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1.
根据2001年10—11月在赤道北太平洋海域(含赤道东太平洋东、西部海区和西太平洋暖池区)的调查资料,分析了该海域水体中二氧化碳体系各组分的含量及其分布状况,并对其与营养盐及碳酸钙饱和度之间的关系进行了初步探讨。结果表明,表层海水总二氧化碳(∑CO2)含量为1.07—2.01mmol.L^-1,自赤道北太平洋东部向西呈逐渐降低趋势;表层海水二氧化碳分压(Pco2)高于大气二氧化碳分压平均值,表明赤道北太平洋可能为大气二氧化碳的海水源区;海水二氧化碳体系的垂直分布主要受生物生命过程和碳酸钙沉淀与溶解过程影响。  相似文献   

2.
海洋是自然界中重要的碳汇,海-气二氧化碳通量通常利用大气和海水表层的二氧化碳分压(pCO2)差进行估算。受制于时空分布不均匀的观测样本和预测数据,目前已有海水表层二氧化碳分压的重构结果在空间分辨率上仍有较大可提升空间。为在高空间分辨率下更好地拟合时空变化,基于表层大洋二氧化碳地图(SOCAT)的海水表层二氧化碳逸度(f CO2)数据集和遥感卫星等多源数据,利用XGBoost模型建立了海水表层二氧化碳分压值与海洋物理、生物、光学等要素的非线性关系,并根据样本时空频率构建权重模型,最终重构了2000-2018年大西洋0.041 7°×0.041 7°下月度海水表层二氧化碳分压分布。预测结果的相关系数为0.966,均方根误差为8.087μatm,平均偏差为4.012μatm,与同类重构结果相比,海水表层二氧化碳分压的时空变化趋势一致性强,且在空间分辨率上具有优势。  相似文献   

3.
海?气界面CO2通量的估算采用块体公式,其等于气体交换速率、CO2溶解度以及海水与大气的CO2分压差的乘积,其中的气体交换速率通常与风速相联系,不同作者提出了气体交换速率为风速不同幂次多项式的参数化方案。本文对比了气体交换速率为风速函数的主要研究结果,发现与风速多项式的依赖关系相比,观测数据所基于的观测方法对于气体交换速率的影响更大。在此基础上,本文用多种不同的气体交换速率参数化公式计算了1982?2018年全球的CO2通量,海洋整体上是大气CO2的汇,赤道海区是源,南北半球40°附近的海域构成沿纬向的强吸收带。37 a间,海洋CO2通量的年平均值(以碳计)为(?1.53±0.15) Pg/a, 1999年前,海洋吸收量逐年减小,1999年达到最小值,之后海洋吸收量开始增大,海洋吸收量的增大主要发生在南大洋。  相似文献   

4.
周日观测对掌握近海碳酸盐体系变化和海-气CO2交换过程是必要的,有助于降低碳源汇评估的不确定性。针对北部湾东北部的英罗湾-安铺港海域,于2018年4月和8月利用24 h定点逐时采样观测了该区域表层海水碳酸盐体系及相关要素,分析了春、夏季的表层海水CO2分压(p CO2)24 h逐时变化规律及其调控因子。观测结果表明,春、夏季p CO2变化范围分别为530~628μatm和427~748μatm,平均海-气CO2通量分别为(1.7±0.8)mmol/(m2·d)和(1.2±0.8)mmol/(m2·d),均表现为大气CO2的弱源。其中春季p CO2 24 h逐时变化受温度的影响相比夏季更显著,而夏季p CO2对潮汐作用以及区域内沿岸河流、地下水等淡水汇入引起的生物生产和呼吸代谢过程增强的响应更明显。海水升温主导了春季区域表层高p CO2的形成,夏季咸淡水的物理混合过程中增...  相似文献   

