期刊文献+
共找到147篇文章
< 1 2 8 >
每页显示 20 50 100
2-D Modeling and Calculations of Stratospheric Ozone and Influences of Convection, Diffusion, and Time
1
作者 Ibraheem Alelmi Laurie Wei Sen Nieh 《Atmospheric and Climate Sciences》 2024年第2期250-276,共27页
An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical react... An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical reaction equations was developed, validated, and used for studying the ozone concentrations, distribution and peak of the layer, ozone depletion and total ozone abundance in the stratosphere. The calculated ozone concentrations and profile at both the Equator and a 60˚N location were found to follow closely with the measured data. The calculated average ozone concentration was within 1% of the measured average, and the deviation of ozone profiles was within 14%. The monthly evolution of stratospheric ozone concentrations and distribution above the Equator was studied with results discussed in details. The influences of slow air movement in both altitudinal and radial directions on ozone concentrations and profile in the stratosphere were explored and discussed. Parametric studies of the influences of gas diffusivities of ozone D<sub>O3</sub> and active atomic oxygen D<sub>O</sub> on ozone concentrations and distributions were also studied and delineated. Having both influences through physical diffusion and chemical reactions, the diffusivity (and diffusion) of atomic oxygen D<sub>O</sub> was found to be more sensitive and important than that of ozone D<sub>O3</sub> on ozone concentrations and distribution. The 2-D ozone model present in this paper for stratospheric ozone and its layer and depletion is shown to be robust, convenient, efficient, and executable for analyzing the complex ozone phenomena in the stratosphere. . 展开更多
关键词 Stratospheric ozone 2-D Model ozone Layer ozone Depletion CONVECTION DIFFUSION
下载PDF
Relationship between the Interannual Variations of Total Ozone in the Northern Hemisphere and the QBO of Basic Flow in the Tropical Stratosphere
2
作者 黄荣辉 王连英 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1990年第1期47-56,共10页
The harmonic analyses of monthly mean total ozone in the atmosphere over the Northern Hemisphere for 26 years (1960-1985) are made by using the Fourier expansion. The analysed results show that there is obviously a qu... The harmonic analyses of monthly mean total ozone in the atmosphere over the Northern Hemisphere for 26 years (1960-1985) are made by using the Fourier expansion. The analysed results show that there is obviously a quasi-biennial oscillation (QBO) in the interannual variations of the amplitudes of total ozone. Generally, the amplitudes of wavenumber 1 and 2 during the westerly of the equatorial QBO are larger than those during the easterly. In the early winter, the amplitude of wavenumber 1 during the easterly phase is larger, and in the late winter, it is larger during the westerly phase. These are in good agreement with the observational distributions. 展开更多
关键词 Relationship between the Interannual Variations of Total ozone in the Northern Hemisphere and the QBO of Basic Flow in the Tropical stratosphere
下载PDF
The Role of Ozone Depletion in the Lack of Cooling in the Antarctic Upper Stratosphere during Austral Winter
3
作者 Xuan MA Lei WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第4期619-633,共15页
Temperature trends in the upper stratosphere are investigated using satellite measurements from Stratospheric Sounding Unit(SSU)outputs and simulations from chemistry-climate models(CCMs)and the Coupled Model Intercom... Temperature trends in the upper stratosphere are investigated using satellite measurements from Stratospheric Sounding Unit(SSU)outputs and simulations from chemistry-climate models(CCMs)and the Coupled Model Intercomparison Project Phase 6(CMIP6).Observational evidence shows a lack of cooling in the Antarctic,in contrast to strong cooling at other latitudes,during austral winter over 1979-97.Analysis of CCM simulations for a longer period of1961-97 also shows a significant contrast in the upper stratospheric temperature trends between the Antarctic and lower latitudes.Results from two sets of model integrations