scholarly journals Sensitivity of <i>CHIMERE</i> to changes in model resolution and chemistry over the northwestern Iberian Peninsula

2019 ◽  
Author(s):  
Swen Brands ◽  
Guillermo Fernández-García ◽  
Marcos Tesouro Montecelo ◽  
Nuria Gallego Fernández ◽  
Anthony David Saunders Estévez ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Iberian Peninsula ◽  
Emission Inventory ◽  
Large Fraction ◽  
Surface Ozone ◽  
Forecasting Model ◽  
Daily Maximum ◽  
Vertical Resolution ◽  
Study Region ◽  
Northwestern Iberian Peninsula

Abstract. Here, the capability of the chemical weather forecasting model CHIMERE (version 2017r4) to reproduce summertime surface ozone, particulate matter and nitrogen dioxide concentrations in complex terrain is investigated. The study area is the northwestern Iberian Peninsula, where both coastal and mountain climates can be found in direct vicinity and a large fraction of the land area is covered by forests. Fed by lateral boundary conditions from the ECMWF Composition Integrated Forecast System, meteorological data from the Weather Research and Forecasting Model (WRF) and the HTAP v2.2 emission inventory, CHIMERE's performance compared to observations is tested with a range of sensitivity experiments, exploring the role of horizontal and vertical resolution and the effects of applying distinct chemistry mechanisms. Using a high horizontal and vertical resolution yields the most balanced verification results. If both the daily maximum and minimum values are important for the given application, then the full Melchior mechanism should be used. If, however, the daily maxima are considered more important than the minima, SAPRC should be used instead. In any case, model performance for nitrogen dioxide is clearly not satisfactory for our study region, probably indicating deficiencies in the emission inventory.

scholarly journals An exploratory performance assessment of the CHIMERE model (version 2017r4) for the northwestern Iberian Peninsula and the summer season

2020 ◽  
Vol 13 (9) ◽  
pp. 3947-3973
Author(s):  
Swen Brands ◽  
Guillermo Fernández-García ◽  
Marta García Vivanco ◽  
Marcos Tesouro Montecelo ◽  
Nuria Gallego Fernández ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Horizontal Resolution ◽  
Chemical Mechanism ◽  
Forecasting Model ◽  
Anthropogenic Emissions ◽  
Vertical Resolution ◽  
Top Down ◽  
Study Region ◽  
General Terms ◽  
Northwestern Iberian Peninsula

Abstract. Here, the capability of the chemical weather forecasting model CHIMERE (version 2017r4) to reproduce surface ozone, particulate matter and nitrogen dioxide concentrations in complex terrain is investigated for the period from 21 June to 21 August 2018. The study area is the northwestern Iberian Peninsula, where both coastal and mountain climates can be found in direct vicinity and a large fraction of the land area is covered by forests. Driven by lateral boundary conditions from the European Centre for Medium-Range Weather Forecasts (ECMWF) Composition Integrated Forecast System, anthropogenic emissions from two commonly used top-down inventories and meteorological data from the Weather Research and Forecasting Model, CHIMERE's performance with respect to observations is tested with a range of sensitivity experiments. We assess the effects of (1) an increase in horizontal resolution, (2) an increase in vertical resolution, (3) the use of distinct model chemistries, and (4) the use of distinct anthropogenic emissions inventories, downscaling techniques and land use databases. In comparison with the older HTAP emission inventory downscaled with basic options, the updated and sophistically downscaled EMEP inventory only leads to partial model improvements, and so does the computationally costly horizontal resolution increase. Model performance changes caused by the choice of distinct chemical mechanisms are not systematic either and rather depend on the considered anthropogenic emission configuration and pollutant. Although the results are thus heterogeneous in general terms, the model's response to a vertical resolution increase confined to the lower to middle troposphere is homogeneous in the sense of improving virtually all verification aspects. For our study region and the two aforementioned top-down emission inventories, we conclude that it is not necessary to run CHIMERE on a horizontal mesh much finer than the native grid of these inventories. A relatively coarse horizontal mesh combined with 20 model layers between 999 and 500 hPa is sufficient to yield balanced results. The chemical mechanism should be chosen as a function of the intended application.

scholarly journals An exploratory performance assessment of the <i>CHIMERE</i> model (version 2017r4) for the northwestern Iberian Peninsula and the summer season

