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1.
位于台湾岛东北部的龟山岛热液区属浅水型海底热液活动区,已探明有超过30处的热液喷口分布在约1030m的水深范围内。通过机械封装、硬件电路以及配套软件的设计和加工,自制了散射光式水下浊度仪;2011年5月2530日,使用该浊度仪,对龟山岛附近海域进行了拖航作业,在此次作业的东北方向发现一处新的热液喷口(24°50′09″N、121°58′08″E);海试结果表明,该水下浊度仪对于浊度较大海域有探测能力,对浊度较小海域的探测精度不高,还有待进一步改进。 相似文献
2.
以多形拟绿球藻(Pseudochlorococcum polymorphum UTEX 1791)和模式拟绿球藻(Pseudochlorococcum typicum UTEX 1792)为材料,采用BG-11培养基,研究其在0.3、0.5、1.0和1.5g·L-1等4个硝酸钠浓度条件下的生长和总脂含量。结果表明：适宜多形拟绿球藻生长的硝酸钠浓度范围为0.31.0g·L-1,其最终生物质干重在3.7g·L-1左右;模式拟绿球藻在1.0g·L-1的硝酸钠浓度条件下生长最好,可获得4.35g·L-1的生物质干重。在培养过程中两株绿藻的叶绿素a含量与总脂的含量关系密切,在培养初期各实验组叶绿素a含量增加,藻体的总脂含量增长不明显,而在培养中期藻细胞叶绿素a的含量增长平缓,总脂含量增长较明显,其中在0.3g·L-1的硝酸钠浓度实验组总脂增长最为显著,多形拟绿球藻增长了11.65%,模式拟绿球藻增长了24.99%。两株绿藻在0.3g·L-1的低氮实验组总脂含量最高,多形拟绿球藻和模式拟绿球藻总脂分别为细胞干重的44.35%和26.28%,在此条件下两株藻的最大总脂收获量分别为0.98g·L-1和1.61g·L-1。 相似文献
3.
海水温度是控制珊瑚生长的关键环境因素之一, 随着全球气候变暖, 海温持续升高已成为珊瑚生长面临的全球性威胁。文章对采自中沙环礁中北暗沙水深约16m的澄黄滨珊瑚岩心样品开展了生长率分析, 揭示出中沙环礁滨珊瑚近165年来的生长历史及变化规律; 并通过与西沙群岛永兴岛滨珊瑚生长率的对比, 探讨了南海中部滨珊瑚生长的区域差异及其对海温升高的响应关系。过去100多年来中北暗沙和永兴岛海区的平均海温分别为(27.4±0.37)℃和(27.09±0.36)℃, 两个海区的海温均呈线性升高趋势, 升温速率一致, 约为0.43℃·ha-1。过去100多年间中北暗沙和永兴岛滨珊瑚的平均生长率分别为(0.70±0.16)cm·a-1和(1.19±0.16)cm·a-1, 但中北暗沙滨珊瑚生长率呈线性下降趋势, 下降速率约为9.4%·ha-1; 而永兴岛滨珊瑚生长率呈线性上升趋势, 增长速率约为10.9%·ha-1。过去100多年间两个礁区的滨珊瑚生长率均存在年代际波动, 大致与海温的年代际波动对应。两个礁区滨珊瑚生长率与海温在趋势上呈现非线性响应关系, 存在滨珊瑚生长的最适宜温度约为27.25℃, 过去100多年来中北暗沙海域海温的增温趋势已经超出了滨珊瑚生长的适宜海温范围, 限制了滨珊瑚的生长趋势, 而永兴岛海域海温仍适宜滨珊瑚的生长。在年代际波动上两个礁区滨珊瑚生长率与海温存在线性正相关关系, 海温的年代际增温有利于滨珊瑚生长。在南海未来持续海水升温的情况下, 中北暗沙珊瑚生长的下降趋势将会进一步加剧, 并将严重威胁中沙珊瑚礁生态系统的维持和发展。 相似文献
4.