with fixed ozone-depleting substances(ODSs)and fixed greenhouse gases(GHGs)at their 1960 levels suggest that the ODSs have made a major contribution to the lack of cooling in the Antarctic upper stratosphere.Results from CMIP6 simulations with prescribed GHGs and ozone confirm that changes in the dynamical processes associated with observed ozone depletion are largely responsible for the lack of cooling in the Antarctic upper stratosphere.The lack of cooling is found to be dynamically induced through increased upward wave activity into the upper stratosphere,which is attributed mainly to ODSs forcing.Specifically,the radiative cooling caused by the ozone depletion results in a stronger meridional temperature gradient between middle and high latitudes in the upper stratosphere,allowing more planetary waves propagating upward to warm the Antarctic upper stratosphere.These findings improve our understanding of the chemistry-climate coupling in the southern upper stratosphere. 展开更多
关键词 Antarctic stratosphere temperature trends ozone wave activity
下载PDF
Anomalously low ozone of 1997 and 2011 Arctic spring: Monitoring results and analysis 被引量:5
4
作者 ZHANG Yan WANG Weihe +3 位作者 LI Xiaojing ZHANG Xingying ZHENG Zhaojun LIU Ruixia 《Advances in Polar Science》 2012年第2期82-86,共5页
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 decli... 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
关键词 Arctic ozone loss polar vortex ozone hole polar stratospheric clouds
下载PDF
Features of Ozone Mini-Hole Events over the Tibetan Plateau 被引量:10
5
作者 卞建春 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2009年第2期305-311,共7页
Based on TOMS total ozone data and SCIAMACHY ozone profile data, climatology of the ozone minihole events over the Tibetan Plateau and ozone vertical structure variations during an ozone mini-hole event in December 20... Based on TOMS total ozone data and SCIAMACHY ozone profile data, climatology of the ozone minihole events over the Tibetan Plateau and ozone vertical structure variations during an ozone mini-hole event in December 2003 are analyzed. The analyses show that before 1990 ozone mini-hole events only occurred in November-December of 1987 but that the number of events increases after 1990. These events only occur from October through February, with maximum occurrence frequency in December. During the event in December 2003, the decrease in total ozone of over 20% is mainly caused by the ozone loss in the upper troposphere and lower stratosphere region due to the horizontal transport of low ozone from the lower latitude subtropics and the uplift of low ozone from the lower troposphere over the Tibetan Plateau. 展开更多
关键词 ozone mini-hole Tibetan Plateau subtropical jet upper troposphere and lower stratosphere
下载PDF
Impact of Increasing Stratospheric Water Vapor on Ozone Depletion and Temperature Change 被引量:16
6
作者 田文寿 Martyn P.CHIPPERFIELD 吕达仁 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2009年第3期423-437,共15页
Using a detailed, fully coupled chemistry climate model (CCM), the effect of increasing stratospheric H20 on ozone and temperature is investigated. Different CCM time-slice runs have been performed to investigate th... Using a detailed, fully coupled chemistry climate model (CCM), the effect of increasing stratospheric H20 on ozone and temperature is investigated. Different CCM time-slice runs have been performed to investigate the chemical and radiative impacts of an assumed 2 ppmv increase in H20. The chemical effects of this H20 increase lead to an overall decrease of the total column ozone (TCO) by ~1% in the tropics and by a maximum of 12% at southern high latitudes. At northern high latitudes, the TCO is increased by only up to 5% due to stronger transport in the Arctic. A 2-ppmv H2O increase in the model's radiation scheme causes a cooling of the tropical stratosphere of no more than 2 K, but a cooling of more than 4 K at high latitudes. Consequently, the TCO is increased by about 2%-6%. Increasing stratospheric H2O, therefore, cools the stratosphere both directly and indirectly, except in the polar regions where the temperature responds differently due to feedbacks between ozone and H2O changes. The combined