登录 | 注册 | 中文  | English  | 用时: 0.57s
元数据
高级检索
首页 > 中国极地考察知识库 > 成果信息库 > 已审查 南北极海区夏季海-气二氧化碳交换特征及其所揭示的海洋学问题研究

南北极海区夏季海-气二氧化碳交换特征及其所揭示的海洋学问题研究

【标题】南北极海区夏季海-气二氧化碳交换特征及其所揭示的海洋学问题研究

【Title】

【作者】 高众勇

【Author】 Gao Zhongyong

【导师】

【Tutor】

【作者基本信息】

【网络出版投稿人】厦门大学

【出版时间】

【关键词】 二氧化碳; 海-气交换; 碳通量; 全球变化; 南大洋; 北冰洋和亚北极水; 中国南; 北极科学考察(CHINARE)

【Keywords】

【摘要】 本研究利用1999年中国首次北极科学考察、以及1999—2000年度的中国第16次南极科学考察机会对沿途航线上全球纬度范围的海区的海-气交换进行了的详细的调查,描绘了大气及表层海水CO_2分压(pCO_2)的全球纬度特征及其在不同海区之间的差异,并着重研究了南大洋及北冰洋的表层海水CO_2分压(pCO_2)的分布特征,讨论并揭示其所代表海洋学问题及意义。文章讨论了各海区CO_2分压(pCO_2)与表层海水温度(SST)、水文物理过程影响及生物吸收等因素的相关关系,研究控制pCO_2变化的主要调控因子。并利用这些关系,研究pCO_2在南大洋及北冰洋的分布特征,讨论其特殊性,探讨其所揭示的有关海洋学问题和规律。借助于全球各海区pCO_2主要调控因子的分析,本论文重点研究了南、北极海区。在南大洋,根据pCO_2的变化特征,找到海冰区与非海冰区的性质的巨大差异,为研究南大洋海冰区在全球变化中的作用与反馈提供了依据;同时,在白令海及北冰洋,根据pCO_2的分布特征,找到了整个白令海水文环流对北极碳汇的显著影响,并发现整个北太平洋亚北极水的保守混合性质,为北极地区在全球变化研究中的作用提供了重要依据。 详细的主要研究结果如下: 1.从南极至北极沿途航线各海区对大气CO_2的吸收能力如下(大气CO_2的汇区之间比较): 南大洋海冰区(夏季3月份)>北冰洋夏季(8月份)>北太平洋西北部(7月份)>东海(3月)>楚克奇海(夏季8月及7月)>北太平洋西北部(8月份)>台湾海峡(11月)>白令海(夏季7月及8月)>鄂霍次克海(7月)>白令海峡(8月)>台湾海峡(3月)>东黄海(7月)>东海(11月)>白令海峡(7月)>30—40°S南印度洋(11月)>30—40°S南印度洋(3月)>日本海(7月)>30°S以北南印度洋(11月) 2.南中国海3月份吸收通量几乎为零外,而在11月份时其为大气CO_2的 5 一。 源,其它CO。的源区主要是热带海区、40“一60”S南印度洋、以及南极 辐散带,其中,40”一60”S南印度洋在 11月份及 3月份都有很高的负通 量,为显著的大气COZ的源。 3.整个南大洋是一个复杂多变的水文学区域,其自身包含着的亚系统以及 & 各种水文锋面,都会对尸COZ的分布特征产生重要的影响。在夏季高生 产力季节,海冰区由于融冰淡水分层带来的水体垂直稳定性的影响等原 因,有利于浮游植物生长,生产力大大提高,逐渐发展成生物因子控制 表层海水的厂COZ特征。而在非海冰区,这种影响并不显著,因而形成 海冰区与非海冰区的巨大差异。这使得南大洋在大规模尺度上,可以划。 分为海冰区和非海冰区两大部分。 4.在海冰区夏季的高生产力季节,生物影响通常都能够发展成尸*Q的主 要调控因子,比如,夏季普里兹湾湾内地区全部被生物过程影响所主控, 并成为CO。的一个强汇区;但在一些海区,水文物理过程依然可以主控 着尸COZ的变化,比如普里兹湾外的南极辐散带,由于绕极深层水(CDW)$ 的向上涌升,本来是强汇的普里兹湾一下子变成大气COZ的源区,这是 由于受到富含CO。的深层水影响的原因,所以,虽然整体上,夏季海冰 区尸CO。的分布特征主要由生物影响所主控,但在一些局部的海区水文 物理过程仍然产生控制作用。 5 相比之下,北冰洋夏季尸CO。的分布受到环流的影响十分明显,并且带 有很显著的保守性。这种保守性为检测北太平洋亚北极水对北极碳汇的 影响起到了十分重要的作用。根据这一特性,可以研究白令海水向楚克 奇海的输移过程、变化以及影响。研究发现,虽然前人的结果表明,白 令海的I7CO。特征受生物生产力影响控制,但这是在高生产力的陆架区 的情况,在深海的白令海盆情况并不相同,其尸*0。的特征显著地受到 水文环流的影响,而不是生物因子在控制。另一方面,其自身带有明显 的HNLC性质。多数研究者也都认同这一观点。 6.北极诲区的这一显著特性为研究北极地区的碳循环及其在全球变化中的 作用与反馈有着十分重要的意义。一方面,由于北太平洋水是北冰洋营。 养盐的一个来源,而北冰洋表层营养盐在夏季几乎耗尽,因此从HNLC 的白令海盆流过来的白令海亚北极水,将有利于北冰洋夏季浮游植物的 生长,形成有机碳汇。另一方面,注人白令海的淡水来源的无机碳在白 令海没有向深海输出,而通过阿拉斯加沿岸流全部注入北冰洋,形成一 个重要的无机碳汇,这两大碳汇都将在北极对全球变化的响应中起着十 分重要的反馈作用。 7 60”E—80”W之间的南大洋海冰区在整个夏季都是大气COZ的净汇区, 其COZ的源汇分布状况可描述为:(对大气COZ的吸收能力)南大西洋 东、西部(45八N一30W及m”W—m”E)>南印度洋>南大西洋中部.

