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  1. Article ; Online: Comparison of profile total ozone from SBUV (v8.6) with GOME-type and ground-based total ozone for a 16-year period (1996 to 2011)

    E. W. Chiou / P. K. Bhartia / R. D. McPeters / D. G. Loyola / M. Coldewey-Egbers / V. E. Fioletov / M. Van Roozendael / R. Spurr / C. Lerot / S. M. Frith

    Atmospheric Measurement Techniques, Vol 7, Iss 6, Pp 1681-

    2014  Volume 1692

    Abstract: This paper describes the comparison of the variability of total column ozone inferred from the three independent multi-year data records, namely, (i) Solar Backscatter Ultraviolet Instrument (SBUV) v8.6 profile total ozone, (ii) GTO (GOME-type total ... ...

    Abstract This paper describes the comparison of the variability of total column ozone inferred from the three independent multi-year data records, namely, (i) Solar Backscatter Ultraviolet Instrument (SBUV) v8.6 profile total ozone, (ii) GTO (GOME-type total ozone), and (iii) ground-based total ozone data records covering the 16-year overlap period (March 1996 through June 2011). Analyses are conducted based on area-weighted zonal means for 0–30° S, 0–30° N, 50–30° S, and 30–60° N. It has been found that, on average, the differences in monthly zonal mean total ozone vary between −0.3 and 0.8 % and are well within 1%. For GTO minus SBUV, the standard deviations and ranges (maximum minus minimum) of the differences regarding monthly zonal mean total ozone vary between 0.6–0.7% and 2.8–3.8% respectively, depending on the latitude band. The corresponding standard deviations and ranges regarding the differences in monthly zonal mean anomalies show values between 0.4–0.6% and 2.2–3.5%. The standard deviations and ranges of the differences ground-based minus SBUV regarding both monthly zonal means and anomalies are larger by a factor of 1.4–2.9 in comparison to GTO minus SBUV. The ground-based zonal means demonstrate larger scattering of monthly data compared to satellite-based records. The differences in the scattering are significantly reduced if seasonal zonal averages are analyzed. The trends of the differences GTO minus SBUV and ground-based minus SBUV are found to vary between −0.04 and 0.1% yr −1 (−0.1 and 0.3 DU yr −1 ). These negligibly small trends have provided strong evidence that there are no significant time-dependent differences among these multi-year total ozone data records. Analyses of the annual deviations from pre-1980 level indicate that, for the 15-year period of 1996 to 2010, all three data records show a gradual increase at 30–60° N from −5% in 1996 to −2% in 2010. In contrast, at 50–30° S and 30° S–30° N there has been a levelling off in the 15 years after 1996. The deviations inferred from GTO and SBUV show agreement within 1%, but a slight increase has been found in the differences during the period 1996–2010.
    Keywords Science ; Q ; Physics ; QC1-999 ; Meteorology. Climatology ; QC851-999
    Subject code 290
    Publishing date 2014-06-01T00:00:00Z
    Publisher Copernicus GmbH
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: An evaluation of the SAGE III version 4 aerosol extinction coefficient and water vapor data products

    L. W. Thomason / J. R. Moore / M. C. Pitts / J. M. Zawodny / E. W. Chiou

    Atmospheric Chemistry and Physics, Vol 10, Iss 5, Pp 2159-

    2010  Volume 2173

    Abstract: Herein, we provide an assessment of the data quality of Stratospheric Aerosol and Gas Experiment (SAGE III) Version 4 aerosol extinction coefficient and water vapor data products. The evaluation is based on comparisons with data from four instruments: ... ...

