scholarly journals Analysis of Ozone Concentrations between 2002–2020 in Urban Air in Northern Spain

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1495
Author(s):  
M. Ángeles García ◽  
Javier Villanueva ◽  
Nuria Pardo ◽  
Isidro A. Pérez ◽  
M. Luisa Sánchez
Keyword(s):  
Empirical Equation ◽  
Surface Ozone ◽  
Early Morning ◽  
Mean Value ◽  
Harmonic Model ◽  
Northern Spain ◽  
Ozone Concentrations ◽  
Deposition Processes ◽  
Experimental Values ◽  
The Relationship

This paper analyses surface ozone measurements at five stations in an urban area (Valladolid) in the upper Spanish plateau over the period 2002–2020. Temporal evolutions, the relationship between ozone and other pollutants such as nitrogen oxides, and the assessment of the ozone concentration trend during the study period were analysed. Daily evolution of ozone at all the stations showed mean maximum concentrations in the afternoon, 15:00 GMT, with values ranging between 73.8 and 80.9 µg m−3, evidencing the influence of photochemical processes favoured by solar radiation in ozone formation. The lowest levels were recorded at night and in the early morning, 7:00 GMT, and were between 23.4 and 32.3 µg m−3, related with the reduction by NO reactions and deposition processes. A broad spring–summer peak between May and July was seen, with the highest values in the latter, with a mean value of up to 73.8 µg m−3. The variation in the monthly mean ozone concentrations of the different percentiles was analysed using a harmonic model. The empirical equation described the experimental values satisfactorily, with a confidence level of 95% and coefficients of determination above 80%, confirming the major decreasing trend in the ozone peak values over the study period.

scholarly journals A multi-model comparison of meteorological drivers of surface ozone over Europe

2018 ◽  
Author(s):  
Noelia Otero ◽  
Jana Sillmann ◽  
Kathleen A. Mar ◽  
Henning W. Rust ◽  
Sverre Solberg ◽  
...  
Keyword(s):  
Time Series ◽  
Air Quality ◽  
Relative Humidity ◽  
Surface Ozone ◽  
Meteorological Variables ◽  
Maximum Temperature ◽  
Quality Models ◽  
The Balkans ◽  
Ozone Concentrations ◽  
The Relationship

Abstract. The implementation of European emission abatement strategies has led to significant reduction in the emission of ozone precursors during the last decade. Ground level ozone is also influenced by meteorological factors such as temperature, which exhibit interannual variability, and are expected to change in the future. The impacts of climate change on air quality are usually investigated through air quality models that simulate interactions between emissions, meteorology and chemistry. Within a multi-model assessment, this study aims to better understand how air quality models represent the relationship between meteorological variables and surface ozone concentrations over Europe. A multiple linear regression (MLR) approach is applied to observed and modelled time series across ten European regions in springtime and summertime for the period of 2000–2010 for both models and observations. Overall, the air quality models are in better agreement with observations in summertime than in springtime, and particularly in certain regions, such as France, Mid-Europe or East-Europe, where local meteorological variables show a strong influence on surface ozone concentrations. Larger discrepancies are found for the southern regions, such as the Balkans, the Iberian Peninsula and the Mediterranean basin, especially in springtime. We show that the air quality models do not properly reproduce the sensitivity of surface ozone to some of the main meteorological drivers, such as maximum temperature, relative humidity and surface solar radiation. Specifically, all air quality models show more limitations to capture the strength of the relationship ozone-relative humidity detected in the observed time series in most of the regions, in both seasons. Here, we speculate that dry deposition schemes in the air quality models might play an essential role to capture this relationship. We further quantify the relationship between ozone and maximum temperature (mo3-T, climate penalty) in observations and air quality models. In summertime, most of the air quality models are able to reproduce reasonably well the observed climate penalty in certain regions such as France, Mid-Europe and North Italy. However, larger discrepancies are found in springtime, where air quality models tend to overestimate the magnitude of observed climate penalty.

scholarly journals The impact of observation nudging on simulated meteorology and ozone concentrations during DISCOVER-AQ 2013 Texas campaign

2016 ◽  
Vol 16 (5) ◽  
pp. 3127-3144 ◽  
Author(s):  
Xiangshang Li ◽  
Yunsoo Choi ◽  
Beata Czader ◽  
Anirban Roy ◽  
Hyuncheol Kim ◽  
...  
Keyword(s):  
Air Quality ◽  
Low Cost ◽  
Surface Ozone ◽  
Chemical Transport ◽  
Early Morning ◽  
Small Scale ◽  
Boundary Layer Height ◽  
Ozone Concentrations ◽  
Houston Ship Channel ◽  
The Impact