【Abstract】 This study has based on the data from the First Chinese National Arctic Research Exploration and the 1 6th Chinese National Antarctic Research Expedition (CHINARE-16), respectively in July to September 1999 and November 1999 to April 2000. The partial pressure of carbon dioxide in surface sea water and atmosphere (pCO2 and PCO2) along the tracks of two cruises was continually measured during the summer voyages. Distributions of pCO2 and PCO2 were described in different areas along the tracks. Characteristics of the distribution of pCO2 in those two regions were specially s tressed and their implications in oceanography were also discussed in more detail. Relationships have been calculated between partial pressure of carbon dioxide and its relative factors, such as the surface seawater temperature (SST), effect of hydrographic processes, and biological uptakes. Using these analyses, the importance of the Arctic and Antarctic Regions in future's global change were revealed. In the Southern Ocean, great differe nces between ice zone and none ice zone were found out based on characteristics of pCO2, which offered important foundation t o t he r ole a nd feedback o f s easonal i ce z one o f t he S outhem Ocean i n g lobal change. Also we found the dominating effect of circulation in Bering Sea on the carbon sink of Arctic, in Bering sea and the Arctic Ocean, and we found the conservative character of whole the subarctic water in the North Pacific Ocean, which is an important foundation on the role of the Arctic in global change. Some results can be summarized as the folio wings: 1. The capacities of absorbing atmospheric carbon dioxide in different sea areas from the Antarctic to the Arctic along the tracks (comparisons of sinks): Seasonal Ice Zone in the Southern Ocean (Mar. in summer) > the Arctic (Aug. in summer) > northeast of Pacific Ocean (July) > East China Sea (Mar.) > Chuckchi Sea (July and Aug. in summer) > northeast of Pacific Ocean (Aug.) > Taiwan Strait (Nov.) > Bering Sea (July and Aug. summer) > Okhotsk (July) > Bering Strait (Aug.) > Taiwan Strait (Mar.) > Yellow Sea and East China Sea (July) > East China Sea (Nov.) > Bering Strait (July) > 30-40癝 belt of the Southern Ocean (Nov.) > 30-40癝 belt of the Southern Ocean (Mar.) > Japan Sea (July) > the north of 30癝 belt in the Southern Indian Ocean(Nov.) 2. The air to sea flux of carbon dioxide in the South China Sea in March is approach to zero, but appears as a source as the atmospheric C02 when November. Also shows as sources are those areas such as the tropic ocean, 40皸60癝 belt of the Southern Indian Ocean, and the Antarctic Divergence. Among those, the Southern Indian Ocean between 40?and 60癝 have all strong negative flux in March and November, suggesting as a strong source as the atmospheric CO2. 3. The Southern Ocean presented a very complicated behavior of distributions of air -sea CO2 with hydrology and biology, including many sub-systems and hydrological fronts, which appeared different distributions of pCO2 greatly. The increasing of primary production will stimulate uptakes of CO: during summer in seasonal ice zone for the reasons of ice melting, by which there are much fresh water overlay the surface and caused the special vertical stability in the whole water column, and its benefit of plankton growth. Thus the biological factors dominate the feature of pCO2 distributions at that time. In none ice zone, however, such biological effects are not showed significantly at all. Therefore, It's the remarkable difference between Ice Zone and None Ice Zone, and by which the Southern Ocean can be divided into such two parts as ice zone and none ice zone. 4. In g eneral, b iological e ffects w ill b ecome a s a m ain d riving force i n t he s easonal ice zone in austral summer, for example, it is strongly controlled by biological factor inside of Prydz Bay in austral summer as a strong sink of atmospheric CO2. In other regions, however, hydrological processes are still dominate distributions of pCO2.

【基金/项目】

【下载】 PDF(7.1 MB)