In order to reveal the variation characteristics of ozone （03） concentration in the atmosphere boundary layer over a desert in winter, an observation experiment was carried out in the Tazhong area by means of a teth...In order to reveal the variation characteristics of ozone （03） concentration in the atmosphere boundary layer over a desert in winter, an observation experiment was carried out in the Tazhong area by means of a tethered balloon during January 18-25, 2008. The vertical distribution of O3 concentration and its correlation with temperature and humidity were analyzed based on experimental observation data and related data. Results show that： （1） The concentration of O3 mainly ranges from 10 to 50 μg/L, with a maximum of 56.1 μg/L, minimum of 2.6 μg/L, and a daily average concentration of 34.4 μg/L. （2） O3 profiles can be divided into three types： peak, uniform, and growth, where uniform accounts for the majority. （3） Temperature and moisture are influential on O3 concentrations in atmospheric boundary layer. Temperature inversion and water vapor increase in an atmospheric boundary layer leads to a decrease of O3. （4） O3 concentration has an obvious daily change in Tazhong. It is lower at night, begins to increase after sunrise, and reaches a maximum at noon. The maximum appears at 17：00 BJT （Beijing Time）, and the minimum appears at 08：00 BJT.展开更多
An analysis of 50 ozonesondings in Xining (36.43 o N, 101.45 o E , 2296 m, ASL), between April 1995 and August 1996 is presented. General vertical distribution characteristics and seasonal changing of ozone p...An analysis of 50 ozonesondings in Xining (36.43 o N, 101.45 o E , 2296 m, ASL), between April 1995 and August 1996 is presented. General vertical distribution characteristics and seasonal changing of ozone profile are reported. The analysis indicates that the stratospheric ozone concentrations of Autumn and Summer are lower than those of Spring and Winter; and the highest value of the tropospheric ozone concentrations is found in Summer; ozone concentration changing is bigger from the troposphere to the lower stratosphere altitude region, while it is stable in the middle and upper stratosphere region; there is a lower ozone concentration region in 10 -1 5 km altitude; the result why higher ozone concentration of the troposphere occurs in Summer is the ozone injecting from the middle and upper stratosphere.展开更多
A two-step method is employed in this study to retrieve vertical ozone profiles using scattered measure- ments from the limb of the atmosphere. The combination of the Differential Optical Absorption Spectroscopy （DOA...A two-step method is employed in this study to retrieve vertical ozone profiles using scattered measure- ments from the limb of the atmosphere. The combination of the Differential Optical Absorption Spectroscopy （DOAS） and the Multiplicative Algebraic Reconstruction Technique （MART） is proposed. First, the limb radiance, measured over a range of tangent heights, is processed using the DOAS technique to recover the effective column densities of atmospheric ozone. Second, these effective column densities along the lines of sight （LOSs） are inverted using the MART coupled with a forward model SCIATRAN （radiative transfer model for SCIAMACHY） to derive the ozone profiles. This method is applied to Optical Spectrograph and Infra Red Imager System （OSIRIS） radiance, using the wavelength windows 571–617 nm. Vertical ozone profiles between 10 and 48 km are derived with a vertical resolution of 1 km. The results illustrate a good agreement with the cloud-free coincident SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY （SCIAMACHY） ozone measurements, with deviations less than ± 10% （ ± 5% for altitudes from 17 to 47 km）. Furthermore, sensitivities of retrieved ozone to aerosol, cloud parameters and NO 2 concentration are also investigated.展开更多
The ozone profiles from August 1991 to December 1993 in Qinghai Gonghe Station (the altitude:3000 m,latitude: 36°16.45’N, longitude: 100°37.11’E) have been got through the measurement with a Brewer Ozone s...The ozone profiles from August 1991 to December 1993 in Qinghai Gonghe Station (the altitude:3000 m,latitude: 36°16.45’N, longitude: 100°37.11’E) have been got through the measurement with a Brewer Ozone spectrophotometer and Umkehr retrieval program of AES. The method we used is the short Umkehr method展开更多
A new remote sensing method is described to determine the vertical distribution and total content of atmospheric ozone. The method combines surface infrared, satellite infrared and ultraviolet channels. The width of t...A new remote sensing method is described to determine the vertical distribution and total content of atmospheric ozone. The method combines surface infrared, satellite infrared and ultraviolet channels. The width of the infrared channels is 0.01 cm-1, less than Lorentz half-width at the earth's surface, rather than the present width, because these channels can obtain information about variations in the ozone profile below the profile main-peak. The numerical experiments show that the method has a satisfactory precision in determining total ozone content, just about I percent error, and vertical distribution from the earth to 65 km space. In addition, some semi-analysis functions lor calculating backscattered ultraviolet and a relaxation equation are described in this paper.展开更多
