A new off-axis integrated cavity output spectroscopy （ICOS） is coupled to Weiss equilibrator for continuous high- resolution dissolved methane measurement in the surface ocean. The time constant for the equilibrator...A new off-axis integrated cavity output spectroscopy （ICOS） is coupled to Weiss equilibrator for continuous high- resolution dissolved methane measurement in the surface ocean. The time constant for the equilibrator in freshwater at room temperature is determined via dis-equilibration and re-equilibration experiments. The constant for methane is about 40 min. The system is calibrated using a standard gas of 3.980×10-6, and the precision of the ICOS for methane is 0.07%. This system is equipped onboard to measure the spatial distribution in methane concentrations of South Yellow Sea （SYS） along the cruise track from Shanghai to Qingdao. Result shows that the methane concentration varies from 2.79 to 36.36 nmol/L, reveals a significant pattern of methane source in SYS, and a distinct decreasing trend from south to north. The peak value occurs at the coast area outside mouth of the Changjiang River, likely to be affected by the Changjiang diluted water mass dissolving a large amount of rich in methane. Moreover, all the surface waters are oversaturated, air-to-sea fluxes range from 98.59 to 5 485.35 μmol/（m2·d） （average value （1 169.74±1 398.46） μmol/（m2·d））, indicating a source region for methane to the atmosphere. Key words： methane, equilibrator, off-axis integrated cavity output spectroscopy （ICOS）, South Yellow Sea展开更多
Nitrous oxide （N2O） distribution patterns in the Bering Sea basin （BSB） and Indian Sector of the Southern Ocean （ISSO） were described and compared. In both sites, the waters were divided into four layers： surfa...Nitrous oxide （N2O） distribution patterns in the Bering Sea basin （BSB） and Indian Sector of the Southern Ocean （ISSO） were described and compared. In both sites, the waters were divided into four layers： surface layer, subsurface layer, N2O maximum layer, and deep water. Simulations were made to find out the most important factors that regulate the N2O distribution patterns in different layers of both sites. The results showed that in the surface water, N2O was more understaturated in the ISSO than the BSB. This phenom- enon in the surface water of ISSO may result from ice melt water intrusion and northeastward transport of the Antarctic surface water. Results of the rough estimation of air-sea fluxes during the expedition were （-0.34±0.07）-（-0.64±0.13） μmol/（m2·d） and （-1.47±0.42）-（-1.77±0.51） μmol/（m-2·d） for the BSB and the ISSO, respectively. Strongly stratified surface layer and temperature minimum layer restricted exchange across the thermocline. The N2O maximum existed in higher concentration and deeper in the BSB than the ISSO, but their contribution to the upper layer by eddy diffusions was negligible. In deep waters, a concentration difference of 5 nmol/L N2O between these two sites was found, which suggested that N2O production occurred during thermohaline circulation. N2O may be a useful tracer to study important large-scale hydrographic processes.展开更多
We analyzed the N20 content of surface seawater sampled from Prydz Bay, Antarctica, on a cruise track between 30°S and 30°N during the twenty-second Chinese National Antarctic Research Expedition during aust...We analyzed the N20 content of surface seawater sampled from Prydz Bay, Antarctica, on a cruise track between 30°S and 30°N during the twenty-second Chinese National Antarctic Research Expedition during austral summer, 2006. The surface water showed an average pN20 value of 311.9a：7.6 nL.L-1 （14.1：t：0.4 nmol-Ll）, which was slightly undersaturated. The air-sea N2O flux in the region was -0.3±0.8 p.mol.mE,dl; howeveh N20 in the surface water was oversaturated in most stations along the cruise track. Saturation anomalies were greater than 10%, with a maximum of 54.7% being observed at the Eqaator, followed by 31% at 10°N in the Sulu Sea. The air-sea fluxes at these locations were 12.4 and 4 μmol-mLd-1, respectively. Overall, the results indicated that surface water in Prydz Bay was near equilibrium with atmospheric N20, and that ocean waters in lower latitudes acted as a N20 source. Physical processes such as stratification, ice-melt water dilution, and solar radiation dominate the factors leading to N20 saturation of surface water of Prydz Bay, while biological production and upwelling are primarily responsible for the N20 oversaturation of surface water observed in subtropical and tropical regions along the cruise track.展开更多
