winds play similar roles in the upper oceanic circulations of the both seas. But the distinct patterns of chlorophyll a(Chl a) concentration are observed between the SCS and the AS.The Chl a concentration in the SCS is generally lower than that in the AS in summer(June–August); the summer Chl a concentration in the AS shows stronger interannual variation, compared with that in the SCS; Moderate resolution imaging spectroradiometer(MODIS)-derived data present higher atmospheric aerosol deposition and stronger wind speed in the AS. And it has also been found that good correlations exist between the index of the dust precipitation indicated by aerosol optical thickness(AOT) and the Chl a concentration, or between wind and Chl a concentration. These imply that the wind and the dust precipitation bring more nutrients into the AS from the sky, the sub-layer or coast regions, inducing higher Chl a concentration. The results indicate that the wind velocity and the dust precipitation can play important roles in the Chl a concentration for the AS and the SCS in summer. However aerosol impact is weak on the biological productivity in the west SCS and wind-induced upwelling is the main source.     

Laws of Chl. a maximum distribution and variation in the northern East China Sea

INTRODUCTIONTheChl.adistributionintheseawaterreflectstheabundanceanddistributionofphytoplankton,andthehighChl.aareasareusuallythedistributionareasofcentralfishingground.Intheearly1960s,Steelein1960andAndersonin1969concludedthatthereweresubsurfaceChl.amaximainthehomogeneouslystratifiedocean.Inthepast10a,ChinesescholarsmademanyinvestigationsonChl.aintheEastChinaSeacontinentalshelfareaanditsadjacentseaarealstudiedthegeneraldistributionofChl.aandtheformationmechanismofitsverticalmaxima,an…     

南海溶解氧垂直结构的季节变化分析

溶解氧在生物活动较小的情况下,与温盐相似,同样具有保守性。本文基于WOD05数据集中实际观测的溶解氧标准层资料,对南海溶解氧的垂直结构及其季节变化进行阐述,指出在浅水陆架区、中央海盆和吕宋岛以东深水区,溶解氧具有不同的垂向分布特点。重点分析了深水区的溶解氧垂向结构,发现其极大值存在季节性变化,量值在冬、春较大,夏、秋较小,出现的深度夏季最深,超过50 m,秋、冬较浅且现象不够明显;极小值基本不存在季节变化,出现的深度约860 m;对比温盐关系曲线,发现溶解氧极大值对应着南海次表层水团上界、衰减缓慢的稳定阶段对应次表层水团高盐核心水层、而极小值则对应中、深层水团的交界。     

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.     

Vertical Structure of Baroclinic Currents over Northern South China Sea Continental Slope

The 28.6 d time series of ADCP currents at 27 depth levels, (11,15,…,115m) which are obtained from a mooring station at the northern South China Sea continental slope, have been decomposed into barotropic and baroclinic components. The emphasis in this paper is on the analysis of the time series of baroclinic currents by means of several methods,such as the tidal harmonic analysis, the power spectra and the kinetic energy estimation.The major results are as follows: (1) In respect of the baroclinic currents, the values of several parameters first decrease and then increase with depth. These parameters include the temporal mean value of the cross-shelf component, the standard deviations, the amplitudes of K1 constituents, the mean eddy kinetic energy, as well as the significant peaks of the power spectra of the cross-shelf components. (2) The diurnal period of the baroclinic currents is dominant. The diumal tidal current rotates clockwise and the major axis of current ellipse is located along the directions of NW-SE. The vertical distribution of the phases of the diurnal constituent varies with the different water layers. Around the 67m depth level, the phase changes very much.At those layers far away from the 67m depth level, the vertical distribution of the phase is relatively stable, but with opposite phases in the upper and lower water layers. For the upper layers between the surface and 67m,the phases are around 300°; for the lower layers between 67m and 115m, the phases are around 120° .(3) The mean eddy kinetic energy of the baroclinic current is quite large, accounting for 41% of the mean kinetic energy of the measured currents. The cross-shelf component is larger than the along-shelf one. The two baroclinic current components correspond to the major and minor axes of the current ellipse of the diurnal constituent respectively. (4) The power spectra of the baroclinic currents show a singnificant period of about 24h, with 23.6h at both 19m and 99m and 24.4h at 55m. The vertical distributions of the significant spectra-peak values of the power spectra of both the crossshelf and along-shelf components of both the baroclinic currents are different. The former increases with depth, then decreases and finally increases again while the latter decreases with depth.     