Abstract. Accurate meteorological fields are imperative for correct chemical transport modeling. Observation nudging, along with objective analysis, is generally considered a low-cost and effective technique to improve meteorological simulations. However, the meteorological impact of observation nudging on chemistry has not been well characterized. This study involved two simulations to analyze the impact of observation nudging on simulated meteorology and ozone concentrations during the 2013 Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Texas campaign period, using the Weather Research and Forecasting (WRF) and Community Multiscale Air Quality (CMAQ) models. The results showed improved correlations between observed and simulated parameters. For example, the index of agreement (IOA) improved by about 9 % for surface temperature and 6–11 % for surface zonal (U-WIND) and meridional (V-WIND) winds when observation nudging was employed. Analysis of a cold front event indicated that nudging improved the timing of wind transition during the front passage. Observation nudging also reduced the model biases for the planetary boundary layer height predictions. Additionally, the IOA for CMAQ simulated surface ozone improved by 6 % during the simulation period. The high-ozone episode on 25 September was a post-front ozone event in Houston. The small-scale morning wind shifts near the Houston Ship Channel combined with higher aloft ozone early morning likely caused the day's ozone exceedance. While observation nudging did not recreate the wind shifts on that day and failed to reproduce the observed high ozone, analyses of surface and aircraft data found that observation nudging helped the model yield improved ozone predictions. In a 2 h period during the event, substantially better winds in the sensitivity case noticeably improved the ozone. The average IOA for ozone in the period increased from just over 0.4 to near 0.7. Further work on improving the capability of nudging to reproduce local meteorological events such as stagnations and wind reversals could enhance a chemical transport model's skill for predicting high-ozone events.

scholarly journals A multi-model comparison of meteorological drivers of surface ozone over Europe

2018 ◽  
Vol 18 (16) ◽  
pp. 12269-12288 ◽  
Author(s):  
Noelia Otero ◽  
Jana Sillmann ◽  
Kathleen A. Mar ◽  
Henning W. Rust ◽  
Sverre Solberg ◽  
...  
Keyword(s):  
Time Series ◽  
Air Quality ◽  
Relative Humidity ◽  
Central Europe ◽  
Surface Ozone ◽  
Meteorological Variables ◽  
Maximum Temperature ◽  
Quality Models ◽  
Ozone Concentrations ◽  
The Relationship

Abstract. The implementation of European emission abatement strategies has led to a significant reduction in the emissions of ozone precursors during the last decade. Ground-level ozone is also influenced by meteorological factors such as temperature, which exhibit interannual variability and are expected to change in the future. The impacts of climate change on air quality are usually investigated through air-quality models that simulate interactions between emissions, meteorology and chemistry. Within a multi-model assessment, this study aims to better understand how air-quality models represent the relationship between meteorological variables and surface ozone concentrations over Europe. A multiple linear regression (MLR) approach is applied to observed and modelled time series across 10 European regions in springtime and summertime for the period of 2000–2010 for both models and observations. Overall, the air-quality models are in better agreement with observations in summertime than in springtime and particularly in certain regions, such as France, central Europe or eastern Europe, where local meteorological variables show a strong influence on surface ozone concentrations. Larger discrepancies are found for the southern regions, such as the Balkans, the Iberian Peninsula and the Mediterranean basin, especially in springtime. We show that the air-quality models do not properly reproduce the sensitivity of surface ozone to some of the main meteorological drivers, such as maximum temperature, relative humidity and surface solar radiation. Specifically, all air-quality models show more limitations in capturing the strength of the ozone–relative-humidity relationship detected in the observed time series in most of the regions, for both seasons. Here, we speculate that dry-deposition schemes in the air-quality models might play an essential role in capturing this relationship. We further quantify the relationship between ozone and maximum temperature (mo3−T, climate penalty) in observations and air-quality models. In summertime, most of the air-quality models are able to reproduce the observed climate penalty reasonably well in certain regions such as France, central Europe and northern Italy. However, larger discrepancies are found in springtime, where air-quality models tend to overestimate the magnitude of the observed climate penalty.

scholarly journals The long-term trend and production sensitivity change of the U.S. ozone pollution from observations and model simulations

