scholarly journals TROPOMI/S5ptotal ozone column data: global ground-based validation & consistency with other satellite missions

2019 ◽  
Author(s):  
Katerina Garane ◽  
Maria-Elissavet Koukouli ◽  
Tijl Verhoelst ◽  
Vitali Fioletov ◽  
Christophe Lerot ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Total Ozone ◽  
Scattered Light ◽  
Optical Absorption Spectroscopy ◽  
Global Comparison ◽  
Percentage Difference ◽  
The Mean ◽  
Ozone Monitoring ◽  
Ozone Column

Abstract. In October 2017, the Sentinel-5 Precursor (S5p) mission was launched, carrying the TROPOspheric Monitoring Instrument, TROPOMI, which provides a daily global coverage at a spatial resolution as high as 7 km × 3.5 km and is expected to extend the European atmospheric composition record initiated with GOME/ERS-2 in 1995, bringing up significant new components to the scientific knowledge of atmospheric processes. Due to the ongoing need to understand and monitor the recovery of the ozone layer, as well as the evolution of tropospheric pollution, total ozone remains one of the leading species of interest during this mission. In this work the TROPOMI Near-Real Time, NRTI, and Offline, OFFL, total ozone column (TOC) products are presented and compared to daily ground-based quality-assured Brewer and Dobson TOC measurements deposited in the World Ozone and Ultraviolet Radiation Data Centre (WOUDC). Additional comparisons to individual Brewer measurements from the Canadian Brewer Network and the European Brewer Network (Eubrewnet) are performed. Furthermore, twilight zenith-sky measurements obtained with ZSL-DOAS (Zenith Scattered Light Differential Optical Absorption Spectroscopy) instruments, that form part of the SAOZ network (Système d'Analyse par Observation Zénitale), are used for the validation. The quality of the TROPOMI TOC data is evaluated in terms of the influence of location, solar zenith and viewing angles, season, effective temperature, surface albedo and clouds. For this purpose, globally distributed ground-based measurements have been utilized as the background truth. The overall statistical analysis of the global comparison shows that the mean bias and the mean standard deviation of the percentage difference between TROPOMI and ground-based TOC is within 0–1.5 % and 2.5–4.5 %, respectively. The mean bias that results from the comparisons is well within the S5p product requirements, while the mean standard deviation is very close to those limits, especially considering that the statistics shown here originate both from the satellite and the ground-based measurements. Additionally, the TROPOMI OFFL and NRTI products are evaluated against already known space-borne sensors, namely, the Ozone Mapping Profiler Suite on board the Suomi National Polar-orbiting Partnership (OMPS/Suomi-NPP), NASA v2 TOCs, and the Global Ozone Monitoring Experiment–2 (GOME-2) on board the MetοpΑ (GOME-2/MetοpΑ) and MetopB (GOME-2/MetopB) satellites. This analysis shows a very good agreement for both TROPOMI products to well established instruments, with the absolute differences in mean bias and mean standard deviation being below 0.7 % and 1 %, respectively. These results assure the scientific community of the good quality of the TROPOMI TOC products during its first year of operation and enhance the already high expectations that S5p TROPOMI will play a very significant role in the continuity of the ozone monitoring from space.

scholarly journals TROPOMI/S5P total ozone column data: global ground-based validation and consistency with other satellite missions

2019 ◽  
Vol 12 (10) ◽  
pp. 5263-5287 ◽  
Author(s):  
Katerina Garane ◽  
Maria-Elissavet Koukouli ◽  
Tijl Verhoelst ◽  
Christophe Lerot ◽  
Klaus-Peter Heue ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Spatial Resolution ◽  
Total Ozone ◽  
Optical Absorption Spectroscopy ◽  
Total Ozone Column ◽  
Global Comparison ◽  
The Mean ◽  
Ozone Monitoring ◽  
Ozone Column