chemical and radiative effects of increasing H2O may give rise to more cooling in the tropics and middle latitudes but less cooling in the polar stratosphere. The combined effects of H2O increases on ozone tend to offset each other, except in the Arctic stratosphere where both the radiative and chemical impacts give rise to increased ozone. The chemical and radiative effects of increasing H2O cause dynamical responses in the stratosphere with an evident hemispheric asymmetry. In terms of ozone recovery, increasing the stratospheric H2O is likely to accelerate the recovery in the northern high latitudes and delay it in the southern high latitudes. The modeled ozone recovery is more significant between 2000 ~2050 than between 2050~2100, driven mainly by the larger relative change in chlorine in the earlier period. 展开更多
关键词 stratospheric water vapor temperature change ozone depletion chemistry-climate model
下载PDF
Evaluating the Ozone Valley over the Tibetan Plateau in CMIP6 Models 被引量:2
7
作者 Kequan ZHANG Jiakang DUAN +3 位作者 Siyi ZHAO Jiankai ZHANG James KEEBLE Hongwen LIU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第7期1167-1183,共17页
Total column ozone(TCO)over the Tibetan Plateau(TP)is lower than that over other regions at the same latitude,particularly in summer.This feature is known as the“TP ozone valley”.This study evaluates long-term chang... Total column ozone(TCO)over the Tibetan Plateau(TP)is lower than that over other regions at the same latitude,particularly in summer.This feature is known as the“TP ozone valley”.This study evaluates long-term changes in TCO and the ozone valley over the TP from 1984 to 2100 using Coupled Model Intercomparison Project Phase 6(CMIP6).The TP ozone valley consists of two low centers,one is located in the upper troposphere and lower stratosphere(UTLS),and the other is in the middle and upper stratosphere.Overall,the CMIP6 models simulate the low ozone center in the UTLS well and capture the spatial characteristics and seasonal cycle of the TP ozone valley,with spatial correlation coefficients between the modeled TCO and the Multi Sensor Reanalysis version 2(MSR2)TCO observations greater than 0.8 for all CMIP6 models.Further analysis reveals that models which use fully coupled and online stratospheric chemistry schemes simulate the anticorrelation between the 150 hPa geopotential height and zonal anomaly of TCO over the TP better than models without interactive chemistry schemes.This suggests that coupled chemical-radiative-dynamical processes play a key role in the simulation of the TP ozone valley.Most CMIP6 models underestimate the low center in the middle and upper stratosphere when compared with the Microwave Limb Sounder(MLS)observations.However,the bias in the middle and upper stratospheric ozone simulations has a marginal effect on the simulation of the TP ozone valley.Most CMIP6 models predict the TP ozone valley in summer will deepen in the future. 展开更多
关键词 Tibetan Plateau stratospheric ozone ozone valley CMIP6
下载PDF
Middle Stratospheric Polar Vortex Ozone Budget during the Warming Arctic Winter, 2002-2003 被引量:1
8
作者 刘毅 刘传熙 +1 位作者 铁学熙 高守亭 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第5期985-996,共12页
The ozone budget inside the middle stratospheric polar vortex (24-36 km) during the 2002-2003 Arctic winter is studied by analyzing Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) satellite data.... The ozone budget inside the middle stratospheric polar vortex (24-36 km) during the 2002-2003 Arctic winter is studied by analyzing Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) satellite data.A comprehensive global chemical transport model (Model for Ozone and Related Chemical Tracers,MOZART-3) is used to analyze the observed variation in polar vortex ozone during the stratospheric sudden warming (SSW) events.Both MIPAS measurement and MOZART-3 calculation show that a pronounced increase (26-28 DU) in the polar vortex ozone due to the SSW events.Due to the weakening of the polar vortex,the exchange of ozone mass across the edge of the polar vortex increases substantially and amounts to about 3.0 × 10 7 kg according to MOZART-3 calculation.The enhanced downward transport