Record ozone loss was observed in the Arctic stratosphere in spring 2020.This study aims to determine what caused the extreme Arctic ozone loss.Observations and simulation results are examined in order to show that th...Record ozone loss was observed in the Arctic stratosphere in spring 2020.This study aims to determine what caused the extreme Arctic ozone loss.Observations and simulation results are examined in order to show that the extreme Arctic ozone loss was likely caused by record-high sea surface temperatures(SSTs)in the North Pacific.It is found that the record Arctic ozone loss was associated with the extremely cold and persistent stratospheric polar vortex over February-April,and the extremely cold vortex was a result of anomalously weak planetary wave activity.Further analysis reveals that the weak wave activity can be traced to anomalously warm SSTs in the North Pacific.Both observations and simulations show that warm SST anomalies in the North Pacific could have caused the weakening of wavenumber-1 wave activity,colder Arctic vortex,and lower Arctic ozone.These results suggest that for the present-day level of ozone-depleting substances,severe Arctic ozone loss could form again,as long as certain dynamic conditions are satisfied.展开更多
The tropospheric impact of Arctic ozone loss events is still debatable.In this study we investigate that question,using the ERA5 reanalysis and long-term integration by a climate-chemistry coupled model(CESM2-WACCM).W...The tropospheric impact of Arctic ozone loss events is still debatable.In this study we investigate that question,using the ERA5 reanalysis and long-term integration by a climate-chemistry coupled model(CESM2-WACCM).We begin with the frequency of Arctic ozone loss events.On average,such events occur once in early spring every 14−15 years in ERA5 data and in the model,both of which estimate that roughly 40%of the strong polar vortex events in March are coupled with Arctic ozone loss,the remaining 60%being uncoupled.The composite difference between the two samples might be attributed to the pure impact of the Arctic ozone loss-that is,to ozone loss alone,without the concurrent impact of strong polar vortices.Arctic ozone loss is accompanied by an increase in total ozone in midlatitudes,with the maximum centered in the Central North Pacific.Contrasting Arctic ozone loss events with pure strong polar vortex events that are uncoupled with ozone loss,observations confirm that the stratospheric Northern Annular Mode reverses earlier for the former.For pure strong vortex events in early spring(without Arctic ozone loss),the cold anomalies can extend from the stratosphere to the middle troposphere;when such events are strong,the near surface warm anomalies are biased toward the continents.In contrast,during the other 40%of strong early-spring polar vortex events,those coupled with ozone loss,a concurrent and delayed warming of the near surface over the Arctic and its neighboring areas is observed,due to vertical redistribution of solar radiation by the change in the ozone.展开更多
Analysis on NASA Total Ozone Mapping Spectrometer (TOMS) ozone shows a clear ozone loss, ?50 DU (15% of the total ozone), over Scandinavia. Correlation analysis between the ozone loss and the east-to-west sea surface ...Analysis on NASA Total Ozone Mapping Spectrometer (TOMS) ozone shows a clear ozone loss, ?50 DU (15% of the total ozone), over Scandinavia. Correlation analysis between the ozone loss and the east-to-west sea surface temperature (SST) contrast in the North Atlantic shows correlation coefficients ?0.96 for seasonal variation and ?0.70 for monthly mean (168 months) in 1979–1992. Correlation coefficients between the ozone loss and the surface-to-atmosphere heat fluxes are higher than ?0.87. There-fore the authors suggest that the warm Atlantic current carries energy northward to Scandina via and causes ozone loss there via the surface-to-atmosphere heating processes. Key words Ozone loss - North Atlantic - Surface heating - Scandina via This work was supported by the key project KZ951-A-205-05 of CAS, NSFC Project 40075029, IAP innovation project 8-2212, CAS, First Chinese Arctic Expedition of NOA and LAPC of IAP, CAS.展开更多
