scholarly journals A new method of deriving time-averaged tropospheric column ozone over the tropics using total ozone mapping spectrometer (TOMS) radiances: Intercomparison and analysis using TRACE A data

1996 ◽  
Vol 101 (D19) ◽  
pp. 24317-24330 ◽  
Author(s):  
J. H. Kim ◽  
R. D. Hudson ◽  
A. M. Thompson
2013 ◽  
Vol 6 (3) ◽  
pp. 4577-4605 ◽  
Author(s):  
K. Bai ◽  
C. Liu ◽  
R. Shi ◽  
W. Gao

Abstract. This study mainly focuses on the validation of total column (TC) ozone data derived from the Ozone Mapping and Profiler Suite (OMPS) on board the NASA's Suomi National Polar-orbiting Partnership satellite (NPP). OMPS is an advanced suite of three hyperspectral instruments that maps global ozone on a daily basis and extends the more than 30 yr total ozone and ozone profile records. The algorithm used to derive OMPS TC ozone is adapted from the heritage of Total Ozone Mapping Spectrometer (TOMS) Version 7 algorithm but with a number of enhancements. Validation is primarily performed through comparisons with an ensemble of 74 global distributed Brewer and Dobson spectrophotometers measurements. Linear regression performs fair agreement between OMPS TC ozone and ground-based TC ozone measurements with root mean square error (RMSE) around of 3% (10 DU). Comparison shows that OMPS TC ozone estimates 0.21% higher than Brewer measurements average, with station-to-station standard deviation of 3.14%. As comparing with Dobson measurements, OMPS TC ozone averages 0.86% higher than the station average with standard deviation of 3.05%. The relative differences between OMPS and ground TC ozone were analysed varying with latitude and time as well as viewing geometry respectively. Comparisons show relative differences within 2% over most of latitude and viewing conditions. Only comparing with Brewer measurements did it show an OMPS TC ozone dependent error, large negative bias was observed as OMPS TC ozone below 220 DU and positive bias shown above 460 DU.


2017 ◽  
Vol 10 (12) ◽  
pp. 4979-4994
Author(s):  
Germar Bernhard ◽  
Irina Petropavlovskikh ◽  
Bernhard Mayer

Abstract. A new method is presented to determine vertical ozone profiles from measurements of spectral global (direct Sun plus upper hemisphere) irradiance in the ultraviolet. The method is similar to the widely used Umkehr technique, which inverts measurements of zenith sky radiance. The procedure was applied to measurements of a high-resolution spectroradiometer installed near the centre of the Greenland ice sheet. Retrieved profiles were validated with balloon-sonde observations and ozone profiles from the space-borne Microwave Limb Sounder (MLS). Depending on altitude, the bias between retrieval results presented in this paper and MLS observations ranges between −5 and +3 %. The magnitude of this bias is comparable, if not smaller, to values reported in the literature for the standard Dobson Umkehr method. Total ozone columns (TOCs) calculated from the retrieved profiles agree to within 0.7±2.0 % (±1σ) with TOCs measured by the Ozone Monitoring Instrument on board the Aura satellite. The new method is called the Global-Umkehr method.


2013 ◽  
Vol 6 (6) ◽  
pp. 10081-10115 ◽  
Author(s):  
E. W. Chiou ◽  
P. K. Bhartia ◽  
R. D. McPeters ◽  
D. G. Loyola ◽  
M. Coldewey-Egbers ◽  
...  

Abstract. This paper describes the comparison of the variability of total column ozone inferred from the three independent multi-year data records, namely, (i) SBUV(v8.6) profile total ozone, (ii) GTO(GOME-Type total ozone), and (iii) Ground-based total ozone data records covering the 16-yr 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 −0.32 to 0.76 % 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 0.58 to 0.66% and 2.83 to 3.82% respectively, depending on the latitude band. The corresponding standard deviations and ranges regarding the differences in monthly zonal mean anomalies show values between 0.40 to 0.59% and 2.19 to 3.53%. 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 to 2.9 in comparison to "GTO minus SBUV". The Ground-based zonal means, while show no systematic differences, 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 0.12% yr−1 (−0.11 and 0.31 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 deviations from pre-1980 level indicate that for the overlap period of 1996 to 2010, all three data records show gradual recovery at (30–60° N) from −5% in 1996 to −2% in 2010. The corresponding recovery at (50–30° S) is not as obvious until after 2006.


2020 ◽  
Author(s):  
Javer A. Barrera ◽  
Rafael P. Fernandez ◽  
Fernando Iglesias-Suarez ◽  
Carlos A. Cuevas ◽  
Jean-Francois Lamarque ◽  
...  