2019 ◽  
Author(s):  
Hao He ◽  
Xin-Zhong Liang ◽  
Chao Sun ◽  
Zhining Tao ◽  
Daniel Q. Tong
Keyword(s):  
United States ◽  
Surface Ozone ◽  
The United States ◽  
Early Morning ◽  
Ozone Pollution ◽  
Late Afternoon ◽  
The Past ◽  
Ozone Concentrations ◽  
The U.S

Abstract. We investigated the ozone pollution trend and its sensitivity to key precursors from 1990 to 2015 in the United States using long-term EPA AQS observations and mesoscale simulations. The modeling system, a coupled regional climate–air quality (CWRF-CMAQ) model, well captured summer surface ozone pollution during the past decades, having a mean slope of linear regression with AQS observations at ~ 0.75. While the AQS network has limited spatial coverage and measures only a few key chemical species, the CWRF-CMAQ provides comprehensive simulations to enable a more rigorous study of the change in ozone pollution and chemical sensitivity. Analysis of seasonal variations and diurnal cycle of ozone observations showed that peak ozone concentrations in the summer afternoon decreased ubiquitously across the United States, up to 0.5 ppbv/yr in major non-attainment areas such as Los Angeles, while concentrations at other hours such as the early morning and late afternoon increased slightly. Consistent with the AQS observations, CMAQ simulated a similar decreasing trend of peak ozone concentrations in the afternoon, up to 0.4 ppbv/yr, and increasing ozone trends in the early morning and late afternoon. While a monotonic decreasing trend (up to 0.5 ppbv/yr) in the odd oxygen (Ox = O3 + NO2) concentrations are simulated by CMAQ at all daytime hours. This result suggests that the increased ozone in the early morning and late afternoon was likely caused by reduced NO-O3 titration driven by continuous anthropogenic NOx emission reductions in the past decades. Furthermore, the CMAQ simulations revealed a shift in chemical regimes of ozone photochemical production. From 1990 to 2015, surface ozone production in some metropolitan areas, such as Baltimore, has transited from VOC-sensitive environment (> 50 % probability) to NOx-sensitive regime. Our results demonstrated that the long-term CWRF-CMAQ simulations can provide detailed information of the ozone chemistry evolution under a changing climate, and may partially explain the U.S. ozone pollution responses to regional and national regulations.

scholarly journals Intraspecific Latitudinal Variation in Nest Orientation Among Ground-Nesting Passerines: A Study Using Published Data

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 441-446 ◽  
Author(s):  
Niall H.K. Burton
Keyword(s):  
Early Morning ◽  
Published Data ◽  
Nest Entrance ◽  
Clear Trend ◽  
European Species ◽  
Statistical Comparison ◽  
Species Comparisons ◽  
Nest Microclimate ◽  
The Relationship ◽  
Ground Nesting

Abstract The relationship between nest entrance orientation and latitude among ground-nesting passerines was reviewed using published information. Data were collated for seven North American and European species. Pooling within-species comparisons, there was a clear trend from a preference for north-facing nests at lower latitudes to eastward- or southward-facing nests farther north. Orientations differed significantly in eight of 12 cases for which statistical comparison was possible, means differing in the expected direction in six of these cases. These results highlight how the influence of solar radiation on nest microclimate typically delineates preferred nest orientation in these species, i.e., at lower latitudes, the need for shade results in a preference for northward orientations; at mid latitudes, eastward orientations predominate, reflecting a probable balance between the benefits of warmth in the early morning and shade in the afternoon; while at high latitudes, nests may be oriented southward to gain warmth throughout the day.

scholarly journals Influence of chronotype on daily mood fluctuations: pilot study in patients with depression

BJPsych Open ◽  
2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Konstantin F. Brückmann ◽  
Jürgen Hennig ◽  
Matthias J. Müller ◽  
Stanislava Fockenberg ◽  
Anne-Marthe Schmidt ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Pilot Study ◽  
Negative Affect ◽  
Clinical Setting ◽  
Early Morning ◽  
Healthy Controls ◽  
Patient Subgroup ◽  
Depression Risk ◽  
Gender And Age ◽  
The Relationship