offsets about 80% of polar vortex ozone mass increase by horizontal transport.A "passive ozone" experiment shows that only ~55% of the vertical ozone mass flux in February and March can be attributed to the variation in vertical transport.It is also shown that the enhanced downward ozone above ~32 km should be attributed to the springtime photochemical ozone production.Due to the increase of air temperature,the NO x reaction rate increases by 40%-80% during the SSW events.As a result,NO x catalytic cycle causes another 44% decrease in polar vortex ozone compared to the net ozone changes due to dynamical transport.It is also shown that the largest change in polar vortex ozone is due to horizontal advection by planetary waves in January 2003. 展开更多
关键词 stratospheric sudden warming planetary wave MIPAS MOZART-3 model ozone depletion
下载PDF
Record Arctic Ozone Loss in Spring 2020 is Likely Caused by North Pacific Warm Sea Surface Temperature Anomalies 被引量:1
9
作者 Yan XIA Yongyun HU +2 位作者 Jiankai ZHANG Fei XIE Wenshou TIAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第10期1723-1736,共14页
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
关键词 Arctic ozone loss stratospheric polar vortex sea surface temperature planetary-scale wave climate change
下载PDF
Modelling,Validation,and Calculations of Stratospheric Ozone Dynamics and Latitudinal Changes 被引量:1
10
作者 Ibraheem Alelmi Laurie Wei Sen Nieh 《Journal of Environmental Science and Engineering(B)》 2023年第6期265-279,共15页
This paper presents an engineering system approach of 2-D cylindrical model of mass balance calculations with convection,diffusion,and all potential photolysis,ozone generating and depleting chemical reactions conside... This paper presents an engineering system approach of 2-D cylindrical model of mass balance calculations with convection,diffusion,and all potential photolysis,ozone generating and depleting chemical reactions considered.This model was developed,validated,and tested under different conditions for the stratospheric ozone.The calculated ozone concentrations and profile in the stratosphere at both the Equator and mid-latitudinal location of 40°S were found to exhibit a similar and close profile and peak value of the published measured data.The discrepancy between the calculations and measurements for the average ozone concentration was shown to be less than 1%and the variation of distributions to be less than 19%.The latitudinal changes of ozone concentrations,distribution,and peak of the layer were found to shift from 9.41 ppm at mid-altitude of z=30 km at the Equator,to 7.81 ppm at z=34.5 km at 40°S,to 5.78 ppm at higher altitude z=39 km at the South Pole.The total ozone abundances at strategic latitudes at 0°S,20°S,40°S,60°S,and 90°S,were found to remain stable and not much changed,from 305 DU to 335 DU,except a smaller value of 288 DU at the South Pole.The possible explanations of ozone profile change and peak shifting as affected by solar/UV radiation,latitudinal locations,and ozone-depleting reactions were discussed and elaborated.The 2-D ozone Model presented in this paper is a robust,efficient,executable,and validated model for studying the complex ozone phenomena in the stratosphere. 展开更多
关键词 2-D ozone model stratospheric ozone validation ozone depletion latitudinal changes
下载PDF
Trend of Antarctic Ozone Hole and Its Influencing Factors 被引量:1
11
作者 BIAN Lin-Gen LIN Zhong +2 位作者 ZHENG Xiang-Dong MA yong-Feng LU Long-Hua 《Advances in Climate Change Research》 2012年第2期68-75,共8页
Influencing factors, and variations and trends of Antarctic ozone hole in recent decades are analyzed, and sudden change processes of ozone at Zhongshan station and the effect of atmospheric dynamic processes on ozone... Influencing factors, and variations and trends of Antarctic ozone hole in recent decades are analyzed, and sudden change processes of ozone at Zhongshan station and the effect of atmospheric dynamic processes on ozone changes are also discussed by using the satellite ozone data and the ground-measured ozone data at two Antarctic stations as well as the NCEP/NCAR reanalysis data. The results show that equivalent effective stratospheric chlorine (EESC) and stratospheric