scholarly journals Referee report on Makar et al, Forest Fire Aerosol – Weather Feedbacks over Western North America Using a High-Resolution, Fully Coupled, Air-Quality Model

2020 ◽  
Author(s):  
Anonymous
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
North America ◽  
Forest Fire ◽  
Western North America ◽  
Air Quality Model ◽  
Quality Model ◽  
Fully Coupled

scholarly journals Forest Fire Aerosol – Weather Feedbacks over Western North America Using a High-Resolution, Fully Coupled, Air-Quality Model

2020 ◽  
Author(s):  
Paul A. Makar ◽  
Ayodeji Akingunola ◽  
Jack Chen ◽  
Balbir Pabla ◽  
Wanmin Gong ◽  
...  
Keyword(s):  
Air Quality ◽  
Forest Fire ◽  
Lower Troposphere ◽  
Cloud Droplet ◽  
Air Quality Model ◽  
Quality Model ◽  
Fire Plume ◽  
Fire Emissions ◽  
On Line ◽  
Fully Coupled

Abstract. The influence of both anthropogenic and forest fire emissions, and their and subsequent chemical and physical processing, on the accuracy of weather and air-quality forecasts, was studied using a high resolution, fully coupled air-quality model. Simulations were carried out for the period 4 July through 5 August 2019, at 2.5-km horizontal grid cell size, over a 2250 x 3425 km2 domain covering western Canada and USA, prior to the use of the forecast system as part of the FIREX-AQ ensemble forecast. Several large forest fires took place in the Canadian portion of the domain during the study period. A feature of the implementation was the incorporation of a new on-line version of the Canadian Forest Fire Emissions Prediction System (CFFEPSv4.0). This inclusion of thermodynamic forest fire plume-rise calculations directly into the on-line air-quality model allowed us to simulate the interactions between forest fire plume development and weather. Incorporating feedbacks resulted in improvements in most metrics of both air-quality and meteorological model forecast performance, through comparison of no-feedback and feedback simulations with surface, radiosonde, and satellite observations. For the meteorological simulations, these improvements occurred at greater than the 90 % confidence level. Relative to the climatological cloud condensation nuclei and aerosol optical properties used in the no-feedback simulations, the fully coupled model’s aerosol indirect and direct effects were shown to result in feedback loops characterized by increased surface temperatures, decreased lower troposphere temperatures, and increased lower troposphere cloud droplet and raindrop number densities. The aerosol direct and indirect effect reduced oceanic cloud droplet number densities and increased oceanic rain drop number densities, relative to the no-feedback climatological simulation. The aerosol direct and indirect effects were responsible for changes to the aerosol concentrations at greater than the 90 % confidence level throughout the model domain, and to NO2 and O3 concentrations within forest fire plumes. The simulations show that incorporating aerosol direct and indirect effect feedbacks can significantly improve the accuracy of weather and air quality forecasts, and that forest fire plume rise calculations within a fully coupled model changes the predicted fire plume dispersion and emissions, the latter through changing the meteorology driving fire behaviour and growth.

scholarly journals Forest-fire aerosol–weather feedbacks over western North America using a high-resolution, online coupled air-quality model

2021 ◽  
Vol 21 (13) ◽  
pp. 10557-10587
Author(s):  
Paul A. Makar ◽  
Ayodeji Akingunola ◽  
Jack Chen ◽  
Balbir Pabla ◽  
Wanmin Gong ◽  
...  
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Forest Fire ◽  
Forest Fires ◽  
Cloud Droplet ◽  
Plume Rise ◽  
Air Quality Model ◽  
Quality Model ◽  
Fire Plume ◽  
Fire Emissions

