The ocean is the largest active carbon reservoir on Earth. Organic carbon(OC), as the primary species of carbon sequestration in the ocean, plays an important role in the global carbon cycle through its deposition and...The ocean is the largest active carbon reservoir on Earth. Organic carbon(OC), as the primary species of carbon sequestration in the ocean, plays an important role in the global carbon cycle through its deposition and burial. In this study,sedimentary OC data from 5796 stations, together with relevant geochemical and sedimentological parameters in the Bohai Sea,Yellow Sea, and East China Sea(BYES) were used to summarize and elucidate the distribution and burial patterns of sedimentary OC, and assess carbon sink effect of sedimentary OC burial. The results show that the OC content in the sediments of the BYES ranges from 0.00% to 2.12%, with an average content of 0.47%±0.26%. OC content is significantly correlated with finegrained sediments, with an average OC content in mud areas being 39% higher than that in non-mud areas. Modern OC buried in the BYES are mainly deposited in 7 major mud areas, with a total sedimentary OC burial flux of approximately 8.20 Mt C yr^(–1).Among them, the burial flux of biospheric OC is 6.92 Mt C yr^(–1), equivalent to the OC consumption amount of silicate weathering of the 9 major river basins in the eastern China. In its natural state, the annually sequestered OC in the sediments of the eastern China seas is equivalent to 25.37 Mt of atmospheric CO_(2), indicating a significant carbon sink effect. The distribution and burial of terrigenous OC in the BYES are mainly influenced by the large river inputs and complex marine hydrodynamic environment,while human activities such as dam construction have significantly altered the OC burial in these coastal mud areas.展开更多
This study explored the ecological effects of the transformation of carbon source and carbon sink in wetlands, that were discussed from four aspects: atmosphere, ocean, plants and soil. The results showed that the wet...This study explored the ecological effects of the transformation of carbon source and carbon sink in wetlands, that were discussed from four aspects: atmosphere, ocean, plants and soil. The results showed that the wetland changed from carbon sink to carbon source, which led to the increase of CO_2 emissions in the atmosphere and the intensification of greenhouse effect, which made the earth face the threat of global warming. At the same time, the content of CO_2 in seawater is increased; the pH value of seawater decreases; the balance of seawater acid-base is destroyed; and the ocean acidification is caused.展开更多
Analytical investigation on a combined heat and mass transfer of air flow near a continuously moving infinite plate with a constant heat sink is performed in the presence of a uniform magnetic field. To observe the th...Analytical investigation on a combined heat and mass transfer of air flow near a continuously moving infinite plate with a constant heat sink is performed in the presence of a uniform magnetic field. To observe the thermal radiation and Soret effect on the flow, thermal radiation and thermal diffusion term are added in energy and concentration equations. A flow of model is established by employing the well known boundary layer approximations. In order to obtain non-dimensional system of equations, a similarity transformation is applied on the flow model. Perturbation technique is used as main tool for the analytical approach. The numerical values of flow variables are computed by a FORTRAN program. The obtain numerical values of fluid velocity, temperature and species concentration are drawn for the different values of various parameters. To observe the effects of various parameters on the flow variables, the results are discussed in detailed with the help of graph.展开更多
流域岩石风化是重要的碳源/汇过程,也是全球碳循环中的重要环节。外源酸参与流域岩石风化,影响碳元素的地球化学循环和流域碳源/汇效应。漾弓江属长江上游金沙江水系,流域岩石风化过程和碳汇效应尚不清楚。在2023年旱季和雨季分别采集...流域岩石风化是重要的碳源/汇过程,也是全球碳循环中的重要环节。外源酸参与流域岩石风化,影响碳元素的地球化学循环和流域碳源/汇效应。漾弓江属长江上游金沙江水系,流域岩石风化过程和碳汇效应尚不清楚。在2023年旱季和雨季分别采集了漾弓江的干流和主要支流的水样品(地表水点9个、地下水点6个),对主要离子浓度进行检测,并利用水化学平衡法和Galy估算模型分析该流域的岩风化类型,估算了碳酸与硫酸共同作用下的岩石风化CO_(2)消耗量。结果表明:(1)漾弓江流域水系离子成分主要源于硅酸盐岩和碳酸盐岩风化,水化学类型为HCO_(3)-Ca型或HCO_(3)-Ca·Mg型。(2)硫酸和碳酸共同参与了漾弓江流域的岩石风化过程。在不考虑硫酸作用时,漾弓江流域岩石风化的大气CO_(2)消耗量为38.35 t CO_(2)·km^(−2)·a^(−1),而当考虑了硫酸参与时,岩石风化碳汇量降至25.54 t CO_(2)·km^(−2)·a^(−1),扣除约33%,大大提高了计算精度。(3)漾弓江流域岩石风化的大气CO_(2)消耗量为4.27×10^(4) t CO_(2)·a^(−1),是一个碳汇过程。硫酸参与流域岩石的风化改变了区域碳循环,这是全球碳循环模型不可忽略重要环节。展开更多