比较了准全球涡分辨率海洋模式（简记为LICOMH）及其海气耦合模式（简记为LICOMHC）中的黑潮入侵南海与观测中黑潮入侵的差异。我们发现在单独海洋模式中黑潮入侵与观测相比过强，而在其海气耦合模式中这一差异得到了改善。冬季的吕宋海峡输送（LST）在LICOMH中为-8.8×106 m3s-1，而在LICOMHC中则下降到-6.0×106 m3s-1 。进一步的研究表明是大尺度风场，局地风应力和吕宋海峡以东中尺度涡旋的共同作用导致了黑潮入侵在两个模式中的不同。LICOMH中吕宋岛东北部相对较强的气旋导致了较弱的黑潮输送及吕宋海峡处较强的黑潮入侵。以上三者共同作用造成的LST差异大约是2.0×106 m3s-1，与两个模式间的LST差异大小基本相当。进一步对LICOMH与LICOMHC中的EKE收支进行分析表明，LICOMH中更强的EKE输送及斜压转换项导致了黑潮以东存在更强的气旋，而海表风场对两个模式中的涡旋差异贡献极小。 相似文献
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南海因受到高纬度气候、低纬度大洋以及东亚季风等多种因素的影响而成为研究古温度和季风变化的理想区域。本文通过研究QH-CL11柱状沉积物的GDGTs组成、含量变化特征及其延伸的86个碳原子的四醚指标(TEX_(86)~H),分析南海北部GDGTs来源,并定量计算QH-CL11柱状沉积物记录的海洋表面温度(SST),从而探讨31 ka以来南海北部古温度变化的驱动机制。通过甲烷指数和支链/异戊二烯类指标等,确定isoGDGTs主要来自于奇古菌,适用于古温度重建。TEX_(86)~H温度显示出明显的冰期一间冰期旋回,与南海北部有孔虫和UK'_(37) SSTs具有很好的相似性。出现在TEX_(86)~H SST中的海因里希冷事件(H1-3)和Bφlling-Allerod暖期之前的温度大幅度上升事件(14.6 ka)反映了高纬度气候对南海的影响。南海SSTs和北太平洋MD01-2421 U~K'_(37)SST的差异(△SST5)可以用来反映东亚冬季风强度的变化。△SSTs显示东亚冬季风强度在Bφlling-Allerφd暖期前增加,在新仙女木时期达到最大值,在全新世早期再次下降,然后在全新世中晚期缓慢增加,这与前人对东亚冬季风强度的认识具有很好的一致性。该方法对重建长周期东亚冬季风强度具有重要的指导意义。 相似文献
6.
利用1958—2019年的观测和再分析数据集，对冷、暖两类厄尔尼诺-南方涛动（El Niño-Southern Oscillation，ENSO）事件与后期华东地区春季降水之间的关系进行了分析。结果表明：（1）在暖ENSO事件中，华东春季降水量与前冬季ENSO海面温度异常存在较强的正相关关系。在冷ENSO事件中，这种强正相关向内陆地区西移，主要集中在江西和湖南。（2）暖ENSO事件通常会导致浙江、江苏和福建等沿海省份春季降水量过剩，而冷ENSO事件往往导致江西和湖南降水偏少。这归因于ENSO对大气环流的非线性影响。（3）与暖ENSO事件相比，冷ENSO事件引起的海面温度异常中心明显西移，造成异常低层大气环流的西移，最终导致华东降水的西移效应。（4）通过分析和发现，强调了华东春季降水对ENSO的非线性响应，这对华东地区的季节性气候预测具有重要意义。 相似文献
7.