Abstract. In October 2017, the Sentinel-5 Precursor (S5P) mission was launched, carrying the TROPOspheric Monitoring Instrument (TROPOMI), which provides a daily global coverage at a spatial resolution as high as 7 km × 3.5 km and is expected to extend the European atmospheric composition record initiated with GOME/ERS-2 in 1995, enhancing our scientific knowledge of atmospheric processes with its unprecedented spatial resolution. Due to the ongoing need to understand and monitor the recovery of the ozone layer, as well as the evolution of tropospheric pollution, total ozone remains one of the leading species of interest during this mission. In this work, the TROPOMI near real time (NRTI) and offline (OFFL) total ozone column (TOC) products are presented and compared to daily ground-based quality-assured Brewer and Dobson TOC measurements deposited in the World Ozone and Ultraviolet Radiation Data Centre (WOUDC). Additional comparisons to individual Brewer measurements from the Canadian Brewer Network and the European Brewer Network (Eubrewnet) are performed. Furthermore, twilight zenith-sky measurements obtained with ZSL-DOAS (Zenith Scattered Light Differential Optical Absorption Spectroscopy) instruments, which form part of the SAOZ network (Système d'Analyse par Observation Zénitale), are used for the validation. The quality of the TROPOMI TOC data is evaluated in terms of the influence of location, solar zenith angle, viewing angle, season, effective temperature, surface albedo and clouds. For this purpose, globally distributed ground-based measurements have been utilized as the background truth. The overall statistical analysis of the global comparison shows that the mean bias and the mean standard deviation of the percentage difference between TROPOMI and ground-based TOC is within 0 –1.5 % and 2.5 %–4.5 %, respectively. The mean bias that results from the comparisons is well within the S5P product requirements, while the mean standard deviation is very close to those limits, especially considering that the statistics shown here originate both from the satellite and the ground-based measurements. Additionally, the TROPOMI OFFL and NRTI products are evaluated against already known spaceborne sensors, namely, the Ozone Mapping Profiler Suite, on board the Suomi National Polar-orbiting Partnership (OMPS/Suomi-NPP), NASA v2 TOCs, and the Global Ozone Monitoring Experiment 2 (GOME-2), on board the Metop-A (GOME-2/Metop-A) and Metop-B (GOME-2/Metop-B) satellites. This analysis shows a very good agreement for both TROPOMI products with well-established instruments, with the absolute differences in mean bias and mean standard deviation being below +0.7 % and 1 %, respectively. These results assure the scientific community of the good quality of the TROPOMI TOC products during its first year of operation and enhance the already prevalent expectation that TROPOMI/S5P will play a very significant role in the continuity of ozone monitoring from space.

scholarly journals 2.5 years of TROPOMI S5P total ozone column data: geophysical global ground-based validation and inter-comparison with other satellite missions

2020 ◽  
Author(s):  
Katerina Garane ◽  
Maria-Elissavet Koukouli ◽  
Tijl Verhoelst ◽  
Christophe Lerot ◽  
Klaus-Peter Heue ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Total Ozone ◽  
Scattered Light ◽  
Atmospheric Composition ◽  
Optical Absorption Spectroscopy ◽  
Total Ozone Column ◽  
Global Comparison ◽  
Percentage Difference ◽  
The Mean ◽  
Ozone Column