基金supported by the Laoshan Laboratory (Grant No.LSKJ202204200)the Chinese Offshore Investigation and Assessment Project (Grant No.908~ZC~I~05)+2 种基金the National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers (Grant No.U1606401)the National Natural Science Foundation of China Shiptime Sharing Project (Grant Nos.42049902,42149902)the Taishan Scholar Program of Shandong (Grant No.tspd20181216)。
文摘The ocean is the largest active carbon reservoir on Earth. Organic carbon(OC), as the primary species of carbon sequestration in the ocean, plays an important role in the global carbon cycle through its deposition and burial. In this study,sedimentary OC data from 5796 stations, together with relevant geochemical and sedimentological parameters in the Bohai Sea,Yellow Sea, and East China Sea(BYES) were used to summarize and elucidate the distribution and burial patterns of sedimentary OC, and assess carbon sink effect of sedimentary OC burial. The results show that the OC content in the sediments of the BYES ranges from 0.00% to 2.12%, with an average content of 0.47%±0.26%. OC content is significantly correlated with finegrained sediments, with an average OC content in mud areas being 39% higher than that in non-mud areas. Modern OC buried in the BYES are mainly deposited in 7 major mud areas, with a total sedimentary OC burial flux of approximately 8.20 Mt C yr^(–1).Among them, the burial flux of biospheric OC is 6.92 Mt C yr^(–1), equivalent to the OC consumption amount of silicate weathering of the 9 major river basins in the eastern China. In its natural state, the annually sequestered OC in the sediments of the eastern China seas is equivalent to 25.37 Mt of atmospheric CO_(2), indicating a significant carbon sink effect. The distribution and burial of terrigenous OC in the BYES are mainly influenced by the large river inputs and complex marine hydrodynamic environment,while human activities such as dam construction have significantly altered the OC burial in these coastal mud areas.
文摘This study explored the ecological effects of the transformation of carbon source and carbon sink in wetlands, that were discussed from four aspects: atmosphere, ocean, plants and soil. The results showed that the wetland changed from carbon sink to carbon source, which led to the increase of CO_2 emissions in the atmosphere and the intensification of greenhouse effect, which made the earth face the threat of global warming. At the same time, the content of CO_2 in seawater is increased; the pH value of seawater decreases; the balance of seawater acid-base is destroyed; and the ocean acidification is caused.
文摘Analytical investigation on a combined heat and mass transfer of air flow near a continuously moving infinite plate with a constant heat sink is performed in the presence of a uniform magnetic field. To observe the thermal radiation and Soret effect on the flow, thermal radiation and thermal diffusion term are added in energy and concentration equations. A flow of model is established by employing the well known boundary layer approximations. In order to obtain non-dimensional system of equations, a similarity transformation is applied on the flow model. Perturbation technique is used as main tool for the analytical approach. The numerical values of flow variables are computed by a FORTRAN program. The obtain numerical values of fluid velocity, temperature and species concentration are drawn for the different values of various parameters. To observe the effects of various parameters on the flow variables, the results are discussed in detailed with the help of graph.
文摘流域岩石风化是重要的碳源/汇过程,也是全球碳循环中的重要环节。外源酸参与流域岩石风化,影响碳元素的地球化学循环和流域碳源/汇效应。漾弓江属长江上游金沙江水系,流域岩石风化过程和碳汇效应尚不清楚。在2023年旱季和雨季分别采集了漾弓江的干流和主要支流的水样品(地表水点9个、地下水点6个),对主要离子浓度进行检测,并利用水化学平衡法和Galy估算模型分析该流域的岩风化类型,估算了碳酸与硫酸共同作用下的岩石风化CO_(2)消耗量。结果表明:(1)漾弓江流域水系离子成分主要源于硅酸盐岩和碳酸盐岩风化,水化学类型为HCO_(3)-Ca型或HCO_(3)-Ca·Mg型。(2)硫酸和碳酸共同参与了漾弓江流域的岩石风化过程。在不考虑硫酸作用时,漾弓江流域岩石风化的大气CO_(2)消耗量为38.35 t CO_(2)·km^(−2)·a^(−1),而当考虑了硫酸参与时,岩石风化碳汇量降至25.54 t CO_(2)·km^(−2)·a^(−1),扣除约33%,大大提高了计算精度。(3)漾弓江流域岩石风化的大气CO_(2)消耗量为4.27×10^(4) t CO_(2)·a^(−1),是一个碳汇过程。硫酸参与流域岩石的风化改变了区域碳循环,这是全球碳循环模型不可忽略重要环节。