Due to the arid and sandy surface of the Taklimakan Desert(TD)in China,the turbulence structure and vertical distribution of ozone exhibit unique and complex characteristics.However,few studies have focused on these i...Due to the arid and sandy surface of the Taklimakan Desert(TD)in China,the turbulence structure and vertical distribution of ozone exhibit unique and complex characteristics.However,few studies have focused on these issues.To reveal the variation characteristics of summertime atmospheric turbulence and ozone concentration over the TD,we conducted joint detection experiments in July 2016 and July 2021 at Tazhong in the hinterland of the TD using an eddy covariance detection system,a GPS(Global Positioning System)sounding system,and a meteorological gradient tower.Using methods such as statistical analysis,nonlinear fitting,and Fast Fourier Transform,this study analyzed and processed parameters including temperature,relative humidity,wind speed,turbulence parameters,turbulence spectra,and ozone concentration.The high average temperature is accompanied by low relative humidity over the TD,showing a negative correlation between the two.The temperature of the 10.0-cm-deep sand layer lags the near-surface air temperature by nearly 4 h.From 09:30 to 21:00(Beijing Time),under conditions where the sensible heat flux is positive but stability parameter(z/L,where z is the height and L is the Obukhov length)is negative,the atmosphere is heated by the land surface,with the occurrence of unstable stratification;however,the conditions are the opposite(sensible heat flux is negative and z/L is positive)after 22:00,which are accompanied with the cooling of the surface radiation,occurrence of temperature inversion in the lower atmosphere,and stable stratification.A positive correlation is identified between the diurnal variation of turbulent kinetic energy(TKE)and the atmospheric boundary layer(ABL)height,with significant contributions from both the buoyancy and shear terms during the daytime.Under unstable stratification,the normalized standard deviations of the three-dimensional wind speed,temperature,and humidity conform to the Monin-Obukhov Similarity Theory(MOST).As the stability parameter z/L transitions from strongly unstable to strongly stable,the energy of the dimensionless turbulent velocity spectra gradually decreases and conforms to the -2/3 power law within the inertial subrange.In the hinterland of the TD,the summertime tropospheric ozone concentration remains below approximately 0.70×10^(-6)(volume concentration).Above the troposphere,within the range of 16,500.0-30,000.0 m,a significant increasing trend is identified in the ozone concentration with altitude.At an altitude of 30,000.0 m,the maximum ozone concentration can reach up to 7.50×10^(-6).The research findings provide both theoretical and data foundations for future in-depth studies of turbulent motion and ozone concentration distribution in the TD,as well as in the similar areas around the world.展开更多
Based on the Stratospheric Aerosol and Gas Experiment (SAGE) II and the Halogen Occultation Ex-periment (HALOE) ozone profiles and the Total Ozone Mapping Spectrometer (TOMS) total ozone data sets,the characteristics ...Based on the Stratospheric Aerosol and Gas Experiment (SAGE) II and the Halogen Occultation Ex-periment (HALOE) ozone profiles and the Total Ozone Mapping Spectrometer (TOMS) total ozone data sets,the characteristics and variations of the vertical distribution of stratospheric ozone covering the latitude bands of 50oN±5oN,40oN±5oN,30oN±5oN,and 20oN±5oN and the longitude range of 75-135oE are investigated.The results indicate that the ozone distribution pattern over China not only has general behaviors,but also has particular char-acteristics.In view of the situation that ozone distribu-tions have substantial deviation from zonal symmetry in northern China,the differences of the vertical ozone dis-tribution between the east and the west part of northern China are studied.The results indicate that during winter,spring,and autumn,in the latitude bands of 50oN±5oN,40oN±5oN,ozone concentrations in the eastern part (105 -135oE) are obviously higher than those of the west (75-105oE) at the altitudes of ozone density maximum and below;during summer,in the latitude band of 50oN±5oN,the east-west ozone profile difference is small,but in the latitude band of 40oN±5oN,the east-west total ozone difference becomes as large as 14.0 DU,and the east-west ozone profile difference mainly exists in the lowermost stratosphere and troposphere.展开更多
