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1.
过去百年来人类活动排放的温室气体已经改变了全球海洋的物理和化学属性,并且,这种变化在未来很可能持续下去.基于IPCC第五次耦合模式比较计划(CMIP5)中IPSL-CM5A-MR地球系统模式的模拟结果,评估了未来百年(~2100年)中国近海区域的海洋环境要素(温度、盐度、溶解氧、pH值和叶绿素a浓度)的变化趋势及空间分布特征.结果表明,未来不同的温室气体排放情景下中国近海区域海温升高、溶解氧(DO)含量减少、海水pH值降低和叶绿素a浓度减少,并且温室气体排放越多上述变化越显著.东中国海区(包括渤海、黄海和东海)盐度可能会增加,而南海盐度会降低.在相同的温室气体排放情景下,东中国海区海温增加、溶解氧减少、海水pH值降低和叶绿素a浓度减少的幅度均显著高于南海区域.在中等浓度和高浓度排放情景(RCP4.5和RCP8.5)情景下,到21世纪末期(2090~2100年间)东中国海相对于历史时期(1980~2005年)的升温幅度可能将分别会超过2、4℃,海水pH值降低幅度将可能分别超过0.15和0.30,并且海洋变暖和酸化还将很可能引起DO含量和叶绿素a浓度的进一步降低,最终影响整个海区的环境与生态.因此,未来东中国海生态系统和生物多样性将面临严重风险,这也使得应对气候变化的适应性措施成为当前的紧迫议题. 相似文献
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基于IPCC-CMIP5的中国东部近海表层水温未来预估分析 总被引：1，自引：0，他引：1
近海海表温度（sea surface temperature，SST）的变化对我国沿岸海洋生态环境和渔业资源具有重要影响，研究其变化规律尤其是预估其未来变化一直是物理海洋学的重要研究课题。政府间气候变化专门委员会（Intergovernmental Panel on Climate Change，IPCC）第五次评估报告（The fifth Assessment Report，AR5）对全球及部分典型区域的未来气候变化进行了预估，已成为全球公认的研究气候变化的科学依据。本文利用IPCC第五次评估报告的模式比较计划（Coupled Model Intercomparison Project phase 5，CMIP5）中五个具有代表性的模式（ACCESS1.3、BCC-CSM1.1、CCSM4、GFDL-ESM2G、MPI-ESM-MR），对未来80年（2030、2060、2090年）相对于2010年中国东部近海（渤海、黄海、东海）表层水温的年代际及季节性变化规律在RCP4.5气候情景下进行了预估分析。通过分析发现中国东部近海表层水温在未来80年内有明显升温趋势：从年代际上看，到2090年表层水温升温幅度达1.18—1.71℃，其中2030—2060年升温最快，2060—2090年升温速度减缓；从季节上看，不同海域不同季节表层水温升温幅度达1.16—2.04℃，中国东部近海各海区在夏季升温幅度较大，冬季较小。 相似文献
3.
《海洋预报》2016,(5)
基于耦合模式比较计划第五阶段(CMIP5)的全球气候预估数据,分析了黄、渤海区域内海表面2m气温的增量,并将该增量叠加在1978—2008年的再分析气象场上,驱动海冰-海洋耦合模式,对2015—2045年黄、渤海的海冰变化特征进行了预估。结果显示:在RCP2.6、RCP4.5、RCP6.0和RCP8.5 4种排放情景下,辽东湾、渤海湾、莱州湾和黄海北部4个海湾的海冰均呈现显著减少的趋势。但随着排放增多,4个海湾的海冰并非单调的减少,而在RCP4.5下减少最多,RCP6.0和RCP8.5次之,RCP2.6最少。对4种情景下的海冰冰情进行平均,可以发现4个海湾结冰面积依次减少438、121、23和84 km2;结冰范围依次减少9、7、2和7 nmi(海里,1 nmi=1.852 km)。就整个黄、渤海而言,未来31a内结冰面积减少24%,结冰范围减少19%,持续天数缩短10%。 相似文献
4.