2020 ◽  
Author(s):  
Swen Brands ◽  
Guillermo Fernández-García ◽  
Marta García-Vivanco ◽  
Marcos Tesouro Montecelo ◽  
Nuria Gallego Fernández ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Surface Ozone ◽  
Horizontal Resolution ◽  
Chemical Mechanism ◽  
Forecasting Model ◽  
Anthropogenic Emissions ◽  
Vertical Resolution ◽  
Top Down ◽  
General Terms ◽  
Northwestern Iberian Peninsula

Abstract. Here, the capability of the chemical weather forecasting model CHIMERE (version 2017r4) to reproduce surface ozone, particulate matter and nitrogen dioxide concentrations in complex terrain is investigated for the period from June 21 to August 21, 2018. The study area is the northwestern Iberian Peninsula, where both coastal and mountain climates can be found in direct vicinity and a large fraction of the land area is covered by forests. Driven by lateral boundary conditions from the ECMWF Composition Integrated Forecast System, anthropogenic emissions from two commonly used top-down inventories and meteorological data from the Weather Research and Forecasting Model, CHIMERE's performance with respect to observations is tested with a range of sensitivity experiments. We assess the effects of 1) an increase in horizontal resolution, 2) an increase in vertical resolution, 3) the use of distinct model chemistries and 4) the use of distinct anthropogenic emissions inventories, downscaling techniques and landuse databases. In comparsion with the older HTAP emission inventory downscaled with basic options, the updated and sophistically downscaled EMEP inventory only leads to partial model improvements and so does the computationally costly horizontal resolution increase. Model performance changes caused by the choice of distinct chemical mechanisms are not systematic either and rather depend on the considered anthropgenic emission configuration and pollutant. Albeit the results are thus heterogeneous in general terms, the model's response to a vertical resolution increase confined to the lower to middle troposphere is homogeneous in the sense of improving virtually all verification aspects. We conclude that, as long as the aforementioned top-down emission inventories are used, it is generally not necessary to use a horizontal model mesh much finer than the native grid of the inventories. A relatively coarse horizontal mesh combined with 20 model layers between 999 and 500 hPa is sufficient to yield balanced results. The chemical mechanism should be chosen as a function of the intended application.

scholarly journals Local and synoptic meteorological influences on daily variability in summertime surface ozone in eastern China

2020 ◽  
Vol 20 (1) ◽  
pp. 203-222 ◽  
Author(s):  
Han Han ◽  
Jane Liu ◽  
Lei Shu ◽  
Tijian Wang ◽  
Huiling Yuan
Keyword(s):  
Surface Ozone ◽  
Eastern China ◽  
River Delta ◽  
Daily Maximum ◽  
Ozone Pollution ◽  
Study Region ◽  
Synoptic Weather ◽  
Daily Variability ◽  
Influential Variable ◽  
The Impact

Abstract. Ozone pollution in China is influenced by meteorological processes on multiple scales. Using regression analysis and weather classification, we statistically assess the impacts of local and synoptic meteorology on daily variability in surface ozone in eastern China in summer during 2013–2018. In this period, summertime surface ozone in eastern China (20–42∘ N, 110–130∘ E) is among the highest in the world, with regional means of 73.1 and 114.7 µg m−3, respectively, in daily mean and daily maximum 8 h average. Through developing a multiple linear regression (MLR) model driven by local and synoptic weather factors, we establish a quantitative linkage between the daily mean ozone concentrations and meteorology in the study region. The meteorology described by the MLR can explain ∼43 % of the daily variability in summertime surface ozone across eastern China. Among local meteorological factors, relative humidity is the most influential variable in the center and south of eastern China, including the Yangtze River Delta and the Pearl River Delta regions, while temperature is the most influential variable in the north, covering the Beijing–Tianjin–Hebei region. To further examine the synoptic influence of weather conditions explicitly, six predominant synoptic weather patterns (SWPs) over eastern China in summer are objectively identified using the self-organizing map clustering technique. The six SWPs are formed under the integral influence of the East Asian summer monsoon, the western Pacific subtropical high, the Meiyu front, and the typhoon activities. On average, regionally, two SWPs bring about positive ozone anomalies (1.1 µg m−3 or 1.7 % and 2.7 µg m−3 or 4.6 %), when eastern China is under a weak cyclone system or under the prevailing southerly wind. The impact of SWPs on the daily variability in surface ozone varies largely within eastern China. The maximum impact can reach ±8 µg m−3 or ±16 % of the daily mean in some areas. A combination of the regression and the clustering approaches suggests a strong performance of the MLR in predicting the sensitivity of surface ozone in eastern China to the variation of synoptic weather. Our assessment highlights the importance of meteorology in modulating ozone pollution over China.

