scholarly journals Examination on total ozone column retrievals by Brewer spectrophotometry using different processing software

2018 ◽  
Author(s):  
Anna Maria Siani ◽  
Francesco Scarlatti ◽  
Arianna Religi ◽  
Henri Diémoz ◽  
Giuseppe R. Casale ◽  
...  
Keyword(s):  
Total Ozone ◽  
Terrestrial Ecosystem ◽  
Ozone Monitoring Instrument ◽  
Web Based ◽  
Software Packages ◽  
Short And Long Term ◽  
Processing Software ◽  
Ozone Column ◽  
Standard Lamp

Abstract. The availability of long-term records of the total ozone content (TOC) represents a valuable source of information in studies on the assessment of short and long-term changes and their impact on the terrestrial ecosystem. In addition, ground-based observations represent a valuable tool to validate satellite-derived products. To our knowledge, details about processing software packages to retrieve the TOC from Brewer spectrophotometer measurements are seldom specified in studies concerning such datasets, although some discrepancies can arise from the use of different algorithms and implementations. The deviations among retrieved TOCs from the Brewer instruments located at Rome and Aosta (Italy), using different processing software (Brewer Processing Software, O3Brewer software and EUBREWNET products (Level 1.5) are investigated. Ground-based TOCs are also compared with the Ozone Monitoring Instrument (OMI) TOC retrievals used as an independent dataset since no other instruments near the Brewer sites, are available. Although the overall agreement of the BPS and O3Brewer TOC data with EUBREWNET data is clearly very good (as expected) and in most cases within the Brewer declared uncertainty less than 2 %, it is worth noticing that slight differences have been seen depending on the software in use. Such differences become larger when the instrumental sensitivity exhibits a long-term drift and even in short-term episodes due to the different algorithm for the standard lamp correction. This work aims to provide useful information both for scientists engaged in ozone measurements with Brewer spectrophotometry and for stakeholders of the Brewer data products available at web-based platforms.

scholarly journals Examination on total ozone column retrievals by Brewer spectrophotometry using different processing software

2018 ◽  
Vol 11 (9) ◽  
pp. 5105-5123 ◽  
Author(s):  
Anna Maria Siani ◽  
Francesca Frasca ◽  
Francesco Scarlatti ◽  
Arianna Religi ◽  
Henri Diémoz ◽  
...  
Keyword(s):  
Total Ozone ◽  
Terrestrial Ecosystem ◽  
Ozone Monitoring Instrument ◽  
Web Based ◽  
Total Uncertainty ◽  
Mean Values ◽  
Brewer Spectrophotometer ◽  
Processing Software ◽  
Atmospheric Changes

Abstract. The availability of long-term records of the total ozone content (TOC) represents a valuable source of information for studies on the assessment of short- and long-term atmospheric changes and their impact on the terrestrial ecosystem. In particular, ground-based observations represent a valuable tool for validating satellite-derived products. To our knowledge, details about software packages for processing Brewer spectrophotometer measurements and for retrieving the TOC are seldom specified in studies using such datasets. The sources of the differences among retrieved TOCs from the Brewer instruments located at the Italian stations of Rome and Aosta, using three freely available codes (Brewer Processing Software, BPS; O3Brewer software; and European Brewer Network (EUBREWNET) level 1.5 products) are investigated here. Ground-based TOCs are also compared with Ozone Monitoring Instrument (OMI) TOC retrievals used as an independent dataset since no other instruments near the Brewer sites are available. The overall agreement of the BPS and O3Brewer TOC data with EUBREWNET data is within the estimated total uncertainty in the retrieval of total ozone from a Brewer spectrophotometer (1 %). However, differences can be found depending on the software in use. Such differences become larger when the instrumental sensitivity exhibits a fast and dramatic drift which can affect the ozone retrievals significantly. Moreover, if daily mean values are directly generated by the software, differences can be observed due to the configuration set by the users to process single ozone measurement and the rejection rules applied to data to calculate the daily value. This work aims to provide useful information both for scientists engaged in ozone measurements with Brewer spectrophotometers and for stakeholders of the Brewer data products available on Web-based platforms.

scholarly journals Investigating Temporal Variability of Total Ozone Column over Kathmandu Using Omi Satellite Observations

2016 ◽  
Vol 21 (1) ◽  
pp. 140-147
Author(s):  
Narayan P. Chapagain
Keyword(s):  
Temporal Variability ◽  
Total Ozone ◽  
Seasonal Pattern ◽  
Winter Season ◽  
Ozone Monitoring Instrument ◽  
Total Ozone Column ◽  
Annual Variations ◽  
Notable Increase ◽  
Ozone Column