Knowledge about the distribution of CH_(4)remains insufficient due to the scarcity of data in the Arctic shelves.We conducted shipboard observations over the Chukchi Sea shelf(CSS)in the western Arctic Ocean in Septem...Knowledge about the distribution of CH_(4)remains insufficient due to the scarcity of data in the Arctic shelves.We conducted shipboard observations over the Chukchi Sea shelf(CSS)in the western Arctic Ocean in September 2012 to obtain the distribution and source characteristics of dissolved CH_(4)in seawater.The oceanographic data indicated that a salinity gradient generated a pronounced pycnocline at depths of 20-30 m.The vertical diffusion of biogenic elements was restricted,and these elements were trapped in the bottom waters.Furthermore,high CH_(4)concentrations were measured below the pycnocline,and low CH_(4)concentrations were observed in the surface waters.The maximum concentrations of nutrients simultaneously occurred in the dense and cold bottom waters,and significant correlations were observed between CH_(4)and SiO_(3)^(2-),PO_(4)^(3-),NO_(2)^(-),and NH_(4)^(+)(p<0.01,n=44).These results suggest that the production of CH_(4)in the CSS has a similar trend as that of nutrient regeneration and is probably associated with the degradation of organic matter.The high primary productivity and high concentration of organic matter support the formation of biogenic CH_(4)in the CSS and the subsequent release of CH_(4)to the water column.展开更多
N2O gas depletes ozone and has a powerful greenhouse effect.Oceans are among the most important N2O sources and have been the subject of extensive studies.Polar oceans are important regions for deep water formation an...N2O gas depletes ozone and has a powerful greenhouse effect.Oceans are among the most important N2O sources and have been the subject of extensive studies.Polar oceans are important regions for deep water formation and global-scale thermohaline circulation.Therefore,these water bodies play an important role in the N2O budget,however,these regions were not well studied.This review of previously published studies and data on polar oceans,including both the Arctic Ocean and Southern Ocean,describes the distribution pattern of N2O and possible regulating mechanism of these distribution patterns and shows that the Arctic Ocean and Southern Ocean both represent source and sink regions,suggesting that the source/sink characteristics of the Arctic and Southern oceans and their strengths need further study.Questions related to N2O circulation in polar oceans were proposed,and future work is suggested.展开更多
Salinization of soil is a worldwide problem concerning resources and ecology,especially serious in coastal areas.Testing of 26 sorts of data or parameters are carried out on leaves of 22 plant species(in 24 plant vari...Salinization of soil is a worldwide problem concerning resources and ecology,especially serious in coastal areas.Testing of 26 sorts of data or parameters are carried out on leaves of 22 plant species(in 24 plant variety) of existing main salt-tolerant plant of the Yellow River Delta region.Data or parameters include the following ele-ments:contents of K+,Na+,Ca2+,Mg2+ and Cl-,contents of protein,fat,total energy,ash and contents of 17 amino acids.The results show that these tested plants have economic values.For example,according to their uses,they can be divided into edible plants,forage plants,medicine or health plants,and some of them can be used for multipurposes.These plants have played important roles in the sustainable utilization of plant resources in coastal areas.This paper has taken evaluations on the economic uses of salt-tolerant plants and given suggestions for saline soil improvement and resource utilization in coastal areas.Based on the results of investigation and experiments,we suppose that the salt-tolerant plants in coastal areas can be grouped into 9 main groups according to their economic value:pioneer plants for saline land improvement,medicine,edible and forage plants,industry material,forestation,breeding material,energy plants and eco-tourism resources.展开更多
基金The Scientific Research Foundation of Third Institute of Oceangraphy under contract No.2013004the National Natural Science Foundation of China(NSFC)under contract Nos 40906102 and 41230529the CHINARE under contract Nos 2012–2013(01–04–02),(01–02–01)and(03–04–02)