<p>The Sentinel-5 Precursor (S5P) mission, launched in October 2017, carries the TROPOspheric Monitoring Instrument (TROPOMI), which provides a daily global coverage at a spatial resolution as high as 5.5 km x 3.5 km and will extend the European atmospheric composition record initiated with GOME/ERS-2 in 1995. Due to the ongoing need to understand and monitor the recovery of the ozone layer, as well as the evolution of tropospheric pollution, ozone remains one of the leading species of interest during this mission.</p><p>In this work, two and a half years of TROPOMI near real time (NRTI) and offline (OFFL) total ozone column (TOC) products are presented and compared to daily and individual, globally distributed, ground-based quality assured Brewer and Dobson TOC measurements. The daily ground-based ozone measurements used here are deposited in the World Ozone and Ultraviolet Radiation Data Centre (WOUDC). The individual Brewer measurements are made available by the European Brewer Network (Eubrewnet). Furthermore, twilight zenith-sky measurements obtained with ZSL-DOAS (Zenith Scattered Light Differential Optical Absorption Spectroscopy) instruments, which form part of the SAOZ network (Système d’Analyse par Observation Zénitale), are used for the validation.</p><p>The quality of the TROPOMI TOC data is evaluated in terms of the influence of various geophysical quantities such as location, solar zenith angle, viewing angle, season, effective temperature, surface albedo and clouds. The overall statistical analysis of the global comparison shows that the mean bias and the mean standard deviation of the percentage difference between TROPOMI and ground-based TOC is within 0 –1.5% and 2.5 %–4.5 %, respectively. Moreover, based on the full available dataset, a first attempt is made for a drift investigation.</p><p>Additionally, the TROPOMI OFFL and NRTI products are evaluated against already known spaceborne sensors, namely, the Ozone Mapping Profiler Suite, on board the Suomi National Polar-orbiting Partnership (OMPS/Suomi-NPP), NASA, and the Global Ozone Monitoring Experiment 2 (GOME-2), on board the Metop-A (GOME-2/Metop-A) and Metop-B (GOME-2/Metop-B) satellites. This analysis shows a very good agreement for both TROPOMI products with well-established instruments, with the absolute differences in mean bias and mean standard deviation being below +0.7% and 1%, respectively.</p>

scholarly journals Total ozone retrieval from GOME UV spectral data using the weighting function DOAS approach

2005 ◽  
Vol 5 (4) ◽  
pp. 1015-1025 ◽  
Author(s):  
M. Coldewey-Egbers ◽  
M. Weber ◽  
L. N. Lamsal ◽  
R. de Beek ◽  
M. Buchwitz ◽  
...  
Keyword(s):  
Total Ozone ◽  
Weighting Function ◽  
Scattered Light ◽  
Companion Paper ◽  
Optical Absorption Spectroscopy ◽  
Wavelength Modulation ◽  
Vertical Column ◽  
Ozone Monitoring ◽  
First Time ◽  
Better Than

Abstract. A new algorithm approach called Weighting Function Differential Optical Absorption Spectroscopy (WFDOAS) is presented which has been developed to retrieve total ozone columns from nadir observations of the Global Ozone Monitoring Experiment. By fitting the vertically integrated ozone weighting function rather than ozone cross-section to the sun-normalized radiances, a direct retrieval of vertical column amounts is possible. The new WFDOAS approach takes into account the slant path wavelength modulation that is usually neglected in the standard DOAS approach using single airmass factors. This paper focuses on the algorithm description and error analysis, while in a companion paper by Weber et al. (2004) a detailed validation with groundbased measurements is presented. For the first time several auxiliary quantities directly derived from the GOME spectral range such as cloud-top-height and cloud fraction (O2-A band) and effective albedo using the Lambertian Equivalent Reflectivity (LER) near 377nm are used in combination as input to the ozone retrieval. In addition the varying ozone dependent contribution to the Raman correction in scattered light known as Ring effect has been included. The molecular ozone filling-in that is accounted for in the new algorithm has the largest contribution to the improved total ozone results from WFDOAS compared to the operational product. The precision of the total ozone retrieval is estimated to be better than 3% for solar zenith angles below 80°.

scholarly journals Comparison of OMI-DOAS total ozone column with ground-based measurements in Argentina

2020 ◽  
pp. 13
Author(s):  
P. F. Orte ◽  
E. Luccini ◽  
E. Wolfram ◽  
F. Nollas ◽  
J. Pallotta ◽  
...  
Keyword(s):  
Linear Regression ◽  
Optical Absorption ◽  
Southern Hemisphere ◽  
Total Ozone ◽  
Buenos Aires ◽  
Optical Absorption Spectroscopy ◽  
Ozone Monitoring Instrument ◽  
Total Ozone Column ◽  
Ozone Monitoring ◽  
Ozone Column