    Abstract Herein, we provide an assessment of the data quality of Stratospheric Aerosol and Gas Experiment (SAGE III) Version 4 aerosol extinction coefficient and water vapor data products. The evaluation is based on comparisons with data from four instruments: SAGE II, the Polar Ozone and Aerosol Measurement (POAM III), the Halogen Occultation Experiment (HALOE), and the Microwave Limb Sounder (MLS). Since only about half of the SAGE III channels have a direct comparison with measurements by other instruments, we have employed some empirical techniques to evaluate measurements at some wavelengths. We find that the aerosol extinction coefficient measurements at 449, 520, 755, 869, and 1021 nm are reliable with accuracies and precisions on the order of 10% in the mission's primary aerosol target range of 15 to 25 km. We also believe this to be true of the aerosol measurements at 1545 nm though we cannot exclude some positive bias below 15 km. We recommend use of the 385 nm measurements above 16 km where the accuracy is on par with other aerosol channels. The 601 nm measurement is much noisier (~20%) than other channels and we suggest caution in the use of these data. We believe that the 676 nm data are clearly defective particularly above 20 km (accuracy as poor as 50%) and the precision is also low (~30%). We suggest excluding this channel under most circumstances. The SAGE III Version 4 water vapor data product appears to be high quality and is recommended for science applications in the stratosphere below 45 km. In this altitude range, the mean differences with all four corroborative data sets are no bigger than 15% and often less than 10% with exceptional agreement with POAM III and MLS. Above 45 km, it seems likely that SAGE III water vapor values are increasingly too large and should be used cautiously or avoided. We believe that SAGE III meets its preflight goal of 15% accuracy and 10% precision between 15 and 45 km. SAGE III water vapor data does not appear to be affected by aerosol loading in the stratosphere.
    Keywords Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 290
    Language English
    Publishing date 2010-03-01T00:00:00Z
    Publisher Copernicus Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: An evaluation of the SAGE III Version 4 aerosol extinction coefficient and water vapor data products

    L. W. Thomason / J. R. Moore / M. C. Pitts / J. M. Zawodny / E.-W. Chiou

    Atmospheric Chemistry and Physics Discussions, Vol 9, Iss 5, Pp 22177-

    2009  Volume 22222

    Abstract: Herein, we provide an assessment of the data quality of Stratospheric Aerosol and Gas Experiment (SAGE III) Version 4 aerosol extinction coefficient and water vapor data products. The evaluation is based on comparisons with data from four instruments: ... ...

    Abstract Herein, we provide an assessment of the data quality of Stratospheric Aerosol and Gas Experiment (SAGE III) Version 4 aerosol extinction coefficient and water vapor data products. The evaluation is based on comparisons with data from four instruments: SAGE II, the Polar Ozone and Aerosol Measurement (POAM III), the Halogen Occultation Experiment (HALOE), and the Microwave Limb Sounder (MLS). Since only about half of the SAGE III channels have a direct comparison with measurements by other instruments, we have employed some empirical techniques to evaluate measurements at some wavelengths. We find that the aerosol extinction coefficient measurements at 449, 520, 755, 869, and 1021 nm are reliable with accuracies and precisions on the order of 10% in the primary aerosol range of 15 to 25 km. We also believe this to be true of the aerosol measurements at 1545 nm though we cannot exclude some positive bias below 15 km. We recommend use of the 385 nm measurements above 16 km where the accuracy is on par with other aerosol channels. The 601 nm measurement is much noisier (~20%) than other channels and we suggest caution in the use of these data. We believe that the 676 nm data are clearly defective particularly above 20 km (accuracy as poor as 50%) and the precision is also low (~30%). We suggest excluding this channel under most circumstances. The SAGE III Version 4 water vapor data product appears to be high quality and is recommended for science applications in the stratosphere below 45 km. In this altitude range, the mean differences with all four corroborative data sets are no bigger than 15% and often less than 10% with exceptional agreement with POAM III and MLS. Above 45 km, it seems likely that SAGE III water vapor values are increasingly too large and should be used cautiously or avoided. We believe that SAGE III meets its preflight goal of 15% accuracy and 10% precision between 15 and 45 km. We do not currently recommend limiting the SAGE III water vapor data utility in the stratosphere by aerosol loading.
    Keywords Environmental sciences ; GE1-350 ; Geography. Anthropology. Recreation ; G ; DOAJ:Environmental Sciences ; DOAJ:Earth and Environmental Sciences ; Geophysics. Cosmic physics ; QC801-809
    Subject code 333
    Language English
    Publishing date 2009-10-01T00:00:00Z
    Publisher Copernicus Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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