《热带海洋学报》2016,(1)
采用国际海—气综合数据集(The International Comprehensive Ocean-Atmosphere Data Set,ICOADS)船舶观测资料及简单海洋同化分析数据(Simple Ocean Data Assimilation,SODA),研究了厄尔尼诺(El Ni?o-Southern Oscillation,ENSO)和印度洋海盆模态(Indian Ocean Basin,IOB)对南海海表温度(sea surface temperature,SST)影响的年代际变化,并着重讨论了不同时期海洋平流输送对SST异常的影响。结果表明,ENSO事件对南海SST的影响呈现显著的年代际变化特征;在1870~2007年期间,扣除资料较少的时期,有4个显著不同的时段,分别是1892~1915年、1930~1940年、1960~1983年、1984~2007年。在1950年之前的两个时段,南海在ENSO期间出现一次显著的增暖,而在1950年之后的两个时段中,南海出现了两次显著的增暖。除第一个时段外,其余三个时段ENSO发展期冬季大气潜热及短波辐射异常是导致南海增暖的主要原因,海洋平流作用较弱;而在最近的两个时段中,海洋平流对ENSO消亡年夏季南海增暖有重要影响。不同时段海洋平流对南海增暖贡献的差异说明ENSO及IOB对南海区域气候的影响具有明显的年代际变化特征。 相似文献
8.
最小含氧带(Oxygen Minimum Zone, OMZ)是指海洋中层水体处存在的稳定的溶解氧(Dissolved Oxygen, DO)极小值层, OMZ的分布与变化对南海生态系统和生地化循环具有重要意义。本文利用2019年7—9月“海翼”号水下滑翔机(Sea-wing Glider)在南海北部陆坡区的组网观测数据, 对南海北部陆坡区OMZ的空间分布特征进行了分析。结果显示, 在垂向上, 研究区域内DO极小值层出现在深度约700~900m处, 其浓度约为80~100μmol·L-1, 且700~900m深度范围内DO浓度变化不大, 形成了厚度约为200m的OMZ。在水平方向上, OMZ自陆坡西南部起向东北方向延伸, 厚度由西南至东北逐渐变薄, 整体呈楔形分布, 并在靠近吕宋海峡处逐渐消失。此外, 本研究还选取了两台水下滑翔机7—8月连续两周内的观测数据, 经计算显示, OMZ区域内的DO浓度在跨陆坡方向上的平均变化速率为0.023μmol·L-1·d-1(增加), 在沿陆坡方向上为-0.034μmol·L-1·d-1(减少)。沿吕宋海峡入侵南海的高氧水能够解释OMZ东北部DO浓度局部升高的现象, OMZ的分布特征和形成原因与海水的平流运动、水团分布和水体层化等物理过程, 以及生物呼吸、有机物分解和还原性物质的氧化等多种影响因素有关。 相似文献
9.
利用中国地壳运动监测网络1999年—2015年GPS观测数据, 基于块体模型与弹性半空间下的螺旋位错模型, 反演红河断裂带不同区段的滑动速率与闭锁深度, 利用插值均匀网格法计算红河断裂带不同区段及周边地区应变积累状况。结果表明: 红河断裂带北段右旋走滑速率为4.76±0.78mm•a-1, 闭锁深度约为10.9km; 中段右旋走滑速率为3.24±0.56mm•a-1, 闭锁深度约为11.5km; 南段右旋走滑速率为2.83±0.34mm•a-1, 闭锁深度约为12.6km。红河断裂带北段与中段拉张应变特征明显, 南段挤压应变特征明显, 北段拉张应变值为(20~40)×10-9•a-1, 南段挤压应变值为(30~50)×10-9•a-1, 中段最大剪应变积累较弱, 量值为(0~30)×10-9•a-1, 北段、南段最大剪应变积累较强, 量值为(40~80)×10-9•a-1。北段和南段元阳地区出现最大剪应变高值区, 地震危险性较大。 相似文献
10.