<p>Total ozone column (TOC) measurements through the Ozone Monitoring Instrument (OMI/NASA EOSAura) are compared with ground-based observations made using Dobson and SAOZ instruments for the period 2004–2019 and 2008–02/2020, respectively. The OMI data were inverted using the Differential Optical Absorption Spectroscopy algorithm (overpass OMI-DOAS). The four ground-based sites used for the analysis are located in subpolar and subtropical latitudes spanning from 34°S to 54°S in the Southern Hemisphere, in the Argentine cities of Buenos Aires (34.58°S, 58.36°W; 25 m a.s.l.), Comodoro Rivadavia (45.86°S, 67.50°W; 46 m a.s.l.), Río Gallegos (51.60°S, 69.30°W; 72 m a.s.l.) and Ushuaia (54.80°S, 68.30°W; 14 m a.s.l.). The linear regression analyzes showed correlation values greater than 0.90 for all sites. The OMI measurements revealed an overestimation of less than 4 % with respect to the Dobson instruments, while the comparison with the SAOZ instrument presented a very low underestimation of less than 1 %.</p>

scholarly journals Evaluation of Total Ozone Column from Multiple Satellite Measurements in the Antarctic Using the Brewer Spectrophotometer

2021 ◽  
Vol 13 (8) ◽  
pp. 1594
Author(s):  
Songkang Kim ◽  
Sang-Jong Park ◽  
Hana Lee ◽  
Dha Hyun Ahn ◽  
Yeonjin Jung ◽  
...  
Keyword(s):  
Satellite Data ◽  
Total Ozone ◽  
Spatiotemporal Pattern ◽  
Satellite Measurements ◽  
Austral Spring ◽  
Total Ozone Column ◽  
Brewer Spectrophotometer ◽  
The Antarctic ◽  
Ozone Column

The ground-based ozone observation instrument, Brewer spectrophotometer (Brewer), was used to evaluate the quality of the total ozone column (TOC) produced by multiple polar-orbit satellite measurements at three stations in Antarctica (King Sejong, Jang Bogo, and Zhongshan stations). While all satellite TOCs showed high correlations with Brewer TOCs (R = ~0.8 to 0.9), there are some TOC differences among satellite data in austral spring, which is mainly attributed to the bias of Atmospheric Infrared Sounder (AIRS) TOC. The quality of satellite TOCs is consistent between Level 2 and 3 data, implying that “which satellite TOC is used” can induce larger uncertainty than “which spatial resolution is used” for the investigation of the Antarctic TOC pattern. Additionally, the quality of satellite TOC is regionally different (e.g., OMI TOC is a little higher at the King Sejong station, but lower at the Zhongshan station than the Brewer TOC). Thus, it seems necessary to consider the difference of multiple satellite data for better assessing the spatiotemporal pattern of Antarctic TOC.

scholarly journals Total Ozone Columns from the Environmental Trace Gases Monitoring Instrument (EMI) Using the DOAS Method

2021 ◽  
Vol 13 (11) ◽  
pp. 2098
Author(s):  
Yuanyuan Qian ◽  
Yuhan Luo ◽  
Fuqi Si ◽  
Haijin Zhou ◽  
Taiping Yang ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Total Ozone ◽  
Scattered Light ◽  
Trace Gases ◽  
Rapid Change ◽  
Differential Optical Absorption Spectroscopy ◽  
Optical Absorption Spectroscopy ◽  
Monitoring Instrument ◽  
Monthly Average

