Total Ozone Determination from the Backscattered Ultraviolet (BUV) Experiment

Klenk, K. F.; Bhartia, P. K.; Kaveeshwar, V. G.; McPeters, R. D.; Smith, Peter M.; Fleig, A. J.

doi:10.1175/1520-0450(1982)021<1672:todftb>2.0.co;2

Cited by 105 publications

(50 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, as discussed, e.g., by Rozanov and Kokhanovsky (2008), the impact of the linearization error is significantly reduced when applying the linear approximation to the logarithm of the intensity. This was the reason to use lnI λ rather than I λ in the retrieval of number density vertical profiles and total columns (Klenk et al, 1982) of ozone from the space borne observations of the backscattered solar radiation.…”

Section: Linearized Forward Modelmentioning

confidence: 99%

Differential optical absorption spectroscopy (DOAS) and air mass factor concept for a multiply scattering vertically inhomogeneous medium: theoretical consideration

Розанов

Rozanov

2010

Atmos. Meas. Tech.

View full text Add to dashboard Cite

Abstract. The Differential Optical Absorption Spectroscopy (DOAS) technique is widely used to retrieve amounts of atmospheric species from measurements of the direct solar light transmitted through the Earth's atmosphere as well as of the solar light scattered in the atmosphere or reflected from the Earth's surface. For the transmitted direct solar light the theoretical basis of the DOAS technique represented by the Beer-Lambert law is well studied. In contrast, scarcely investigated is the theoretical basis and validity range of the DOAS method for those cases where the contribution of the multiple scattering processes is not negligible. Our study is intended to fill this gap by means of a theoretical investigation of the applicability of the DOAS technique for the retrieval of amounts of atmospheric species from observations of the scattered solar light with a non-negligible contribution of the multiple scattering.Starting from the expansion of the intensity logarithm in the functional Taylor series we formulate the general form of the DOAS equation. The thereby introduced variational derivative of the intensity logarithm with respect to the variation of the gaseous absorption coefficient, which is often referred to as the weighting function, is demonstrated to be closely related to the air mass factor. Employing some approximations we show that the general DOAS equation can be rewritten in the form of the weighting function (WF-DOAS), the modified (MDOAS), and the standard DOAS equations. For each of these forms a specific equation for the air mass factor follows which, in general, is not suitable for other forms of the DOAS equation. Furthermore, the vaCorrespondence to: V. V. Rozanov (rozanov@iup.physik.uni-bremen.de) lidity range of the standard DOAS equation is quantitatively investigated using a suggested criterion of a weak absorption.The results presented in this study are intended to provide a basis for a better understanding of the applicability range of different forms of the DOAS equation as well as of the relationship between the air mass factor and the weighting function. To facilitate the understanding of the paper content for unexperienced reader we start our discussion considering in detail the standard DOAS technique applied to the observations of the direct solar light transmitted through the Earth's atmosphere.

show abstract

Section: Linearized Forward Modelmentioning

confidence: 99%

Differential optical absorption spectroscopy (DOAS) and air mass factor concept for a multiply scattering vertically inhomogeneous medium: theoretical consideration

Розанов

Rozanov

2010

Atmos. Meas. Tech.

View full text Add to dashboard Cite

show abstract

“…El Niño events do not cause much change to the annual average fraction, but they do produce significant regional effects. The 1982The -1983 El Niño events increase the fraction of NOAs over the tropical eastern Pacific Ocean by ∼40% during December-February. During the EP TOMS period, there are more NOAs but fewer POAs relative to the N7 TOMS period, especially in tropical areas.…”

Section: Discussionmentioning

confidence: 99%

“…Because the P correction is based on the TOMS standard ozone profiles, it would overestimate or underestimate the cloudy total ozone if the actual lower tropospheric ozone is different from the standard lower tropospheric ozone (Klenk et al, 1982;Hudson et al, 1995). The actual tropospheric ozone is usually smaller (larger) than the TOMS climatological tropospheric ozone over the Pacific Ocean (Atlantic Ocean) (Fishman et al, 1990;Hudson et al, 1998;Ziemke et al, 2000;Thompson et al, 2003); therefore, the P correction overestimates (underestimates) the fraction and slope of OAs over the western Pacific Ocean (Atlantic Ocean).…”