2012年南海西北陆架冬季水文特征的观测分析 总被引：1，自引：0，他引：1
本文基于2012年12月南海西北部陆架海区的温盐和流速实测资料，分析了粤西和琼东陆架海区冬季三维温、盐结构和流场特征，给出沿陆架和跨陆架方向的水体和热盐通量。结果表明：（1）在50m以浅，粤西和琼东海区温度均由近岸向外海递增，深层则相反；冬季近岸海区混合层较深，外海密度跃层位于60—120m深度且层结较强，浮力频率大于10–2/s；（2）海流大致沿等深线向西南流动，30m以深流速大小在0.03—0.40m/s之间，且随着深度增加而略有减小；琼东海区100m等深线附近在60m以浅水层观测到水体辐聚并有明显温度锋面存在；（3）沿陆架方向的水体和热盐输送均大于跨陆架方向，其中粤西单位面积沿/跨陆架水体通量平均值为0.13×10–6/0.03×10–6Sv/m2，低于琼东海区的0.91×10–6/0.56×10–6Sv/m2。 相似文献
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12.
南海冬季海浪的时空变率特征 总被引：4，自引：1，他引：3
The spatial and temporal variation characteristics of the waves in the South China Sea(SCS) in the boreal winter during the period of 1979/1980–2011/2012 have been investigated based on the European Centre for Medium-range Weather Forecasts interim(ERA-Interim) reanalysis dataset. The results show that the leading mode of significant wave height anomalies(SWHA) in the SCS exhibits significant interannual variation and a decadal shift around the mid-1990 s, and features a basin-wide pattern in the entire SCS with a center located in the west of the Luzon Strait. The decadal change from a weak regime to a strong regime is mainly associated with the enhancement of winter monsoon modulated by the Pacific decadal oscillation(PDO). The interannual variation of the SWHA has a significant negative correlation with the El Ni?o Southern Oscillation(ENSO) in the same season and the preceding autumn. For a better understanding of the physical mechanism between the SCS ocean waves and ENSO, further investigation is made by analyzing atmospheric circulation. The impact of the ENSO on the SWHA over the SCS is bridged by the East Asian winter monsoon and Pacific-East Asian teleconnection in the lower troposphere. During the El Ni?o(La Ni?a), the anomalous Philippine Sea anticyclone(cyclone) dominates over the Western North Pacific, helps to weaken(enhance) East Asian winter monsoon and then emerges the negative(positive) SWHA in the SCS. 相似文献
13.
北黄海冷水团温度年际变化研究 总被引：6，自引：2，他引：4
本文基于1976—2006年国家标准断面(大连—成山头)调查资料,结合ECMWF气温、风速以及辐射等再分析资料,研究了北黄海冷水团的低温中心以及北部锋面的年际变化规律,并对其与气候年际变化信号的关系做了相关性分析以及EOF分析,研究了影响北黄海冷水团的诸多因素。研究结果表明,北黄海冷水团及其北部锋面强度存在明显的年际变化特征,北黄海冷水团中心最低温度具有升温趋势,北部锋面强度具有减弱趋势。分析发现,前冬海温,当地气温,经向风场以及辐射通量都对来年北黄海冷水团的强度存在影响,东亚冬季风的年际变异是影响北黄海冷水团温度年际变化的主要机制,El Nio、La Nia事件成熟期滞后于北黄海冷水团最低温度的相对低值、高值出现,ENSO通过与东亚冬季风的相互作用与北黄海冷水团相联系。 相似文献
14.