temperature are two important factors influencing the ozone hole. The column ozone at Zhongshan and Syowa stations is significantly related with EESC and stratospheric temperature, which means that even though the two stations are both located on the edge of the ozone hole, EESC and stratospheric temperature still played a very important role in column ozone changes, and mean while verifies that EESC is applicable on the coast of east Antarctic continent. Decadal changes in EESC are similar with those of the ozone hole, and inter-annual variations of ozone are closely related with stratospheric temperature. Based on the relation of EESC and ozone hole size, it can be projected that the ozone hole size will gradually reduce to the 1980's level from 2010 to around 2070. Of course there might exist many uncertainties in the projection, which therefore needs to be further studied. 展开更多
关键词 Antarctic ozone hole equivalent effective stratospheric chlorine (EESC) stratospheric temperature TREND
下载PDF
Total Ozone Content Trend during the Last Decade over Western Indian Tropical Station i.e. Udaipur
12
作者 Abhishek Saxena Brij Mohan Vyas 《American Journal of Climate Change》 2016年第2期193-201,共9页
This study focuses on multi-year change in Total Ozone Content (TOC) values measured simultaneously by ground based instrument, i.e., MICROTOPS-II sun photometer and space based TOMS satellite experiment during the la... This study focuses on multi-year change in Total Ozone Content (TOC) values measured simultaneously by ground based instrument, i.e., MICROTOPS-II sun photometer and space based TOMS satellite experiment during the last decade, i.e., the period from 2002 to 2009 in the outskirts of the semi-arid and semi-urban tropical region of Udaipur (24.6°N, 74°E;580 m asl), India. The negative declining trend in TOC value has been detected about 2 DU/decade by using Linear Regression Analysis (LRA) of the monthly averaged TOC levels. The LRA presents the best statistically significant percentage level (p) of greater than 99%. From the comparison of present result with the observations reported over mid, high and polar latitude sites, long-term TOC variability from tropical site is found to be the lowest, followed by their intermediate range from 10 to 30 DU/ decade over mid latitude sites and the highest range from 30 to 50 DU/decade over high to polar latitude. In order to establish the possible linking of reduction in TOC level per decade with other stratospheric dynamic parameters and atmospheric UV aerosols parameter, inter-annual change in average monthly TOC level has shown a strong correlation coefficient (r) of the order of 0.73 (p > 99.9990) with the stratospheric temperature, followed by its observed lower r value of 0.25 (p = 99%) for stratospheric zonal wind and then a significant correlation (r = 0.17;p = 95%) for AI 300 nm (Aerosols Index 300 nm) parameter. The variation of monthly mean meridional wind component does not illustrate a statistically significant correlation (r = 0.13;p < 80%) with their respective multi-year change in mean monthly TOC values. The consequence of such reduction of TOC per decade may be identified as the result of expected enhancement in incident ground UV-radiation level. At the same time, the harmful influence of increasing the UV level seems to be counteracted and reduced with the evidence of observed higher level of AI at 300 nm as high as 3 in the summer months over selected tropical environmental site. 展开更多
关键词 Total ozone Content AI 300 nm Stratospheric Parameters Tropical Latitude
下载PDF
Ozone during Stratospheric Warmings at Uccle
13
作者 V. N. R. Mukku C. S. Bhosale 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1991年第2期251-255,共5页
The day-to-day variations in ozone content at Uccle (51°N) during some stratospheric warming events are examined. In particular, the attention is focused on the timing of commencement of ozone enhancement prior t... The day-to-day variations in ozone content at Uccle (51°N) during some stratospheric warming events are examined. In particular, the attention is focused on the timing of commencement of ozone enhancement prior to peak day of warming and on the relationship in the ozone content between the upper and lower stratosphere. These two features are compared with the predictions of ozone transport models. There seems to be an agreement between model predictions and observed features in some cases. 展开更多