5.
依托2017年8月23日至2017年9月6日在长江口及邻近海域连续走航测得的二氧化碳分压(pCO2)值,结合温度、盐度、溶解氧等数据,阐述该海域pCO2的分布特征,并利用一次大风事件前后一个断面的重复观测数据,讨论天气事件对长江口海-气CO2通量的影响。夏季长江口及邻近海域表层海水pCO2范围为145~929 μatm,总体呈近岸高远岸低的分布特征,在受长江冲淡水影响的区域,海表pCO2较低,整体表现为大气CO2的汇。大风事件(最大风速达9.7 m·s-1)加强了水体的垂直混合,导致近岸区域从大气CO2的弱源变为强源(CO2通量从0.2±1.9上升到 55.0±12.4 mmol·m-2·d-1),而远岸区域的碳汇略有加强(CO2通量从-12.7±2.3变为-16.8±2.5 mmol·m-2·d-1)。因此,在估算东海海-气CO2通量时,台风、冷空气等短时间尺度天气事件的影响也不容忽视。  相似文献   

6.
表层海水二氧化碳分压是评估海洋碳源汇强度的关键参数,但其实测数据较少、时空分布极不均匀,导致二氧化碳交换通量的估算有很大的不确定性,海洋源汇特征就不能确切获取。为了解决这个难题,在收集的表层大洋二氧化碳地图(Surface Ocean CO2 Atlas,SOCAT)实测数据集基础上,运用广义回归神经网络建立二氧化碳分压与经纬度、时间、温度、盐度和叶绿素浓度间的非线性关系,构建了1998?2018年间全球1°×1°经纬度的表层海水二氧化碳分压格点数据,其标准误差为16.93 μatm,平均相对误差为2.97%,优于现有研究中的前反馈神经网络、自组织映射神经网络和机器学习算法等方法。根据构建的数据所绘制的全球表层海水二氧化碳分压的分布与现有研究有较好的一致性。  相似文献   

7.
采用船载海?气CO2连续观测系统于2011年和2014年夏季在琼州海峡开展了现场观测,分析研究了表层海水二氧化碳分压(pCO2)时空变化及其影响因子。2011年和2014年夏季pCO2分别为(516±29) μatm和(533±15) μatm,海?气CO2交换通量分别为(8.4±1.7) mmol/(m2·d)和(4.5±0.4) mmol/(m2·d),均是大气CO2的强源,高于相邻及相似海域,主要受控于东口海域上升流和海峡中部狭管效应。2011年夏季东口上升流增大pCO2的同时也促进了浮游植物繁殖,光合作用吸收水体CO2,降低了pCO2,而且受其影响,西口口门附近叶绿素a和溶解氧含量陡增,pCO2突降。2014年夏季东口海域上升流较弱,且观测海域垂直混合作用显著,pCO2和溶解氧分布特征与2001年夏季明显不同。海峡中部狭管效应造成水体输运速率大、混合作用强,浮游植物“来不及”生长,pCO2较高。  相似文献   

8.
姜正  张荣华  宫勋 《海洋与湖沼》2023,3(3):689-702
为研究赤道太平洋海表二氧化碳分压(pCO2sw)年际变化的机制,基于中科院海洋所宋金明研究团队于2021年发布的中国首套全球海表二氧化碳分压数据产品,使用相关性分析、经验正交函数(empirical orthogonal function, EOF)分析和奇异值分解(singular value decomposition, SVD)等方法,研究了2005~2019年赤道太平洋pCO2sw气候态分布及其去趋势后的年际异常的时空演变特征;结合pCO2sw与多种参数的相关性和厄尔尼诺-南方涛动(El Ni?o-Southern Oscillation, ENSO)过程探讨了赤道中西太平洋pCO2sw年际异常中心形成的原因。研究结果显示,热带太平洋pCO2sw季节变化、年际异常及其EOF第一模态特征向量沿赤道均出现两个中心,其中一个在赤道中西太平洋日界线附近,另一个在赤道中东...  相似文献   

9.
利用海-气界面浮标观测得到的高频数据,分析了春季青岛近岸海域海表二氧化碳分压(pCO2)的变化规律及驱动因素,并对海-气CO2通量进行了估算。观测期间该海域由大气的碳汇转变为碳源,主要是由海表pCO2的不断增长所致。对海表pCO2控制因素进行分析,发现温度升高是pCO2增长的主要驱动因素,生物过程起到一定的抑制作用。海表pCO2呈现出日变化特征,温度和生物因素对海表pCO2日变化的作用均与太阳辐射相关,但两者的作用相反。此外,分析发现浮标的不同采样频率会对海-气CO2通量估算产生影响,缩短采样间隔能有效降低海-气CO2通量估算的偏差,提高估算的准确性。  相似文献   