scholarly journals The Role of Recent (1985–2014) Patterns of Land Abandonment and Environmental Factors in the Establishment and Growth of Secondary Forests in the Iberian Peninsula

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 817
Author(s):  
Marina Palmero-Iniesta ◽  
Josep Maria Espelta ◽  
Mario Padial-Iglesias ◽  
Òscar Gonzàlez-Guerrero ◽  
Lluís Pesquer ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Iberian Peninsula ◽  
Forest Cover ◽  
Secondary Forest ◽  
Forest Growth ◽  
Deciduous Forests ◽  
Secondary Forests ◽  
Study Region ◽  
Leaf Habit ◽  
Forest Establishment

Farmland abandonment has been a widespread land-use change in the Iberian Peninsula since the second half of the 20th century, leading to the establishment of secondary forests across the region. In this study, we aimed to address changes in the recent (1985–2014) emergence patterns of these forests and examine how environmental factors affected their growth by considering differences in leaf-habit types. We used a combination of Landsat-derived land-cover maps and aboveground biomass (AGB) maps from the European Space Agency to assess the secondary forest establishment and growth, respectively, in the study region. We also obtained a set of topographic, climatic and landscape variables from diverse GIS layers and used them for determining changes over time in the environmental drivers of forest establishment and AGB using general linear models. The results highlight that secondary forest cover was still increasing in the Iberian Peninsula at a rate above the European average. Yet, they also indicate a directional change in the emergence of secondary forests towards lower and less steep regions with higher water availability (mean rainfall and SPEI) and less forest cover but are subjected to greater drought events. In addition, these environmental factors differentially affect the growth of forests with different leaf-habit types: i.e., needleleaf secondary forests being less favoured by high temperature and precipitation, and broadleaf deciduous forests being most negatively affected by drought. Finally, these spatial patterns of forest emergence and the contrasting responses of forest leaf-habits to environmental factors explained the major development of broadleaf evergreen compared to broadleaf deciduous forests and, especially, needleleaf secondary forests. These results will improve the knowledge of forest dynamics that have occurred in the Iberian Peninsula in recent decades and provide an essential tool for understanding the potential effects of climate warming on secondary forest growth.

Temporal patterns and trends of surface ozone concentrations over Portugal

2021 ◽  
Author(s):  
Carla Gama ◽  
Alexandra Monteiro ◽  
Myriam Lopes ◽  
Ana Isabel Miranda
Keyword(s):  
Air Quality ◽  
Iberian Peninsula ◽  
Human Health ◽  
Temporal Variability ◽  
Urban Areas ◽  
Surface Ozone ◽  
Quality Data ◽  
Ozone Concentrations ◽  
Long Term Study

&lt;p&gt;Tropospheric ozone (O&lt;sub&gt;3&lt;/sub&gt;) is a critical pollutant over the Mediterranean countries, including Portugal, due to systematic exceedances to the thresholds for the protection of human health. Due to the location of Portugal, on the Atlantic coast at the south-west point of Europe, the observed O&lt;sub&gt;3&lt;/sub&gt; concentrations are very much influenced not only by local and regional production but also by northern mid-latitudes background concentrations. Ozone trends in the Iberian Peninsula were previously analysed by Monteiro et al. (2012), based on 10-years of O&lt;sub&gt;3&lt;/sub&gt; observations. Nevertheless, only two of the eleven background monitoring stations analysed in that study are located in Portugal and these two stations are located in Porto and Lisbon urban areas. Although during pollution events O&lt;sub&gt;3&lt;/sub&gt; levels in urban areas may be high enough to affect human health, the highest concentrations are found in rural locations downwind from the urban and industrialized areas, rather than in cities. This happens because close to the sources (e.g., in urban areas) freshly emitted NO locally scavenges O&lt;sub&gt;3&lt;/sub&gt;. A long-term study of the spatial and temporal variability and trends of the ozone concentrations over Portugal is missing, aiming to answer the following questions:&lt;/p&gt;&lt;p&gt;-&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; What is the temporal variability of ozone concentrations?&lt;/p&gt;&lt;p&gt;-&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; Which trends can we find in observations?&lt;/p&gt;&lt;p&gt;-&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; How were the ozone spring maxima concentrations affected by the COVID-19 lockdown during spring 2020?&lt;/p&gt;&lt;p&gt;In this presentation, these questions will be answered based on the statistical analysis of O&lt;sub&gt;3&lt;/sub&gt; concentrations recorded within the national air quality monitoring network between 2005 and 2020 (16 years). The variability of the surface ozone concentrations over Portugal, on the timescales from diurnal to annual, will be presented and discussed, taking into account the physical and chemical processes that control that variability. Using the TheilSen function from the OpenAir package for R (Carslaw and Ropkins 2012), which quantifies monotonic trends and calculates the associated p-value through bootstrap simulations, O&lt;sub&gt;3&lt;/sub&gt; concentration long-term trends will be estimated for the different regions and environments (e.g., rural, urban).&amp;#160; Moreover, taking advantage of the unique situation provided by the COVID-19 lockdown during spring 2020, when the government imposed mandatory confinement and citizens movement restriction, leading to a reduction in traffic-related atmospheric emissions, the role of these emissions on ozone levels during the spring period will be studied and presented.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Carslaw and Ropkins, 2012. Openair&amp;#8212;an R package for air quality data analysis. Environ. Model. Softw. 27-28,52-61. https://doi.org/10.1016/j.envsoft.2011.09.008&lt;/p&gt;&lt;p&gt;Monteiro et al., 2012. Trends in ozone concentrations in the Iberian Peninsula by quantile regression and clustering. Atmos. Environ. 56, 184-193. https://doi.org/10.1016/j.atmosenv.2012.03.069&lt;/p&gt;