Understanding the vertical distribution of ozone is crucial when assessing both its horizontal and vertical transport,as well as when analyzing the physical and chemical properties of the atmosphere.One of the most ef...Understanding the vertical distribution of ozone is crucial when assessing both its horizontal and vertical transport,as well as when analyzing the physical and chemical properties of the atmosphere.One of the most effective ways to obtain high spatial resolution ozone profiles is through satellite observations.The Environmental Trace Gases Monitoring Instrument(EMI)deployed on the Gaofen-5 satellite is the first Chinese ultraviolet-visible hyperspectral spectrometer.However,retrieving ozone profiles using backscattered radiance values measured by the EMI is challenging due to unavailable measurement errors and a low signal-to-noise ratio.The algorithm developed for the Tropospheric Monitoring Instrument did not allow us to retrieve 87%of the EMI pixels.Therefore,we developed an algorithm specific to the characteristics of the EMI.The fitting residuals are smaller than 0.3%in most regions.The retrieved ozone profiles were in good agreement with ozonesonde data,with maximum mean biases of 20%at five latitude bands.By applying EMI averaging kernels to the ozonesonde profiles,the integrated stratospheric column ozone and tropospheric column ozone also showed excellent agreement with ozonesonde data,The lower layers(0-7.5 km)of the EMI ozone profiles reflected the seasonal variation in surface ozone derived from the China National Environmental Monitoring Center(CNEMC).However,the upper layers(9.7-16.7 km)of the ozone profiles show different trends,with the ozone peak occurring at an altitude of 9.7-16.7 km in March,2019.A stratospheric intrusion event in central China from August 11 to 15,2019,is captured using the EMI ozone profiles,potential vorticity data,and relative humidity data.The increase in the CNEMC ozone co ncentration showed that downward transport enhanced surface ozone pollution.展开更多
Data from FY-3B SBUS and NOAA SBUV/2 were used to monitor ozone levels in the Arctic region from March 1 to April 5,2011.Results revealed a significant ozone depletion in the area,with total ozone levels between 200-2...Data from FY-3B SBUS and NOAA SBUV/2 were used to monitor ozone levels in the Arctic region from March 1 to April 5,2011.Results revealed a significant ozone depletion in the area,with total ozone levels between 200-250 DU.The ozone levels recorded were 100-200 DU below normal,and in some parts the levels were as low as 200 DU,indicating a mini ozone-hole.During the sampling period,the ozone depletion area underwent identifiable expansion and detraction,a rotation around the North Pole from the west to the east,and a longitudinal movement from the Pole,spreading to the mid latitudes.The effects of these rare low ozone events were not only felt in the Arctic,but also extended to densely populated areas between Europe and the middle of Russia.In this region,rapidly increasing levels of ultraviolet radiation were detected at the Earth's surface.Given the significant risk that this poses to both the environment and people's health,this occurrence has significant global implications.展开更多
The objective of this study is to evaluate the accuracy of the daily nadir total column ozone products derived from the nadir mapper instrument on the Ozone Mapping and Profiler Suite （OMPS） flying onboard the Suomi...The objective of this study is to evaluate the accuracy of the daily nadir total column ozone products derived from the nadir mapper instrument on the Ozone Mapping and Profiler Suite （OMPS） flying onboard the Suomi National Polar-orbiting Partnership satellite （S- NPP） launched as a part of the Joint Polar Satellite System （JPSS） program between NOAA and NASA. Since NOAA is already operationally processing OMPS nadir total ozone products, evaluations were made in this study on the total column ozone research products generated by NASA＇s science team, utilizing the latest version of their Backscatter Ultraviolet （BUV） retrieval algorithms, to provide insight into the performance of the operation system. Comparisons were made with globally distributed ground-based Brewer and Dobson spectrophotometer total column ozone measurements. Linear regressions show fair agreement between OMPS and ground-based total column ozone measurements with a root-mean-square error （RMSE） of approximately 3% （10 DU）. The comparison results indicate that the OMPS total column ozone data are 0.59% higher than the Brewer measurements with a standard deviation of 2.82% while 1.09% higher than the Dobson measurements with a standard deviation of 3.27%. Additionally, the variability of relative differences between OMPS and ground total column ozone were analyzed as a function of latitude, time, viewing geometry, and total column ozone value. Results show a 2% bias over most latitudes and viewing conditions when total column ozone value varies between 220 DU and 450 DU.展开更多
