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91.
冰芯作为气候环境信息的良好载体,在研究过去大气环流异常中具有其他气候代用指标难以比拟的优势。本文重点综述了南极冰芯气候记录与南半球环状模(SAM-Southern Annular Mode)的关联特征:SAM与冰芯记录为同期变化,冰芯中NO-3、海盐组分(以Na+为代表)和水同位素比值δ18O同SAM指数具有较好的关联性;冰芯中SO2-4和MSA同SAM存在一定的关联,但相关性不显著;西南极冰芯记录的积累率同SAM具有较强的关联。需要说明的是,冰芯中各参数与SAM的相关性存在较大的空间差异。 相似文献
92.
针对南极普里兹湾内达恩利角附近海域的3个测站共12份海水样品,采用寡营养培养基分离培养极地浮游细菌,通过PCR方法获取其中95株细菌的16S rRNA基因序列。序列分析结果表明,分离获得的95株细菌分属α-变形杆菌纲(Alphaproteobactia)、γ-变形杆菌纲(Gammaproteobacteria)和拟杆菌门(Bacteroidetes)3个类群下的35个不同分类单元,其中α-变形杆菌纲为优势细菌,在不同水层中所占的比例为52.6%—62.5%。通过Shannon多样性指数分析发现,南极普里兹湾陆架区测站P2-14多样性指数较陆坡区两测站P2-11和P2-8的高,细菌多样性与浮游植物量和生产力水平呈现正相关。表层细菌Shannon多样性指数最低,50 m水层最高,100和200 m水层多样性指数变化不明显,真光层水体中细菌垂直分布与营养盐和溶解氧浓度存在关联。此外,采用寡营养陈海水培养基,还获得了一些与已报道的16S rRNA基因序列相似性较低的菌株,它们代表了微生物新物种,可能也是南极真光层特有的细菌。研究工作表明,南极普里兹湾真光层水体中蕴藏着丰富的浮游细菌资源,它们有待保护、开发和利用。 相似文献
93.
利用中国南极科学考察第21和27航次采集的普里兹湾表层沉积物样品,分析了其中BBa的含量及分布特征,并讨论了控制其分布的相关因素。结果表明:分别利用直接扣除法和分步萃取法获得的BBa含量差别较大,直接扣除法获得的含量明显高于分步萃取法,这是因为扣除法获得的BBa中包含了大量的非生源钡,比如与样品中含砂量有密切联系的铁锰氧化物结合态钡,从而导致在该海域采用直接扣除法缺乏合理性。分步萃取法获得表层沉积物中BBa含量为104—445μg·g-1,平均值为227μg·g-1,呈现明显的空间分布差异,整体分布趋势为湾中心区域较高,浅滩及冰缘区较低。表层沉积物样品中BBa的含量及分布与BSi、OC以及上层水体的叶绿素a和初级生产力情况密切相关,说明上层水体的生物生产状况是BBa分布的主要控制因素。 相似文献
94.
基于南极半岛周边海域表层沉积物调查以及收集的资料,并通过分析表层沉积物粒度数据研究沉积物类型和分布特征,探讨沉积物的变化规律。南极半岛周边海域的沉积物类型比较丰富,主要分为四大类:砾质、砂质、粉砂质以及泥质沉积物;根据不同的水深和地貌单元可分为陆架(或岛架)碎屑沉积物、陆坡(或岛坡)沉积物和深海沉积物。研究区沉积物属于冰海沉积物,并可划分为残副冰碛物和混合副冰碛物。沉积物的搬运介质以冰川、冰筏为主,海流对沉积物的影响较为明显,沉积物类型随地形变化而呈有规律的分布。 相似文献
95.
《Polar Science》2014,8(4):370-384
An anomalous phytoplankton bloom was recorded in the Indian Ocean sector of the Antarctic Zone (AZ) of the Southern Ocean (SO) during the austral summer, 2011. Possible mechanisms for the triggering of such a large bloom were analyzed with the help of in situ and satellite data. The bloom, which formed in January 2011, intensified during February and weakened by March. High surface chlorophyll (Chl) concentrations (0.76 mg m−3) were observed in the area of the bloom (60°S, 47°E) with a Deep Chlorophyll Maximum (DCM) of 1.15 mg m−3 at a depth of 40–60 m. During 2011, both the concentration and spatial extent of sea ice were high on the western side of the bloom, between 0°E and 40°E, and enhanced freshwater influx was observed in the study area as a result of melting ice. A positive Southern Annular Mode (SAM) (with a resultant northward horizontal advection) and an intense La Niña during 2010–2011 are possible reasons for the high sea-ice concentrations. The enhanced Chl a observed in the study region, which can be attributed to the phytoplankton bloom, likely resulted from the influx of nutrient-laden freshwater derived from melting sea ice. 相似文献
96.
