菲律宾海底层水体在1990s—2010s之间的暖化*

跨菲律宾海的重复断面水文观测揭示: 菲律宾海底层水体从1990s到2010s增暖了0.002~0.01℃。在西马里亚纳海盆和四国海盆, 较冷的下层绕极深层水(Lower Circumpolar Deep Water, LCDW)减少, 较暖的LCDW增加; 而在菲律宾海盆, 较冷的变性LCDW减少, 较暖的变性LCDW增加。菲律宾海盆4000dbar的热通量是0.0413W·m^-2, 而西马里亚纳海盆和四国海盆的是0.0221W·m^-2。菲律宾海盆由于深层海洋热膨胀引起的局地海平面上升速度是0.0621mm·yr^-1, 而西马里亚纳海盆和四国海盆的是0.0333mm·yr^-1。     

The hydrogen sulphide boundary in the Black Sea in the 1920s and 1980s

Maps of the boundary topography for anaerobic waters in the Black Sea are plotted for the summers of the 1920s and 1980s. The mean depths of the H₂S boundary for this period are determined. It is shown that the variation in the distribution and average location of the hydrogen sulphide zone has remained constant for the last 60 years.Translated by Mikhail M. Trufanov.     

The distribution of tritium and CFCs in the Weddell Sea during the mid-1980s

Transient tracer data (tritium, CFC11 and CFC12) from the southern, central and northwestern Weddell Sea collected during Polarstern cruises ANT III-3, ANT V-2/3/4 and during Andenes cruise NARE 85 are presented and discussed in the context of hydrographic observations. A kinematic, time-dependent, multi-box model is used to estimate mean residence times and formation rates of several water masses observed in the Weddell Sea.Ice Shelf Water is marked by higher tritium and lower CFC concentrations compared to surface waters. The tracer signature of Ice Shelf Water can only be explained by assuming that its source water mass, Western Shelf Water, has characteristics different from those of surface waters. Using the transient nature of tritium and the CFCs, the mean residence time of Western Shelf Water on the shelf is estimated to be approximately 5 years. Ice Shelf Water is renewed on a time scale of about 14 years from Western Shelf Water by interaction of this water mass with glacial ice underneath the Filchner-Ronne Ice shelf. The Ice Shelf Water signature can be traced across the sill of the Filchner Depression and down the continental slope of the southern Weddell Sea. On the continental slope, new Weddell Sea Bottom Water is formed by entrainment of Weddell Deep Water and Weddell Sea Deep Water into the Ice Shelf Water plume. In the northwestern Weddell Sea, new Weddell Sea Bottom Water is observed in two narrow, deep boundary currents flowing along the base of the continental slope. Classically defined Weddell Sea Bottom Water (θ ≤ −0.7°C) and Weddell Sea Deep Water (−0.7°C ≤ θ ≤ 0°C) are ventilated from the deeper of these boundary currents by lateral spreading and mixing. Model-based estimates yield a total formation rate of 3.5Sv for new Weddell Sea Bottom Water (θ = −1.0°C) and a formation rate of at least 11Sv for Antarctic Bottom Water (θ = −0.5°C).     

Seasonal and spatial variations of zooplankton in the central and southeastern Bering Sea during the mid-1990s

Hydrographic and plankton surveys were conducted over the basin and slope of the southeastern Bering Sea during April, June/July and September of 1994 and in June/July 1995, and seasonal and spatial variations of zooplankton community were investigated in relation to the oceanographic conditions. In July 1994, sea surface temperature (SST) ranged 5.3–8.7 °C, and the thermocline was between 30 and 50 m. In July 1995, however, SST was warmer (7.3–12.4 °C), and the thermocline was shallower (20–30 m). The thermal front at the shelf was also stronger in July 1995 than in July 1994. Surface salinity was higher in 1994 than 1995. A total of 17 taxonomic groups of zooplankton were identified from the plankton samples. In 1994, the highest density was observed in September. Copepods were the major taxon during all surveys. While some taxa such as euphausiids, ostracods, and Neocalanus spp. were most abundant in spring, others such as Calanus spp., Metridia pacifica, chaetognaths, and pteropods were most abundant in September. Adults and late-stage copepodites of Eucalanus bungii were abundant in spring, and were replaced by 1st–3rd stages of copepodites in summer. Zooplankton density was ca. 4 times higher in 1995 than in 1994, in part because of warm water temperature.     

