Ozone(O3) concentration and flux(Fo) were measured using the eddy covariance technique over a wheat field in the Northwest-Shandong Plain of China. The O3-induced wheat yield loss was estimated by utilizing O3expo...Ozone(O3) concentration and flux(Fo) were measured using the eddy covariance technique over a wheat field in the Northwest-Shandong Plain of China. The O3-induced wheat yield loss was estimated by utilizing O3exposure-response models. The results showed that:(1) During the growing season(7 March to 7 June, 2012), the minimum(16.1 ppb V) and maximum(53.3 ppb V)mean O3 concentrations occurred at approximately 6:30 and 16:00, respectively. The mean and maximum of all measured O3 concentrations were 31.3 and 128.4 ppb V, respectively. The variation of O3 concentration was mainly affected by solar radiation and temperature.(2) The mean diurnal variation of deposition velocity(V d) can be divided into four phases, and the maximum occurred at noon(12:00). Averaged V d during daytime(6:00–18:00) and nighttime(18:00–6:00) were 0.42 and 0.14 cm/sec, respectively. The maximum of measured V d was about1.5 cm/sec. The magnitude of V d was influenced by the wheat growing stage, and its variation was significantly correlated with both global radiation and friction velocity.(3) The maximum mean F o appeared at 14:00, and the maximum measured F o was-33.5 nmol/(m^2·sec). Averaged F o during daytime and nighttime were-6.9 and-1.5 nmol/(m^2·sec), respectively.(4) Using O3 exposure-response functions obtained from the USA, Europe, and China, the O3-induced wheat yield reduction in the district was estimated as 12.9% on average(5.5%–23.3%). Large uncertainties were related to the statistical methods and environmental conditions involved in deriving the exposure-response functions.展开更多
基金supported by the National Natural Science Foundation of China (No.31070400)the National Basic Research Program of China (No.2010CB833501-01)+1 种基金the Innovation Project of the Institute of Geographic Sciences and Natural Resources Research, CAS (Grant No.201003001)the Max Planck Society (Germany)
文摘Ozone(O3) concentration and flux(Fo) were measured using the eddy covariance technique over a wheat field in the Northwest-Shandong Plain of China. The O3-induced wheat yield loss was estimated by utilizing O3exposure-response models. The results showed that:(1) During the growing season(7 March to 7 June, 2012), the minimum(16.1 ppb V) and maximum(53.3 ppb V)mean O3 concentrations occurred at approximately 6:30 and 16:00, respectively. The mean and maximum of all measured O3 concentrations were 31.3 and 128.4 ppb V, respectively. The variation of O3 concentration was mainly affected by solar radiation and temperature.(2) The mean diurnal variation of deposition velocity(V d) can be divided into four phases, and the maximum occurred at noon(12:00). Averaged V d during daytime(6:00–18:00) and nighttime(18:00–6:00) were 0.42 and 0.14 cm/sec, respectively. The maximum of measured V d was about1.5 cm/sec. The magnitude of V d was influenced by the wheat growing stage, and its variation was significantly correlated with both global radiation and friction velocity.(3) The maximum mean F o appeared at 14:00, and the maximum measured F o was-33.5 nmol/(m^2·sec). Averaged F o during daytime and nighttime were-6.9 and-1.5 nmol/(m^2·sec), respectively.(4) Using O3 exposure-response functions obtained from the USA, Europe, and China, the O3-induced wheat yield reduction in the district was estimated as 12.9% on average(5.5%–23.3%). Large uncertainties were related to the statistical methods and environmental conditions involved in deriving the exposure-response functions.