基金funded by the National Department Public Benefit (Meteorology) Research Foundation (No.GYHY201006012)the National Natural Science Foundation Project (No.40775019)+1 种基金the central level,scientific research institutes for the basic research and development special fund business (No.IDM2006002)Xinjiang Uighur Autonomous Region Science and Technology Key Project (No.200833119)
文摘In order to reveal the variation characteristics of ozone （03） concentration in the atmosphere boundary layer over a desert in winter, an observation experiment was carried out in the Tazhong area by means of a tethered balloon during January 18-25, 2008. The vertical distribution of O3 concentration and its correlation with temperature and humidity were analyzed based on experimental observation data and related data. Results show that： （1） The concentration of O3 mainly ranges from 10 to 50 μg/L, with a maximum of 56.1 μg/L, minimum of 2.6 μg/L, and a daily average concentration of 34.4 μg/L. （2） O3 profiles can be divided into three types： peak, uniform, and growth, where uniform accounts for the majority. （3） Temperature and moisture are influential on O3 concentrations in atmospheric boundary layer. Temperature inversion and water vapor increase in an atmospheric boundary layer leads to a decrease of O3. （4） O3 concentration has an obvious daily change in Tazhong. It is lower at night, begins to increase after sunrise, and reaches a maximum at noon. The maximum appears at 17：00 BJT （Beijing Time）, and the minimum appears at 08：00 BJT.
文摘An analysis of 50 ozonesondings in Xining (36.43 o N, 101.45 o E , 2296 m, ASL), between April 1995 and August 1996 is presented. General vertical distribution characteristics and seasonal changing of ozone profile are reported. The analysis indicates that the stratospheric ozone concentrations of Autumn and Summer are lower than those of Spring and Winter; and the highest value of the tropospheric ozone concentrations is found in Summer; ozone concentration changing is bigger from the troposphere to the lower stratosphere altitude region, while it is stable in the middle and upper stratosphere region; there is a lower ozone concentration region in 10 -1 5 km altitude; the result why higher ozone concentration of the troposphere occurs in Summer is the ozone injecting from the middle and upper stratosphere.
基金Supported by the National High Tech Research and Development (863) Program of China(2006AA12Z102)Graduate Innovation Fund of Jilin University(20091023)
文摘A two-step method is employed in this study to retrieve vertical ozone profiles using scattered measure- ments from the limb of the atmosphere. The combination of the Differential Optical Absorption Spectroscopy （DOAS） and the Multiplicative Algebraic Reconstruction Technique （MART） is proposed. First, the limb radiance, measured over a range of tangent heights, is processed using the DOAS technique to recover the effective column densities of atmospheric ozone. Second, these effective column densities along the lines of sight （LOSs） are inverted using the MART coupled with a forward model SCIATRAN （radiative transfer model for SCIAMACHY） to derive the ozone profiles. This method is applied to Optical Spectrograph and Infra Red Imager System （OSIRIS） radiance, using the wavelength windows 571–617 nm. Vertical ozone profiles between 10 and 48 km are derived with a vertical resolution of 1 km. The results illustrate a good agreement with the cloud-free coincident SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY （SCIAMACHY） ozone measurements, with deviations less than ± 10% （ ± 5% for altitudes from 17 to 47 km）. Furthermore, sensitivities of retrieved ozone to aerosol, cloud parameters and NO 2 concentration are also investigated.
基金Project supported by the Nationd Natural Science Foundation of China.
文摘The ozone profiles from August 1991 to December 1993 in Qinghai Gonghe Station (the altitude:3000 m,latitude: 36°16.45’N, longitude: 100°37.11’E) have been got through the measurement with a Brewer Ozone spectrophotometer and Umkehr retrieval program of AES. The method we used is the short Umkehr method
文摘A new remote sensing method is described to determine the vertical distribution and total content of atmospheric ozone. The method combines surface infrared, satellite infrared and ultraviolet channels. The width of the infrared channels is 0.01 cm-1, less than Lorentz half-width at the earth's surface, rather than the present width, because these channels can obtain information about variations in the ozone profile below the profile main-peak. The numerical experiments show that the method has a satisfactory precision in determining total ozone content, just about I percent error, and vertical distribution from the earth to 65 km space. In addition, some semi-analysis functions lor calculating backscattered ultraviolet and a relaxation equation are described in this paper.