Summary Depression risk is associated with a late chronotype pattern often described as an ‘evening chronotype’. Fluctuations in mood over consecutive days have not yet been measured according to chronotype in in-patients with depression. A total of 30 in-patients with depression and 32 healthy controls matched for gender and age completed a chronotype questionnaire and twice-daily ratings on mood for 10 consecutive days (registered in the German Clinical Trials Register: DRKS00010215). The in-patients had Saturdays and Sundays as hospital-leave days. The relationship between chronotype and daily mood was mediated by the weekday–weekend schedule with higher levels of negative affect in the evening-chronotype patient subgroup at weekends. Results are discussed with respect to a probably advantageous standardised clinical setting with early morning routines, especially for patients with evening chronotypes.

scholarly journals Cardiorespiratory Functioning in Youth with Persistent Post-Concussion Symptoms: A Pilot Study

2021 ◽  
Vol 10 (4) ◽  
pp. 561
Author(s):  
Aliyah Snyder ◽  
Christopher Sheridan ◽  
Alexandra Tanner ◽  
Kevin Bickart ◽  
Molly Sullan ◽  
...  
Keyword(s):  
Processing Speed ◽  
Mean Value ◽  
Exhaled Breath ◽  
Post Injury ◽  
The Past ◽  
Neurobehavioral Outcomes ◽  
End Tidal ◽  
Relationship Of ◽  
The Relationship ◽  
End Tidal Co2

Dysregulation of the autonomic nervous system (ANS) may play an important role in the development and maintenance of persistent post-concussive symptoms (PPCS). Post-injury breathing dysfunction, which is influenced by the ANS, has not been well-studied in youth. This study evaluated cardiorespiratory functioning at baseline in youth patients with PPCS and examined the relationship of cardiorespiratory variables with neurobehavioral outcomes. Participants were between the ages of 13–25 in two groups: (1) Patients with PPCS (concussion within the past 2–16 months; n = 13) and (2) non-injured controls (n = 12). Capnometry was used to obtain end-tidal CO2 (EtCO2), oxygen saturation (SaO2), respiration rate (RR), and pulse rate (PR) at seated rest. PPCS participants exhibited a reduced mean value of EtCO2 in exhaled breath (M = 36.3 mmHg, SD = 2.86 mmHg) and an altered inter-correlation between EtCO2 and RR compared to controls. Neurobehavioral outcomes including depression, severity of self-reported concussion symptoms, cognitive catastrophizing, and psychomotor processing speed were correlated with cardiorespiratory variables when the groups were combined. Overall, results from this study suggest that breathing dynamics may be altered in youth with PPCS and that cardiorespiratory outcomes could be related to a dimension of neurobehavioral outcomes associated with poorer recovery from concussion.

scholarly journals AB0101 THE IMPACT OF TIME SPAN TO ACHIEVE BOOLEAN REMISSION FOR MAINTAINING DISEASE ACTIVITY AFTER ACQUISITION IN RHEUMATOID ARTHRITIS PATIENT

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1079.1-1079
Author(s):  
I. Yoshii
Keyword(s):  
Rheumatoid Arthritis ◽  
Disease Activity ◽  
Disease Duration ◽  
Remission Rate ◽  
Mean Value ◽  
Time Span ◽  
Mean Values ◽  
The Mean ◽  
The Relationship