10.
本文选用1951—1986年赤道太平洋(10°S—10°N,180—85°W)海表面温度(SST)与南方涛动指数及副热带高压特征指数,重点探讨了海洋与大气之间的相互作用过程,得出了起主导作用的因素,认为与选取代表赤道太平洋平均海面温度的海区范围和选用代表南方涛动的两个气压站有直接关系。  相似文献   

11.
On the basis of the data of the partial pressure of CO2 (PCO2)and the concentration of the total dissolved CO2(TCO2) in surface water during the expeditions in Nov.-Dec. 1991, the world ocean circulation experiment (WOCE) and Oct. 1992-Mar. 1993, the tropical ocean-global atmosphere coupled ocean-atmosphere response experiment (TOGA COARE) in the western tropical Pacific and of the comparison with data from 1986 to 1990 TOGA expeditions and that from Japan Meteorological Agency, the response of CO2 in surface water to ENSO event is proved. The CO2 signals indicated that the air-sea system in the western and central tropical Pacific from 1991 to 1993, except for a short period in autumn of 1992, was in a strong state of ENSO.
The change of CO2 in the floating stations near 2°S, 155°E from Nov. 1992 to Mar. 1993 reflected the change of currents, water mass and its thermal and salt content during the forming and developing of ENSO.  相似文献   

12.
The Prydz Bay in the Antarctic is an important area in the Southern Ocean due to its unique geographic feature. It plays an important role in the carbon cycle in the Southern Ocean. To investigate the distributions of carbon dioxide in the atmosphere and surface seawater and its air-sea exchange rates in this region, the Chinese National Antarctic Research Expedition (CHINARE) had set up several sections in the Prydz Bay. Here we present the results from the CHINARE-XVI cruises were presented onboard R/V Xue/ong from November 1999 to April 2000 and the main driving forces were discussed controlling the distributions of partial pressure of carbon dioxide. According to the partial pressure of carbon dioxide distributions, the Prydz Bay can be divided into the inside and outside regions. The partial pressure of carbon dioxide was low in the inside region but higher in the outside region during the measurement period. This distribution had a good negative correlation with the concentrations of ehlorophyll-a in general, suggesting that the partial pressure of carbon dioxide was substantially affected by biological production. The results also indicate that the biological produetion is most likely the main driving force in the marginal ice zone in the Southern Ocean in summer. However, in the Antarctic divergence sector of the Prydz Bay (about 64°S), the hydrological processes become the controlling factor as the sea surface partial pressure of carbon dioxide is much higher than the atmospheric one due to the upwelling of the high DIC CDW, and this made the outside of Prydz Bay a source of carbon dioxide. On the basis of the calculations, the CO2 flux in January (austral summer) was -3.23 mmol/(m^2 · d) in the inner part of Prydz Bay, i.e. , a sink of atmospheric CO2, and was 0.62 mmol/(m^2 · d) in the outside part of the bay, a weak source of atmospheric CO2. The average air-sea flux of CO2 in the Prydz Bay was 2.50 mmol/(m^2 · d).  相似文献   

13.
CharacteristicsofsummerandwintercirculationsandtheirvariabilityinthesourceareaoftheTsushimaWarmCurrent¥SongWanxian(ReceivedNo...  相似文献   

14.
为了探讨珠江三角洲西江磨刀门水道枯季咸淡水混合特征与水体二氧化碳分压变化的关系,2006年12月18日沿磨刀门水道实测了36个样点表层水体的理化参数。采用相关分析和曲线拟合的方法,分析了表层水体二氧化碳分压的分布特征,结果表明,水体二氧化碳分压值介于147~364 Pa,平均值为201 Pa,随航距呈现出复杂多变的减小趋势,其复杂突变发生在航距24~38 km(即盐度3~6)内。分析认为,咸淡水混合及其潮汐冲刷作用影响了理化参数的时空变化,控制着河流碳的生物地球化学行为。  相似文献   