基金financially supported by"Tianshan Talent"Training Program-Science and Technology Innovation Team(Tianshan Innovation Team)Project(2022TSYCTD0007)the Youth Innovation Team of China Meteorological Administration(CMA2024QN13)+2 种基金the Central Government Guidance Funds for Local Science and Technology Development Program(ZYYD2025ZY21)the S&T Development Fund of Chinese Academy of Meteorological Sciences(2021KJ034)the Xinjiang Science Fund for Distinguished Young Scholars(2022D01E07).
文摘Due to the arid and sandy surface of the Taklimakan Desert(TD)in China,the turbulence structure and vertical distribution of ozone exhibit unique and complex characteristics.However,few studies have focused on these issues.To reveal the variation characteristics of summertime atmospheric turbulence and ozone concentration over the TD,we conducted joint detection experiments in July 2016 and July 2021 at Tazhong in the hinterland of the TD using an eddy covariance detection system,a GPS(Global Positioning System)sounding system,and a meteorological gradient tower.Using methods such as statistical analysis,nonlinear fitting,and Fast Fourier Transform,this study analyzed and processed parameters including temperature,relative humidity,wind speed,turbulence parameters,turbulence spectra,and ozone concentration.The high average temperature is accompanied by low relative humidity over the TD,showing a negative correlation between the two.The temperature of the 10.0-cm-deep sand layer lags the near-surface air temperature by nearly 4 h.From 09:30 to 21:00(Beijing Time),under conditions where the sensible heat flux is positive but stability parameter(z/L,where z is the height and L is the Obukhov length)is negative,the atmosphere is heated by the land surface,with the occurrence of unstable stratification;however,the conditions are the opposite(sensible heat flux is negative and z/L is positive)after 22:00,which are accompanied with the cooling of the surface radiation,occurrence of temperature inversion in the lower atmosphere,and stable stratification.A positive correlation is identified between the diurnal variation of turbulent kinetic energy(TKE)and the atmospheric boundary layer(ABL)height,with significant contributions from both the buoyancy and shear terms during the daytime.Under unstable stratification,the normalized standard deviations of the three-dimensional wind speed,temperature,and humidity conform to the Monin-Obukhov Similarity Theory(MOST).As the stability parameter z/L transitions from strongly unstable to strongly stable,the energy of the dimensionless turbulent velocity spectra gradually decreases and conforms to the -2/3 power law within the inertial subrange.In the hinterland of the TD,the summertime tropospheric ozone concentration remains below approximately 0.70×10^(-6)(volume concentration).Above the troposphere,within the range of 16,500.0-30,000.0 m,a significant increasing trend is identified in the ozone concentration with altitude.At an altitude of 30,000.0 m,the maximum ozone concentration can reach up to 7.50×10^(-6).The research findings provide both theoretical and data foundations for future in-depth studies of turbulent motion and ozone concentration distribution in the TD,as well as in the similar areas around the world.
基金supported by the National Basic Research Program of China (Grant No.2006CB403702)the National Natural Science Foundation of China (Grant No. 40475014)
文摘Based on the Stratospheric Aerosol and Gas Experiment (SAGE) II and the Halogen Occultation Ex-periment (HALOE) ozone profiles and the Total Ozone Mapping Spectrometer (TOMS) total ozone data sets,the characteristics and variations of the vertical distribution of stratospheric ozone covering the latitude bands of 50oN±5oN,40oN±5oN,30oN±5oN,and 20oN±5oN and the longitude range of 75-135oE are investigated.The results indicate that the ozone distribution pattern over China not only has general behaviors,but also has particular char-acteristics.In view of the situation that ozone distribu-tions have substantial deviation from zonal symmetry in northern China,the differences of the vertical ozone dis-tribution between the east and the west part of northern China are studied.The results indicate that during winter,spring,and autumn,in the latitude bands of 50oN±5oN,40oN±5oN,ozone concentrations in the eastern part (105 -135oE) are obviously higher than those of the west (75-105oE) at the altitudes of ozone density maximum and below;during summer,in the latitude band of 50oN±5oN,the east-west ozone profile difference is small,but in the latitude band of 40oN±5oN,the east-west total ozone difference becomes as large as 14.0 DU,and the east-west ozone profile difference mainly exists in the lowermost stratosphere and troposphere.