The objective of this work was to analyze the trend of temporal variability of the atmospheric Total ozone column (TOC) over Kathmandu, during the last 13 years of observations using remote sensing-derived data. For this study, long-term TOC data derived from the Ozone Monitoring Instrument (OMI) for the period of October 2004–April 2016 were used. The daily, monthly, seasonal, and annual variations of TOC were analyzed. During the whole study period, the highest value of TOC is found to be 344 DU in March and the lowest value of TOC is 219 DU in December. The average TOC calculated during the whole study period over Kathmandu is found to be 268 DU. The trend of TOC shows a distinct seasonal pattern, with maximum in summer and minimum in winter season, specifically high value in April or May and lower value in December and January. The long-term variability also represents a notable increase in TOC for the period from 2004 to 2015 illustrating the significant recovery atmospheric ozone over Kathmandu. The ozone recovery during the recent years may be due to the reduction of the ozone depletory agents.Journal of Institute of Science and TechnologyVolume 21, Issue 1, August 2016, Page: 140-147

scholarly journals Türkiye’nin İzmir ve Ankara İllerinde Su Ürünleri Tüketimi

2015 ◽  
Vol 3 (5) ◽  
pp. 248 ◽  
Author(s):  
Hülya Saygı ◽  
Bahar Bayhan ◽  
Müge Aliye Hekimoğlu
Keyword(s):  
Survey Data ◽  
Local Governments ◽  
Consumer Preferences ◽  
White Meat ◽  
Microsoft Excel ◽  
Software Packages ◽  
The People ◽  
Short And Long Term ◽  
Aquaculture Products

This study is one of Turkey at the sea coast in Izmir and Ankara in other inland fisheries are conducted to determine consumer preferences. 306 people in Izmir and 405 people in Ankara were directly interviewed and the orginal data for the research was gathered. Survey data were anlyzed with using SPSS and Microsoft Excel software packages. According to the survey data; it is determined that individuals consumed mostly white meat at the rate of 81%, and consumed white meat at the rate of 19%. At least 46% of these individuals consume fish once a week at a minimum. It is determined that 83% of the individuals in Ankara consumed white meat, 17% consumed red meat. It is found out that at least 30% of these indiviudals consumed fish once a week at a minimum. Aquaculture products are highly important for the nutrition due to its being animal protein resource. In spite of the fast growing population and big problems seen in balanced diets, aquaculture products are not efficiently benefited. As a result of our country to increase fish consumption habits and consumption of fishery products on human health in the short and long term benefits should be explained. To this end, local governments and other regional organizations and institutions of the people in the area where the handle will be of interest to fisheries and should be in promoting.

scholarly journals Spectral UV measurements in Austria from 1994 to 2006: investigations of short- and long-term changes

2008 ◽  
Vol 8 (23) ◽  
pp. 7033-7043 ◽  
Author(s):  
S. Simic ◽  
P. Weihs ◽  
A. Vacek ◽  
H. Kromp-Kolb ◽  
M. Fitzka
Keyword(s):  
Confidence Level ◽  
Total Ozone ◽  
Sunshine Duration ◽  
Trend Test ◽  
Total Column Ozone ◽  
Clear Sky ◽  
Uv Irradiance ◽  
Long Term Changes ◽  
Short And Long Term

Abstract. The influence of variability of atmospheric parameters on short- and long-term changes of spectral UV irradiance measured at the Sonnblick observatory (47.03° N, 12.57° E, 3106 m) during the period from 1994 to 2006 is studied. Measurements were performed with the Brewer #093 single-monochromator spectrophotometer and with a Bentham DM 150 spectroradiometer (double-monochromator). The influence of ozone, albedo, snowline and clouds on UV variability is evaluated for each parameter separately using 10-year climatology. It is found that the effect of total ozone on short-term variability of UV irradiance at 305 nm can be more than 200% and on average more than 50%. Clouds can cause variability of 150% or more and on average 35%. Variability caused by albedo reaches a maximum of 32% in April (6% on average). In summer and autumn, total ozone and clouds strongly influence the variability of UV radiation, whereas in winter and spring ozone has the more pronounced effect. A decrease in snowline height from 3000 m to 800 m a.s.l. enhances the UV irradiance by a factor of 1.24 for clear sky conditions and by a factor of 1.7 for 8/8 cloud cover. Long-term trends are investigated for the time period from 1994 to 2006 based on clear-sky measurements, using the non-parametric Mann-Kendall trend test. Significant downward trends (99% confidence level) are found for solar zenith angle 55° at wavelengths from 305 nm to 324 nm and erythemally weighted irradiance according to CIE, which are caused by an increase in sunshine duration during periods of high total column ozone. Significant trends (90% confidence level) were also found for other combinations of wavelength and SZA.

