2002年1月份南极普里兹湾海域南极磷虾(Euphausia superba Dana)的丰度和种群结构研究

对2002年1月份在南极普里兹湾海域三条断面(68.5°E、70.5°E和73°E)用IKMT网采集的幼体后期南极磷虾(E.superba)的水平分布和种群结构进行了研究.南极磷虾主要位于64°S以南的海域,64°S以北磷虾数量很少.南极磷虾的平均丰度和生物量分别为68.85 ind·1 000 m-3和24.16 g...     

南极普里兹湾溶解态镉的分布

利用25次南极科考获得的海水样,采用原子分光光度法(AAS)测定了海水中溶解态镉的含量,研究了东南极普里兹湾不同空间与时间尺度下海水中溶解态镉的分布特征.并利用同航次相关的营养盐、叶绿素a等数据,分析了影响海水中溶解态镉分布的主要因素.研究结果显示,普里兹湾表层海水中溶解态镉的分布与叶绿素a具有良好的相关性,生物过程是...     

Cold-adaptive alkaline protease from the psychrophilic Planomicrobium sp.547: enzyme characterization and gene cloning

A psychrophilic bacterium strain 547 producing cold-adaptive alkaline protease was isolated from the deep sea sediment of Prydz Bay, Antarctica. The organism was identified as a Planomicrobium species by 16S rRNA analysis. The optimal and highest growth temperatures for strain 547 were 15℃ and 30℃, respectively. The extracellular protease was purified by ammonium sulfate precipitation and DEAE cellulose-52 chromatography. The optimal temperature and pH for the activity of the purified enzyme were 35 ℃ and pH 9.0, respectively. The enzyme retained approximately 40% of its activity after 2 h of incubation at 50℃. The enzymatic activity was inhibited by 1 mmol/L phenylmethyl sulfonylfluoride (PMSF) and hydrochloride 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF), indicating that it was a serine protease. The presence of Ca2+ and Mn2+ increased the activity of the enzyme. The protease gene with a size of 1 269 bp was cloned from Planomicrobium sp. 547 using primers designed based on the conserved sequences of proteases in GenBank. The Planomicrobium sp. 547 protease contained a domain belonging to the peptidase S8 family, which has a length of 309 amino acid (AA) residues. The alignment and phylogenetic analysis of the AA sequence indicated that the protease belonged to the subtilisin family.     

Thickness distribution and extent of sea ice and snow in Prydz Bay and surrounding waters observed in 2012/2013 austral summer

Three ship-based observational campaigns were conducted to survey sea ice and snow in Prydz Bay and the surrounding waters(64.40°S–69.40°S, 76.11°E–81.29°E) from 28 November 2012 to 3 February 2013. In this paper, we present the sea ice extent and its variation, and the ice and snow thickness distributions and their variations with time in the observed zone. In the pack ice zone, the southern edge of the pack ice changed little, whereas the northern edge retreated significantly during the two earlier observation periods. Compared with the pack ice, the fast ice exhibited a significantly slower variation in extent with its northernmost edge retreating southwards by 6.7 km at a rate of 0.37 km?d-1. Generally, ice showed an increment in thickness with increasing latitude from the end of November to the middle of December. Ice and snow thickness followed an approximate normal distribution during the two earlier observations(79.7±28.9 cm, 79.1±19.1 cm for ice thickness, and 11.6±6.1 cm, 9.6±3.4 cm for snow thickness, respectively), and the distribution tended to be more concentrated in mid-December than in late November. The expected value of ice thickness decreased by 0.6 cm, whereas that of snow thickness decreased by 2 cm from 28 November to 18 December 2012. Ice thickness distribution showed no obvious regularity between 31 January and 3 February, 2013.     

南极普里兹湾夏季海冰边缘区内破碎海冰的分布特征

基于中国第21次南极考察中获得的69°00'S、76°24'E附近普里兹湾夏季海冰边缘区内破碎海冰的航拍照片,利用图像处理的方法从中提取了破碎海冰的若干几何参数,得到了海冰边缘区内随着与开阔水域距离增大,海冰面积、平均钳测直径等几何参数的变化规律。并按其尺寸的变化规律将海冰边缘区划分为边界区、过渡区和内部区三部分,其变化和波浪在冰边缘区中的衰减过程紧密相关。圆度的变化则说明海冰边缘区中海冰磨损最充分的地方是在冰间相互作用最明显的过渡区。另外,一种改进的幂函数分布和Weibull分布用来对破碎海冰尺寸的累积频率进行拟合,分布函数中各参数的变化情况很好的反映了海冰边缘区内破碎海冰的分布变化。其中,参数L_r随着与开阔水距离增加而增大(说明由于波能衰减导致可以出现的破碎海冰最大尺寸的增加);尺度参数L₀随着与开阔水距离增加而增大(反映了破碎海冰平均尺寸的增加以及由于波能的衰减而导致单位面积区域内尺寸较大的破碎海冰所占比例的增加);分布维数D随着与开阔水距离增加而减小(说明了由于波能的衰减导致破碎海冰所受约束条件的减弱);形状参数γ随着与开阔水距离增加而减小(说明了随着波能的衰减破碎海冰尺寸分布范围的增大)。     

