Simple relationship between the uv radiation backscattered by the earth’s atmosphere and the vertical ozone profile

Thomas, Richard P.; Holland, A. C.

doi:10.1364/ao.16.002581

Cited by 8 publications

(13 citation statements)

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“…A slightly warm T(p) at 1-2 hPa will lead to a small deficit in LIMSretrieved ozone for the same layer, followed by a slight, compensating excess of ozone in the layer from 2- There are also small biases for the SBUV ozone of the upper stratosphere related to its forward model, vertical resolution, and assumed a priori profiles. For example, one assumption for the earlier SBUV V6 algorithm was that the ratio of the ozone scale height to the atmospheric scale height is a constant for the ozone column above a given pressure level in the upper stratosphere [22,29]. Certainly, the atmospheric scale height is becoming larger from about 10 to 1 hPa as T(p) increases.…”

Section: Results Of the Lims/sbuv Zonal-mean Comparisons Formentioning

confidence: 99%

On the quality of the Nimbus 7 LIMS version 6 ozone for studies of the middle atmosphere

Remsberg

Lingenfelser

Natarajan

et al. 2007

Journal of Quantitative Spectroscopy and Radiative Transfer

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The Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) radiance profile dataset of 1978/79 was reconditioned and reprocessed to Version 6 (V6) profiles of temperature and species that are improved significantly over those from Version 5 (V5). The LIMS V6 dataset was archived for public use in 2002.Improvements for its ozone include: (1) a more accurate accounting for instrument and spacecraft motion effects in the radiances, (2) the use of better spectroscopic line parameters for its ozone forward model, (3) retrievals of all its scans, (4) more accurate and compatible temperature versus pressure profiles (or T(p)), which are needed for the registration of the ozone radiances and for the removal of temperature effects from them, and (5) a better accounting for interfering species in the lower stratosphere. The retrieved V6 ozone profiles extend from near cloud top altitudes to about 80 km and from 64S to 84N latitude with better sampling along the orbit than for the V5 dataset. Calculated estimates of the single-profile precision and accuracy are provided for the V6 ozone from this study. Precision estimates based on the data themselves are of order 3% or better from 1 to 30 hPa. Estimates of total systematic error for a single profile are hard to generalize because the separate sources of error may not all be of the same sign and they depend somewhat on the atmospheric state. It is estimated that the V6 zonal mean ozone distributions are accurate to within ±9% to ±7% from 50 hPa to 3 hPa, respectively. Effects of a temperature bias can be significant and may be present at 1 to 2 hPa though. There may be ozone biases of order 10% at those levels due to possible biases of up to +2 K, but there is no indication of a similar problem elsewhere in the stratosphere.Simulation studies show that the LIMS retrievals are also underestimating slightly the small amplitudes of the atmospheric temperature tides, which affect its retrieved day/night ozone differences. There are small biases in the middle to lower stratosphere for the ascending versus descending node LIMS ozone, due principally to not accounting for the asymmetric weighting of its radiances across the tangent layer. The estimates of total accuracy were assessed by comparing the daily zonal mean LIMS ozone distributions against those from the Nimbus 7 SBUV Version 8 (V8) dataset for the same period. Generally, the LIMS V6 ozone agrees well with SBUV, except perhaps in the tropical lower stratosphere where the LIMS ozone is less. Still, the accuracy for LIMS V6 ozone in the lower stratosphere is improved over that found for LIMS V5, as indicated by several LIMS comparisons with ECC ozonesonde profiles. The LIMS V6 ozone 2 is considered especially suitable for detailed studies of large-scale stratospheric processes above the 100-hPa level. Comparison of diurnal, photochemical model calculations with the monthly-averaged, upper stratospheric ozone observed from LIMS V6 indicates only a slight ozone deficit for the model at about 2 hPa. However, that ...

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Section: Results Of the Lims/sbuv Zonal-mean Comparisons Formentioning

confidence: 99%

On the quality of the Nimbus 7 LIMS version 6 ozone for studies of the middle atmosphere

Remsberg

Lingenfelser

Natarajan

et al. 2007

Journal of Quantitative Spectroscopy and Radiative Transfer

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“…Along with auxiliary atmospheric soundings for pressure and temperature, ROCOZ-A data can duplicate the fundamental ozone value of backscatter ultraviolet measurements from satellites. Since ozone attenuation of flux is a function of the total number of ozone molecules in a given column, this value is o2one overburden (or column content) as a function of pressure [Thomas and Holland, 1977;Thomas et al, 1982]. The assembly of ROCOZ-A measurements can also duplicate the standard data products from the current NIMBUS 7 solar backscatter ultraviolet (SBUV) inversion algorithm' ozone column content within the pressure ranges of individual Umkehr layers, and ozone mixing ratios at the pendulation on the instrument as it descends on the parachute.…”

