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利用我国第六次—第九次北极科学考察雪龙船走航探空数据,计算北极太平洋扇区和白令海的夏季对流层高度,分析对流层内的风速、温度、水汽廓线,从而确定对流层结构,并分析各要素的垂直分布和经向分布特征。结果表明:夏季北极太平洋扇区和白令海的递减率对流层顶、冷点对流层顶平均值分别为10 003 m、10 116 m,对流层高度随纬度增加而降低。夏季北极大气对流层低层和对流层顶存在逆温,对流层顶的逆温高度和厚度随纬度增加而降低。大气可降水量与纬度呈负相关,且集中于对流层中低层。近地面的风速受地表摩擦力的影响较明显,对流层内的风速随高度增加而增大,高空急流的强度和高度随纬度增加而减小,风廓线和急流易受天气尺度过程的影响。研究结果揭示了夏季北极太平洋扇区和白令海的对流层结构,并可用于检验数值预报模式对北极大气垂直结构的预报效果、评估再分析资料描述北极大气垂直结构的能力。 相似文献
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采用特征量和线性拟合的方法,对1976～2003年8月的B1断面温盐调查资料进行分析.结果表明:夏季渤海暖水深入沿岸两端及渤海中部,深水处具有南北2个冷水区,形成冷、暖水体并存的分布特征.渤海夏季温度场结构分布是多种海洋物理环境要素的综合影响所致,太阳辐射和地形是基本原因之一,北黄海冷水侵入是冷暖水区维持的重要原因.冷水区多年温度有正变化率,温度变化正距平的信号来自大气气候变暖;而渤海中部高温水体则具有负变化率,温度变化负距平的信号来自北黄海次表层温度的变化,可能与北黄海冷水侵入渤海有关.夏季近岸盐度低,底层盐度高.盐度多年变化以正变率为主,造成岸边盐度升值明显的主要原因是河流入海淡水量的减少和工业污染. 相似文献
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基于中国第7次北极科学考察白令海现场调查资料与数据,分析了2016年夏季白令海海水颗粒态(DMSOp)和溶解态二甲亚砜(DMSOd)浓度的空间变化特征及其影响因素。研究表明,夏季白令海二甲亚砜(DMSO)浓度高于全球多数大洋和近岸海域。夏季白令海DMSOd和DMSOp浓度空间变化相似。表层海水DMSOp浓度为6.47～169.40 nmol/L,平均值为(79.62±56.10) nmol/L;DMSOd浓度的变化范围是20.07～153.70 nmol/L,平均值为(72.67±39.20) nmol/L。平面分布上,白令海表层DMSO浓度由海盆区、中外陆架区至内陆架区依次降低;垂直分布上由表至底随深度增加而降低,表层DMSOd和DMSOp浓度高于55 nmol/L,底层低于25 nmol/L。海盆区DMSOd主要源于DMS氧化和浮游生物直接合成的DMSOp,海盆区深层水团DMSOd浓度主要受控于温度和盐度。中外陆架区表层暖水团DMSO浓度主要受控于温度,陆架冷水团DMSO浓度则受盐度影响较大。内陆架区陆架水团DMSOp浓度和阿拉斯加沿岸水团DMSOd浓度分别受温度和DMS光化学氧化影响。 相似文献
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基于2019年夏季中国第十次北极科学考察("十北"科考)中"海燕"水下滑翔机观测的温度和溶解氧(Dissolved Oxygen, DO)数据,对白令海海盆区水团分类,及其温度和溶解氧分布特征进行了分析研究。结果表明:北极白令海海盆区水体一般由温度差异较为明显的上层水,中层水和深层水组成,其温度水平分布具有东高西低的特点,且随着深度的增加,水平温差逐渐减小。白令海上层水位于50 m以浅的位置,在约30～50 m深度处存在强温跃层,温跃层自西向东深度略有增加,且厚度不均匀,跃层强度约为0.31℃/m;白令海中层水位于50～250 m深度处,主要为冬季残留水,中层冬季残留水分布具有一定地区性差异,在此位置存在温度最小值,约为2.7℃;白令海深层水水体较稳定,温度随深度缓慢降低。对比垂直断面温度特征和溶解氧特征可知,白令海中层冬季残留水溶解氧含量较高,高于上层水团;在中层水与深层水之间存在氧跃层,氧含量从250μmol/L快速下降至50μmol/L,并随着深度的增加,在1 000 m深处降至20μmol/L。 相似文献
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研究渤海的可持续发展.根据 1979～1999 年渤海中部断面温度、盐度、溶解氧、营养盐的调查资料,分析了它们的分布结构和20年来的变化趋势.结果显示断面各个要素冬季的垂向分布均匀,夏季有2个冷水中心,盐度、溶解氧、营养盐在冷中心位置也出现了类似的高值或者低值中心.各要素的距平图显示盐度有上升趋势,溶解氧含量下降,无机氮逐年增加,磷酸盐和硅酸盐夏季有下降的趋势,但是冬季没有明显的增加或者减少的趋势. 相似文献
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根据珠江口外沿岸海域2006年夏季(7-8月)及冬季(2006年12月-2007年1月)航次的CTD调查资料,分析了调查海域夏季与冬季的温度、盐度分布,温度、盐度、密度跃层特征及其与上升流、中尺度涡旋和海流的关系.结果表明:1)夏季调查海域冲淡水扩展、上升流、中尺度涡等现象在温度、盐度分布中都有很明显的表征,并对跃层分布有显著的影响,形成了复杂的跃层类型;在冲淡水扩展的影响下,还形成了双跃层与障碍层现象.2)冬季海水混合剧烈,沿岸浅水区域跃层现象不明显,在陆坡深水区存在跃层现象. 相似文献
