Annual Anthropogenic Carbon Transport into the North Pacific Intermediate Water through the Kuroshio/Oyashio Interfrontal Zone: An Estimation from CFCs Distribution

Vertical distribution of anthropogenic carbon content of the water (exDIC) in the Oyashio area just outside of the Kuroshio/Oyashio Interfrontal Zone (K/O Zone) was estimated by the simple 1-D advection-diffusion model calibrated by the distribution of chlorofluorocarbons (CFCs). The average concentration of exDIC for = 26.60–27.00 is multiplied by the volume transport of Oyashio water into the North Pacific Intermediate Water (NPIW) to estimate the annual transport of exDIC into NPIW through K/O Zone. The estimated transport of exDIC was 0.018–0.020 GtC/y, which corresponds to 15% of the whole total exDIC accumulation in the temperate North Pacific. A simple assessment using the NPIW 1-box model indicates that the current study explains at least 70% of the total annual transport of exDIC into NPIW, and that small exDIC sources for NPIW still exists in addition to K/O Zone.     

High Precision Geoid Models HKGEOID-2000 for Hong Kong and SZGEOID-2000 for Shenzhen, China

High precision geoid models HKGEOID-2000 for Hong Kong and SZGEOID-2000 for Shenzhen, China, have been developed with a hybrid approach of so-called sequential processing, using high precision GPS/leveling data, land and sea gravity anomalies, and digital terrain models. These two local geoid models have the same 1-km resolution. The estimated accuracy (external accuracy) is better than 1.7 cm for HKGEOID-2000 and 1.4 cm for SZGEOID-2000. Some common areas are covered by HKGEOID-2000 and SZGEOID-2000. So these two geoid models, along with high quality GPS/leveling data collected on the overlapping areas, can be used to detect the systematic bias between HKGEOID-2000 and SZGEOID-2000, as well as the difference between Hong Kong Principal Datum and 1956 yellow sea height datum of China, yielding RMS errors of 1.011 m and 1,003 m, respectively. Moreover, HKGEOID-2000, along with GPS ellipsoidal heights, is employed to determine the errors of the “orthometric heights” from purely trigonometric heighting, yielding an RMS error of 0.102 m. The combination of SZGEOID-2000 and GPS ellipsoidal heights has been used to replace the traditional spirit leveling and mapping, called GPS mapping.     

1998年夏季季风爆发前后南海上层环流的诊断分析

基于1998年南海季风试验（SCSMEX，South China Sea Monsoon Experiment)期间2个强化观测航次（4－5月及6－7）所获温盐深（CTD）资料，利用一个改进逆模式研究了夏季季风爆发前后南海环流的演变特征。诊断计算表明，在此期间南海环流主要表现为两脊两槽型，即越南以东和菲律宾以西呈反气旋式环流，南海北部和南海中部呈气旋式环流。但对局部区域而言，可以发现在季风爆发前后其环流结构有明显的差异。上述计算结果亦与等压面上海水密度分布的定性分析结果及同期观测的ADCP资料进行了比较，结果表明模式计算所得到的南海上层环流主要特征与定性分析结果及实测资料大体一致，诊断结果可作为南海上层季风环流演变机制研究的依据。     

冲绳海槽热流机制浅析

冲绳海槽是一个高热流区，平均热流值极高，但不均匀，实测最小值与最大值相差三个数量级以上，结合海槽地区的构造和地球物理特征，探讨了导致这一高而分散热流特征的多种因素。包括异常壳幔结构。海底热液循环以及地下水对流等，并分析了相应的控制机制。     

黑潮和中国近海环流

本文根据历史资料总结和讨论了黑潮对中国近海环流影响的基本结果,指出经巴士海峡进入南海和沿台湾海峡向北运动的黑潮分支,其年际变化明显,并认为该黑潮分支的运动状况对中国近海特别是南海和东海南部的中、下层环流影响显著,需要作进一步的调查研究。     

渤海海峡断面温度结构及流量的季节变化

作者采用 POM模式 ,利用从卫星遥感资料反演的风和海表温度 (SST)数据并考虑 M2分潮作用 ,对渤海海域的温度、流场的三维结构进行数值计算。根据数值模式的计算结果 ,重点分析渤海海峡温度结构和水交换的季节变化特征。结果表明风应力和 SST的季节性变化导致渤海海峡的水交换流型、温度结构和流量有明显的季节性变化。     

P矢量方法在南海夏季环流诊断计算中的应用

基于1998年6～7月南海调查航次的CTD资料,对南海环流采用最近发展的P矢量方法进行诊断计算.计算结果:黑潮向西入侵南海,然后做反气旋弯曲向东北方向流动,最终有通过巴士海峡流出南海的趋势.在南海北部存在一个气旋性环流,这个环流的强度和范围随深度增加而减小.该环流的冷中心位置随深度增加稍向南移.南海中部、越南以东海域存在一个明显的气旋涡和反气旋涡,尤其在200m及其以上水层均相当稳定,反气旋涡位于越南以东,其中心位置在11°53'N,111°50'E,气旋涡的中心位置在13°17'N,112°55'E,两者的尺度皆约为250km.吕宋岛西侧存在一个反气旋涡.在计算海区南部、巴拉望岛西南海域,100m以上层存在一个反气旋式涡.从各层流场分布均可以显示海流在西部强化的现象.     

Observations of the Labrador Sea eddy field

This paper is an observational study of small-scale coherent eddies in the Labrador Sea, a region of dense water formation thought to be of considerable importance to the North Atlantic overturning circulation. Numerical studies of deep convection emphasize coherent eddies as a mechanism for the lateral transport of heat, yet their small size has hindered observational progress. A large part of this paper is therefore devoted to developing new methods for identifying and describing coherent eddies in two observational platforms, current meter moorings and satellite altimetry. Details of the current and water mass structure of individual eddy events, as they are swept past by an advecting flow, can then be extracted from the mooring data. A transition is seen during mid-1997, with long-lived boundary current eddies dominating the central Labrador Sea year-round after this time, and convectively formed eddies similar to those seen in deep convection modeling studies apparent prior to this time. The TOPEX / Poseidon altimeter covers the Labrador Sea with a loose “net” of observations, through which coherent eddies can seem to appear and disappear. By concentrating on locating and describing anomalous events in individual altimeter tracks, a portrait of the spatial and temporal variability of the underlying eddy field can be constructed. The altimeter results reveal an annual “pulsation” of energy and of coherent eddies originating during the late fall at a particular location in the boundary current, pinpointing the time and place of the boundary current-type eddy formation. The interannual variability seen at the mooring is reproduced, but the mooring site is found to be within a localized region of greatly enhanced eddy activity. Notably lacking in both the annual cycle and interannual variability is a clear relationship between the eddies or eddy energy and the intensity of wintertime cooling. These eddy observations, as well as hydrographic evidence, suggest an active role for boundary current dynamics in shaping the energetics and water mass properties of the interior region.     

好望角附近海域春季大风的几种主要形势分析

通过普查和分析，概括出了春季好望角附近海域三种主要大风出现时的模型图，并以一个月中逐日4次船舶测风报告为例，分析了好望角大风的某些主要特征。