Investigating the occurrence, likelihood and regional variability of extreme ozone pollution episodes across the UK

2021 ◽  
Author(s):  
Lily Gouldsbrough ◽  
Ryan Hossaini ◽  
Emma Eastoe ◽  
Paul J. Young
Keyword(s):  
Surface Ozone ◽  
Extreme Value Analysis ◽  
Daily Maximum ◽  
Monitoring Site ◽  
Ozone Pollution ◽  
Threshold Method ◽  
Regional Variability ◽  
Value Analysis ◽  
The Uk ◽  
Pollution Episodes

&lt;p&gt;Warm summer temperatures provide ideal conditions for the occurrence of extreme ground level ozone pollution episodes. Given the well-established negative impacts of ozone on human and plant health, understanding and attributing these extreme events is of importance to the scientific and wider community, particularly as heatwaves may become more frequent due to climate change. Extreme Value Analysis provides a powerful and flexible framework in which to statistically model unusually large observed values of ozone extracted from historical data. Here, a temperature dependent Peaks-Over-Threshold method based upon the Generalised Pareto Distribution is used to carry out a regional comparison of extreme ozone pollution episodes within the UK. Our analysis uses surface ozone observations from the UK&amp;#8217;s extensive Automatic Urban and Rural Network. The statistical model was used to quantify the frequency and magnitude of extreme ozone events, including a probabilistic assessment of exceeding UK public health thresholds, conditional on temperature. Return levels are provided for each monitoring site demonstrating the expected future projections of extreme ozone pollution events across the UK. We find that across UK rural background sites, return periods for a daily maximum 8-hr ozone level of 100 ug/m3 (a 'moderate' level of air pollution in the UK's Air Quality Index) range from 32-147 days, based on analysis of the data in the decade 2010-2019. Similarly, for urban background sites the range is 36-869 days. An analysis of the spatio temporal variability in UK ozone extremes, along with their temperature dependence, will be presented.&lt;/p&gt;

scholarly journals Ozone and NO<sub>x</sub> chemistry in the eastern US: evaluation of CMAQ/CB05 with satellite (OMI) data

2015 ◽  
Vol 15 (4) ◽  
pp. 4427-4461 ◽  
Author(s):  
T. P. Canty ◽  
L. Hembeck ◽  
T. P. Vinciguerra ◽  
D. C. Anderson ◽  
D. L. Goldberg ◽  
...  
Keyword(s):  
Air Quality ◽  
Surface Ozone ◽  
Quality Standards ◽  
Ambient Air ◽  
Daily Maximum ◽  
Air Quality Model ◽  
Ozone Monitoring Instrument ◽  
Air Quality Standards ◽  
The Us ◽  
Us Northeast