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根据南黄海断面1977—2016年历年8月标准层温度、盐度与气候要素观测资料,采用时空分析等方法,分析了南黄海断面夏季温度、盐度年际时空变化与气候响应。断面温度主要有4种时空模态,夏季风生环流、冷水团强度、面积与断面冬季温度模态是主要温度模态年际变化的主要影响因素;夏季风生流场形态、春季PDO指数与断面冬季温度模态是次要温度模态年际变化的主要影响因素;温度模态时间分量均为准平衡态长期变化。断面盐度主要有4种时空模态,夏季苏北沿海低盐度水体、南黄海中部高盐度水体与夏季黄海风生流输送作用是盐度主要模态年际变化的主要影响因素;夏季南黄海降水量减少与风生流输送减弱是盐度次要模态年际变化的主要影响因素。盐度主要模态时间分量为准平衡态长期变化,次要模态时间分量存在显著线性低盐趋势变化。断面夏季温盐多年平均分布主要受到夏季多年平均风生环流影响。断面核心冷水团月平均温度为准平衡态长期变化;面积存在显著线性减小趋势,黄海风生流场季节与年际变化是南黄海核心冷水团年际变化主要影响因素,春季PDO指数对冷水团面积年际变化有显著非线性影响。断面冷水团、核心冷水团月平均盐度为显著线性低盐趋势周期年际变化。由于黄海温盐长期线性趋势变化,与30多年前状况相比,目前黄海温盐场季节循环时空变化形态可能已经发生显著改变。 相似文献
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舟山渔场及其邻近海域水团的季节特征 总被引：5，自引：0，他引：5
根据2001年夏季和2002年冬季两次现场调查所收集的CTD和营养盐资料,利用模糊聚类分析法,对舟山渔场及其邻近海域水团的季节特征进行了分析.结果表明,舟山渔场及其邻近海域水团的配置、分布范围、温盐特性和营养盐含量都有明显的季节特征.其中,冬季在全海域共有3个水团(江浙沿岸水、台湾暖流表层水和黄海混合水),而夏季则存在4个水团(江浙沿岸水、台湾暖流表层水、台湾暖流深层水和黄海混合水);冬季,江浙沿岸水的分布范围较小,温度偏低,盐度略高,营养盐偏高,而夏季,其分布范围较大,温度偏高,盐度偏低,营养盐偏低;冬季,台湾暖流表层水北伸最强,厚度最厚,温度最低,盐度最高,硅酸盐和硝酸盐偏高,而夏季,则北伸最弱,厚度最薄,温度最高,盐度最低,硅酸盐和硝酸盐偏低;台湾暖流深层水是一个季节性水团,它含有较丰富的营养盐;黄海混合水的分布范围和营养盐含量也都呈现出明显的季节特征. 相似文献
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北极河流径流是北冰洋淡水的最大来源，其变化会对北冰洋中的诸多过程有重要影响。本文基于全球高分辨率海洋?海冰耦合模式的模拟结果，研究北冰洋温盐、海冰以及环流对北极河流径流的敏感性。通过对比有气候态北极河流径流输入的控制实验结果和径流完全关闭的敏感性实验结果，研究发现北极径流对北冰洋温度、盐度、海冰以及海洋环流等有显著的影响。关闭北极河流径流后，在河口附近的陆架上温度降低、盐度升高，且导致500 m深度处温度下降以及盐度升高；河口附近的陆架处，海冰密集度与海冰厚度增加。关闭北极河流径流也对北冰洋内的环流有影响:由于缺少来自欧亚大陆的北极径流的输入，穿极漂流与东格陵兰流流速减小且盐度增加；关闭北极径流导致近岸海表面高度降低，沿欧亚陆架的北冰洋边界流减弱，白令海入流增强。通过对比关闭北极径流实验与控制实验的温度和盐度剖面，发现关闭北极径流后大西洋层温度降低，各陆架海盐跃层的梯度减小，盐跃层厚度减小。 相似文献
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1 IntroductionTheBeringStrait, with them aximum depth lessthan 60 m , isthe uniquepassagebetween the ArcticOcean and the North Pacific Ocean, and links twoshelfseas:theBeringSeainthesouthandtheChukchiSea in the north. The background flow field oftheBering… 相似文献
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北白令海夏季冷水团的分布及其年际变化研究 总被引：4，自引：3，他引：4
利用1982-2008年间的高分辨率CTD数据,对夏季位于北白令海陆架底层的冷水团性质及其多年变化进行了研究.结果表明,依据该区域水体在温盐性质上的差异可以分为4类:陆架冷水团(BSW_C),白令海陆坡流水(BSCW),混合变性水(MW),陆架表层暖水(BSW_S).以-1℃,2℃和4℃温度等值线指示水团边界,清楚地将... 相似文献
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2003-2012年间白令海峡断面淡水构成的时空变化 总被引：3，自引：1，他引：2
