This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer f...This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer for atmospheric chartography(SCIAMACHY).This technique is based on SaskMART(the combination of the multiplicative algebraic reconstruction technique and SaskTRAN radiative transfer model),which was originally developed for optical spectrometer and infrared imaging system(OSIRIS)data.One of the objectives of this study was to obtain consistent ozone profiles from the two satellites.In this study,the WMART algorithm is combined with a radiative transfer model(SCIATRAN),as well as a set of measurement vectors comprising five Hartley pairing vectors(HPVs)and one Chappuis triplet vector(CTV),to retrieve ozone profiles in the altitude range of 10–69 km.Considering that the weighting factors in WMART have a significant effect on the retrievals,we propose a novel approach to calculate the pair/triplet weighting factors using wavelength weighting functions.The results of the application of the proposed ozone retrieval scheme are compared with the SCIAMACHY v3.5 ozone product by University of Bremen and validated against profiles derived from other passive satellite observations or measured by ozonesondes.Between 18 and 55 km,the retrieved ozone profiles typically agree with data from the SCIAMACHY ozone product within 5%for tropics and middle latitudes,whereas a negative deviation exists between 35 and 50 km for northern high latitudes,with a deviation of less than 10%above 50 km.Comparison of the retrieved profiles with microwave limb sounder(MLS)v5.0 indicates that the difference is within±5%between 18 and 55 km,and an agreement within 10%is achieved in other altitudes for tropics and middle latitudes.Comparison of the retrieved profiles with OSIRIS v7.1 indicates that the average deviation is within±5%between 20 and 59 km,and difference of approximately 10%is achieved below 20 km.Compared with ozonesondes data,a general validity of the retrievals is no more than 5%between 15 and 30 km.展开更多
Scanning Imaging Absorption Spectrometer for Atmospheric Cartography（SCIAMACHY） limb observation data are used to retrieve stratospheric aerosol extinction profiles. The retrieved aerosol profiles are compared with ...Scanning Imaging Absorption Spectrometer for Atmospheric Cartography（SCIAMACHY） limb observation data are used to retrieve stratospheric aerosol extinction profiles. The retrieved aerosol profiles are compared with Stratospheric Aerosol and Gas Experiment（SAGE） Ⅱ aerosol data records. The comparisons are made over the period 2003–2004. The results show that the SCIAMACHY aerosol profile retrievals exhibit general agreement with the coincident SAGE Ⅱ data records. In the 15–35 km altitude range, the percentage differences between the SCIAMACHY-retrieved and SAGE Ⅱ–measured zonal mean aerosol extinction profiles are less than 20% for the 20–30°N and 30–40°N latitude zones, and less than 25% for the 40–50°N zone. The stratospheric aerosol optical depths in this altitude range calculated from SCIAMACHY retrievals are in good agreement with SAGE Ⅱ measurements, with present differences less than 6% for the three latitude zones. The aerosol retrievals from SCIAMACHY observations are combined with the SAGE Ⅱ aerosol data records, form a long-term data-set for the period 2000–2010. Using the combined SAGE Ⅱ and SCIAMACHY dataset, the variation trends of the stratospheric aerosol layer over East Asia（20–50°N, 70–150°E） are analyzed. The results indicate that the stratospheric aerosols have a significant trend of increase over East Asia during 2000–2010. The stratospheric aerosol optical depths increase by about 5% per year over the 11-yr period. The increase in stratospheric aerosols is found to be obviously related to moderate volcanic eruptions.展开更多