20世纪90年代后期南海上层海温变化趋势的转折

In this paper, the interdecadal variability of upper-ocean temperature in the South China Sea(SCS) is investigated based on several objectively analyzed data sets and two reanalysis data sets. The trends of the SCS sea surface temperature(SST) have changed from warming to cooling since the late 1990 s. A heat budget analysis suggests that the warming of the surface mixed layer during 1984–1999 is primarily attributed to the horizontal heat advection and the decrease of upward long wave radiation, with the net surface heat flux playing a damping role due to the increase of upward latent and sensible heat fluxes. On the other hand, the cooling of the surface mixed layer during 2000–2009 is broadly controlled by net surface heat flux, with the radiation flux playing the dominant role. A possible mechanism is explored that the variation of a sea level pressure(SLP) over the North Pacific Ocean may change the prevailing winds over the SCS, which contributes to the change of the SST in the SCS through the horizontal heat advection and heat fluxes.     

末次冰消期以来渤、黄、东海陆架潮汐、潮流演变过程模拟研究

末次盛冰期结束、海侵开始后渤、黄、东海陆架潮汐、潮流的演变对该区泥沙的输运与沉积 ,以及海底地貌的形成、分布以及演变等具有深刻影响。文中数值模拟末次冰消期以来 4个特定时期 ,即比现在海面低 80 m、5 2 m、30 m海面以及全新世最大海侵时渤、黄、东海陆架的潮汐、潮流。根据不同时期的潮汐、潮流分布特征得出 ,末次冰消期以来渤、黄、东海陆架潮汐、潮流的演变过程大致以全新世最大海侵为界划分为两个阶段 :1全新世最大海侵前为渤、黄、东海陆架潮汐、潮流基本分布格局的形成阶段 ;2全新世最大海侵后 ,为基本分布格局的局部调整阶段。末次冰消期以来基本海岸轮廓的变迁是渤、黄、东海陆架区潮汐、潮流演变的主要控制因素     

渤黄东海潮能通量与潮能耗散

利用同化高度计资料和沿岸验潮站资料对潮汐数值模式进行同化,根据同化后的数值模式结果,对渤黄东海中的潮能通量和潮能耗散进行了研究.M2分潮从太平洋进入渤黄东海的潮能为122.499GW,占4个主要分潮进入总量的79%.黄海是半日分潮潮能耗散的主要海区.全日分潮则主要耗散在东海.全日分潮在遇到陆坡的阻挡以后有一部分潮能沿着冲绳海槽向西南传播,并有一部分潮能反射回太平洋,其中O1分潮通过C3断面反射回太平洋的潮能,约占其传入东海潮能的44%.     

Ecological characteristics of Walleye pollock eggs and larvae in the southeastern Bering Sea during the late 1970s

Walleye pollock (Theragra chalcogramma) is an ecologically and economically important groundfish in the eastern Bering Sea. Its population size fluctuates widely, driving and being driven by changes in other components of the ecosystem. It is becoming apparent that dramatic shifts in climate occur on a decadal scale, and these “regime shifts” strongly affect the biota. This paper examines quantitative collections of planktonic eggs and larvae of pollock from the southeastern Bering Sea during 1976–1979. Mortality, advection, and growth rates were estimated, and compared among the years encompassing the 1970s’ regime shift. These data indicate that pollock spawning starts in late February over the basin north of Bogoslof Island. Over the shelf, most spawning occurs north of Unimak Island near the 100 m isobath in early or mid April. Pollock eggs are advected to the northwest from the main spawning area at 5–10 cm/sec. Larvae are found over the basin north of Bogoslof Island in April, and over the shelf between Unimak Island and the Priblof Islands in May. Compared to 1977, the spawning period appeared to be later in 1976 (a cold year) and earlier in 1978 (a warm year) in the study area. At the lower temperatures in 1976, egg duration would be longer and thus egg mortality would operate over a longer period than in the other years. Mean larval growth appeared to be lower in 1976 than in 1977 and 1979. Estimated egg mortality rate in 1977 was 0.6 in April and 0.3 in early May.     