冬季婆罗洲岛西北沿岸上升流的时空特征及机理研究 总被引：1，自引：0，他引：1
Winter coastal upwelling off northwest Borneo in the South China Sea(SCS) is investigated by using satellite data, climatological temperature and salinity fields and reanalysis data. The upwelling forms in December, matures in January, starts to decay in February and almost disappears in March. Both Ekman transport induced by the alongshore winter monsoon and Ekman pumping due to orographic wind stress curl are favorable for the upwelling. Transport estimates demonstrate that the month-to-month variability of Ekman transport and Ekman pumping are both consistent with that of winter coastal upwelling, but Ekman transport is two times larger than Ekman pumping in January and February. Under the influence of El Ni?o-Southern Oscillation(ENSO), the upwelling shows remarkable interannual variability: during winter of El Ni?o(La Ni?a) years, an anticyclonic(a cyclonic) wind anomaly is established in the SCS, which behaves a northeasterly(southwesterly) anomaly and a positive(negative) wind stress curl anomaly off the northwest Borneo coast, enhancing(reducing) the upwelling and causing anomalous surface cooling(warming) and higher(lower) chlorophyll concentration. The sea surface temperature anomaly(SSTA) associated with ENSO off the northwest Borneo coast has an opposite phase to that off southeast Vietnam, resulting in a SSTA seesaw pattern in the southern SCS in winter. 相似文献
15.
Variations of monsoon wind field in the sea area along the southeastern coast of China during the ENSO events and its influence on the sea level and sea surface temperature (SST) are explored mainly on the basis of the data of monthly mean wind at 850 hPa and five coastal stations during 1973-1987. The results from the analyses of the data and theoretical estimation show that the southwest wind anomalies appeared in the study area during the events, and northeast wind anomalies occurred in general before the events. With the coastline of the area being parallel basically to the direction of the wind, an Ekman transport will result in an accumulation of the water near the coast or a departure of the water from the coast. As a result , the sea level and SST there will be affected markedly. During the events, southwest wind will intensify in the summer, and northeast wind will weaken in the winter. Their total effect is that a large negative anomaly of the sea level and SST will occur. The estimations indi 相似文献
16.
Akira Masuda Tadao Kusaba Kenji Marubayashi Michiyoshi Ishibashi 《Journal of Oceanography》1999,55(2):289-305
The variability of the sea surface wind and wind waves in the coastal area of the Eastern Tsushima Strait was investigated
based on the hourly data from 1990 to 1997 obtained at a station 2 km off Tsuyazaki, Fukuoka. The annual mean wind speed was
4.84 m s−1, with strong northwesterly monsoon in winter and weak southwesterly wind in summer. Significant wave heights and wave periods
showed similar sinusoidal seasonal cycles around their annual means of 0.608 m and 4.77 s, respectively. The seasonal variability
relative to the annual mean is maximum for wave heights, medium for wind speeds, and minimum for wave periods. Significant
wave heights off Tsuyazaki turned out to be bounded by a criterion, which is proportional to the square of the significant
wave period corresponding to a constant steepness, irrespective of the season or the wind speed. For terms shorter than a
month, the significant wave height and the wave period were found to have the same spectral form as the inshore wind velocity:
white for frequencies less than 0.2 day−1 and proportional to the frequency to the −5/3 power for higher frequencies, where the latter corresponds to the inertial
subrange of turbulence. The spectral levels of wave heights and wave periods in that inertial range were also correlated with those of the inshore wind velocity, though the scatter was large.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
尝试恢复了中全新世东亚冬季风表现出的太阳活动以及ENSO周期变化。通过对东海内陆架泥质沉积区EC2005孔进行粒度分析以及AMS碳-14测年,对高分辨率敏感粒度资料揭示的中全新世近700a(距今5.2~5.9ka)东亚冬季风记录与GRIP冰心氧同位素记录的气候变化进行了对比,良好的对应关系说明,东亚冬季风变化与格陵兰冰心揭示的古气候变化有某种内在联系,期间东亚冬季风的增强得到了良好的区域性响应,同时又具有全球性背景。中全新世东亚冬季风具有明显的周期变化,主要表现为62,11a的太阳活动周期以及与现代ENSO周期相似的6,5a周期。东海内陆架EC2005孔泥质沉积物揭示的中全新世东亚冬季风变化与格陵兰冰心氧同位素记录的良好对应说明两者有相似的发生机制,可能是太阳活动以及古ENSO对全球气候系统的影响所致。 相似文献
18.