黄海溶解氧垂直分布最大值的成因

本文对黄海溶解氧垂直分布中最大值的成因进行了探讨．认为：浮游植物春花期光合作用产生的大量氧，是溶解氧垂直分布最大值得以在春季（5月）形成的基础；而良好的温、密跃层的存在是氧最大值得以形成的必要条件，夏季叶绿素最大值层中较强的光合作用，是氧最大值在夏季得以维持甚至增强的主要原因．提出：黄海春、夏季溶解氧垂直分布中的最大值并非主要由冬季保持而来．     

南海北部表层沉积物中浮游有孔虫分布特征与环境意义

对南海北部12°以北海域表层沉积物中的浮游有孔虫丰度、属种数量与组合、碳酸盐含量以及硅质生物相对丰度等进行了分析和鉴定,结果表明:随水深的增加,浮游有孔虫的丰度降低、属种数量减少,碳酸盐含量降低,硅质生物相对丰度升高,浮游有孔虫优势种由易溶种转变为抗溶种。浮游有孔虫以及碳酸盐含量等的这些变化与深海碳酸盐的溶解作用密切相关,同时,浊流沉积作用和水团等环境因素也是影响浮游有孔虫丰度与组合以及碳酸盐含量变化的重要因子。     

南海表层水中的溶解态Cu,Pb, Zn,Cd

于1998年“南海海洋环境调查”外业工作期间在南海的各个站位,按照严格的防沾污措施采集了106个表层海水样品.采用溶剂萃取-石墨炉原子吸收法对样品中的痕量重金属Cu,Pb,Zn,Cd含量进行了分析测试.测得各重金属的平均值如下:Cu 0.100 μg/dm3,Pb 0.060μg/dm3,Zn 0.086 μg/dm3,Cd 0.007μg/dm3,接近世界大洋水的浓度水平.各重金属的空间分布呈现出海区周边含量高于中央,浓度有自近岸向远海逐渐减小的趋势.相关分析的结果表明各重金属夏季相关性优于冬季,Cu与Cd存在良好的正相关关系,并且首次在南海表层水发现Cu,Cd与营养盐的相关关系.将重金属浓度值作数理统计分析,得到它们在南海的基线值.     

南海中北部热带气旋强度突变的天气气候特征分析

本文对1960-2002年在南海中北部活动的热带气旋进行分析统计,发现有如下气候特征：南海中北部平均每年有6.7个热带气旋,有4.9个热带气旋强度发生突变,其中有3%的热带气旋只发生突然增强,72%的热带气旋只发生突然减弱,25%的热带气旋既发生突然增强又发生突然减弱过程.强度突然减弱发生在4-12月,主要集中在登陆和登陆后的陆地区域,分布较广;强度突然增强发生在4-11月,主要出现在珠江口以西至海南岛东部海面、东沙群岛和西沙群岛海面.     

Dissolved Cu, Pb, Zn and Cd in the South China Sea surface waters

The understanding of the distribution of trace heavy metals in the world ocean has greatlyimProved in the past decades. But most of the data are of vertical profiles of certain stations(Bruland, l980; Paul et al., l992; RObert et al., l990) and large--scale study of temporaland spatial variability of trace heaVy metals in the ocean is rather few. In fact, affected by ver-tical mixing by upwelling or convection, biogenic removal, atmospheric fallout and continentalinput frorn rivers, the dist…     

南海北部海域中东部陆架坡折带类型与迁移演化及成因

为了研究南海北部海域中、东部陆架坡折带在不同年代的迁移特征,分析了高精度单道地震剖面与地质浅钻等资料。在南海北部海域珠江口外区、东沙区和台湾浅滩区的陆架及陆坡带附近第四纪地层中,共识别出6个三级层序界面以及相应的沉积层序,同时识别了6个区域下切侵蚀面,并以此为依据认识了本区第四纪河道的演化特征,建立了层序地层格架。在此基础上,将该区第四纪陆架坡折带由西至东划分为建设型、侵蚀型和转换型三种类型,讨论了各段陆架坡折带的演化规律,提出构造地貌成因、水下河道发育与沉积物供给等作用均为控制陆架坡折带发育和迁移的主要因素。