Abstract. Regulatory air quality models, such as the Community Multiscale Air Quality model (CMAQ), are used by federal and state agencies to guide policy decisions that determine how to best achieve adherence with National Ambient Air Quality Standards for surface ozone. We use observations of ozone and its important precursor NO2 to test the representation of the photochemistry and emission of ozone precursors within CMAQ. Observations of tropospheric column NO2 from the Ozone Monitoring Instrument (OMI), retrieved by two independent groups, show that the model overestimates urban NO2 and underestimates rural NO2 under all conditions examined for July and August 2011 in the US Northeast. The overestimate of the urban to rural ratio of tropospheric column NO2 for this baseline run of CMAQ (CB05 mechanism, mobile NOx emissions from the National Emissions Inventory; isoprene emissions from MEGAN v2.04) suggests this model may under estimate the importance of interstate transport of NOx. This CMAQ simulation leads to a considerable overestimate of the 2 month average of 8 h daily maximum surface ozone in the US Northeast, as well as an overestimate of 8 h ozone at AQS sites during days when the state of Maryland experienced NAAQS exceedances. We have implemented three changes within CMAQ motivated by OMI NO2 as well as aircraft observations obtained in July 2011 during the NASA DISCOVER-AQ campaign: (a) the modeled lifetime of organic nitrates within CB05 has been reduced by a factor of 10, (b) emissions of NOx from mobile sources has been reduced by a factor of 2, and (c) isoprene emissions have been reduced by using MEGAN v2.10 rather than v2.04. Compared to the baseline simulation, the CMAQ run using all three of these changes leads to a considerably better simulation of the ratio of urban to rural column NO2, better agreement with the 2 month average of daily 8 h maximum ozone in the US Northeast, fewer number of false positives of an ozone exceedance throughout the domain, as well as an unbiased simulation of surface ozone at ground based AQS sites in Maryland that experienced an ozone exceedance during July and August 2007. These modifications to CMAQ may provide a framework for use in studies focused on achieving future adherence to specific air quality standards for surface ozone by reducing emission of NOx from various anthropogenic sectors.

scholarly journals Spatio-temporal of surface ozone (O3) variations at urban and suburban sites in Sarawak region of Malaysia

2021 ◽  
Vol 880 (1) ◽  
pp. 012004
Author(s):  
H Mahidin ◽  
M T Latif ◽  
A Hamdan ◽  
J Salleh ◽  
D Dominick ◽  
...  
Keyword(s):  
Air Quality ◽  
Surface Ozone ◽  
Ambient Air ◽  
Quality Standard ◽  
Transportation Systems ◽  
Pollutant Emissions ◽  
Daily Maximum ◽  
Spatio Temporal ◽  
Ambient Air Quality Standard ◽  
The Relationship

Abstract Sarawak Region of Malaysia is currently experiencing a high demand for capital needs such as transformation forest to plantations, economic development, and improving transportation systems. Those land cover changes will increase primary pollutant emissions and trigger surface O3 formation. Surface O3 is a secondary pollutant and a significant greenhouse gas contributing to climate change and declining air quality. In this study, variations in surface O3 concentrations at urban and suburban sites in Sarawak were explored using the Malaysian Department of Environment data spanning a two-year cycle (2018-2019). The primary aim of this study is to ascertain the variation of surface O3 concentrations reported at four monitoring stations in Sarawak, namely Kuching (SQ1) (Urban), Sibu (SQ2) (Suburban), Bintulu (SQ3) (Suburban), and Miri (SQ4) (Suburban). The study also analysed the relationship between O3 distribution and nitrogen oxides (NO and NO2). The findings showed that O3 concentrations observed in the region during the study period were lower than the maximum permissible value of 100 ppbv suggested by the Malaysian Ambient Air Quality Standard (2020). SQ4 (Miri) at suburban sites recorded the highest average surface O3 concentrations with an hourly average and daily maximum O3 concentration of 15.7 and 89.5 ppbv, respectively. Temperatures, UV exposure, and wind speed all impact the concentration of surface O3 in Sarawak. In all stations, concentrations of O3 were inversely linked with NO, NO2, and relative humidity (RH). This research will assist the relevant agency in forecast, monitor, and mitigate the level of O3 in the ambient environment, especially in the Sarawak Region.

The Temperature Component of the Common-Sense Index in Northwestern Iberian Peninsula

2001 ◽  
pp. 143-151 ◽  
Author(s):  
Luis Gimeno ◽  
Juan Antonio Añel ◽  
Higinio González ◽  
Pedro Ribera ◽  
Ricardo García ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Common Sense ◽  
Temperature Component ◽  
The Common ◽  
Northwestern Iberian Peninsula
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