文摘A new off-axis integrated cavity output spectroscopy （ICOS） is coupled to Weiss equilibrator for continuous high- resolution dissolved methane measurement in the surface ocean. The time constant for the equilibrator in freshwater at room temperature is determined via dis-equilibration and re-equilibration experiments. The constant for methane is about 40 min. The system is calibrated using a standard gas of 3.980×10-6, and the precision of the ICOS for methane is 0.07%. This system is equipped onboard to measure the spatial distribution in methane concentrations of South Yellow Sea （SYS） along the cruise track from Shanghai to Qingdao. Result shows that the methane concentration varies from 2.79 to 36.36 nmol/L, reveals a significant pattern of methane source in SYS, and a distinct decreasing trend from south to north. The peak value occurs at the coast area outside mouth of the Changjiang River, likely to be affected by the Changjiang diluted water mass dissolving a large amount of rich in methane. Moreover, all the surface waters are oversaturated, air-to-sea fluxes range from 98.59 to 5 485.35 μmol/（m2·d） （average value （1 169.74±1 398.46） μmol/（m2·d））, indicating a source region for methane to the atmosphere. Key words： methane, equilibrator, off-axis integrated cavity output spectroscopy （ICOS）, South Yellow Sea
基金The National Natural Science Foundation of China(NSFC)under contract Nos 40906102 and 41230529the CHINARE under contract Nos 2012-2015(-01-04-02),2012-2015(01-02-01)and 2012-2015(03-04-02)the CAA International Cooperation Projects under contract Nos IC201201 and IC201308
文摘Nitrous oxide （N2O） distribution patterns in the Bering Sea basin （BSB） and Indian Sector of the Southern Ocean （ISSO） were described and compared. In both sites, the waters were divided into four layers： surface layer, subsurface layer, N2O maximum layer, and deep water. Simulations were made to find out the most important factors that regulate the N2O distribution patterns in different layers of both sites. The results showed that in the surface water, N2O was more understaturated in the ISSO than the BSB. This phenom- enon in the surface water of ISSO may result from ice melt water intrusion and northeastward transport of the Antarctic surface water. Results of the rough estimation of air-sea fluxes during the expedition were （-0.34±0.07）-（-0.64±0.13） μmol/（m2·d） and （-1.47±0.42）-（-1.77±0.51） μmol/（m-2·d） for the BSB and the ISSO, respectively. Strongly stratified surface layer and temperature minimum layer restricted exchange across the thermocline. The N2O maximum existed in higher concentration and deeper in the BSB than the ISSO, but their contribution to the upper layer by eddy diffusions was negligible. In deep waters, a concentration difference of 5 nmol/L N2O between these two sites was found, which suggested that N2O production occurred during thermohaline circulation. N2O may be a useful tracer to study important large-scale hydrographic processes.
基金the National Natural Science Foundation of China (Grant nos.40671062,41106168)the National High Technique Research & Development Program of China (Grant no.2008AA121703)+1 种基金the Ministry of Science and Technology of China (Grant nos.2004DIB5J178,2009DFA22920)the Chinese Arctic and Antarctic Admini-stration (CAA) Cooperation Program (Grant nos.IC2010013,IC2011114,IC201201)
文摘We analyzed the N20 content of surface seawater sampled from Prydz Bay, Antarctica, on a cruise track between 30°S and 30°N during the twenty-second Chinese National Antarctic Research Expedition during austral summer, 2006. The surface water showed an average pN20 value of 311.9a：7.6 nL.L-1 （14.1：t：0.4 nmol-Ll）, which was slightly undersaturated. The air-sea N2O flux in the region was -0.3±0.8 p.mol.mE,dl; howeveh N20 in the surface water was oversaturated in most stations along the cruise track. Saturation anomalies were greater than 10%, with a maximum of 54.7% being observed at the Eqaator, followed by 31% at 10°N in the Sulu Sea. The air-sea fluxes at these locations were 12.4 and 4 μmol-mLd-1, respectively. Overall, the results indicated that surface water in Prydz Bay was near equilibrium with atmospheric N20, and that ocean waters in lower latitudes acted as a N20 source. Physical processes such as stratification, ice-melt water dilution, and solar radiation dominate the factors leading to N20 saturation of surface water of Prydz Bay, while biological production and upwelling are primarily responsible for the N20 oversaturation of surface water observed in subtropical and tropical regions along the cruise track.