《Polar Science》2014,8(1):10-23
This study compares the common harmonic constants of the O1, K1, P1, Q1, M2, S2, N2, and K2 tidal constituents from eight global and four regional tide models with harmonic constants from satellite altimeter and tide gauge data for the northern region of the Antarctic Peninsula (58°S–66°S, 53°W–66°W). To obtain a more representative comparison, the study area was divided into three zones with different physical characteristics but similar maximum tidal amplitude variations: Zone I (north of 62°S), Zone II (south of 62°S and west of the Antarctic Peninsula), and Zone III (between 62°S and 64.3°S, and east of 58.5°W). Root sum square (RSS) values are less than or equal to 3.0, 4.2, and 8.4 cm for zones I, II, and III, respectively. No single model shows superior performance in all zones. Because there are insufficient satellite altimetry observations in the vicinity of Matienzo Base (64.9761°S, 60.0683°W), this station was analyzed separately and presents the greatest values of both root mean square misfit and RSS. The maximum, minimum, and average amplitude values of the constituents that follow in importance after the eight common tidal constituents, and which have amplitudes greater than 1 cm, are also analyzed. 相似文献
97.
《Polar Science》2014,8(3):242-254
In this paper we examine 2- and 3-way chemometric methods for analysis of Arctic and Antarctic water samples. Standard CTD (conductivity–temperature–depth) sensor devices were used during two oceanographic expeditions (July 2007 in the Arctic; February 2009 in the Antarctic) covering a total of 174 locations. The output from these devices can be arranged in a 3-way data structure (according to sea water depth, measured variables, and geographical location). We used and compared 2- and 3-way statistical tools including PCA, PARAFAC, PLS, and N-PLS for exploratory analysis, spatial patterns discovery and calibration. Particular importance was given to the correlation and possible prediction of fluorescence from other physical variables. MATLAB's mapping toolbox was used for geo-referencing and visualization of the results. We conclude that: 1) PCA and PARAFAC models were able to describe data in a satisfactory way, but PARAFAC results were easier to interpret; 2) applying a 2-way model to 3-way data raises the risk of flattening the covariance structure of the data and losing information; 3) the distinction between Arctic and Antarctic seas was revealed mostly by PC1, relating to the physico-chemical properties of the water samples; and 4) we confirm the ability to predict fluorescence values from physical measurements when the 3-way data structure is used in N-way PLS regression. 相似文献
98.
ZHANG Ling LU Xiaoqi WANG Zhangmin QIN Liqiang LIN Zhiqin YUAN Linxi ZHANG Wen YIN Xuebin 《极地研究(英文版)》2014,(1)
Antarctic krill is a potentially nutritious food source for humans, but fluorine(F) toxicity is a matter of concern. To evaluate the toxicity of F in Antarctic krill, 30 Wistar rats were divided into three groups with different dietary regimens: a control group, a krill treatment group(150 mg·kg-1 F), and a sodium fluoride(NaF) treatment group(150 mg·kg-1 F). After three months, F concentrations in feces, plasma, and bone were determined, and the degree of dental and skeletal fluorosis was assessed. The F concentrations in plasma and bone from the krill treatment group were 0.167 0±0.020 4 mg.L-1 and 2 709.8±301.9 mg·kg-1, respectively, compared with 0.043 8±0.005 5 mg·L-1 and 442.4±60.7 mg·kg-1, respectively, in samples from the control group. Concentrations of F in plasma and bone in the krill treatment group were higher than in the control group, but lower than in the NaF treatment group. The degree of dental fluorosis in the krill treatment group was moderate, compared with severe in the NaF treatment group and normal in the control group. The degree of skeletal fluorosis did not change significantly in any group. These results showed that the toxicity of F in Antarctic krill was lower than for an equivalent concentration of F in NaF, but it was toxic for rats consuming krill in large quantities. To conclude, we discuss possible reasons for the reduced toxicity of F in Antarctic krill. The present study provides a direct toxicological reference for the consideration of Antarctic krill for human consumption. 相似文献
99.
????2004??2008???ICESat???????????????GLA12???????????????????????????????????????仯????????????????????????????????????仯??????????????????????????????3 m??????????????????????仯????????????????????????????????? 相似文献
100.
南极普里兹湾及其邻近海域水团研究 总被引:3,自引:3,他引:0
普里兹湾及其邻近海域是中国南大洋调查研究的传统优势海域与重点区域。围绕夏季表层水、冬季水、陆架水、绕极深层水、南极底层水、普里兹湾底层水、冰架水等研究海区主要水团的特征和分布,总结了前人在南极普里兹湾及其邻近海域基于调查资料开展的水团研究中所取得的成果。研究表明,前人在对陆架水的示性指标界定上,将陆架水是否区分为高盐陆架水和低盐陆架水存在较大争议,在高盐陆架水和普里兹湾底层水的定义上存在重叠;目前尚没有证据表明绕极深层水向南可以伸展到普里兹湾的陆架区域,也没有发现在普里兹湾附近海域生成南极底层水的直接证据。 相似文献