1990s年代际转型前后南海季风系统的季节变化

利用多变量经验正交分解(MV-EOF)等方法,研究了在季节变化尺度上南海季风系统的时空分布特征。结果表明:南海夏季风的爆发时间在1993—1994年前后存在显著的年代际转型,由爆发偏晚转变成爆发偏早。第一模态表现为冬夏反位相的年周期变化,但爆发早年夏季风持续时间略长于爆发晚年,空间上都反映了南海中央海盆区的夏季强降水和850 hPa上南海北部的气旋性环流异常,但夏季风爆发早年中国华南沿海降水加强而南海南部降水偏少。相应的大范围环流场上主要反映了南海夏季风爆发后进入盛夏时节亚太地区大范围的环流特征,南海夏季风爆发偏早年索马里越赤道气流偏强,东亚季风槽位置偏北,爆发偏晚年则相反。第二模态反映了南海季风系统春秋反位相的季节变化,且秋季的振幅更强,空间降水场上对应着秋季华南沿海和南海北部与南海中南部北旱南涝的跷跷板式分布,850 hPa风场上则主要表现为异常的东北季风,该模态时空特征表明南海夏季风爆发偏早年的秋季,冬季风建立也偏早,越南及周边地区的降水偏多。相应的大范围环流场上则主要反映了冬季风的环流特征,在南海夏季风爆发偏早年的秋季,菲律宾以东的热带对流减弱,PJ波列增强,爆发晚年则相反。     

Earth’s Free Oscillations Excited by the 2013 Okhotsk Sea Earthquake

Izvestiya, Atmospheric and Oceanic Physics - Based on the deformation data measured by the Baksan laser interferometer-strainmeter, Earth’s free oscillations (EFO) excited by the Okhotsk Sea...     

渤、黄海海冰的变化和预报结果分析

利用1951—2000年的渤、黄海的海冰资料，用小波分析和最优气候均态法对渤、黄海的海冰冰级进行分析和预测。小波分析结果较好地反映了渤、黄海海冰的变化规律，使对海冰的研究更符合实际情况。这必将有助于研究海冰变化的机理和不同尺度变化的相互作用。最优气候均态法较好地实现了对渤、黄海海冰的预测。此方法在海冰预报中不失为一种可用的方法。     

1990s年代际转型前后南海季风系统的季节变化

利用多变最经验正交分解(MV-EOF)等方法,研究了在季节变化尺度上南海季风系统的时空分布特征.结果表明:南海夏季风的爆发时间在1993-1994年前后存在显著的年代际转型,由爆发偏晚转变成爆发偏早.第一模态表现为冬夏反位相的年周期变化,但爆发早年夏季风持续时间略长于爆发晚年,空间上都反映了南海中央海盆区的夏季强降水和850 hPa上南海北部的气旋性环流异常,但夏季风爆发早年中国华南沿海降水加强而南海南部降水偏少.相应的大范围环流场上主要反映了南海夏季风爆发后进人盛夏时节亚太地区大范围的环流特征,南海夏季风爆发偏早年索马里越赤道气流偏强,东亚季风槽位置偏北,爆发偏晚年则相反.第二模态反映了南海季风系统春秋反位相的季节变化,且秋季的振幅更强,空间降水场上对应着秋季华南沿海和南海北部与南海中南部北旱南涝的跷跷板式分布,850 hPa风场上则主要表现为异常的东北季风,该模态时空特征表明南海夏季风爆发偏早年的秋季,冬季风建立也偏早,越南及周边地区的降水偏多.相应的大范嗣环流场上则主要反映了冬季风的环流特征,在南海夏季风爆发偏早年的秋季,菲律宾以东的热带对流减弱,PJ波列增强,爆发晚年则相反.     

Dramatic weakening of the ear-shaped thermal front in the Yellow Sea during 1950s–1990s

The ear-shaped thermal front(ESTF), formed by the convergence of the Yellow Sea Warm Current(YSWC) and the Shandong Coastal Current(SCC), is a very important oceanic phenomenon in the Yellow Sea(YS) in winter. In situ measurements and reanalysis datasets all demonstrate that the ESTF has been weakening during1950s–1990s, and a similar weakening trend is also found in winter monsoon over the YS. Numerical experiments show that the weakening of winter monsoon can induce an anomalous circulation in the YS on multi-decadal timescale with northward anomalous currents along China's coast and southward anomalous currents in the central YS—generally opposite to seasonal mean circulation. The anomalous circulation causes slowdown of the YSWC and the SCC, and thus weakens the ESTF. Since the ESTF plays important roles in regional ocean dynamics and air-sea interactions, its weakening has important implications for regional climate in the YS in winter.     