Air-Sea Interaction, Coastal Circulation and Primary Production in the Eastern Arabian Sea: A Review
Air-sea interaction, coastal circulation and primary production exhibit an annual cycle in the eastern Arabian Sea (AS). During
June to September, strong southwesterly winds (4∼9 m s−1) promote sea surface cooling through surface heat loss and vertical mixing in the central AS and force the West India Coastal
Current equatorward. Positive wind stress curl induced by the Findlater jet facilitates Ekman pumping in the northern AS,
and equatorward-directed alongshore wind stress induces upwelling which lowers sea surface temperature by about 2.5°C (compared
to the offshore value) along the southwestern shelf of India and enhances phytoplankton concentration by more than 70% as
compared to that in the central AS. During winter monsoon, from November to March, dry and weak northeasterly winds (2–6 m
s−1) from the Indo-China continent enhance convective cooling of the upper ocean and deepen the mixed layer by more than 80 m,
thereby increasing the vertical flux of nutrients in the photic layer which promotes wintertime phytoplankton blooms in the
northern AS. The primary production rate integrated for photic layer and surface chlorophyll-a estimated from the Coastal
Zone Color Scanner, both averaged for the entire western India shelf, increases from winter to summer monsoon from 24 to 70
g C m−2month and from 9 to 24 mg m−2, respectively. Remotely-forced coastal Kelvin waves from the Bay of Bengal propagate into the coastal AS, which modulate
circulation pattern along the western India shelf; these Kelvin waves in turn radiate Rossby waves which reverse the circulation
in the Lakshadweep Sea semiannually. This review leads us to the conclusion that seasonal monsoon forcing and remotely forced
waves modulate the circulation and primary production in the eastern AS.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
The seasonal variability of sonic layer depth (SLD) in the central Arabian Sea (CAS) (0 to 25°N and 62-66°E) was studied using
the temperature and salinity (T/S) profiles from Argo floats for the years 2002–2006. The atmospheric forcing responsible
for the observed changes was explored using the meteorological data from NCEP/NCAR and Quickscat winds. SLD was obtained from
sound velocity profiles computed from T/S data. Net heat flux and wind forcing regulated SLD in the CAS. Up-welling and down-welling
(Ekman dynamics) associated with the Findlater Jet controlled SLD during the summer monsoon. While in winter monsoon, cooling
and convective mixing regulated SLD in the study region. Weak winds, high insolation and positive net heat flux lead to the
formation of thin, warm and stratified sonic layer during pre and post summer monsoon periods, respectively. 相似文献
20.
本文基于SWAN(Simulating Waves Nearshore)模式研究了2001～2016年石岛海浪有效波高的季节和年际变化特征,评估了不同区域风场对其贡献,并探讨了其与ENSO的关系。结果表明,石岛有效波高受黄海季风系统的影响呈现显著的季节变化:12月份最大, 6月份最小, 1%大波有效波高季节变化不显著。石岛有效波高年际变化信号显著,其与风速年际变化之间的关系存在季节性差异:石岛有效波高和石岛、黄海区域平均风速不同月份的年际异常分别在7、10月份相关性较高,而石岛1%大波有效波高和石岛、黄海区域平均1%大风风速不同月份的年际异常则在8月份左右相关性最高。不同区域风场对石岛有效波高场的影响也呈现了季节性差异:夏季,黄海南部区域风场对石岛海浪的贡献较大,而石岛风场的贡献较小;冬季,石岛风场的贡献较大。ENSO(El Ni?o-Southern Oscillation)事件会对石岛有效波高的年际变化产生一定的影响,但影响比较小。本研究旨在对石岛海浪在季节和年际尺度上的变化特征以及风场等影响因素进行研究,对该海域海浪场进行了详细的认识,对了解该海域海浪有重要意义。 相似文献