Global measurements of total ozone are necessary to evaluate ozone hole recovery above Antarctica. The Environmental Trace Gases Monitoring Instrument (EMI) onboard GaoFen 5, launched in May 2018, was developed to measure and monitor the global total ozone column (TOC) and distributions of other trace gases. In this study, some of the first global TOC results of the EMI using the differential optical absorption spectroscopy (DOAS) method and validation with ground-based TOC measurements and data derived from Ozone Monitoring Instrument (OMI) and TROPOspheric Monitoring Instrument (TROPOMI) observations are presented. Results show that monthly average EMI TOC data had a similar spatial distribution and a high correlation coefficient (R ≥ 0.99) with both OMI and TROPOMI TOC. Comparisons with ground-based measurements from the World Ozone and Ultraviolet Radiation Data Centre also revealed strong correlations (R > 0.9). Continuous zenith sky measurements from zenith scattered light differential optical absorption spectroscopy instruments in Antarctica were also used for validation (R = 0.9). The EMI-derived observations were able to account for the rapid change in TOC associated with the sudden stratospheric warming event in October 2019; monthly average TOC in October 2019 was 45% higher compared to October 2018. These results indicate that EMI TOC derived using the DOAS method is reliable and has the potential to be used for global TOC monitoring.

EVALUATION OF QUALITY OF POULTRY FEEDS SOLD IN KATSINA METROPOLIS, KATSINA STATE, NIGERIA

2021 ◽  
Vol 5 (1) ◽  
pp. 601-607
Author(s):  
A. U. Uduma ◽  
Joseph Akumah Ojogba ◽  
O. E. Okafor
Keyword(s):  
Standard Deviation ◽  
Crude Protein ◽  
Proximate Analysis ◽  
Crude Protein Content ◽  
Poultry Feeds ◽  
Crude Fiber Content ◽  
Percent Moisture ◽  
The Mean ◽  
The Difference

In Katsina metropolitan, a variety of poultry feeds are available, and the quality and standards of these feeds are critical for the production of eggs and meat. As a result, the quality of selected chicken feeds sold in Katsina metropolitan was assessed by performing proximate analysis using AOAC methodology. Super starter, grower concentrate, broiler finisher, broiler starter, broiler super starter, layer mesh, grower mesh, and layer concentrate were among the samples used. The percentage mean to standard deviation was used to express the findings. The crude protein content of the diets studied ranged from 0.46 ± 0.00 percent to, 8.24± 0.02 percent, ash content 6.31± 0.01 percent – 33.30± 0.04 percent, crude fiber content 1.03 ±0.00 percent – 3.21± 0.00 percent, lipid content 0.11± 0.00 percent, 2.30 ±0.00 percent, moisture content 4.28 ±0.25 – 6.66 ±0.78 percent, and carbohydrate content 51.78± 2.68 – 83.72 ±0.57 percent. Although there was variation in the mean and standard deviation levels among the samples analyzed, such variations were not statistically significant (P>0.05) according to a one-way analysis of variance (ANOVA) for the difference in the mean levels of parameters evaluated in eight samples

scholarly journals Brewer spectrometer total ozone column measurements in Sodankylä

2016 ◽  
Vol 5 (1) ◽  
pp. 229-239 ◽  
Author(s):  
Tomi Karppinen ◽  
Kaisa Lakkala ◽  
Juha M. Karhu ◽  
Pauli Heikkinen ◽  
Rigel Kivi ◽  
...  
Keyword(s):  
Time Series ◽  
Total Ozone ◽  
Montreal Protocol ◽  
High Quality ◽  
Automatic Data ◽  
Mean Values ◽  
Total Ozone Column ◽  
Measurement Practices ◽  
Ozone Column

Abstract. Brewer total ozone column measurements started in Sodankylä in May 1988, 9 months after the signing of The Montreal Protocol. The Brewer instrument has been well maintained and frequently calibrated since then to produce a high-quality ozone time series now spanning more than 25 years. The data have now been uniformly reprocessed between 1988 and 2014. The quality of the data has been assured by automatic data rejection rules as well as by manual checking. Daily mean values calculated from the highest-quality direct sun measurements are available 77 % of time with up to 75 measurements per day on clear days. Zenith sky measurements fill another 14 % of the time series and winter months are sparsely covered by moon measurements. The time series provides information to survey the evolution of Arctic ozone layer and can be used as a reference point for assessing other total ozone column measurement practices.

scholarly journals Internal consistency of the Regional Brewer Calibration Centre for Europe triad during the period 2005–2016