scholarly journals Geophysical validation and long-term consistency between GOME-2/MetOp-A total ozone column and measurements from the sensors GOME/ERS-2, SCIAMACHY/ENVISAT and OMI/Aura

2012 ◽  
Vol 5 (9) ◽  
pp. 2169-2181 ◽  
Author(s):  
M. E. Koukouli ◽  
D. S. Balis ◽  
D. Loyola ◽  
P. Valks ◽  
W. Zimmer ◽  
...  
Keyword(s):  
Total Ozone ◽  
Satellite Monitoring ◽  
Total Ozone Column ◽  
Satellite Sensors ◽  
Data Processor ◽  
Ozone Monitoring ◽  
Scanning Imaging ◽  
Ozone Column ◽  
Seasonal Dependence

Abstract. The main aim of the paper is to assess the consistency of five years of Global Ozone Monitoring Experiment-2/Metop-A [GOME-2] total ozone columns and the long-term total ozone satellite monitoring database already in existence through an extensive inter-comparison and validation exercise using as reference Brewer and Dobson ground-based measurements. The behaviour of the GOME-2 measurements is being weighed against that of GOME (1995–2011), Ozone Monitoring Experiment [OMI] (since 2004) and the Scanning Imaging Absorption spectroMeter for Atmospheric CartograpHY [SCIAMACHY] (since 2002) total ozone column products. Over the background truth of the ground-based measurements, the total ozone columns are inter-evaluated using a suite of established validation techniques; the GOME-2 time series follow the same patterns as those observed by the other satellite sensors. In particular, on average, GOME-2 data underestimate GOME data by about 0.80%, and underestimate SCIAMACHY data by 0.37% with no seasonal dependence of the differences between GOME-2, GOME and SCIAMACHY. The latter is expected since the three datasets are based on similar DOAS algorithms. This underestimation of GOME-2 is within the uncertainty of the reference data used in the comparisons. Compared to the OMI sensor, on average GOME-2 data underestimate OMI_DOAS (collection 3) data by 1.28%, without any significant seasonal dependence of the differences between them. The lack of seasonality might be expected since both the GOME data processor [GDP] 4.4 and OMI_DOAS are DOAS-type algorithms and both consider the variability of the stratospheric temperatures in their retrievals. Compared to the OMI_TOMS (collection 3) data, no bias was found. We hence conclude that the GOME-2 total ozone columns are well suitable to continue the long-term global total ozone record with the accuracy needed for climate monitoring studies.

Temporal and Spatial Variability and Trend Investigation of Total Ozone Column over Iraq Employing Remote Sensing Data: 1979-2012

2015 ◽  
Vol 53 ◽  
pp. 1-18
Author(s):  
Ali M. Al-Salihi ◽  
Zehraa M. Hassan
Keyword(s):  
Remote Sensing ◽  
Spatial Variability ◽  
Total Ozone ◽  
Positive Trend ◽  
Climate Change Research ◽  
Total Ozone Column ◽  
Temporal And Spatial Variability ◽  
Temporal And Spatial ◽  
Ozone Column

The objective of this paper is to analyze the temporal and spatial variability of the total ozone column (TOC) distributions and trends over Iraq, during the last 30 years (1979–2012) using remote sensing-derived TOC data. Due to shortage of ground-based TOC measurements. TOC data derived from the Total Ozone Mapping Spectrometer (TOMS) for the period 1979–2004 and Ozone Monitoring Instrument (OMI) for the period 2005–2012 with spatial resolution (1o×1o) were used in present study. The spatial, long-term, monthly variations of TOC over Iraq were analysed. For the spatial variability, the latitudinal variability has a large range between (45 to 55) DU in winter and spring whereas during summer and autumn months ranged between (6 to 10) DU. Also represents an annual cycle with maximum in March and minimum in October. In contrast, the longitudinal variability is not significant. The long-term variability represented a notable decline for the period 1979–2012. The ozone negative trend was observed significantly during 1979–2004, for all months with trend ranged between (− 0.3 to 2) DU/year whereas the ozone positive trend was appear clearly during 2005–2007, for all months (0.1 to 2.3) DU/year ,except February and September which presented negative trends. The results can provide comprehensive descriptions of the TOC variations in Iraq and benefit climate change research in this region.

scholarly journals NDACC UV-visible total ozone measurements: improved retrieval and comparison with correlative satellite and ground-based observations

