The South Pacific Subtropical Mode Water in the Tasman Sea

From the synopical CTD sections in the WOCE PR11 repeated cruises, the South Pacific Subtropical Mode Water (SPSTMW) has been identified in the region of the Tasman Front Extension (TFE) around 29?S to the east of Australia. In the depth range of 150-250 m, the SPSTMW appears as a thermostad with vertical temperature gradient lower than 1.6℃(100 m)-1 and a tem- perature range of 16.5-19.5℃ and as a pycnostad with PV lower than 2×10-10 m-1 s-1 and a potential density range of 25.4-26.0 kg m-3. Like the subtropical mode waters in the North Atlantic and North Pacific, the formation of the SPSTMW is associated with the convective mixing during the austral wintertime as manifested from the time series of the Argo floats. And cold water entrains into the mixed layer with the deepening mixed layer from September to the middle of October. During the wintertime formation process, mesoscale eddies prevailing in the TFE region play an important role in the SPSTMW formation, and have a great effect on the SPSTMW distribution in the next year. The deeper (shallower) mixed layer in wintertime, consistent with the depressed (uplifted) permanent thermocline, is formed by the anticyclonic (cyclonic) eddies, and the substantial mode water thicker than 50 m is mainly found in the region of the anticyclonic eddies where the permanent thermocline is deeper than 450 m.     

利用遥感SST反演上层海洋三维温度场

通过统计相关分析验证了一个简单的温度参数模型在太平洋海域的较好适用性。基于Argo观测资料及WOA09气候态温度数据,采用最大角度法求得此模型的相关参数,并利用高分辨率卫星遥感海表温度反演了太平洋上层海域空间分辨率为1°×1°的气候态月平均三维温度场。与实测资料的比较分析表明反演结果是较为真实可靠的,并可作为海洋数值模式积分的初猜场,为实现现场观测(如:Argo)与卫星观测的优势互补,构建太平洋海域完整的三维温度分析场提供一种新途径。     

利用 Argo 数据计算吕宋海峡以东海域水文特性参数和流场 *

利用2006年Argo浮标资料分析吕宋海峡以东海域水团季节特性和混合层的月平均变化规律;并分别利用Argo多年季节平均资料与2006年资料,以秋季为例,基于P矢量方法计算该区域流场;同时考虑风生流的影响,将所得结果分别与利用Levitus和高度计资料计算的流场进行比较。结果表明,水团特性季节变化不明显,春冬季表层水团与夏秋季比较表现为低温高盐;次表层、中层和深层季节变化不大;混合层深度明显表现为冬季最深、夏季最浅的季节性变化。利用2002—2009年Argo季节平均资料基于P矢量方法能得到地转流场的基本结构,与Levitus资料的计算结果相比较,除可以反映黑潮,还可以反映一些涡旋结构;利用2006年秋季Argo资料计算流场与高度计资料计算的地转流场比较,其流场结构位置吻合得比较好,但存在流速偏小等不足,这可能与Argo资料较少且分布不均以及插值误差等有关,但其可以获得流场的三维结构,而利用高度计资料计算只能得到表层流场结构。     

全球大洋混合层深度的计算及其时空变化特征分析

本文利用2005-2009年的全球网格化Argo数据,分别采用温度判据和密度判据计算了全球大洋混合层深度(Mixed Layer Depth, MLD),讨论了障碍层(Barrier Layer, BL)和补偿层(Compensated Layer, CL)对混合层深度计算的影响,得到了合成的混合层深度,并研究了其时空变化特征. 研究表明:(1)在赤道西太平洋(10°S -5°N,150°E-150°W),孟加拉湾,热带西大西洋(10°N-20°N,30°W-60°W)是障碍层高发区域. 冬季的北太平洋副热带区域(30°N附近)以及东北大西洋(40°N-60°N,0°-30°W)是补偿层发生的区域. (2) 在各个半球的夏季MLD都比较浅,在各个半球的冬季MLD则普遍比较深. 北太平洋和北大西洋的MLD的分布和变化比较相似,印度洋MLD受季风影响显著,呈现半年周期变化. 太平洋和大西洋的MLD 的经向分布大致呈现出"两端深,中间浅"的拱形特点. (3)混合层深度距平场EOF第一模态时间变化为周期的年信号,北太平洋和北大西洋、南大洋(尤其是南极绕流区)都是MLD变化剧烈的海域,第二模态显示全球大洋混合层深度距平存在着一个半年的变化周期.     

太平洋不同海水层结条件下的内波波致声场起伏研究

基于Argo资料对太平洋海域海水层结进行分类区划,利用内波动力学方法对内波致声起伏进行数值求解,对不同层结状况下的内波致声起伏进行模拟试验。结果表明:垂直方向海水层结的不均匀和跃层的存在,使海洋内波斜压模态受到了歪曲变形。层结峰的个数和深度与声速起伏存在很好的对应关系。有内波的声传播特征总体上与没有内波时的相似。不同层结情况下,声场对内波扰动的响应不一致。     

Annual and interannual variations of the Western Pacific Warm Pool volume and sources of warm water revealed by Argo data

