热带太平洋海温异常对北极海冰的可能影响   总被引：1，自引：1，他引：0  

罗蕊  祁莉  张文君  何金海 《海洋学报》2017,39(7):53-69

本文利用1950-2015年间Hadley环流中心海冰和海温资料及NCEP/NCAR再分析资料,研究了热带太平洋海温异常对北极海冰的可能影响,并从大气环流和净表面热通量两个角度探讨了可能的物理机制。结果表明,在ENSO事件发展年的夏、秋季节,EP型与CP型El Niño事件与北极海冰异常的联系无明显信号。而La Niña事件期间北极海冰出现显著异常,并且EP型与CP型La Niña之间存在明显差异。EP型La Niña发生时,北极地区巴伦支海、喀拉海关键区海冰异常减少,CP型La Niña事件则对应着东西伯利亚海、楚科奇海地区海冰异常增加。在EP型La Niña发展年的夏、秋季节,热带太平洋海温异常通过遥相关波列,使得巴伦支海、喀拉海海平面气压为负异常并与中纬度气压正异常共同构成类似AO正位相的结构,形成的风场异常有利于北大西洋暖水的输入,同时造成暖平流,偏高的水汽含量进一步加强了净表面热通量收入,使得巴伦支海、喀拉海海冰异常减少。而在CP型La Niña发展年的夏季,东西伯利亚海、楚科奇海关键区受其东侧气旋式环流的影响,以异常北风分量占主导,将海冰从极点附近由北向南输送到关键区,海冰异常增加,而净表面热通量的作用较小。  相似文献   

HY-2卫星扫描微波辐射计数据反演北极海冰漂移速度   总被引：1，自引：1，他引：0  

王利亚  何宜军  张彪  刘保昌 《海洋学报》2017,39(9):110-120

本文基于最大互相关法,利用海洋二号（HY-2）卫星扫描微波辐射计37 GHz通道多时相垂直极化亮温数据,获取了北极海冰漂移速度。采用2012年和2013年国际北极浮标计划海冰现场观测数据,对利用微波辐射计亮温资料反演的冬季北极海冰漂移速度进行了定量验证,结果表明:流速和流向均方根误差分别为1.12 cm/s和16.37°,从一定程度上说明了HY-2卫星扫描微波辐射计亮温数据反演海冰漂移速度的可行性。此外,使用美国国防气象卫星F-17搭载的专用微波成像仪91 GHz通道垂直极化亮温,采用高斯拉普拉斯滤波方法进行处理,结合最大互相关法反演的海冰漂移速度,优于法国海洋开发研究院海冰漂移速度产品。  相似文献   

1982-2016年北极开阔水域变化   总被引：1，自引：0，他引：1  

李海丽  柯长青 《海洋学报》2017,39(12):109-121

近30年来,北极海冰覆盖范围大幅缩减,开阔水域也相应地发生显著变化。本文利用美国雪冰中心的海冰密集度产品以及美国海洋和大气科学管理局的海水表面温度数据产品,分析了1982-2016年北极开阔水域面积以及开阔水域季节长度的年际变化,并进一步探讨了海水表面温度对开阔水域时空变化的影响。结果表明北极开阔水域面积平均每年增加55.89×103 km2,海冰消退时间以平均0.77 d/a的速度在提前,海冰出现时间以平均0.82 d/a的速度在延迟,导致开阔水域季节长度以平均1.59 d/a的速度在增加。2016年达到了有遥感观测资料以来开阔水域面积和开阔水域季节长度的最大值,分别为13.52×106 km2和182 d。9个海区的开阔水域变化特征有一定的差异,对开阔水域变化贡献最大的有北冰洋核心区、喀拉海和巴伦支海。海水表面温度对开阔水域的变化有着重要影响,且影响的程度与纬度相关,即高纬度地区的海水表面温度对开阔水域的影响高于低纬度地区。  相似文献   