关键词 ozone during Stratospheric Warmings at Uccle
下载PDF
The Effect of Super Volcanic Eruptions on Ozone Depletion in a Chemistry–Climate Model 被引量:4
14
作者 Luyang XU Ke WEI +3 位作者 Xue WU S. P. SMYSHLYAEV Wen CHEN V. Ya. GALIN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第8期823-836,共14页
With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery ... With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery of the ozone layer is predicted in this century. However, strong volcanic activity can also cause ozone depletion that might be severe enough to threaten the existence of life on Earth. In this study, a transport model and a coupled chemistry–climate model were used to simulate the impacts of super volcanoes on ozone depletion. The volcanic eruptions in the experiments were the 1991 Mount Pinatubo eruption and a 100 × Pinatubo size eruption. The results show that the percentage of global mean total column ozone depletion in the 2050 RCP8.5 100 × Pinatubo scenario is approximately 6% compared to two years before the eruption and 6.4% in tropics. An identical simulation, 100 × Pinatubo eruption only with natural source ODSs, produces an ozone depletion of 2.5% compared to two years before the eruption, and with 4.4% loss in the tropics. Based on the model results,the reduced ODSs and stratospheric cooling lighten the ozone depletion after super volcanic eruption. 展开更多
关键词 STRATOSPHERIC ozone VOLCANIC ERUPTIONS STRATOSPHERIC AEROSOLS chemistry–climate model
下载PDF
On the Nonlinear Response of Lower Stratospheric Ozone to NO_x and ClO_x Perturbations for Different CH_4 Sources 被引量:3
15
作者 王革丽 杨培才 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2006年第5期750-757,共8页
The impact of sulfate aerosol, ClOx and NOx perturbations for two different magnitudes of CH4 sources on lower stratospheric ozone is studied by using a heterogeneous chemical system that consists of 19 species belong... The impact of sulfate aerosol, ClOx and NOx perturbations for two different magnitudes of CH4 sources on lower stratospheric ozone is studied by using a heterogeneous chemical system that consists of 19 species belonging to 5 chemical families (oxygen, hydrogen, nitrogen, chlorine and carbon). The results show that the present modeled photochemical system can present several different solutions, for instance, periodic states and multi-equilibrium states appearing in turn under certain parameter domains, through chlorine chemistry and nitrogen chemistry together with sulfate aerosol as well as the increasing magnitude of CH4 sources. The existence of catastrophic transitions could produce a dramatic reduction in the ozone concentration with the increase of external sources. 展开更多
关键词 lower stratosphere atmospheric ozone AEROSOL multi-equilibrium catastrophic transition
下载PDF
Satellite Measurements of the Madden–Julian Oscillation in Wintertime Stratospheric Ozone over the Tibetan Plateau and East Asia 被引量:3
16
作者 ZHANG Yuli LIU Yi +1 位作者 LIU Chuanxi V.F.SOFIEVA 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第11期1481-1492,共12页
We investigate the Madden-Julian Oscillation (MJO) signal in wintertime stratospheric ozone over the Tibetan Plateau and East Asia using the harmonized dataset of satellite ozone profiles. Two different MJO indices ... We investigate the Madden-Julian Oscillation (MJO) signal in wintertime stratospheric ozone over the Tibetan Plateau and East Asia using the harmonized dataset of satellite ozone profiles. Two different MJO indices -- the all-season Real-Time multivariate MJO index (RMM) and outgoing longwave radiation-based MJO index (OMI) -- are used to compare the MJO- related ozone anomalies. The results show that there are pronounced eastward-propagating MJO-related stratospheric ozone anomalies (mainly within 20-200 hPa) over the subtropics, The negative stratospheric ozone anomalies are over the Tibetan Plateau and East Asia in MJO phases 4-7, when MJO-related tropical deep convective anomalies