Total ozone observations from the Total Ozone Unit(TOU)aboard the Chinese second generation polar orbiting mete-orological satellite,Fengyun-3/A(FY-3/A),revealed that total column ozone over the Arctic declined rapidl...Total ozone observations from the Total Ozone Unit(TOU)aboard the Chinese second generation polar orbiting mete-orological satellite,Fengyun-3/A(FY-3/A),revealed that total column ozone over the Arctic declined rapidly from the beginning of March 2011.An extensive region of low column amount formed around mid March;monthly mean total column ozone in March 2011 was about 30%lower than the average observed during 1979-2010.Daily total column density of ozone near the center of low ozone area in mid March was less than 240 Dobson units,about half the total column ozone amount observed during the same period of the prior 10 years.We analyzed total column ozone data from different satellites during 1979-2011.Results show that the Arctic depletion of ozone in spring 2011 was initiated by the cold polar vortex in the lower stratosphere.The March mean total ozone over the Arctic has shown a decreasing trend over the past 32 years,and its variation is strongly correlated with the polar vortex.A similar low ozone process of spring 1997 was compared to that of 2011,but daily variations of total ozone in March over the Northern Hemisphere in 1997 and 2011 have different patterns.展开更多
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
Ozone photochemical production and loss in very different environments at Waliguan baseline station and Lin'an background station were simulated by using the measurement data and photo- chemical box model.The resu...Ozone photochemical production and loss in very different environments at Waliguan baseline station and Lin'an background station were simulated by using the measurement data and photo- chemical box model.The results show that net ozone photochemical production rate is negative, about 0.5 ppb/d,at Waliguan baseline sation,because of very low precursor concentrations.But at Lin'an background station,the net photochemical ozone production is positive,about 2—3 ppb/ h.which is very closed with the measurement at Lin'an.That means ozone production was con- trolled by photochemical reactions at Lin'an background station,because of the higher precursor concentrations.The net destruction rate,at Waliguan Mt.,is not large,so that future increase in anthropogenic emission of reactive nitrogen will lead to larger production rates of steady-state O_3 concentration.展开更多
Liquid and solid particles in polar stratospheric clouds （PSCs） have been known to play a crucial role in the chemical loss of stratospheric ozone over the Antarctic and Arctic regions in late winter and early sprin...Liquid and solid particles in polar stratospheric clouds （PSCs） have been known to play a crucial role in the chemical loss of stratospheric ozone over the Antarctic and Arctic regions in late winter and early spring. The stratospheric aerosol and cloud particles provide the sites where fast heterogeneous chemical reactions convert inactive halogen reservoir species into potential ozone destroying radicals. The sedimentation of nitric acid-containing PSC particles irreversibly removes HNO3 gas （denitrification） from the lower stratosphere, which slows the return of chlorine to its inactive forms, resulting in more severe stratospheric ozone destruction. Although these clouds have been investigated extensively during the past decade using in situ field observation, laboratory experiment and modeling studies, the detailed microphysics processes under cold stratospheric conditions are still uncertain. This paper reviews the recent advances in our understanding of PSCs.展开更多
基金We thank Dr.Jian YUE for helpful com-ments.This work is supported by the National Natural Science Foundation of China(NSFC)under Grant No.41888101.Y.XIA is supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP),Grant No.2019QZKK0604,Key Laboratory of Middle Atmosphere and Global Environment Observa-tion(LAGEO-2020-09)the Fundamental Research Funds for the Central Universities.
文摘Record ozone loss was observed in the Arctic stratosphere in spring 2020.This study aims to determine what caused the extreme Arctic ozone loss.Observations and simulation results are examined in order to show that the extreme Arctic ozone loss was likely caused by record-high sea surface temperatures(SSTs)in the North Pacific.It is found that the record Arctic ozone loss was associated with the extremely cold and persistent stratospheric polar vortex over February-April,and the extremely cold vortex was a result of anomalously weak planetary wave activity.Further analysis reveals that the weak wave activity can be traced to anomalously warm SSTs in the North Pacific.Both observations and simulations show that warm SST anomalies in the North Pacific could have caused the weakening of wavenumber-1 wave activity,colder Arctic vortex,and lower Arctic ozone.These results suggest that for the present-day level of ozone-depleting substances,severe Arctic ozone loss could form again,as long as certain dynamic conditions are satisfied.
基金supported by the National Natural Science Foundation of China(Grant NO.91837311).