CMIP5模式对中国近海海表温度的模拟及预估 总被引：2，自引：0，他引：2
基于观测和再分析资料;利用多种指标和方法评估了国际耦合模式比较计划（CMIP5）中21个模式对中国近海海温的月、季节和年际变化模拟能力。多模式集合能够再现气候平均意义下近海海温的空间分布特征;但量值上存在一定的低估。在渤海和黄海;集合平均与观测差别比较明显。在年际尺度上;与观测数据对比;模式模拟海温与Niño3指数相关性较小。中国近海海表面温度在1960-2002年有明显的升高趋势;从2003年开始增温趋缓。评估结果表明;ACCESS1.0、BCC-CSM1.1、HadGEM2-ES、IPSL-CM5A-MR、CMCC-CM、FGOALS-g2、CNRM-CM5-2、INMCM4八个模式对中国近海海温的变化有较好的模拟能力。利用ACCESS1.0、INMCM4、BCC-CSM1.1、IPSL-CM5A-MR、CMCC-CM这5个模式结果对中国近海海温未来的变化进行了预估。在RCP4.5、RCP8.5情景下;未来近100年中国近海海温有明显升高趋势;最优模式多模式集合平均增温分别可达到1.5℃、3.3℃;净热通量变化和平流变化共同促进了东海升温。 相似文献
5.
中国近年来空气污染严重,尤其是臭氧污染问题日益突出,因此,探讨全球变暖下未来气候变化和污染源等综合作用如何影响中国臭氧污染,对中国未来污染控制具有重要意义。本研究主要利用Atmospheric Chemistry and Climate Model Intercomparison Project(ACCMIP)中GFDL和UMCAM模式评估气候和污染源变化对中国华北地区未来臭氧的影响,其中2001—2010年代为历史时段(Hist),其臭氧模拟浓度代表基准情况下气候和污染源排放的影响,未来情景包括中等排放强度情景(RCP4.5)和高排放强度情景(RCP8.5)。相对于Hist,RCP 4.5和RCP 8.5情景,本世纪末(2100)的华北地区臭氧显著降低,其主要原因在于人为源挥发性有机物和氮氧化物的降低所致。同时,在RCP 4.5和RCP 8.5两个情景中,华北地区2100年代夏季臭氧浓度低于春季,这意味着夏季浓度降低幅度更大,这主要在于臭氧前体物的减少对于光化学活跃在夏季的影响大于其它季节。如果保持污染源不变,仅考虑气候变化的影响,本研究通过对臭氧超标天数、频率和污染事件持续时间的分析,发现气候变化可进一步加剧华北地区未来臭氧超标天数,并且这种影响具有明显的空间差异性。对于ACCMIP全球模式空间分辨率不足问题,在未来的研究中,应结合区域模式来解析气候变化对臭氧影响的空间特征方面来加强研究。 相似文献
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近几十年来,在气候变化和人类活动的影响下,我国近岸河口海域尤其是长江口及邻近海域生态灾害频繁发生,严重影响了海洋生态系统的健康及其服务功能。本研究基于政府间气候变化专门委员会（Intergovernmental Panel on Climate Change, IPCC）气候变化风险理论框架,构建了河口浮游植物生态系统的气候变化综合风险评估指标体系,并利用IPCC 第五次耦合模式比较计划（CMIP5）地球系统模式数据,分别计算分析了在温室气体低（RCP 2.6）、中等（RCP 4.5）和高（RCP 8.5）浓度排放情景下未来不同时期（2030—2039、2050—2059、2090—2099年）长江口及邻近海域浮游植物生态的致灾因子危害性、承灾体暴露度和脆弱性及其综合风险。结果表明： RCP 2.6、4.5和8.5情景下,到21世纪中期,致灾因子危害性均有明显上升,其中RCP 4.5和8.5情景下,到21世纪末,还将大幅度增加,且以RCP 8.5情景最为显著,而RCP 2.6情景下则相反,有所下降;RCP 2.6情景下,高暴露度区域主要位于长江口附近,不同年代的变化差异较小;RCP 4.5和8.5情景下高暴露度区域明显大于RCP 2.6情景,尤其是后者到21世纪末期扩大至长江口邻近海域;脆弱性总体呈现近岸高远岸低的分布特征,且变化均较小;RCP 2.6、4.5和8.5情景下,综合风险均呈现近岸高远岸低,且有增加的趋势,但以RCP 8.5情景最为明显,并在21世纪末达到最大。 相似文献
7.