日本海、鄂霍次克海和白令海的古海洋学研究进展

边缘海的存在使大陆和大洋之间的物质和能量交换变得相当复杂。在构造运动和海平面升降的控制下,边缘海和大洋之间时而连通时而隔绝,各种古气候变化信号都在一定程度上被放大。基于近期有关西北太平洋边缘海的古海洋学研究成果,简要概述了日本海、鄂霍次克海、白令海以及北太平洋地区自中新世以来的古气候和古海洋环境演化特征,并认为它们与全球其它地区一样也受控于因地球轨道参数变化引起的太阳辐射率的变化,大尺度的气候变化具有与地球轨道偏心率周期相对应的100ka周期,而41ka的小尺度周期则受地球自转轴斜率变化的控制。一些突发性的气候变化则是由气候不稳定性、海峡的关闭与开启和其它一些地球气候系统的非线性活动所驱动。但同时作为中高纬度边缘海,它们的古海平面、古海水温度、古洋流等古海洋环境因子的变化特征还受到冰盖扩张和退缩、构造运动、冰川性地壳均衡补偿、东亚季风等因素的影响,具有一定的区域特点。     

Sediment transport in the Yellow Sea and East China Sea

Eight survey cruises in different seasons have been conducted in the Yellow Sea (YS) and East China Sea (ECS) during the period from 2000 to 2008. Suspended sediment concentration (SSC) and hydrological data were collected during each cruise. Data analysis showed that total suspended sediment mass was approximately 0.18 × 10⁹ tons in the surveyed area during spring and autumn seasons. Highly turbid waters were found in the shallow waters between the Subei coast, the Changjiang estuary and the Zhejiang coast with seasonal variations.     

Decadal evolution of anthropogenic CO2 in the northwestern Mediterranean Sea from the mid-1990s to the mid-2000s

Monthly observations accumulated over more than a decade at the DYFAMED time-series station allow us to estimate the temporal evolution of anthropogenic CO₂ in the western Mediterranean Sea. This objective is reached by using recognized interpolation procedures to reconstruct the incomplete distributions of measured total dissolved inorganic carbon and total alkalinity. These reconstructed fields, associated with those available for dissolved oxygen and temperature, are used to estimate the distribution of anthropogenic CO₂. This is done with the recently developed Tracer combining Oxygen, inorganic Carbon, and total alkalinity (TrOCA) approach. The main results indicate that (1) the concentrations of anthropogenic CO₂ are much higher than those found in the Atlantic Ocean (the minimum concentration at the DYFAMED site is 50 μmol kg⁻¹), and (2) the temporal trend for anthropogenic CO₂ is decreasing, especially in the intermediate and the deep layers of the water column at the DYFAMED site. This decrease in anthropogenic CO₂ is significantly correlated with a decrease in the dissolved oxygen and with an increase in both salinity and temperature. These trends are discussed in the light of recent published works that propose explanations for the observed increases in salinity and temperature that occurred in the western basin since the 1950s. We conclude that the decrease in anthropogenic CO₂ probably resulted from an invasion of old water masses. Different hypotheses on the origin of these water masses are considered and several arguments indicate that the eastern Mediterranean transient (EMT) could have played an important role in the observed decrease in anthropogenic CO₂ concentrations at the DYFAMED site.     

It's Scotland's oil?: Hypothetical boundaries in the North Sea — a case study

The author explores the issues involved in the delimitation, in the event of Scotland gaining independence from the UK, of the boundaries of Scotland's continental shelf in the North Sea. The exploration involves an analysis of the rules of both international conventional law and international customary law, either of which might be applicable, depending on the policy adopted by an independent Scotland. Moreover, since it is possible that a new Caracas Convention on the Law of the Sea will emerge from UNCLOS III, the author also considers the latest version of the draft rules under discussion at the Conference.