通过对2003-2012年间白令海峡64.3°N断面海水氧同位素组成的分析,应用海水δ18 O值和盐度的质量平衡关系区分出淡水中河水和海冰融化水组分的贡献,探讨白令海峡淡水组成的分布特征及其年际变化。研究表明,断面东侧阿拉斯加沿岸水影响区呈现低δ18 O值、低盐、高温、高河水组分的特征,西侧阿拉德尔水具有高δ18 O值、高盐、低海冰融化水的特征,中部白令陆架水的δ18 O值、盐度和淡水组成则居于上述二者之间。阿拉斯加沿岸水影响区河水组分的份额约为阿拉德尔水和白令陆架水的2倍,并呈现出2010年2012年2003年2008年的时间变化规律,受控于育空河入海径流量的时间变化。白令陆架水和阿拉斯加沿岸水影响区的海冰融化水份额较为接近,均比阿拉德尔水影响区的海冰融化水份额高约45%。海冰融化水的年际变化表现出2003年2008年≈2012年2010年的规律,受控于白令海海冰的年际变动。从断面淡水构成看,通过白令海峡的淡水平均由46%的河水和54%的海冰融化水构成,且阿拉德尔水、白令陆架水和阿拉斯加沿岸水影响区河水组分与海冰融化水组分的比值自2003年至2012年间呈增加趋势,证明太平洋入流中淡水构成的变化对北冰洋海冰的融化也起着一定的作用。 相似文献
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On the basis of the CTD data obtained within the Bering Sea shelf by the Second to Sixth Chinese National Arctic Research Expedition in the summers of 2003, 2008, 2010, 2012 and 2014, the classification and interannual variation of water masses on the central Bering Sea shelf and the northern Bering Sea shelf are analyzed. The results indicate that there are both connection and difference between two regions in hydrological features. On the central Bering Sea shelf, there are mainly four types of water masses distribute orderly from the slope to the coast of Alaska: Bering Slope Current Water(BSCW), MW(Mixed Water), Bering Shelf Water(BSW) and Alaska Coastal Water(ACW). In summer, BSW can be divided into Bering Shelf Surface Water(BSW_S) and Bering Shelf Cold Water(BSW_C). On the northern Bering Sea shelf near the Bering Strait,it contains Anadyr Water(AW), BSW and ACW from west to east. But the spatial-temporal features are also remarkable in each region. On the central shelf, the BSCW is saltiest and occupies the west of 177°W, which has the highest salinity in 2014. The BSW_C is the coldest water mass and warmest in 2014; the ACW is freshest and mainly occupies the east of 170°W, which has the highest temperature and salinity in 2012. On the northern Bering Sea shelf near the Bering Strait, the AW is saltiest with temperature decreasing sharply compared with BSCW on the central shelf. In the process of moving northward to the Bering Strait, the AW demonstrates a trend of eastward expansion. The ACW is freshest but saltier than the ACW on the central shelf,which is usually located above the BSW and is saltiest in 2014. The BSW distributes between the AW and the ACW and coldest in 2012, but the cold water of the BSW_C on the central shelf, whose temperature less than 0°C, does not exist on the northern shelf. Although there are so many changes, the respond to a climate change is synchronized in the both regions, which can be divided into the warm years(2003 and 2014) and cold years(2008, 2010 and 2012). The year of 2014 may be a new beginning of warm period. 相似文献