基于高光谱遥感的渤海海冰厚度半经验模型   总被引：1，自引：0，他引：1  

袁帅  顾卫  刘成玉  谢锋 《海洋学报(英文版)》2017,36(1):80-89

Sea ice thickness is one of the most important input parameters for the prevention and mitigation of sea ice disasters and the prediction of local sea environments and climates. Estimating the sea ice thickness is currently the most important issue in the study of sea ice remote sensing. With the Bohai Sea as the study area, a semiempirical model of the sea ice thickness(SEMSIT) that can be used to estimate the thickness of first-year ice based on existing water depth estimation models and hyperspectral remote sensing data according to an optical radiative transfer process in sea ice is proposed. In the model, the absorption and scattering properties of sea ice in different bands(spectral dimension information) are utilized. An integrated attenuation coefficient at the pixel level is estimated using the height of the reflectance peak at 1 088 nm. In addition, the surface reflectance of sea ice at the pixel level is estimated using the 1 550–1 750 nm band reflectance. The model is used to estimate the sea ice thickness with Hyperion images. The first validation results suggest that the proposed model and parameterization scheme can effectively reduce the estimation error associated with the sea ice thickness that is caused by temporal and spatial heterogeneities in the integrated attenuation coefficient and sea ice surface. A practical semi-empirical model and parameterization scheme that may be feasible for the sea ice thickness estimation using hyperspectral remote sensing data are potentially provided.  相似文献   

不同氮源下南极冰藻Chlamydomonas sp.ICE-L的生物量、氮吸收与脂肪酸组成研究     

安美玲  王以斌  刘芳明  綦晓青  郑洲  叶乃好  孙承君  缪锦来 《海洋学报(英文版)》2017,36(2):105-110

微藻培养过程中氮缺失有利于油脂和生物量的积累,然而不同氮源条件下微藻生长与生物量的研究有限,限制了生物油脂的相关研究。本文研究通过研究南极冰藻Chlamydomonas sp.ICE-L在不同氮源条件下的细胞生长与油脂积累,进一步探究其作为富集油脂微藻的潜力。研究发现：在含有NH₄CL的培养基中,Chlamydomonas sp.ICE-L生长速率最大;在含有NH₄NO₃的条件下,获得了最大干重量0.28 g/L。最高油脂含量0.21 g/g是在缺氮条件下获得,同时得到干重0.24 g/L。在多不饱和脂肪酸的产出方面,NH₄NO₃和NH₄Cl为氮源培养基时要好于缺氮和KNO₃培养基,在NH₄NO₃和NH₄Cl为氮源的培养条件下ICE-L胞内C18：3和C20：5的含量高。比较而言,缺氮和KNO₃培养基时C16：0、C18：1和C18：2的含量要高。  相似文献   

CMIP5气候模式模拟的北极海冰特征及其季节变化     

黄菲  周晓  王宏 《海洋学报(英文版)》2017,36(8):1-8

This paper is focused on the seasonality change of Arctic sea ice extent(SIE) from 1979 to 2100 using newly available simulations from the Coupled Model Intercomparison Project Phase 5(CMIP5).A new approach to compare the simulation metric of Arctic SIE between observation and 31 CMIP5 models was established.The approach is based on four factors including the climatological average,linear trend of SIE,span of melting season and annual range of SIE.It is more objective and can be popularized to other comparison of models.Six good models(GFDL-CM3,CESM1-BGC,MPI-ESM-LR,ACCESS-1.0,Had GEM2-CC,and Had GEM2-AO in turn) are found which meet the criterion closely based on above approach.Based on ensemble mean of the six models,we found that the Arctic sea ice will continue declining in each season and firstly drop below 1 million km~2(defined as the ice-free state) in September 2065 under RCP4.5 scenario and in September 2053 under RCP8.5 scenario.We also study the seasonal cycle of the Arctic SIE and find out the duration of Arctic summer(melting season) will increase by about 100 days under RCP4.5 scenario and about 200 days under RCP8.5 scenario relative to current circumstance by the end of the 21 st century.Asymmetry of the Arctic SIE seasonal cycle with later freezing in fall and early melting in spring,would be more apparent in the future when the Arctic climate approaches to "tipping point",or when the ice-free Arctic Ocean appears.Annual range of SIE(seasonal melting ice extent) will increase almost linearly in the near future 30–40 years before the Arctic appears ice-free ocean,indicating the more ice melting in summer,the more ice freezing in winter,which may cause more extreme weather events in both winter and summer in the future years.  相似文献   