Abstract. Biogenic very short-lived bromine (VSLBr) represents, nowadays, ~ 25 % of the total stratospheric bromine loading. Owing to their much shorter lifetime compared to anthropogenic long-lived bromine (LLBr, e.g., halons) and chlorine (LLCl, e.g., chlorofluorocarbons) substances, the impact of VSLBr on ozone peaks at the extratropical lowermost stratosphere, a key climatic and radiative atmospheric region. Here we present a modelling study of the evolution of stratospheric ozone and its chemical losses in extra-polar regions during the 21st century, under two different scenarios: considering and neglecting the additional stratospheric injection of 5 ppt biogenic VSLBr naturally released from the ocean. Our analysis shows that the inclusion of VSLBr result in a realistic stratospheric bromine loading and improves the quantitative 1980–2015 model-satellite agreement of total ozone column (TOC) in the mid-latitudes. We show that the overall ozone response to VSLBr within the mid-latitudes follows the stratospheric abundances evolution of long-lived inorganic chlorine and bromine throughout the 21st century. Additional ozone losses due to VSLBr are maximised during the present-day period (1990–2010), with TOC differences of −8 DU (−3 %) and −5.5 DU (−2 %) for the southern (SH-ML) and northern (NH-ML) mid-latitudes, respectively. Moreover, the projected TOC differences at the end of the 21st century are at least half of the values found for the present-day period. In the tropics, a small (


2008 ◽  
Vol 8 (6) ◽  
pp. 20223-20237 ◽  
Author(s):  
F. Li ◽  
R. S. Stolarski ◽  
P. A. Newman

Abstract. Vertical and latitudinal changes in the stratospheric ozone in the post-chlorofluorocarbon (CFC) era are investigated using simulations of the recent past and the 21st century with a coupled chemistry-climate model. Model results reveal that, in the 2060s when the stratospheric halogen loading is projected to return to its 1980 values, the extratropical column ozone is significantly higher than that in 1975–1984, but the tropical column ozone does not recover to 1980 values. Upper and lower stratospheric ozone changes in the post-CFC era have very different patterns. Above 15 hPa ozone increases almost latitudinally uniformly by 6 Dobson Unit (DU), whereas below 15 hPa ozone decreases in the tropics by 8 DU and increases in the extratropics by up to 16 DU. The upper stratospheric ozone increase is a photochemical response to greenhouse gas induced strong cooling, and the lower stratospheric ozone changes are consistent with enhanced mean advective transport due to a stronger Brewer-Dobson circulation. The model results suggest that the strengthening of the Brewer-Dobson circulation plays a crucial role in ozone recovery and ozone distributions in the post-CFC era.


2018 ◽  
Vol 18 (10) ◽  
pp. 7625-7637 ◽  
Author(s):  
James Keeble ◽  
Hannah Brown ◽  
N. Luke Abraham ◽  
Neil R. P. Harris ◽  
John A. Pyle

Abstract. Total column ozone values from an ensemble of UM-UKCA model simulations are examined to investigate different definitions of progress on the road to ozone recovery. The impacts of modelled internal atmospheric variability are accounted for by applying a multiple linear regression model to modelled total column ozone values, and ozone trend analysis is performed on the resulting ozone residuals. Three definitions of recovery are investigated: (i) a slowed rate of decline and the date of minimum column ozone, (ii) the identification of significant positive trends and (iii) a return to historic values. A return to past thresholds is the last state to be achieved. Minimum column ozone values, averaged from 60° S to 60° N, occur between 1990 and 1995 for each ensemble member, driven in part by the solar minimum conditions during the 1990s. When natural cycles are accounted for, identification of the year of minimum ozone in the resulting ozone residuals is uncertain, with minimum values for each ensemble member occurring at different times between 1992 and 2000. As a result of this large variability, identification of the date of minimum ozone constitutes a poor measure of ozone recovery. Trends for the 2000–2017 period are positive at most latitudes and are statistically significant in the mid-latitudes in both hemispheres when natural cycles are accounted for. This significance results largely from the large sample size of the multi-member ensemble. Significant trends cannot be identified by 2017 at the highest latitudes, due to the large interannual variability in the data, nor in the tropics, due to the small trend magnitude, although it is projected that significant trends may be identified in these regions soon thereafter. While significant positive trends in total column ozone could be identified at all latitudes by ∼ 2030, column ozone values which are lower than the 1980 annual mean can occur in the mid-latitudes until ∼ 2050, and in the tropics and high latitudes deep into the second half of the 21st century.


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