The Scanning Imaging Absorption spectroMeter for Atmospheric ChartographY(SCIAMACHY) instrument,launched on the Envisat satellite in March 2002,measures the earthshine radiance,simultaneously from the ultraviolet(UV) ...The Scanning Imaging Absorption spectroMeter for Atmospheric ChartographY(SCIAMACHY) instrument,launched on the Envisat satellite in March 2002,measures the earthshine radiance,simultaneously from the ultraviolet(UV) to the near infrared(NIR),in the three viewing geometries:nadir,limb,and occultation.These measurements are used to retrieve both the total amount and vertical profiles of a large number of atmospheric constituents.In this paper,stratospheric ozone profiles between 15 and 40 km altitude are retrieved on 3 km grids from SCIAMACHY limb scattered radiance in the Chappuis-Wulf band.The study employs a new multiplicative algebraic reconstruction technique(MART) coupled with the radiative transfer model SCIATRAN.This technique is outstanding in that more than one measurement vector element can be used to retrieve the ozone density at any altitude.Furthermore,it is straightforward to understand,easy to implement and likely to produce stable results.Radiance normalization and wavelength pairing is applied to radiance as an intermediate step,using the wavelengths 525 nm,600 nm and 675 nm.The sensitivity of ozone retrieval by this method to tangent altitude pointing,surface albedo,aerosol and cloud parameters is studied,and the results show that the retrieval impact due to tangent altitude pointing bias is the biggest up to 75% with 1 km shift,and the impact of albedo is limited within 5%.The effect of boundary visibility and cloud parameters can be ignored since their impact is too small.The effectiveness of the retrieval is demonstrated using a set of coincident SCIAMACHY products at Hefei that shows a mean bias of less than 12% between 15 and 40 km,and with a better accuracy of 5% from 16 to 36 km.展开更多
In order to validate the atmospheric chemistry measurements by MIPAS,SCIAMACHY,and GOMOS onboard the ENVISAT,three flights of the balloon-borne Michelson Interferometer for Passive Sounding(MIPAS-B) were carried out i...In order to validate the atmospheric chemistry measurements by MIPAS,SCIAMACHY,and GOMOS onboard the ENVISAT,three flights of the balloon-borne Michelson Interferometer for Passive Sounding(MIPAS-B) were carried out in 2002 and 2003 at Aire sur l'Adour(France 44°N,0°E) and Esrange,Kiruna(Sweden 68°N,21°E).The validation campaign activities are summarized in this paper.The MIPAS-B instrument and its data processing procedure as well as the validation approaches are discussed in detail.The satellite and balloon measurements are matched with high coincidence in time and space,allowing a coincident approach to be applied for their comparisons.Further,a trajectory model is used to confirm and enhance the statistical significance of the validation.The validation results show that MIPAS measurements of accuracy for temperature,H2O,O3,HNO3,CH4,N2O,and NO2 are good in the altitude range of 8-39 km(No2,22-39 km).And the precision is good between the altitudes of 15-33 km(No2,22-23 km).However,some exceptions were also found for temperature,H2O,HNO3,and NO2.The SCIAMACHY data of accuracy for O3 and NO2 are within expectations between the altitudes 9-38 km except for O3 in 28-38 km.The GOMOS data about O3 and NO2 are promising according to the preliminary comparison results.展开更多
This study employs a linear inversion algorithm to retrieve volume emission rates(VERs)of molecular O_(2) nightglow at 1.27μm,utilizing Limb-Viewed spectra obtained from the SCanning Imaging Absorption spectroMeter f...This study employs a linear inversion algorithm to retrieve volume emission rates(VERs)of molecular O_(2) nightglow at 1.27μm,utilizing Limb-Viewed spectra obtained from the SCanning Imaging Absorption spectroMeter for Atmospheric for CHartographY(SCIAMACHY)payload on board the Envisat satellite.The retrieved results are compared with VERs data from the SABER payload on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics(TIMED)satellite,exhibiting consistency.This will help to facilitate accurate revelation of spatial distribution and periodic variation in O_(2) nightglow.VERs are extracted monthly within the altitude range of 75-110 km from 2002 to 2012,yielding a climatology of spatial and temporal distributions.The meridional structure exhibits two maxima,at the equator and at 45°N.Between August and October,the VERs exhibit a meridional bimodal structure,with the weaker one above the equator and the stronger one above 45°N.In April,the VERs reach their annual maximum.Additionally,harmonic analysis reveals significant temporal variations on different scales.The emission shows characteristics of annual and semi-annual variation,and a non-linear long-term trend associated with solar cycle activity.展开更多