move from the equatorial Indian Ocean towards the western Pacific Ocean. Compared with the results based on RMM, the MJO-related stratospheric column ozone anomalies based on OM1 are stronger and one phase ahead. Further analysis suggests that different sampling errors, observation principles and retrieval algorithms may be responsible for the discrepancies among different satellite measurements. The MJO-related stratospheric ozone anomalies can be attributed to the MJO-related circulation anomalies, i.e., the uplifted tropopanse and the northward shifted westerly jet in the upper troposphere. Compared to the result based on RMM, the upper tropospheric westerly jet may play a less important role in generating the stratospheric column ozone anomalies based on OMI. Our study indicates that the circulation-based MJO index (RMM) can better characterize the MJO- related anomalies in tropopause pressure and thus the MJO influence on atmospheric trace gases in the upper troposphere and lower stratosphere, especially over subtropical East Asia. 展开更多
关键词 Madden-Julian Oscillation stratospheric ozone TROPOPAUSE subtropical jet stream
下载PDF
Simulation of the Madden-Julian Oscillation in Wintertime Stratospheric Ozone over the Tibetan Plateau and East Asia: Results from the Specified Dynamics Version of the Whole Atmosphere Community Climate Model 被引量:2
17
作者 LIU Chuan-Xi LIU Yi ZHANG Yu-Li 《Atmospheric and Oceanic Science Letters》 CSCD 2015年第5期264-270,共7页
The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2... The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2004 and 2010. Comparison with European Centre for Medium-Range Weather Forecasts Interim Reanalysis(ERA-Interim) data suggested that the model simulation represented well the three-dimensional structure of the MJO-related ozone anomalies in the upper troposphere and stratosphere(i.e., between 200 and 20 h Pa). The negative ozone anomalies were over the Tibetan Plateau and East Asia in MJO phases 3–7, when the MJO convective anomalies travelled from the equatorial Indian Ocean towards the equatorial western Pacific Ocean. Due to the different vertical structures of the MJO-related circulation anomalies, the MJO-related stratospheric ozone anomalies showed different vertical structure over the Tibetan Plateau(25–40°N, 75–105°E) and East Asia(25–40°N, 105–135°E). As a result of the positive bias in the model-calculated ozone in the upper troposphere and lower stratosphere, the amplitude of MJO-related stratospheric ozone column anomalies(10–16 Dobson Units(DU)) in the SD-WACCM simulation was slightly larger than that(8–14 DU) in the ERA-Interim reanalysis. 展开更多
关键词 Madden-Julian OSCILLATION STRATOSPHERIC ozone trop
下载PDF
The Impacts of Two Types of El Nińo on Global Ozone Variations in the Last Three Decades 被引量:2
18
作者 XIE Fei LI Jianping +2 位作者 TIAN Wenshou ZHANG Jiankai SHU Jianchuan 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2014年第5期1113-1126,共14页
The effects of E1Nifio Modoki events on global ozone concentrations are investigated from 1980 to 2010 E1 Nifio Modoki events cause a stronger Brewer-Dobson (BD) circulation which can transports more ozone-poor air ... The effects of E1Nifio Modoki events on global ozone concentrations are investigated from 1980 to 2010 E1 Nifio Modoki events cause a stronger Brewer-Dobson (BD) circulation which can transports more ozone-poor air from the troposphere to stratosphere, leading to a decrease of ozone inthe lower-middle stratosphere from 90~S to 90~N. These changes in ozone concentrations reduce stratospheric column ozone. The reduction in stratospheric column ozone during E1 Nifio Modoki events is more pronounced over the tropical eastern Pacific than over other tropical areas because transport of ozone-poor air from middle-high latitudes in both hemispheres to low latitudes is the strongest between 60°W and 120°W. Because of the decrease in stratospheric column ozone during E1 Nifio Modoki events more UV radiation reaches the tropical troposphere leading to significant increases in tropospheric column ozone An empirical orthogonal function (EOF) analysis of the time series from 1980 to 2010 of stratospheric and tropospheric ozone monthly anomalies reveals that: E1 Nifio Modoki events are associated with the primary EOF modes of both time series. We also found that E1 Nifio Modoki events can affect global ozone more significantly than canonical E1 Nifio events. These results imply that E1 Nifio Modoki is a key contributor to variations in global ozone from 1980 to 2010. 展开更多