Section: Introductionmentioning

confidence: 99%

An improved rocket ozonesonde (ROCOZ‐A): 2. Preparation of stratospheric ozone profiles

Barnes¹,

Holland

Lee

1986

J. Geophys. Res.

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The ROCOZ‐A radiometer measures ozone by long pathlength photometry in the stratosphere and lower mesosphere. After a rocket launch to an apogee of 70 km, the instrument measures the solar ultraviolet irradiance over its four filter wavelengths as it descends on a parachute. The fundamental values from ROCOZ‐A are ozone overburdens versus radar altitude from 53 to 20 km. The slope of these values gives ozone number density. At one standard deviation the repeatability of the ozone overburden measurements averages 2.4%. For ozone number density the repeatability averages 3.2% with a significant increase at altitudes below the ozone number density maximum. The accuracy limits for overburden and number density are estimated at 5–7%. With auxiliary measurements of pressure and temperature, ozone results are also produced in terms of ozone mixing ratio, albeit with a slight broadening of the estimated accuracy limits. The vertical response of ROCOZ‐A ozone measurements (full width at half maximum) is 4 km. The assembly of ROCOZ‐A profiles can be used to compare with measurements from each of the current NASA and NOAA satellite ozone instruments. In addition, the repeatability of ROCOZ‐A allows the use of this instrument as a transfer standard between satellite instruments with different fundamental ozone measurements.

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“…An increase in ozone absorption within the stratosphere causes the observed albedo to decrease. For shorter wavelengths, if A is the albedo and X is the column content of ozone above some pressure altitude p, then (starting from Thomas and Holland's [1977] where S is the ratio of atmospheric scale height to ozone scale height. Typically S ranges from 1.67 to 2.…”

Section: Recentlymentioning

confidence: 99%

Analysis of the eight‐year trend in ozone depletion from empirical models of solar backscattered ultraviolet instrument degradation

Herman¹,

Hudson²,

Serafino³

1990

J. Geophys. Res.

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Currently archived ozone data from the Solar Backscatter Ultraviolet (SBUV) spectrometer experiment on the Nimbus 7 satellite has been reported to show large global decreases in the amount of atmospheric ozone, both total content and as a function of altitude, for the period from 1978 to 1987. Analysis of atmospheric albedo data leading to these reported trends was based on empirical models of the SBUV spectrometer and diffuser plate degradation with time. Their combined degradation can be obtained from apparent decreases in measured solar irradiance at wavelengths where little or no long‐term intensity changes are expected. The central problem in analyzing SBUV data is to separately specify the diffuser plate degradation [Husdon et al., 1988]. Ratios of radiance to solar irradiance used to obtain ozone amounts are proportional only to diffuser reflectivity and independent of any spectrometer degradation. Even observations of relatively short‐term solar irradiance changes with time must be based on a model of diffuser plate degradation, since the SBUV data provide no internal means to uniquely specify diffuser plate reflectivity changes at ail wavelengths. A new class of explicitly empirical models have been developed that produce a better fit to all of the SBUV solar flux data. The models have a single free parameter to separately specify the diffuser plate and spectrometer degradation. This parameter must be within a narrow range to bring the calculated ozone trend into approximate agreement with data from the Dobson network, Solar Mesospheric Explorer (SME) and Stratospheric Aerosol Gas Experiment (SAGE) satellites, or with the different trends reported from the Umkehr ground stations. It is shown that outside sources of ozone data must be used to obtain a unique solution from SBUV radiance data within the precision necessary to determine the existence of a global annual ozone decrease. A correction factor is given as a function of time and altitude that brings the SBUV data into approximate agreement with SAGE, SME, and Dobson ozone trends. The total ozone results also agree with a recently developed wavelength pair justification method of internal calibration for the SBUV instrument. In our opinion, the currently archived SBUV ozone data should be used with caution for periods of analysis exceeding 1 year, since it is likely that the yearly decreases contained in the archived data are too large.

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Simple relationship between the uv radiation backscattered by the earth’s atmosphere and the vertical ozone profile

Cited by 8 publications

References 9 publications

On the quality of the Nimbus 7 LIMS version 6 ozone for studies of the middle atmosphere

On the quality of the Nimbus 7 LIMS version 6 ozone for studies of the middle atmosphere

An improved rocket ozonesonde (ROCOZ‐A): 2. Preparation of stratospheric ozone profiles

Analysis of the eight‐year trend in ozone depletion from empirical models of solar backscattered ultraviolet instrument degradation

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