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基于PHC3.0极地科学中心水文气候数据集(简称PHC3.0数据集)的温度和盐度资料,使用聚类分析和Bayes判别分析的方法,对北纬70°以北海域的水团结构进行了分析,在北冰洋区域划分出4个水团:北冰洋表层水(ASW)、大西洋中层水(AIW)、太平洋水(PW)和北冰洋深层水(ADW)。北冰洋表层水(ASW)遍布于欧亚海盆和加拿大海盆,以低温低盐为特征。大西洋中层水(AIW)位于约200～900m深度,在北冰洋环极边界流的作用下,其影响可达到加拿大海盆。太平洋水(PW)受经白令海峡进入北冰洋的海水影响,相对高温低盐,夏季时影响显著。北冰洋深层水(ADW)在海盆中相当均匀,几乎没有季节变化,盐度约在34.95psu,温度在加拿大海盆约为-0.3℃,欧亚海盆约为-0.7℃。 相似文献
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State Estimation of the North Pacific Ocean by a Four-Dimensional Variational Data Assimilation Experiment 总被引：1，自引：0，他引：1
Toshiyuki Awaji Shuhei Masuda Yoichi Ishikawa Nozomi Sugiura Takahiro Toyoda Tomohiro Nakamura 《Journal of Oceanography》2003,59(6):931-943
A four-dimensional variational data assimilation system has been applied to an experiment to describe the dynamic state of
the North Pacific Ocean. A synthesis of available observational records and a sophisticated ocean general circulation model
produces a dynamically consistent dataset, which, in contrast to the nudging approach, provides realistic features of the
seasonally-varying ocean circulation with no artificial sources/sinks for temperature and salinity fields. This new dataset
enables us to estimate heat and water mass transports in addition to the qualification of water mass formation and movement
processes. A sensitivity experiment on our assimilation system reveals that the origin of the North Pacific Intermediate Water
can be traced back to the Sea of Okhotsk and the Bering Sea in the subarctic region and to the subtropical Kuroshio region
further south. These results demonstrate that our data assimilation system is a very powerful tool for the identification
and characterization of ocean variabilities and for our understanding of the dynamic state of ocean circulation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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白令海峡夏季流量的年际变化及其成因 总被引：1，自引：1，他引：0
白令海峡是连接太平洋和北冰洋的唯一通道,穿过海峡的海水体积通量在年际尺度上的变化主要取决于海峡南北两侧的海面高度差,白令海峡的入流对北冰洋海洋过程有重要的意义。利用SODA资料计算夏季白令海峡海水体积通量,对其年际变化及成因进行分析。结果表明夏季白令海峡的体积通量主要是正压地转的;当体积通量为正距平时,楚科奇海、东西伯利亚海、拉普捷夫海以及波弗特海南部海面高度为负距平,同时,白令海陆架海面高度为正距平;对这些海域的Ekman运动、上层海洋温度、盐度和垂直流速进行分析,发现海面高度异常与海峡体积通量的这种关系主要是与海面气压异常分布所产生的Ekman运动有关。当白令海峡的体积通量为正距平时,北冰洋中央海面气压为正距平,白令海海盆海面气压为负距平。这种气压的异常分布在一定程度上解释了上层海洋运动、海水温盐结构与白令海峡入流的关系,从而把夏季大尺度大气环流和白令海峡体积通量的年际变化联系了起来。 相似文献
19.