为了研究第六次国际耦合模式比较计划(CMIP6)中新提出的“情景模式比较计划”(ScenarioMIP)下中国近海气象要素的变化情况, 本文选取了其中6个海气耦合模型, 对其模拟的风速、气温、降水进行评估与预测。评估结果表明选取的模式对中国近海模拟效果整体都不错, 但在菲律宾群岛附近模拟结果相对欠佳。模型平均预估结果表明未来21世纪中叶4个情景下渤黄海风速夏季增加、冬季减弱; 至21世纪末, 研究海域夏季15°N以北(南)风速主要呈增加(减小)的趋势, 冬季25°N以北(南)风速主要呈减小(增加)的趋势。4个未来情景下的中国近海气温都将持续升高, 高纬区域增幅大于低纬。可持续发展情景(SSP1-2.6)能有效减缓升温, 其他放任温室气体大量排放的情景(如SSP5-8.5), 则会加剧升温。未来中国近海降水变化总体上呈增加趋势, 渤黄海与东海降水增幅在SSP5-8.5情景下最大, 世纪末分别增加约15.87%与5.61%; 南海降水增幅在SSP2-4.5情景下最大, 世纪末增加约4.84%。 相似文献
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9.
CMIP5模式对南海SST的模拟和预估 总被引：4，自引：1，他引：3
分析了32个CMIP5模式对南海历史海表温度(SST)的模拟能力和不同排放情景下未来SST变化的预估。通过检验各气候模式对南海历史SST增温趋势和均方差的模拟,发现大部分模式都能较好地模拟出南海20世纪历史SST的基本特征和变化规律,但也有部分模式的模拟存在较大偏差。尽管这些模拟偏差较大的模式对SST多模式集合平均的影响不大,但会增加未来情景预估的不确定性。剔除15个模式后,分析了南海SST在RCP26、RCP45和RCP85三种排放情景下的变化趋势,发现在未来百年呈明显的增温趋势,多模式集合平均的增温趋势分别为0.42、1.50和3.30℃/(100a)。这些增温趋势在空间上变化不大,但随时间并不是均匀变化的。在前两种排放情景下,21世纪前期的增温趋势明显强于后期,而在RCP85情景下,21世纪后期的增温趋势强于前期。 相似文献
10.
《海洋预报》2016,(6)
基于中国气象局热带气旋最佳路径数据集,结合7个全球耦合模式在4个气候情景(Historical、RCP2.6、RCP4.5、RCP8.5)下的模拟场,对比分析了模式模拟1986—2005年登陆我国热带气旋(LTC)活动的气候特征,并评估了未来(2026—2045年)不同气候情景下LTC活动的频数和强度变化特征。结果表明:在Historical情景下虽然各模式模拟的1986—2005年LTC均少于观测值,但仍然较好的再现LTC的季节分布、地理位置分布和强度分布特征。未来气候情景下不同强度LTC的频数预估则显示,相对于Historical情景,RCP2.6和RCP8.5情景下较弱的LTC有减少的趋势,而较强的LTC则表现为略微的增加。另外,对比不同模式的结果可以发现,模式中若中国大陆近海区域平均垂直风切变和海平面气压较大,则其对应的LTC活动较少;若模式中海表温度较高,则LTC的平均登陆强度较大。 相似文献
11.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
12.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
13.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
16.
The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
17.
Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
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Hoi-Soo Jung Kap-Sik Jeong Yong-Shik Chu Sung-Hyun Park Ki-Hyune Kim 《Marine Georesources & Geotechnology》2001,19(3):181-195
Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors. 相似文献
20.
Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献