Abstract. The influence of both anthropogenic and forest-fire emissions, and their subsequent chemical and physical processing, on the accuracy of weather and air-quality forecasts, was studied using a high-resolution, online coupled air-quality model. Simulations were carried out for the period 4 July through 5 August 2019, at 2.5 km horizontal grid cell size, over a 2250×3425 km2 domain covering western Canada and USA, prior to the use of the forecast system as part of the FIREX-AQ ensemble forecast. Several large forest fires took place in the Canadian portion of the domain during the study period. A feature of the implementation was the incorporation of a new online version of the Canadian Forest Fire Emissions Prediction System (CFFEPSv4.0). This inclusion of thermodynamic forest-fire plume-rise calculations directly into the online air-quality model allowed us to simulate the interactions between forest-fire plume development and weather. Incorporating feedbacks resulted in weather forecast performance that exceeded or matched the no-feedback forecast, at greater than 90 % confidence, at most times and heights in the atmosphere. The feedback forecast outperformed the feedback forecast at 35 out of 48 statistical evaluation scores, for PM2.5, NO2, and O3. Relative to the climatological cloud condensation nuclei (CCN) and aerosol optical properties used in the no-feedback simulations, the online coupled model's aerosol indirect and direct effects were shown to result in feedback loops characterized by decreased surface temperatures in regions affected by forest-fire plumes, decreases in stability within the smoke plume, increases in stability further aloft, and increased lower troposphere cloud droplet and raindrop number densities. The aerosol direct and indirect effect reduced oceanic cloud droplet number densities and increased oceanic raindrop number densities, relative to the no-feedback climatological simulation. The aerosol direct and indirect effects were responsible for changes to the near-surface PM2.5 and NO2 concentrations at greater than the 90 % confidence level near the forest fires, with O3 changes remaining below the 90 % confidence level. The simulations show that incorporating aerosol direct and indirect effect feedbacks can significantly improve the accuracy of weather and air-quality forecasts and that forest-fire plume-rise calculations within an online coupled model change the predicted fire plume dispersion and emissions, the latter through changing the meteorology driving fire intensity and fuel consumption.

scholarly journals Seasonal ozone vertical profiles over North America using the AQMEII group of air quality models: model inter-comparison and stratospheric intrusions

2018 ◽  
Author(s):  
Marina Astitha ◽  
Ioannis Kioutsoukis ◽  
Ghezae Araya Fisseha ◽  
Roberto Bianconi ◽  
Johannes Bieser ◽  
...  
Keyword(s):  
United States ◽  
Air Quality ◽  
North America ◽  
Vertical Profiles ◽  
Lateral Boundary ◽  
Air Quality Model ◽  
Quality Model ◽  
Mixing Ratios ◽  
Lateral Boundary Conditions ◽  
Stratospheric Intrusions

Abstract. This study evaluates simulated vertical ozone profiles produced in the framework of the third phase of the Air Quality Model Evaluation International Initiative (AQMEII3) against ozonesonde observations in North America for the year 2010. Four research groups from the United States (U.S.) and Europe have provided ozone vertical profiles to conduct this analysis. Because some of the modeling systems differ in their meteorological drivers, wind speed and temperature are also included in the analysis. In addition to the seasonal ozone profile evaluation for 2010, we also analyze chemically inert tracers designed to track the influence of lateral boundary conditions on simulated ozone profiles within the modeling domain. Finally, cases of stratospheric ozone intrusions during May–June 2010 are investigated by analyzing ozonesonde measurements and the corresponding model simulations at Intercontinental Chemical Transport Experiment Ozonesonde Network Study (IONS) experiment sites in the western United States. The evaluation of the seasonal ozone profiles reveals that at a majority of the stations, ozone mixing ratios are under-estimated in the 1–6 km range. The seasonal change noted in the errors follows the one seen in the variance of ozone mixing ratios, with the majority of the models exhibiting less variability than the observations. The analysis of chemically inert tracers highlights the importance of lateral boundary conditions up to 250 hPa for the lower tropospheric ozone mixing ratios (0–2 km). Finally, for the stratospheric intrusions, the models are generally able to reproduce the location and timing of most intrusions but underestimate the magnitude of the maximum mixing ratios in the 2–6 km range and overestimate ozone up to the first km possibly due to marine air influences that are not accurately described by the models. The choice of meteorological driver appears to be a greater predictor of model skill in this altitude range than the choice of air quality model.

scholarly journals Exploring the nature of air quality over southwestern Ontario: main findings from the Border Air Quality and Meteorology Study

2013 ◽  
Vol 13 (20) ◽  
pp. 10461-10482 ◽  
Author(s):  
J. R. Brook ◽  
P. A. Makar ◽  
D. M. L. Sills ◽  
K. L. Hayden ◽  
R. McLaren
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Great Lakes ◽  
The United States ◽  
Urban Heat Islands ◽  
Anthropogenic Emissions ◽  
Lake Breeze ◽  
Aerosol Formation ◽  
Air Quality Model ◽  
Quality Model