According to data obtained in the Bering Sea during the 4th Chinese National Arctic Research Expedition, the distribution of dissolved oxygen(DO) was studied, causes of its maximum concentration were discussed, and the relationships between DO and other parameters, such as salinity, temperature, and chlorophyll a were analyzed. The results showed DO concentration ranged from 0.53 to 12.05 mg/L in the Bering Sea basin. The upper waters contained high concentrations and the maximum occurred at the depth range from 20 to 50 m. The DO concentration decreased rapidly when the depth was deeper than 200 m and reached the minimum at the depth range from 500 to 1 000 m, and then increased slowly with the depth increasing but still kept at a low level. On the shelf, the DO concentration ranged from 6.53 to 16.63 mg/L with a mean value of 10.75 mg/L, and showed a characteristic of decreasing from north to south. The DO concentration was higher in the area between the Bering Sea and Lawrence Island and was lower in the southeast and southwest of Lawrence Island at the latitude of 62°N. The formation of maximum DO concentration was concerned with phytoplankton photosynthesis and formation of the themocline. To the south of Sta. B07 in the Bering Sea basin, the oxygen produced by photosynthesis permeated to the deeper water and the themocline made it difficult to exchange vertically, and to the north of Sta. B07, the maximum DO concentration occurred above the themocline due to phytoplankton activities. On the shelf, the oxygen produced by phytoplankton photosynthesis gathered at the bottom of the thermocline and formed the DO maximum concentration. In the Bering Sea basin, the DO and salinity showed a weak negative correlation(r=0.40) when the salinity was lower than 33.1, a significant negative correlation(r=0.92) when the salinity ranged from 33.1 to 33.7, and an irregular reversed parabola(r=0.95) when the salinity was greater than 33.7. 相似文献
20.
AbstractBased on hydrological data obtained during the 7th to 9th Chinese National Arctic Research Expeditions in the summers of 2016–2018, the main water structure on the shelf of the northern Bering Sea and the volume and heat fluxes of the Bering Strait throughflow were analyzed. Distinct variability was identified in the three Pacific water masses feeding the strait - Anadyr Water (AW), Bering Shelf Water (BSW) and Alaskan coastal water (ACW). Overall, the temperature and salinity of the entire section increased each year, with 2018 showing significant anomalies, i.e., a temperature anomaly of up to 1?°C and a maximum salinity anomaly of 2. From 2016 to 2018, the extent of the ACW gradually narrowed in the eastern part of this section, while the AW expanded eastward each year. The net volume transport through each of the three sections increased poleward from 1.65?Sv to 2.76?Sv, with the AW increasing from 0?Sv to 1.03?Sv, the BSW varying between 0.52–1.65?Sv, and the ACW gradually decreasing from 1.04?Sv to disappearing completely. The net heat fluxes were also poleward, varying between 25.77 TW and 61.50 TW, and showing a significant increase. Significant variations in magnitude and extent were observed in each water mass of the Bering Strait throughflow, which could produce widespread effects in the Arctic Ocean and the global ocean beyond. 相似文献