基金supported by the National Natural Science Foundation of China(42225504 and 41977184)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23020301)+3 种基金the Key Research and Development Project of Anhui Province(202104i07020002)the Major Projects of High Resolution Earth Observation Systems of National Science and Technology(05-Y30B01-9001-19/20-3)the Key Laboratory of Atmospheric Chemistry/China Meteorological Administration(LAC/CMA)(2022B06)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021443).
文摘Understanding the vertical distribution of ozone is crucial when assessing both its horizontal and vertical transport,as well as when analyzing the physical and chemical properties of the atmosphere.One of the most effective ways to obtain high spatial resolution ozone profiles is through satellite observations.The Environmental Trace Gases Monitoring Instrument(EMI)deployed on the Gaofen-5 satellite is the first Chinese ultraviolet-visible hyperspectral spectrometer.However,retrieving ozone profiles using backscattered radiance values measured by the EMI is challenging due to unavailable measurement errors and a low signal-to-noise ratio.The algorithm developed for the Tropospheric Monitoring Instrument did not allow us to retrieve 87%of the EMI pixels.Therefore,we developed an algorithm specific to the characteristics of the EMI.The fitting residuals are smaller than 0.3%in most regions.The retrieved ozone profiles were in good agreement with ozonesonde data,with maximum mean biases of 20%at five latitude bands.By applying EMI averaging kernels to the ozonesonde profiles,the integrated stratospheric column ozone and tropospheric column ozone also showed excellent agreement with ozonesonde data,The lower layers(0-7.5 km)of the EMI ozone profiles reflected the seasonal variation in surface ozone derived from the China National Environmental Monitoring Center(CNEMC).However,the upper layers(9.7-16.7 km)of the ozone profiles show different trends,with the ozone peak occurring at an altitude of 9.7-16.7 km in March,2019.A stratospheric intrusion event in central China from August 11 to 15,2019,is captured using the EMI ozone profiles,potential vorticity data,and relative humidity data.The increase in the CNEMC ozone co ncentration showed that downward transport enhanced surface ozone pollution.
基金supported by the National Natural Science Foundation of China(40975016)the National High-Tech Research&Development Program of China(2008AA121703)
文摘Data from FY-3B SBUS and NOAA SBUV/2 were used to monitor ozone levels in the Arctic region from March 1 to April 5,2011.Results revealed a significant ozone depletion in the area,with total ozone levels between 200-250 DU.The ozone levels recorded were 100-200 DU below normal,and in some parts the levels were as low as 200 DU,indicating a mini ozone-hole.During the sampling period,the ozone depletion area underwent identifiable expansion and detraction,a rotation around the North Pole from the west to the east,and a longitudinal movement from the Pole,spreading to the mid latitudes.The effects of these rare low ozone events were not only felt in the Arctic,but also extended to densely populated areas between Europe and the middle of Russia.In this region,rapidly increasing levels of ultraviolet radiation were detected at the Earth's surface.Given the significant risk that this poses to both the environment and people's health,this occurrence has significant global implications.
文摘The objective of this study is to evaluate the accuracy of the daily nadir total column ozone products derived from the nadir mapper instrument on the Ozone Mapping and Profiler Suite （OMPS） flying onboard the Suomi National Polar-orbiting Partnership satellite （S- NPP） launched as a part of the Joint Polar Satellite System （JPSS） program between NOAA and NASA. Since NOAA is already operationally processing OMPS nadir total ozone products, evaluations were made in this study on the total column ozone research products generated by NASA＇s science team, utilizing the latest version of their Backscatter Ultraviolet （BUV） retrieval algorithms, to provide insight into the performance of the operation system. Comparisons were made with globally distributed ground-based Brewer and Dobson spectrophotometer total column ozone measurements. Linear regressions show fair agreement between OMPS and ground-based total column ozone measurements with a root-mean-square error （RMSE） of approximately 3% （10 DU）. The comparison results indicate that the OMPS total column ozone data are 0.59% higher than the Brewer measurements with a standard deviation of 2.82% while 1.09% higher than the Dobson measurements with a standard deviation of 3.27%. Additionally, the variability of relative differences between OMPS and ground total column ozone were analyzed as a function of latitude, time, viewing geometry, and total column ozone value. Results show a 2% bias over most latitudes and viewing conditions when total column ozone value varies between 220 DU and 450 DU.