15.
-Mainly on the basis of the data obtained during PRC/US bilateral TOGA cruises, abnormal variation occurred during the 1986/1987 El Nino is shown in this paper about the thermal structure and circulation of the upper western tropical Pacific Ocean. The effects of the abmormal variation on the subtropical high over the Northwest Pacific Ocean are discussed. During the El Nino: (1) In the east part of the western tropical Pacific Ocean (the subsurface temperature data on the 165° E section are taken as an example), the water wanner than 29 C in the upper layer spread on the longitudinal section and positive temperature anormalies appeared in a large area of the sea surface. (2) In the west part of the western tropical Pacific Ocean (the subsurface temperature data on the 137°E section are representative ), the cross section occupied by the upper layer warmer water ( T >28 ℃ ) became shrunk, and the sea surface temperature showed negative amomalies. (3) The eastward flows in the upper layer of the 165°  相似文献   

16.
南极普里兹湾沉积物中有机碳和总氮的含量与分布   总被引:1,自引:1,他引:0  
利用中国多次南极科学考察获得的沉积物样品,对普里兹湾沉积物中有机碳(OC)、总氮(TN)的含量和分布以及OC/TN进行了分析。结果表明:普里兹湾表层沉积物中OC和TN的含量变化范围分别为0.14%~1.20%和0.02%~0.20%,平均值分别为0.63%和0.11%。OC/TN的变化范围为5.5~8.2,平均值为6.8。OC和TN含量呈现明显的正相关性,表明有机质来源相同,比值接近6.6,说明有机质主要为海洋生源沉积。两者平面分布趋势非常一致,且与沉积物中泥质含量呈显著正相关,湾内73°E以西区域OC和TN含量较低,而以东区域含量较高,这是上层水体生产过程和冰川携带陆源砂等因素共同作用的结果。垂直分布上,OC和TN含量总体上表层高于深层,OC含量随深度增加逐渐降低,达到一定深度后趋于稳定。较高的沉积速率加速OC的埋藏,5根柱样中OC的埋藏率为39%~91%,平均为66%,表明普里兹湾是重要的碳汇区。  相似文献   

17.
胶州湾水体中的二氧化碳体系   总被引:1,自引:0,他引:1  
刘辉  姬泓巍  辛梅 《海洋科学》1998,22(6):44-47
采用库仑滴定法测定了胶州湾海域4个航次的总二氧化碳,根据测定的总二氧化碳的数据计算了二氧化碳各分量的含量及二氧化碳分压,得到了胶州湾水体中二氧化碳体系的平面分布、垂直分布及周日变化规律,并对结果进行了初步探讨 。  相似文献   

18.
This paper is based on the data for the period from 1953 to 1977, which are the monthly averaged ice cover in the Arctic area within 160° E-110° W and north of 50?N, the areal index of the North Pacific subtropical high and the monthly averaged sea surface temperature of the North Pacific. A statistical analysis of the lag correlations between the polar ice from November to July and the sea surface temperature from January to July, and the sea surface temperature from January to July and the subtropical high lagging zero through eleven months is performed.The analysis shows that the lag correlation regions between the polar ice during spring and the sea surface temperature almost coincide with the regions of the California Current and the paitial north equatorial current, and the regions of the California Current and the partial north equatorial current coincide with the principal lag correlation regions between the sea surface temperature and the subtropical high. All the results suggest that the tra  相似文献   

19.
The distributions of partial pressure of carbon dioxide (p CO2 ) in the surface waters of the Changjiang River Estuary and adjacent Hangzhou Bay were examined in the summer of 2010. Surface water p CO2 ranged from 751-2 095 μatm (1 atm=101 325 Pa) in the inner estuary, 177-1 036 μatm in the outer estuary, and 498-1 166 μatm in Hangzhou Bay. Overall, surface p CO2 behaved conservatively during the estuary mixing. In the inner estuary, surface p CO2 was relatively high due to urbanized pollution and a high respiration rate. The lowest p CO2 was observed in the outer estuary, which was apparently induced by a phytoplankton bloom because the dissolved oxygen and chlorophyll a were very high. The Changjiang River Estuary was a significant source of atmospheric CO2 and the degassing fluxes were estimated as 0-230 mmol/(m2 d) [61 mmol/(m2 d) on average] in the inner estuary. In contrast, the outer estuary acted as a CO2 sink.  相似文献   

20.
AtmosphericinputoftraceelementstothewesternPacificOceanandtheKuroshiooceanarea¥QianFenlan;YuHongjian;LanYouchang;ChenZhi;Zhou...  相似文献   

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