This study aims to predict monthly columnar ozone in Peninsular Malaysia based on concentrations of several atmospheric gases. Data pertaining to five atmo- spheric gases （CO2, 03, CH4, NO2, and H2O vapor） were retr...This study aims to predict monthly columnar ozone in Peninsular Malaysia based on concentrations of several atmospheric gases. Data pertaining to five atmo- spheric gases （CO2, 03, CH4, NO2, and H2O vapor） were retrieved by satellite scanning imaging absorption spectro- metry for atmospheric chartography from 2003 to 2008 and used to develop a model to predict columnar ozone in Peninsular Malaysia. Analyses of the northeast monsoon （NEM） and the southwest monsoon （SWM） seasons were conducted separately. Based on the Pearson correlation matrices, columnar ozone was negatively correlated with HzO vapor but positively correlated with COz and NO2 during both the NEM and SWM seasons from 2003 to 2008. This result was expected because NO/is a precursor of ozone. Therefore, an increase in columnar ozone concentration is associated with an increase in NO2 but a decrease in H/O vapor. In the NEM season, columnar ozone was negatively correlated with H20 （-0.847）, NO2 （0.754）, and CO2 （0.477）; columnar ozone was also negatively but weakly correlated with CH4 （-0.035）. In the SWM season, columnar ozone was highly positively correlated with NO2 （0.855）, CO2 （0.572）, and CH4（0.321） and also highly negatively correlated with H2O（-0.832）. Both multiple regression and principal component analyses were used to predict the columnar ozone value in Peninsular Malaysia. We obtained the best-fitting regression equations for the columnar ozone data using four independent variables. Our results show approxi- mately the same R value （≈0.83） for both the NEM and SWM seasons.展开更多
基金supported by the National Science Foundations of China(No.61905256)the National Key Research and Development Program of China(No.2019YFC0214702)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020439)。
文摘This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer for atmospheric chartography(SCIAMACHY).This technique is based on SaskMART(the combination of the multiplicative algebraic reconstruction technique and SaskTRAN radiative transfer model),which was originally developed for optical spectrometer and infrared imaging system(OSIRIS)data.One of the objectives of this study was to obtain consistent ozone profiles from the two satellites.In this study,the WMART algorithm is combined with a radiative transfer model(SCIATRAN),as well as a set of measurement vectors comprising five Hartley pairing vectors(HPVs)and one Chappuis triplet vector(CTV),to retrieve ozone profiles in the altitude range of 10–69 km.Considering that the weighting factors in WMART have a significant effect on the retrievals,we propose a novel approach to calculate the pair/triplet weighting factors using wavelength weighting functions.The results of the application of the proposed ozone retrieval scheme are compared with the SCIAMACHY v3.5 ozone product by University of Bremen and validated against profiles derived from other passive satellite observations or measured by ozonesondes.Between 18 and 55 km,the retrieved ozone profiles typically agree with data from the SCIAMACHY ozone product within 5%for tropics and middle latitudes,whereas a negative deviation exists between 35 and 50 km for northern high latitudes,with a deviation of less than 10%above 50 km.Comparison of the retrieved profiles with microwave limb sounder(MLS)v5.0 indicates that the difference is within±5%between 18 and 55 km,and an agreement within 10%is achieved in other altitudes for tropics and middle latitudes.Comparison of the retrieved profiles with OSIRIS v7.1 indicates that the average deviation is within±5%between 20 and 59 km,and difference of approximately 10%is achieved below 20 km.Compared with ozonesondes data,a general validity of the retrievals is no more than 5%between 15 and 30 km.