2010 ◽  
Vol 10 (8) ◽  
pp. 20405-20460
Author(s):  
F. Hendrick ◽  
J.-P. Pommereau ◽  
F. Goutail ◽  
R. D. Evans ◽  
D. Ionov ◽  
...  
Keyword(s):  
Cross Sections ◽  
Total Ozone ◽  
Complete Removal ◽  
Temperature Correction ◽  
Atmospheric Composition ◽  
Vertical Column ◽  
Stratospheric Temperature ◽  
Uv Visible ◽  
Ozone Column

Abstract. Accurate long-term monitoring of total ozone is one of the most important requirements for identifying possible natural or anthropogenic changes in the composition of the stratosphere. For this purpose, the NDACC (Network for the Detection of Atmospheric Composition Change) UV-visible Working Group has made recommendations for improving and homogenizing the retrieval of total ozone columns from twilight zenith-sky visible spectrometers. These instruments, deployed all over the world in about 35 stations, allow measurements of total ozone twice daily with little sensitivity to stratospheric temperature and cloud cover. The NDACC recommendations address both the DOAS retrieval parameters and the calculation of air mass factors (AMF) needed for the conversion of O3 slant column densities into vertical column amounts. The most important improvement is the use of O3 AMF look-up tables calculated using the TOMS V8 O3 profile climatology, that allows accounting for the dependence of the O3 AMF on the seasonal and latitudinal variations of the O3 vertical distribution. To investigate their impact on the retrieved ozone columns, the recommendations have been applied to measurements from the NDACC/SAOZ (Système d'Analyse par Observation Zénithale) network. The revised SAOZ ozone data from eight stations covering all latitude regions have been compared to TOMS, GOME-GDP4, SCIAMACHY-TOSOMI, OMI-TOMS, and OMI-DOAS satellite overpass observations, as well as to those of collocated Dobson and Brewer instruments. A significant improvement is obtained after applying the new O3 AMFs, although systematic seasonal differences between SAOZ and all other instruments remain. These are shown to mainly originate from i) the temperature dependence of the ozone absorption cross sections in the UV being not or improperly corrected by some retrieval algorithms, and ii) the longitudinal differences in tropospheric ozone column being ignored by zonal climatologies. For those measurements sensitive to stratospheric temperature like TOMS, OMI-TOMS, Dobson and Brewer, the application of a temperature correction results in the almost complete removal of the seasonal difference with SAOZ, improving significantly the consistency between all ground-based and satellite total ozone observations.

scholarly journals GUV long-term measurements of total ozone column and effective cloud transmittance at three Norwegian sites

2021 ◽  
Vol 21 (10) ◽  
pp. 7881-7899
Author(s):  
Tove M. Svendby ◽  
Bjørn Johnsen ◽  
Arve Kylling ◽  
Arne Dahlback ◽  
Germar H. Bernhard ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Total Ozone ◽  
Monitoring Network ◽  
High Time Resolution ◽  
Data Sets ◽  
Total Ozone Column ◽  
Ice Melt ◽  
Arctic Ice ◽  
Ozone Column

Abstract. Measurements of total ozone column and effective cloud transmittance have been performed since 1995 at the three Norwegian sites Oslo/Kjeller, Andøya/Tromsø, and in Ny-Ålesund (Svalbard). These sites are a subset of nine stations included in the Norwegian UV monitoring network, which uses ground-based ultraviolet (GUV) multi-filter instruments and is operated by the Norwegian Radiation and Nuclear Safety Authority (DSA) and the Norwegian Institute for Air Research (NILU). The network includes unique data sets of high-time-resolution measurements that can be used for a broad range of atmospheric and biological exposure studies. Comparison of the 25-year records of GUV (global sky) total ozone measurements with Brewer direct sun (DS) measurements shows that the GUV instruments provide valuable supplements to the more standardized ground-based instruments. The GUV instruments can fill in missing data and extend the measuring season at sites with reduced staff and/or characterized by harsh environmental conditions, such as Ny-Ålesund. Also, a harmonized GUV can easily be moved to more remote/unmanned locations and provide independent total ozone column data sets. The GUV instrument in Ny-Ålesund captured well the exceptionally large Arctic ozone depletion in March/April 2020, whereas the GUV instrument in Oslo recorded a mini ozone hole in December 2019 with total ozone values below 200 DU. For all the three Norwegian stations there is a slight increase in total ozone from 1995 until today. Measurements of GUV effective cloud transmittance in Ny-Ålesund indicate that there has been a significant change in albedo during the past 25 years, most likely resulting from increased temperatures and Arctic ice melt in the area surrounding Svalbard.

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