关键词 stratospheric ozone tropospheric ozone canonical E1 Nifio E1 Nifio Modoki
下载PDF
What Causes the Springtime Tropospheric Ozone Maximum over Northeast Asia? 被引量:3
19
作者 Jae H.KIM Hyunjin LEE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2010年第3期543-551,共9页
Scientists have long debated the relative importance of tropospheric photochemical production versus stratospheric influx as causes of the springtime tropospheric ozone maximum over northern mid-latitudes. This paper ... Scientists have long debated the relative importance of tropospheric photochemical production versus stratospheric influx as causes of the springtime tropospheric ozone maximum over northern mid-latitudes. This paper investigates whether or not stratospheric intrusion and photochemistry play a significant role in the springtime ozone maximum over Northeast Asia, where ozone measurements are sparse. We examine how tropospheric ozone seasonalities over Naha (26°N, 128°E), Kagoshima (31°N, 131°E), and Pohang (36°N, 129°E), which are located on the same meridional line, are related to the timing and location of the jet stream. The ozone seasonality shows a gradual increase from January to the maximum ozone month, which corresponds to April at Naha, May at Kagoshima, and June at Pohang. In order to examine the occurrence of stratospheric intrusion, we analyze a correlation between jet stream activity and tropospheric ozone seasonality. From these analyses, we did not find any favorable evidence supporting the hypothesis that the springtime enhancement may result from stratospheric intrusion. According to trajectory analysis for vertical and horizontal origins of the airmass, a gradual increasing tendency in ozone amounts from January until the onset of monsoon was similar to the increasing ozone formation tendency from winter to spring over China's Mainland, which has been observed during the build-up of tropospheric ozone over Central Europe in the winter-spring transition period due to photochemistry. Overall, the analyses suggest that photochemistry is the most important contributor to observed ozone seasonality over Northeast Asia. 展开更多
关键词 tropospheric ozone photochemistry stratospheric intrusion jet stream activity trajectory
下载PDF
Increasing Surface UV Radiation in the Tropics and Northern Mid-Latitudes due to Ozone Depletion after 2010 被引量:2
20
作者 Fei XIE Yan XIA +1 位作者 Wuhu FENG Yingli NIU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第10期1833-1843,共11页
Excessive exposure to ultraviolet(UV)radiation harms humans and ecosystems.The level of surface UV radiation had increased due to declines in stratospheric ozone in the late 1970s in response to emissions of chloroflu... Excessive exposure to ultraviolet(UV)radiation harms humans and ecosystems.The level of surface UV radiation had increased due to declines in stratospheric ozone in the late 1970s in response to emissions of chlorofluorocarbons.Following the implementation of the Montreal Protocol,the stratospheric loading of chlorine/bromine peaked in the late 1990s and then decreased;subsequently,stratospheric ozone and surface UV radiation would be expected to recover and decrease,respectively.Here,we show,based on multiple data sources,that the May–September surface UV radiation in the tropics and Northern Hemisphere mid-latitudes has undergone a statistically significant increasing trend[about 60.0 J m^(–2)(10 yr)^(–1)]at the 2σlevel for the period 2010–20,due to the onset of total column ozone(TCO)depletion[about−3.5 DU(10 yr)^(–1)].Further analysis shows that the declines in stratospheric ozone after 2010 could be related to an increase in stratospheric nitrogen oxides due to increasing emissions of the source gas nitrous oxide(N_(2)O). 展开更多
关键词 surface UV radiation stratospheric ozone stratospheric chemistry N_(2)O
下载PDF
上一页 1 2 8 下一页 到第
使用帮助 返回顶部