基金funded by the National Natural Science Foundation of China[grant number 41275047],[grant number41675032],[grant number 41575034]
文摘Scanning Imaging Absorption Spectrometer for Atmospheric Cartography（SCIAMACHY） limb observation data are used to retrieve stratospheric aerosol extinction profiles. The retrieved aerosol profiles are compared with Stratospheric Aerosol and Gas Experiment（SAGE） Ⅱ aerosol data records. The comparisons are made over the period 2003–2004. The results show that the SCIAMACHY aerosol profile retrievals exhibit general agreement with the coincident SAGE Ⅱ data records. In the 15–35 km altitude range, the percentage differences between the SCIAMACHY-retrieved and SAGE Ⅱ–measured zonal mean aerosol extinction profiles are less than 20% for the 20–30°N and 30–40°N latitude zones, and less than 25% for the 40–50°N zone. The stratospheric aerosol optical depths in this altitude range calculated from SCIAMACHY retrievals are in good agreement with SAGE Ⅱ measurements, with present differences less than 6% for the three latitude zones. The aerosol retrievals from SCIAMACHY observations are combined with the SAGE Ⅱ aerosol data records, form a long-term data-set for the period 2000–2010. Using the combined SAGE Ⅱ and SCIAMACHY dataset, the variation trends of the stratospheric aerosol layer over East Asia（20–50°N, 70–150°E） are analyzed. The results indicate that the stratospheric aerosols have a significant trend of increase over East Asia during 2000–2010. The stratospheric aerosol optical depths increase by about 5% per year over the 11-yr period. The increase in stratospheric aerosols is found to be obviously related to moderate volcanic eruptions.
基金supported by the National High Technology Research and Development Program (Grant No 2006AA12Z102)Graduate Innovation Fund of Jilin University (Grant No20091023)
文摘The Scanning Imaging Absorption spectroMeter for Atmospheric ChartographY(SCIAMACHY) instrument,launched on the Envisat satellite in March 2002,measures the earthshine radiance,simultaneously from the ultraviolet(UV) to the near infrared(NIR),in the three viewing geometries:nadir,limb,and occultation.These measurements are used to retrieve both the total amount and vertical profiles of a large number of atmospheric constituents.In this paper,stratospheric ozone profiles between 15 and 40 km altitude are retrieved on 3 km grids from SCIAMACHY limb scattered radiance in the Chappuis-Wulf band.The study employs a new multiplicative algebraic reconstruction technique(MART) coupled with the radiative transfer model SCIATRAN.This technique is outstanding in that more than one measurement vector element can be used to retrieve the ozone density at any altitude.Furthermore,it is straightforward to understand,easy to implement and likely to produce stable results.Radiance normalization and wavelength pairing is applied to radiance as an intermediate step,using the wavelengths 525 nm,600 nm and 675 nm.The sensitivity of ozone retrieval by this method to tangent altitude pointing,surface albedo,aerosol and cloud parameters is studied,and the results show that the retrieval impact due to tangent altitude pointing bias is the biggest up to 75% with 1 km shift,and the impact of albedo is limited within 5%.The effect of boundary visibility and cloud parameters can be ignored since their impact is too small.The effectiveness of the retrieval is demonstrated using a set of coincident SCIAMACHY products at Hefei that shows a mean bias of less than 12% between 15 and 40 km,and with a better accuracy of 5% from 16 to 36 km.