Based on gridded Argo profile data from January 2004 to December 2010, together with the P-vector inverse method, the three-dimensional structure, annual and inter-annual variations in volume of the Western Pacific Warm Pool(WPWP) are studied. The variations of latitudinal and longitudinal warm water flowing into and out of the WPWP and the probable mechanism of warm water maintenance are also discussed. From the surface to the bottom, climatic WPWP tilts southward and its area decreases. The maximum depth could extend to 120 m, such that its volume could attain 1.86×1015 m3. Annual variation of the WPWP volume shows two obvious peaks that occur in June and October, whereas its inter-annual variations are related to ENSO events. Based on a climatic perspective, the warm water flowing latitudinally into the pool is about 52 Sv, which is mainly through upper layers and via the eastern boundary. Latitudinally, warm water flowing outward is about 49 Sv, and this is mainly through lower layers and via the western boundary. In contrast, along the latitude, warm water flowing into and out of the pool is about 28 Sv and 23 Sv, respectively. Annual and inter-annual variations of the net transportation of the warm water demonstrate that the WPWP mainly loses warm water in the west-east direction, whereas it receives warm water from the north-south direction. The annual variation of the volume of WPWP is highly related to the annual variation of the net warm water transportation, however, they are not closely related on inter-annual time scale. On the inter-annual time scale, influences of ENSO events on the net warm water transportation in the north-south direction are much more than that in the west-east direction. Although there are some limitations and simplifications when using the P-vector method, it could still help improve our understanding of the WPWP, especially regarding the sources of the warm water.     

西北太平洋海表温度融合产品交叉比对分析

海表温度产品是研究全球海洋大气系统的重要数据源,在海洋相关领域的研究和应用方面具有重要价值。以西北太平洋海域为研究区域,本文对2007-2014年的3个海表温度融合数据（AVHRR OISST,MISST和OSTIA）的产品特性与Argo浮标进行了真实性检验,并对融合产品进行了交叉比对分析。结果表明,3个融合产品在空间尺度上均能反映西北太平洋海域的海表温度变化趋势。融合数据与Argo浮标的平均偏差在±0.1℃之间,均方根误差小于0.9℃。融合数据与浮标数据存在明显的季节性变化,其中冬季融合数据与浮标数据的平均偏差和均方根误差较小。在高纬海域,融合产品和浮标存在正偏差。与另两个融合产品相比,OSTIA的数据质量与Argo浮标最为接近。3个融合产品在近岸和高纬海域差异较大,三者对海冰的标识和处理方式不同对融合结果也有影响。在2012年6月之前MISST和OSTIA的海表温度数据质量更为接近,但在此之后MISST存在系统误差。红外数据、微波数据和实测数据作为输入数据,是制作高时空分辨率高精度海表温度融合产品必不可少的要素。     

环南澳大利亚太平洋-印度洋海洋间南极中层水环流

On the basis of the salinity distribution of isopycnal(σ_0=27.2 kg/m~3) surface and in salinity minimum, the Antarctic Intermediate Water(AAIW) around South Australia can be classified into five types corresponding to five regions by using in situ CTD observations. Type 1 is the Tasman AAIW, which has consistent hydrographic properties in the South Coral Sea and the North Tasman Sea. Type 2 is the Southern Ocean(SO) AAIW, parallel to and extending from the Subantarctic Front with the freshest and coldest AAIW in the study area. Type 3 is a transition between Type 1 and Type 2. The AAIW transforms from fresh to saline with the latitude declining(equatorward). Type 4, the South Australia AAIW, has relatively uniform AAIW properties due to the semienclosed South Australia Basin. Type 5, the Southeast Indian AAIW, progressively becomes more saline through mixing with the subtropical Indian intermediate water from south to north. In addition to the above hydrographic analysis of AAIW, the newest trajectories of Argo(Array for real-time Geostrophic Oceanography) floats were used to constructed the intermediate(1 000 m water depth) current field, which show the major interocean circulation of AAIW in the study area. Finally, a refined schematic of intermediate circulation shows that several currents get together to complete the connection between the Pacific Ocean and the Indian Ocean. They include the South Equatorial Current and the East Australia Current in the Southwest Pacific Ocean, the Tasman Leakage and the Flinders Current in the South Australia Basin, and the extension of Flinders Current in the southeast Indian Ocean.     

利用Argo浮标定位信息估算分析赤道太平洋中层流场状况

本文利用Argo浮标的定位信息,经过较为严格的质量控制与误差估算,得到2003～2005年赤道太平洋区域中层流场信息,并对其进行较为详细的诊断与分析,得到以下几个结论:(1)棉兰老涡、赤道逆流和南赤道流在中层流场中多数时间清晰可辨,北赤道流较弱,有时不易分辨。(2)棉兰老涡、赤道逆流和南赤道流都存在明显的季节变化。一般在2、3月间最弱,8、9月间最强。(3)棉兰老涡、赤道逆流和南赤道流存在较明显的年际变化。(4)赤道逆流通常表现为两支,分别位于东赤道太平洋和西赤道太平洋,东太平洋支主轴位置大约在7～8°N附近,西太平洋支主轴位置大约在3°N附近。     

Argo数据的网络可视化集成平台开发及其应用

为了方便广大用户实时获取和使用A rgo资料,研制开发了“A rgo网络数据库可视化平台”。该平台以数据库管理的形式,使用W eb-G IS技术,并采取可视化方式向用户提供查询和获取全球海洋中的A rgo资料。文中就该平台的设计、组成与功能和应用等作一系统介绍,以帮助广大A rgo资料用户熟悉和了解该平台,推动A rgo资料的应用研究进程。