基金supported by the Scientific Research Foundation of the Third Institute of Oceanography, MNR (Grant nos. 2022011, 2018031 and 2018024)the Natural Science Foundation of Fujian Province, China (Grant no. 2020J01102)
文摘Knowledge about the distribution of CH_(4)remains insufficient due to the scarcity of data in the Arctic shelves.We conducted shipboard observations over the Chukchi Sea shelf(CSS)in the western Arctic Ocean in September 2012 to obtain the distribution and source characteristics of dissolved CH_(4)in seawater.The oceanographic data indicated that a salinity gradient generated a pronounced pycnocline at depths of 20-30 m.The vertical diffusion of biogenic elements was restricted,and these elements were trapped in the bottom waters.Furthermore,high CH_(4)concentrations were measured below the pycnocline,and low CH_(4)concentrations were observed in the surface waters.The maximum concentrations of nutrients simultaneously occurred in the dense and cold bottom waters,and significant correlations were observed between CH_(4)and SiO_(3)^(2-),PO_(4)^(3-),NO_(2)^(-),and NH_(4)^(+)(p<0.01,n=44).These results suggest that the production of CH_(4)in the CSS has a similar trend as that of nutrient regeneration and is probably associated with the degradation of organic matter.The high primary productivity and high concentration of organic matter support the formation of biogenic CH_(4)in the CSS and the subsequent release of CH_(4)to the water column.
文摘N2O gas depletes ozone and has a powerful greenhouse effect.Oceans are among the most important N2O sources and have been the subject of extensive studies.Polar oceans are important regions for deep water formation and global-scale thermohaline circulation.Therefore,these water bodies play an important role in the N2O budget,however,these regions were not well studied.This review of previously published studies and data on polar oceans,including both the Arctic Ocean and Southern Ocean,describes the distribution pattern of N2O and possible regulating mechanism of these distribution patterns and shows that the Arctic Ocean and Southern Ocean both represent source and sink regions,suggesting that the source/sink characteristics of the Arctic and Southern oceans and their strengths need further study.Questions related to N2O circulation in polar oceans were proposed,and future work is suggested.
文摘Salinization of soil is a worldwide problem concerning resources and ecology,especially serious in coastal areas.Testing of 26 sorts of data or parameters are carried out on leaves of 22 plant species(in 24 plant variety) of existing main salt-tolerant plant of the Yellow River Delta region.Data or parameters include the following ele-ments:contents of K+,Na+,Ca2+,Mg2+ and Cl-,contents of protein,fat,total energy,ash and contents of 17 amino acids.The results show that these tested plants have economic values.For example,according to their uses,they can be divided into edible plants,forage plants,medicine or health plants,and some of them can be used for multipurposes.These plants have played important roles in the sustainable utilization of plant resources in coastal areas.This paper has taken evaluations on the economic uses of salt-tolerant plants and given suggestions for saline soil improvement and resource utilization in coastal areas.Based on the results of investigation and experiments,we suppose that the salt-tolerant plants in coastal areas can be grouped into 9 main groups according to their economic value:pioneer plants for saline land improvement,medicine,edible and forage plants,industry material,forestation,breeding material,energy plants and eco-tourism resources.