2018 ◽  
Vol 11 (7) ◽  
pp. 4059-4072 ◽  
Author(s):  
Sergio Fabián León-Luis ◽  
Alberto Redondas ◽  
Virgilio Carreño ◽  
Javier López-Solano ◽  
Alberto Berjón ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Data Sets ◽  
Individual Values ◽  
Relative Standard ◽  
The World ◽  
The Mean ◽  
The Individual ◽  
Ozone Column

Abstract. Total ozone column measurements can be made using Brewer spectrophotometers, which are calibrated periodically in intercomparison campaigns with respect to a reference instrument. In 2003, the Regional Brewer Calibration Centre for Europe (RBCC-E) was established at the Izaña Atmospheric Research Center (Canary Islands, Spain), and since 2011 the RBCC-E has transferred its calibration based on the Langley method using travelling standard(s) that are wholly and independently calibrated at Izaña. This work is focused on reporting the consistency of the measurements of the RBCC-E triad (Brewer instruments #157, #183 and #185) made at the Izaña Atmospheric Observatory during the period 2005–2016. In order to study the long-term precision of the RBCC-E triad, it must be taken into account that each Brewer takes a large number of measurements every day and, hence, it becomes necessary to calculate a representative value of all of them. This value was calculated from two different methods previously used to study the long-term behaviour of the world reference triad (Toronto triad) and Arosa triad. Applying their procedures to the data from the RBCC-E triad allows the comparison of the three instruments. In daily averages, applying the procedure used for the world reference triad, the RBCC-E triad presents a relative standard deviation equal to σ = 0.41 %, which is calculated as the mean of the individual values for each Brewer (σ157 = 0.362 %, σ183 = 0.453 % and σ185 = 0.428 %). Alternatively, using the procedure used to analyse the Arosa triad, the RBCC-E presents a relative standard deviation of about σ = 0.5 %. In monthly averages, the method used for the data from the world reference triad gives a relative standard deviation mean equal to σ = 0.3 % (σ157 = 0.33 %, σ183 = 0.34 % and σ185 = 0.23 %). However, the procedure of the Arosa triad gives monthly values of σ = 0.5 %. In this work, two ozone data sets are analysed: the first includes all the ozone measurements available, while the second only includes the simultaneous measurements of all three instruments. Furthermore, this paper also describes the Langley method used to determine the extraterrestrial constant (ETC) for the RBCC-E triad, the necessary first step toward accurate ozone calculation. Finally, the short-term or intraday consistency is also studied to identify the effect of the solar zenith angle on the precision of the RBCC-E triad.

scholarly journals Caring for the carer: quality of life and burden of female caregivers

2019 ◽  
Vol 72 (3) ◽  
pp. 728-736
Author(s):  
Michelly Guedes de Oliveira Araújo ◽  
Michelinne Oliveira Machado Dutra ◽  
Carla Carolina Silva Leite Freitas ◽  
Tatiane Gomes Guedes ◽  
Francisco Stélio de Souza ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Standard Deviation ◽  
Low Income ◽  
Statistical Significance ◽  
Cross Sectional ◽  
Level Of Education ◽  
Kolmogorov Smirnov ◽  
Status Number ◽  
The Mean

ABSTRACT Objective: To assess the quality of life and the burden of female caregivers. Method: Descriptive, cross-sectional, quantitative study carried out with 224 informal caregivers from March to July 2016. Three instruments were used: a characterization form for the caregiver, the WHOQOL-Bref questionnaire and the Zarit Burden Interview. The following tests were used: Cronbach’s Alpha, Kolmogorov-Smirnov, Kruskal-Wallis, Spearman and Mann-Whitney. Results: The mean age of caregivers was 51.8 years with a standard deviation of 13.7. They were predominantly married, had a low income and low level of education, were first-degree relatives, had been providing care for one to five years and presented some pathology. The associations of quality of life that presented statistical significance were: income, marital status, number of people living with the caregiver and time of care. Conclusion: The burden was negatively correlated with QOL, that is, the greater the burden, the more impaired will be the life of these caregivers.

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