基金support by the Deutsches Zentrum für Luft-und Raumfahrt (DLR) (Project 50EE0020)support from the International Scientific and Technological Cooperation Project of Henan Provinces (Grant No.104300510068) for publication
文摘In order to validate the atmospheric chemistry measurements by MIPAS,SCIAMACHY,and GOMOS onboard the ENVISAT,three flights of the balloon-borne Michelson Interferometer for Passive Sounding(MIPAS-B) were carried out in 2002 and 2003 at Aire sur l'Adour(France 44°N,0°E) and Esrange,Kiruna(Sweden 68°N,21°E).The validation campaign activities are summarized in this paper.The MIPAS-B instrument and its data processing procedure as well as the validation approaches are discussed in detail.The satellite and balloon measurements are matched with high coincidence in time and space,allowing a coincident approach to be applied for their comparisons.Further,a trajectory model is used to confirm and enhance the statistical significance of the validation.The validation results show that MIPAS measurements of accuracy for temperature,H2O,O3,HNO3,CH4,N2O,and NO2 are good in the altitude range of 8-39 km(No2,22-39 km).And the precision is good between the altitudes of 15-33 km(No2,22-23 km).However,some exceptions were also found for temperature,H2O,HNO3,and NO2.The SCIAMACHY data of accuracy for O3 and NO2 are within expectations between the altitudes 9-38 km except for O3 in 28-38 km.The GOMOS data about O3 and NO2 are promising according to the preliminary comparison results.
基金supported by the National Key R&D program of China(2021YFE0110200)the Project of Stable Support for Youth Team in Basic Research Field,CAS(YSBR-018)+3 种基金the National Natural Science Foundation of China(41831073,42174196 and 42174212)the Chinese Meridian Projectthe Specialized Research Fund for State Key Laboratoriesthe International Partnership Program of Chinese Academy of Sciences.Grant No.183311KYSB20200003.
文摘This study employs a linear inversion algorithm to retrieve volume emission rates(VERs)of molecular O_(2) nightglow at 1.27μm,utilizing Limb-Viewed spectra obtained from the SCanning Imaging Absorption spectroMeter for Atmospheric for CHartographY(SCIAMACHY)payload on board the Envisat satellite.The retrieved results are compared with VERs data from the SABER payload on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics(TIMED)satellite,exhibiting consistency.This will help to facilitate accurate revelation of spatial distribution and periodic variation in O_(2) nightglow.VERs are extracted monthly within the altitude range of 75-110 km from 2002 to 2012,yielding a climatology of spatial and temporal distributions.The meridional structure exhibits two maxima,at the equator and at 45°N.Between August and October,the VERs exhibit a meridional bimodal structure,with the weaker one above the equator and the stronger one above 45°N.In April,the VERs reach their annual maximum.Additionally,harmonic analysis reveals significant temporal variations on different scales.The emission shows characteristics of annual and semi-annual variation,and a non-linear long-term trend associated with solar cycle activity.
文摘This study aims to predict monthly columnar ozone in Peninsular Malaysia based on concentrations of several atmospheric gases. Data pertaining to five atmo- spheric gases （CO2, 03, CH4, NO2, and H2O vapor） were retrieved by satellite scanning imaging absorption spectro- metry for atmospheric chartography from 2003 to 2008 and used to develop a model to predict columnar ozone in Peninsular Malaysia. Analyses of the northeast monsoon （NEM） and the southwest monsoon （SWM） seasons were conducted separately. Based on the Pearson correlation matrices, columnar ozone was negatively correlated with HzO vapor but positively correlated with COz and NO2 during both the NEM and SWM seasons from 2003 to 2008. This result was expected because NO/is a precursor of ozone. Therefore, an increase in columnar ozone concentration is associated with an increase in NO2 but a decrease in H/O vapor. In the NEM season, columnar ozone was negatively correlated with H20 （-0.847）, NO2 （0.754）, and CO2 （0.477）; columnar ozone was also negatively but weakly correlated with CH4 （-0.035）. In the SWM season, columnar ozone was highly positively correlated with NO2 （0.855）, CO2 （0.572）, and CH4（0.321） and also highly negatively correlated with H2O（-0.832）. Both multiple regression and principal component analyses were used to predict the columnar ozone value in Peninsular Malaysia. We obtained the best-fitting regression equations for the columnar ozone data using four independent variables. Our results show approxi- mately the same R value （≈0.83） for both the NEM and SWM seasons.