Section: Causes Of Ozone Anomaly Occurrence Over Cloudy Areasmentioning

confidence: 99%

Occurrence of ozone anomalies over cloudy areas in TOMS version-7 level-2 data

2003

View full text Add to dashboard Cite

Abstract. This study investigates anomalous ozone distributions over cloudy areas in Nimbus-7 (N7) and Earth-Probe (EP) TOMS version-7 data and analyzes the causes for ozone anomaly formation. A 5 • -longitude by 5 • -latitude region is defined to contain a Positive Ozone Anomaly (POA) or Negative Ozone Anomaly (NOA) if the correlation coefficient between total ozone and reflectivity is ≥ 0.5 or ≤ −0.5. The average fractions of ozone anomalies among all cloud fields are 31.8 ± 7.7% and 35.8 ± 7.7% in the N7 and EP TOMS data, respectively. Some ozone anomalies are caused by ozone retrieval errors, and others are caused by actual geophysical phenomena. Large cloud-height errors are found in the TOMS version-7 algorithm in comparison to the Temperature Humidity Infrared Radiometer (THIR) cloud data. On average, cloud-top pressures are overestimated by ∼200 hPa (THIR cloud-top pressure ≤ 200 hPa) for high-altitude clouds and underestimated by ∼150 hPa for low-altitude clouds (THIR cloud-top pressure ≥ 750 hPa). Most tropical NOAs result from negative errors induced by large cloud-height errors, and most tropical POAs are caused by positive errors due to intra-cloud ozone absorption enhancement. However, positive and negative errors offset each other, reducing the ozone anomaly occurrence in TOMS data. Large ozone/reflectivity slopes for mid-latitude POAs show seasonal variation consistent with total ozone fluctuation, indicating that they result mainly from synoptic and planetary wave disturbances. POAs with an occurrence fraction of 30-60% occur in regions of marine stratocumulus off the west coast of South Africa and off the west coast of South America. Both fractions and ozone/reflectivity slopes of these POAs show seasonal variations consistent with that in the tropospheric ozone. About half the ozone/reflectivity slope can be explained by ozone retrieval errors over clear and cloudy areas. The remaining slope may result from there being more ozone production because of rich ozone precurCorrespondence to: X. Liu (xliu@cfa.harvard.edu) sors and higher photolysis rates over high-frequency, lowaltitude clouds than in clear areas. Ozone anomalies due to ozone retrieval errors have important implications in TOMS applications such as tropospheric ozone derivation and analysis of ozone seasonal variation.

show abstract

“…BUV, SBUV, TOMS, SBUV-2, GOME, SCIAMACHY, OMI and GOME-2), with accuracies typically between 0.5 and 2 % (Klenk et al, 1982;Loyola et al, 2011;van Roozendael et al, 2012, and references therein). Ozone profiles have also been produced from UV nadir-sounders (e.g.…”

Section: G M Miles Et Al: Tropospheric Ozone and Ozone Profiles Rementioning

confidence: 99%

Tropospheric ozone and ozone profiles retrieved from GOME-2 and their validation

et al. 2015

View full text Add to dashboard Cite

Abstract. This paper describes and assesses the performance of the RAL (Rutherford Appleton Laboratory) ozone profile retrieval scheme for the Global Ozone Monitoring Experiment 2 (GOME-2) with a focus on tropospheric ozone. Developments to the scheme since its application to GOME-1 measurements are outlined. These include the approaches developed to account sufficiently for UV radiometric degradation in the Hartley band and for inadequacies in knowledge of instrumental parameters in the Huggins bands to achieve the high-precision spectral fit required to extract information on tropospheric ozone.The assessment includes a validation against ozonesondes (sondes) sampled worldwide over 2 years (2007)(2008). Standard deviations of the ensemble with respect to the sondes are considerably lower for the retrieved profiles than for the a priori, with the exception of the lowest subcolumn. Once retrieval vertical smoothing (averaging kernels) has been applied to the sonde profiles there is a retrieval bias of 6 % (1.5 DU) in the lower troposphere, with smaller biases in the subcolumns above. The bias in the troposphere varies with latitude. The retrieval underestimates lower tropospheric ozone in the Southern Hemisphere (SH) (15-20 % or ∼ 1-3 DU) and overestimates it in the Northern Hemisphere (NH) (10 % or 2 DU).The ability of the retrieval to reflect the geographical distribution of lower tropospheric ozone, globally (rather than just ozonesonde launch sites) is demonstrated by comparison with the chemistry transport model TOMCAT. For a monthly mean of cloud-cleared GOME-2 pixels, a correlation of 0.66 is found between the retrieval and TOMCAT sampled accordingly, with a bias of 0.7 Dobson Units. GOME-2 estimates higher concentrations in NH pollution centres but lower ozone in the Southern Ocean and South Pacific, which is consistent with the comparison to ozonesondes.

show abstract

Total Ozone Determination from the Backscattered Ultraviolet (BUV) Experiment

Cited by 105 publications

References 0 publications

Differential optical absorption spectroscopy (DOAS) and air mass factor concept for a multiply scattering vertically inhomogeneous medium: theoretical consideration

Differential optical absorption spectroscopy (DOAS) and air mass factor concept for a multiply scattering vertically inhomogeneous medium: theoretical consideration

Occurrence of ozone anomalies over cloudy areas in TOMS version-7 level-2 data

Tropospheric ozone and ozone profiles retrieved from GOME-2 and their validation

Contact Info

Product

Resources

About