Background:Boolean remission criteria is one most popular and stringent criteria in treating patient with rheumatoid arthritis (RA), because it may guarantees a stable clinical course after attaining remission.Objectives:Impact of time span from initiation to achieving Boolean remission on maintaining disease activity, daily activities, and quality of life after attaining Boolean remission was investigated from daily clinical practice data.Methods:685 patients with RA since August 2010 under the T2T strategy were treated. They were monitored for their TJC, SJC, PGA, EGA, CRP, and disease activity indices such as CDAI, SDAI, DAS28, and Boolean criteria at every visit. HAQ-DI score, pain score using visual analog scale (PS-VAS), and EQ-5D were also monitored, and the quality of life score (QOLS) calculated from EQ-5D was determined at every visit from the time of diagnosis (baseline).Of 685 patients, 465 patients had achieved Boolean remission >1 times, and were consecutively followed up for >3 years. These patients were enrolled in the study. Time span from the first visit to first Boolean remission was calculated. The relationship between the time span and each of background parameters, and the relationship between the time span and each of the mean values of the SDAI score, HAQ score, PS-VAS, SHS, and QOLS at the first Boolean remission and thereafter was evaluated statistically.Patients were subsequently divided into the G ≤ 6 and G > 6 groups based on the achievement of first Boolean remission within two groups: time span G ≤ 6 months and G > 6 months. The two groups were compared with regard to the SDAI score, HAQ score, PS-VAS, SHS, and QOLS at first visit and at the time of first Boolean remission, and the mean values of these parameters after remission were evaluated statistically. Moreover, changes of these parameters and the mean Boolean remission rate after the first remission, and SDAI remission rate at the first Boolean remission to thereafter were compared between the two groups statistically.Results:Out of 465 patients, females comprised 343 (73.7%), and the mean age was 67.8 years (range, from 21–95 years). The mean disease duration at first visit was 6.1 years (range, from 1 months–45 years). The mean follow up length was 88.1 months (range: 36–122 months; median: 85 months) and mean time span from the first visit to the first Boolean remission was 8.1 months. The mean SDAI score, HAQ score, PS-VAS, and the QOLS at first visit were 13.3, 0.467, 33.2, and 0.834, respectively. Among the study parameters, PS-VAS and QOLS were significantly correlated with the time span. For parameters at the first Boolean remission, HAQ-DI score, PS-VAS, and QOLS demonstrated significant correlation with the time span, whereas SDAI, HAQ-DI score, PS-VAS, SHS, and QOLS after the Boolean remission demonstrated significant correlation with the time span.The comparison between the G ≤ 6 and the G > 6 groups revealed that the disease duration, HAQ score, and PS-VAS at baseline in the G > 6 were significantly higher than that in the G ≤ 6 group, and QOLS in the G ≤ 6 group was significantly higher than that in the G > 6 group at baseline. Similarly, the HAQ score and PS-VAS at the first Boolean remission in the G > 6 group were significantly higher than that in the G ≤ 6 group, whereas QOLS in the G ≤ 6 group demonstrated no significant difference compared with that in the G > 6 group.The mean value of the SDAI score after the first Boolean remission in the G > 6 group was significantly higher than that in the G ≤ 6 group. Similarly, the SDAI score, HAQ score, and PS-VAS after the first Boolean remission in the G > 6 group were also significantly higher than those in the G ≤ 6 group, and the mean value of the QOLS in the G ≤ 6 group were significantly higher than that in the G > 6 group. The Boolean remission rate and SDAI remission rate after the first Boolean remission were significantly higher in the G ≤ 6 group than those in the G > 6 group.Conclusion:Attaining Boolean remission ≤ 6 months for RA has significant benefit for more stable disease control, that leads good maintenance of ADL.Disclosure of Interests:None declared

Transverse Young's Moduli and Cell Shapes in Coniferous Early Wood

Holzforschung ◽  
2002 ◽  
Vol 56 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Ugai Watanabe ◽  
Minoru Fujita ◽  
Misato Norimoto
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Bending Moment ◽  
Cell Models ◽  
Young’S Moduli ◽  
Cell Shapes ◽  
The Difference ◽  
Square Cells ◽  
Experimental Values ◽  
The Relationship

Summary The relationship between transverse Young's moduli and cell shapes in coniferous early wood was investigated using cell models constructed by two dimensional power spectrum analysis. The calculated values of tangential Young's modulus qualitatively explained the relationship between experimental values and density as well as the difference in experimental values among species. The calculated values of radial Young's modulus for the species having hexagonal cells agreed well with the experimental values, whereas, for the species having square cells, the calculated values were much larger than the experimental values. This result was ascribed to the fact that the bending moment on the radial cell wall of square cell models was calculated to be small. It is suggested that the asymmetrical shape of real wood cells or the behavior of nodes during ell deformation is an important factor in the mechanism of linear elastic deformation of wood cells.

scholarly journals Osmotic water permeability of human red cells.

1981 ◽  
Vol 77 (5) ◽  
pp. 549-570 ◽  
Author(s):  
T C Terwilliger ◽  
A K Solomon
Keyword(s):  
Systematic Error ◽  
Water Permeability ◽  
Perturbation Technique ◽  
Mean Value ◽  
Red Cells ◽  
Osmotic Water Permeability ◽  
Osmotic Water ◽  
New Perturbation ◽  
The Relationship ◽  
Human Red Cells

The osmotic water permeability of human red cells has been reexamined with a stopped-flow device and a new perturbation technique. Small osmotic gradients are used to minimize the systematic error caused by nonlinearities in the relationship between cell volume and light scattering. Corrections are then made for residual systematic error. Our results show that the hydraulic conductivity, Lp, is essentially independent of the direction of water flow and of osmolality in the range 184-365 mosM. the mean value of Lp obtained obtained was 1.8 +/- 0.1 (SEM) X 10-11 cm3 dyne -1 s-1.

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