2008年夏季加拿大海盆永久冰区的淡水累积现象     

童金炉  陈敏  杨伟锋  张润  潘红  郑敏芳  邱雨生  胡王江  曾健 《海洋学报(英文版)》2017,36(8):101-108

A combination of δ~(18)O and salinity data was employed to explore the freshwater balance in the Canada Basin in summer 2008.The Arctic river water and Pacific river water were quantitatively distinguished by using different saline end-members.The fractions of total river water,including the Arctic and Pacific river water,were high in the upper 50 m and decreased with depth as well as increasing latitude.In contrast,the fraction of Pacific river water increased gradually with depth but decreased toward north.The inventory of total river water in the Canada Basin was higher than other arctic seas,indicating that Canada Basin was a main storage region for river water in the Arctic Ocean.The fraction of Arctic river water was higher than Pacific river water in the upper 50 m while the opposite was true below 50 m.As a result,the inventories of Pacific river water were higher than those of Arctic river water,demonstrating that the Pacific inflow through the Bering Strait is the main source of freshwater in the Canada Basin.Both the river water and sea-ice melted water in the permanent ice zone were more abundant than those in the region with sea-ice just melted.The fractions of total river water,Arctic river water,Pacific river water increased northward to the north of 82°N,indicating an additional source of river water in the permanent ice zone of the northern Canada Basin.A possible reason for the extra river water in the permanent ice zone is the lateral advection of shelf waters by the Trans-Polar Drift.The penetration depth of sea-ice melted waters was less than 30 m in the southern Canada Basin,while it extended to 125 m in the northern Canada Basin.The inventory of seaice melted water suggested that sea-ice melted waters were also accumulated in the permanent ice zone,attributing to the trap of earlier melted waters in the permanent ice zone via the Beaufort Gyre.  相似文献   

格陵兰冰盖表面消融研究进展   总被引：3，自引：1，他引：2  

杨康 《冰川冻土》2013,35(1):101-109

冰盖表面消融是格陵兰冰盖物质平衡的重要组成部分, 已成为近年来格陵兰冰盖研究的热点. 格陵兰冰盖表面消融研究的关键在于理解冰盖融水的产生、 运移和释放等水文过程, 需要解决如下关键科学问题: 1) 冰盖表面产生了多少融水;2)冰盖表面水文系统具有什么特征; 3)冰盖表面融水如何影响冰盖运动; 围绕这些科学问题, 总结了格陵兰冰盖表面消融的研究进展. 冰盖表面消融建模、 冰盖表面湖的信息提取与面积特征变化、 深度反演与体积量算等是目前研究冰盖表面融水量的主要途径, 冰盖表面湖、 冰盖表面径流、 锅穴与冰裂隙等表面水文要素的空间分布规律研究则可用于揭示冰盖表面水文系统特征, 冰盖表面融水与冰盖运动速率的关系、 表面融水进入冰盖内部与底部的水文过程是目前揭示表面融水如何影响冰盖运动的主要手段.  相似文献   

The role of the Arctic and Antarctic and their impact on global climate change： Further findings since the release of IPCC AR4, 2007   总被引：1，自引：0，他引：1  

CHEN Liqi 《极地研究(英文版)》2013,(2):79-85

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杨元德  熊云琪  王泽民  鄂栋臣 《大地测量与地球动力学》2013,33(5):63-66

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