南极普里兹湾地区近10a来的气候变化特征

1引言南极地区是全球气候与环境变化的敏感区,已成为国内外学者研究的重点地区。研究表明,南极地区近40a的温度上升了约0.6℃,但南极不同区域的气候变化存在较明显的差异,如南极半岛地区的增温趋势明显,而东南极大陆许多测站的温度呈降温趋势。因此分析区域性气候变化特征时,除     

1999/2000年夏季南极普里兹湾及湾口区叶绿素a和初级生产力

20 0 0年 1月 1 9日至 2 7日在 70°3 0′E- 75°3 0′E,6 2°S以南的南极普里兹湾近岸陆架区的陆隆向深海区设三条纵断面进行浮游生物现存量、真光层深度和光合作用速率的现场观测。并在冰间湖站 - 1 2进行连续昼夜观测。结果表明 ,观测海区叶绿素 a浓度高值位于近岸海湾、冰间湖和测区中部的陆坡区 ;陆坡中部站 - 6和 - 8,0 - 5 0 m的浅水层为叶绿素 a高值区 (2 .1 6- 5 .0 8μg/dm3 )。各测站平均叶绿素 a浓度 2 5 m次表层 (1 .49± 1 .6 1 μg/dm3 )高于表层 (1 .1 4±1 .1 9μg/dm3 ) ,5 0 m以下更深层的浓度随深度的增加而降低 ,2 0 0 m层叶绿素 a浓度仅 0 .0 3±0 .0 2μg/dm3 。昼夜观测结果表明表层叶绿素 a浓度在南极夏季的午后出现最大值 ,晨间出现最小值 ;2 5 m以浅水层的叶绿素 a浓度明显高于深层水 ,与封冰消融冰藻的释放有关。测区真光层潜在初级生产力为 0 .76 - 1 2 .5 9mg C/(m3· h) ,平均值为 4.0 1± 4.0 7mg C/(m3· h) ;海湾和陆架区现场生产力均超过 1 .5 g C/(m2 · d) ,陆坡、深海区约 0 .5 g C/(m2 · d)。高生产力位于高生物量的近岸海湾、陆架冰间湖区。光合作用同化数在 0 .88- 3 .1 0 mg C/(mg Chla· h)。表层叶绿素a浓度与海水中溶解氧浓度呈紧密相关 (Y=0 .0 5 9X     

南极普里兹湾NP951柱样元素地层与古环境初步研究

对南极普里兹湾ＮＰ９５１柱样的元素地球化学特征及其古环境意义进行了研究。结果表明，本区沉积物在沉积过程中受冰盖消融、淡水涌入和陆源物质的影响较大；沉积物中ＳｉＯ２、Ａｌ２Ｏ３、Ｆｅ２Ｏ３、ＣａＯ、ＭｇＯ、Ｐ、Ｓ、Ｃｏｒｇ等元素组分较好地记录了由古气候变化而引起的物源改变，这些元素组分在地层中的分布规律与古海洋沉积环境及古气候变迁相一致；自晚更新世末期以来的气候大致可分为温暖期、寒冷期、高温期、转冷期和转暖期五个区段；在柱样的１４５ｃｍ（１４．４ｋａＢ．Ｐ．）、８５ｃｍ（１０．３ｋａＢ．Ｐ．）和２５ｃｍ（６．３ｋａＢ．Ｐ．）处出现了古气温的高值点，指示了气候的变化；８５ｃｍ处元素含量的突变指示了异常事件的发生，该层位正好对应于哥德堡地球磁场漂移，全球气温突然变暖，标志着１０．３ｋａＢ．Ｐ．以后南极地区进入了全新世。     

南极普里兹湾及邻近海域二氧化碳的分布及其海气通量

本文根据１９９１年１２月至１９９２年１月在普里兹湾及其邻近海域所作的现场观测，采用红外分析法测定了表层水和大气ＣＯ２分压，结果表明，表层水ＰＣＯ２的分布大致呈近岸低、远岸高的特征，其分布变化主要受生物活动控制。利用通量计算模式，估算出ＣＯ２在调查海域的平均海－气通量为－７１．９ｇ／（ｍ２ａ），通量的可能误差主要来自与风速有关的交换系数。     

南极洲普里兹湾岩石圈各向异性:海底地震仪观测

为了研究南极普里兹湾岩石圈深部应力场及其动力学,采用S波分裂旋转相关法,对中国第31次南极科学考察成功回收的3个站位海底地震仪数据(5个远震记录)进行了反演,获得了普里兹湾洋陆过渡带岩石圈各向异性特征.结果表明,台站所在区域各向异性显著,在较小的范围内存在明显的空间差异,快S波偏振方向变化范围是N40°E ~ N60°E,快慢波时间延迟变化范围为0.2~1.3 s.洋盆的各向异性主要取决于海底扩张地幔流作用,大陆及附近的各向异性主要受上地幔顶部残留构造的影响,而中间过渡带各向异性层厚度较小集中在地壳内,它可能受海底扩张地幔流和残留构造共同作用.