Carbon monoxide(CO) concentrations, sea-to-air fluxes and microbial consumption rate constants, along with atmospheric CO mixing ratios, were measured in the East China Sea(ECS) in autumn. Atmospheric CO mixing ratios...Carbon monoxide(CO) concentrations, sea-to-air fluxes and microbial consumption rate constants, along with atmospheric CO mixing ratios, were measured in the East China Sea(ECS) in autumn. Atmospheric CO mixing ratios varied from 96 to 256 ppbv, with an average of 146 ppbv(SD = 54 ppbv, n = 31). Overall, the atmospheric CO concentrations displayed a decreasing trend from inshore to offshore stations. The surface water CO concentrations in the investigated area ranged from 0.24 to 6.12 nmol L^(-1), with an average of 1.68 nmol L^(-1)(SD = 1.50 nmol L^(-1), n = 31). The surface water CO concentrations were affected significantly by sunlight. Vertical profiles showed that CO concentrations declined rapidly with depth, with the maximum appearing in the surface water. The surface CO concentrations were oversaturated, with the saturation factors ranging from 1.4 to 56.9, suggesting that the ECS was a net source of atmospheric CO. The sea-to-air fluxes of CO in the ECS ranged from 0.06 to 11.31 μmol m^(-2) d^(-1), with an average of 2.90 μmol m^(-2) d^(-1)(SD = 2.95μmol m^(-2) d^(-1), n = 31). In the incubation experiments, CO concentrations decreased exponentially with incubation time and the processes conformed to the first order reaction characteristics. The microbial CO consumption rate constants in the surface water(KCO) ranged from 0.063 to 0.22 h^(-1), with an average of 0.12 h^(-1)(SD = 0.062 h^(-1), n = 6). A negative correlation between KCO and salinity was observed in the present study.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.40976043 and 41320104008)the National Natural Science Foundation for Creative Research Groups(No.41221004)the Changjiang Scholars Programme,Ministry of Education of China,the Taishan Scholars Programme of Shandong Province
文摘Carbon monoxide(CO) concentrations, sea-to-air fluxes and microbial consumption rate constants, along with atmospheric CO mixing ratios, were measured in the East China Sea(ECS) in autumn. Atmospheric CO mixing ratios varied from 96 to 256 ppbv, with an average of 146 ppbv(SD = 54 ppbv, n = 31). Overall, the atmospheric CO concentrations displayed a decreasing trend from inshore to offshore stations. The surface water CO concentrations in the investigated area ranged from 0.24 to 6.12 nmol L^(-1), with an average of 1.68 nmol L^(-1)(SD = 1.50 nmol L^(-1), n = 31). The surface water CO concentrations were affected significantly by sunlight. Vertical profiles showed that CO concentrations declined rapidly with depth, with the maximum appearing in the surface water. The surface CO concentrations were oversaturated, with the saturation factors ranging from 1.4 to 56.9, suggesting that the ECS was a net source of atmospheric CO. The sea-to-air fluxes of CO in the ECS ranged from 0.06 to 11.31 μmol m^(-2) d^(-1), with an average of 2.90 μmol m^(-2) d^(-1)(SD = 2.95μmol m^(-2) d^(-1), n = 31). In the incubation experiments, CO concentrations decreased exponentially with incubation time and the processes conformed to the first order reaction characteristics. The microbial CO consumption rate constants in the surface water(KCO) ranged from 0.063 to 0.22 h^(-1), with an average of 0.12 h^(-1)(SD = 0.062 h^(-1), n = 6). A negative correlation between KCO and salinity was observed in the present study.