文摘The tropospheric impact of Arctic ozone loss events is still debatable.In this study we investigate that question,using the ERA5 reanalysis and long-term integration by a climate-chemistry coupled model(CESM2-WACCM).We begin with the frequency of Arctic ozone loss events.On average,such events occur once in early spring every 14−15 years in ERA5 data and in the model,both of which estimate that roughly 40%of the strong polar vortex events in March are coupled with Arctic ozone loss,the remaining 60%being uncoupled.The composite difference between the two samples might be attributed to the pure impact of the Arctic ozone loss-that is,to ozone loss alone,without the concurrent impact of strong polar vortices.Arctic ozone loss is accompanied by an increase in total ozone in midlatitudes,with the maximum centered in the Central North Pacific.Contrasting Arctic ozone loss events with pure strong polar vortex events that are uncoupled with ozone loss,observations confirm that the stratospheric Northern Annular Mode reverses earlier for the former.For pure strong vortex events in early spring(without Arctic ozone loss),the cold anomalies can extend from the stratosphere to the middle troposphere;when such events are strong,the near surface warm anomalies are biased toward the continents.In contrast,during the other 40%of strong early-spring polar vortex events,those coupled with ozone loss,a concurrent and delayed warming of the near surface over the Arctic and its neighboring areas is observed,due to vertical redistribution of solar radiation by the change in the ozone.
基金the key project KZ951-A-205-05 of CAS, NSFC Project 40075029,IAP innovation project 8-2212, CAS, First Chinese Arctic Expediti
文摘Analysis on NASA Total Ozone Mapping Spectrometer (TOMS) ozone shows a clear ozone loss, ?50 DU (15% of the total ozone), over Scandinavia. Correlation analysis between the ozone loss and the east-to-west sea surface temperature (SST) contrast in the North Atlantic shows correlation coefficients ?0.96 for seasonal variation and ?0.70 for monthly mean (168 months) in 1979–1992. Correlation coefficients between the ozone loss and the surface-to-atmosphere heat fluxes are higher than ?0.87. There-fore the authors suggest that the warm Atlantic current carries energy northward to Scandina via and causes ozone loss there via the surface-to-atmosphere heating processes. Key words Ozone loss - North Atlantic - Surface heating - Scandina via This work was supported by the key project KZ951-A-205-05 of CAS, NSFC Project 40075029, IAP innovation project 8-2212, CAS, First Chinese Arctic Expedition of NOA and LAPC of IAP, CAS.
文摘Total ozone observations from the Total Ozone Unit(TOU)aboard the Chinese second generation polar orbiting mete-orological satellite,Fengyun-3/A(FY-3/A),revealed that total column ozone over the Arctic declined rapidly from the beginning of March 2011.An extensive region of low column amount formed around mid March;monthly mean total column ozone in March 2011 was about 30%lower than the average observed during 1979-2010.Daily total column density of ozone near the center of low ozone area in mid March was less than 240 Dobson units,about half the total column ozone amount observed during the same period of the prior 10 years.We analyzed total column ozone data from different satellites during 1979-2011.Results show that the Arctic depletion of ozone in spring 2011 was initiated by the cold polar vortex in the lower stratosphere.The March mean total ozone over the Arctic has shown a decreasing trend over the past 32 years,and its variation is strongly correlated with the polar vortex.A similar low ozone process of spring 1997 was compared to that of 2011,but daily variations of total ozone in March over the Northern Hemisphere in 1997 and 2011 have different patterns.
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.
基金This work partly sponsored by the Foundation of Ministry of Labour and Personnel,and the National Natural Science Foundation of China.
文摘Ozone photochemical production and loss in very different environments at Waliguan baseline station and Lin'an background station were simulated by using the measurement data and photo- chemical box model.The results show that net ozone photochemical production rate is negative, about 0.5 ppb/d,at Waliguan baseline sation,because of very low precursor concentrations.But at Lin'an background station,the net photochemical ozone production is positive,about 2—3 ppb/ h.which is very closed with the measurement at Lin'an.That means ozone production was con- trolled by photochemical reactions at Lin'an background station,because of the higher precursor concentrations.The net destruction rate,at Waliguan Mt.,is not large,so that future increase in anthropogenic emission of reactive nitrogen will lead to larger production rates of steady-state O_3 concentration.
文摘Liquid and solid particles in polar stratospheric clouds （PSCs） have been known to play a crucial role in the chemical loss of stratospheric ozone over the Antarctic and Arctic regions in late winter and early spring. The stratospheric aerosol and cloud particles provide the sites where fast heterogeneous chemical reactions convert inactive halogen reservoir species into potential ozone destroying radicals. The sedimentation of nitric acid-containing PSC particles irreversibly removes HNO3 gas （denitrification） from the lower stratosphere, which slows the return of chlorine to its inactive forms, resulting in more severe stratospheric ozone destruction. Although these clouds have been investigated extensively during the past decade using in situ field observation, laboratory experiment and modeling studies, the detailed microphysics processes under cold stratospheric conditions are still uncertain. This paper reviews the recent advances in our understanding of PSCs.
