The locations,magnitudes,variations and mechanisms responsible for the global CO2 sink are uncer-tain and under debate.Here,we show,based on theoretical calculations and evidences from field monitoring results,that th...The locations,magnitudes,variations and mechanisms responsible for the global CO2 sink are uncer-tain and under debate.Here,we show,based on theoretical calculations and evidences from field monitoring results,that there is a possible important CO2 sink(as DIC-dissolved inorganic carbon)by the global water cycle.The sink constitutes up to 0.8013 Pg C/a(or 10.1% of the total anthropogenic CO2 emission,or 28.6% of the missing CO2 sink),and is formed by the CO2 absorption of water and subsequent enhanced consumption by carbonate dissolution and aquatic plant photosynthesis.Of the sink,0.5188 Pg C/a goes to sea via precipitation over sea(0.2748 Pg C/a)and continental rivers(0.244 Pg C/a),0.158 Pg C/a is released to the atmosphere again,and 0.1245 Pg C/a is stored in the continental aquatic ecosystem.Therefore,the net sink could be 0.6433 Pg C/a.This sink may increase with the global-warming-intensified global water cycle,the increase in CO2 and carbonate dust in atmosphere,and reforestation/afforestation,the latter increasing soil CO2,and thus the concentration of the DIC in water.展开更多
For researching the spatio-temporal variation of the stable isotopic composition of the riverine dissolved inorganic carbon（DIC）,we had carried out a survey throughout the hydrologic year during which theδ^13CDIC o...For researching the spatio-temporal variation of the stable isotopic composition of the riverine dissolved inorganic carbon（DIC）,we had carried out a survey throughout the hydrologic year during which theδ^13CDIC of the surface water and its physicochemical parameter were examined along the Xijiang River Inner Estuarine waterway from September 2006 to June 2007.There was a striking seasonal variation on the averageδ^13CDIC,as the averageδ^13CDIC in summer（-13.91‰）or autumn（-13.09‰）was much less than those in spring（-11.71‰）or winter（-12.26‰）.The riverineδ13C DIC was controlled by decomposed condition of the riverine organic matter linking the seasonal variation of the physicochemical parameter in the surface water according to the correlation analysis which indicated notable relations betweenδ^13CDIC and water temperature（p=0.000;r=-0.569）or betweenδ^13CDIC and oxide-reduction potential（p=0.000;r=0.646）.The striking positive correlation between δ^13CDIC and the sampling distance happened in the summer rainy season,while striking negative correlation happened in the spring dry season,indicating that river-sea interaction influenced water physicochemical parameters and controlled the riverine DIC property in the survey waterway.In view of the riverineδ^13CDIC decreasing for the decomposition of the terrestrial organic matter in the rainy season in summer and increasing for the briny invaded zone extending in the spring dry season along the waterway from the Makou gauging station to the Modaomen outlet,theδ^13CDIC spatio-temporal variation was closely related to the geographical environment of the Xijiang drainage basin.展开更多
基金the Hundred Talent Program of Chinese Academy of Sciences,Knowledge Innovation Program the Chinese Academy of Sciences(Grant No.KZCX2-YW-306)the National Natural Science Foundation of China(Grant No.40572017)the Ministry of Science and Technology of China(Grant No.2005DIB3J067)
文摘The locations,magnitudes,variations and mechanisms responsible for the global CO2 sink are uncer-tain and under debate.Here,we show,based on theoretical calculations and evidences from field monitoring results,that there is a possible important CO2 sink(as DIC-dissolved inorganic carbon)by the global water cycle.The sink constitutes up to 0.8013 Pg C/a(or 10.1% of the total anthropogenic CO2 emission,or 28.6% of the missing CO2 sink),and is formed by the CO2 absorption of water and subsequent enhanced consumption by carbonate dissolution and aquatic plant photosynthesis.Of the sink,0.5188 Pg C/a goes to sea via precipitation over sea(0.2748 Pg C/a)and continental rivers(0.244 Pg C/a),0.158 Pg C/a is released to the atmosphere again,and 0.1245 Pg C/a is stored in the continental aquatic ecosystem.Therefore,the net sink could be 0.6433 Pg C/a.This sink may increase with the global-warming-intensified global water cycle,the increase in CO2 and carbonate dust in atmosphere,and reforestation/afforestation,the latter increasing soil CO2,and thus the concentration of the DIC in water.
基金National Natural Science Foundation of China, No.40671027 No.40471120+2 种基金 Guangdong Provincial Natural Science Foundation, No.7003669 Specialized Research Fund for the Doctoral Program of Higher Education, No.20040558025 The Program for New Century Excellent Talents in University
文摘For researching the spatio-temporal variation of the stable isotopic composition of the riverine dissolved inorganic carbon（DIC）,we had carried out a survey throughout the hydrologic year during which theδ^13CDIC of the surface water and its physicochemical parameter were examined along the Xijiang River Inner Estuarine waterway from September 2006 to June 2007.There was a striking seasonal variation on the averageδ^13CDIC,as the averageδ^13CDIC in summer（-13.91‰）or autumn（-13.09‰）was much less than those in spring（-11.71‰）or winter（-12.26‰）.The riverineδ13C DIC was controlled by decomposed condition of the riverine organic matter linking the seasonal variation of the physicochemical parameter in the surface water according to the correlation analysis which indicated notable relations betweenδ^13CDIC and water temperature（p=0.000;r=-0.569）or betweenδ^13CDIC and oxide-reduction potential（p=0.000;r=0.646）.The striking positive correlation between δ^13CDIC and the sampling distance happened in the summer rainy season,while striking negative correlation happened in the spring dry season,indicating that river-sea interaction influenced water physicochemical parameters and controlled the riverine DIC property in the survey waterway.In view of the riverineδ^13CDIC decreasing for the decomposition of the terrestrial organic matter in the rainy season in summer and increasing for the briny invaded zone extending in the spring dry season along the waterway from the Makou gauging station to the Modaomen outlet,theδ^13CDIC spatio-temporal variation was closely related to the geographical environment of the Xijiang drainage basin.