Abstract. This paper serves as an overview and discusses the main findings from the Border Air Quality and Meteorology Study (BAQS-Met) in southwestern Ontario in 2007. This region is dominated by the Great Lakes, shares borders with the United States and consistently experiences the highest ozone (O3) and fine particulate matter concentrations in Canada. The purpose of BAQS-Met was to improve our understanding of how lake-driven meteorology impacts air quality in the region, and to improve models used for forecasting and policy scenarios. Results show that lake breeze occurrence frequencies and inland penetration distances were significantly greater than realized in the past. Due to their effect on local meteorology, the lakes were found to enhance secondary O3 and aerosol formation such that local anthropogenic emissions have their impact closer to the populated source areas than would otherwise occur in the absence of the lakes. Substantial spatial heterogeneity in O3 was observed with local peaks typically 30 ppb above the regional values. Sulfate and secondary organic aerosol (SOA) enhancements were also linked to local emissions being transported in the lake breeze circulations. This study included the first detailed evaluation of regional applications of a high-resolution (2.5 km grid) air quality model in the Great Lakes region. The model showed that maxima in secondary pollutants occur in areas of convergence, in localized updrafts and in distinct pockets over the lake surfaces. These effects are caused by lake circulations interacting with the synoptic flow, with each other or with circulations induced by urban heat islands. Biogenic and anthropogenic emissions were both shown to play a role in the formation of SOA in the region. Detailed particle measurements and multivariate receptor models reveal that while individual particles are internally mixed, they often exist within more complex external mixtures. This makes it difficult to predict aerosol optical properties and further highlights the challenges facing aerosol modelling. The BAQS-Met study has led to a better understanding of the value of high-resolution (2.5 km) modelling for air quality and meteorological predictions and has led to several model improvements.

Networks of Air Quality Sensors and Their Use for High-resolution Mapping of Urban Air Quality

2020 ◽  
Author(s):  
Philipp Schneider ◽  
Nuria Castell ◽  
Paul Hamer ◽  
Sam-Erik Walker ◽  
Alena Bartonova
Keyword(s):  
Sensor Networks ◽  
Air Quality ◽  
High Resolution ◽  
Air Pollutants ◽  
Low Cost ◽  
Urban Air Quality ◽  
Urban Air ◽  
Sensor Systems ◽  
Air Quality Model ◽  
Quality Model

<p>One of the most promising applications of low-cost sensor systems for air quality is the possibility to deploy them in relatively dense networks and to use this information for mapping urban air quality at unprecedented spatial detail. More and more such dense sensor networks are being set up worldwide, particularly for relatively inexpensive nephelometers that provide PM<sub>2.5</sub> observations with often quite reasonable accuracy. However, air pollutants typically exhibit significant spatial variability in urban areas, so using data from sensor networks alone tends to result in maps with unrealistic spatial patterns, unless the network density is extremely high. One solution is to use the output from an air quality model as an a priori field and as such to use the combined knowledge of both model and sensor network to provide improved maps of urban air quality. Here we present our latest work on combining the observations from low-cost sensor systems with data from urban-scale air quality models, with the goal of providing realistic, high-resolution, and up-to-date maps of urban air quality.</p><p>In previous years we have used a geostatistical approach for mapping air quality (Schneider et al., 2017), exploiting both low-cost sensors and model information. The system has now been upgraded to a data assimilation approach that integrates the observations from a heterogeneous sensor network into an urban-scale air quality model while considering the sensor-specific uncertainties. The approach further ensures that the spatial representativity of each observation is automatically derived as a combination of a model climatology and a function of distance. We demonstrate the methodology using examples from Oslo and other cities in Norway. Initial results indicate that the method is robust and provides realistic spatial patterns of air quality for the main air pollutants that were evaluated, even in areas where only limited observations are available. Conversely, the model output is constrained by the sensor data, thus adding value to both input datasets.</p><p>While several challenging issues remain, modern air quality sensor systems have reached a maturity level at which some of them can provide an intra-sensor consistency and robustness that makes it feasible to use networks of such systems as a data source for mapping urban air quality at high spatial resolution. We present our current approach for mapping urban air quality with the help of low-cost sensor networks and demonstrate both that it can provide realistic results and that the uncertainty of each individual sensor system can be taken into account in a robust and meaningful manner.</p><p> </p><p>Schneider, P., Castell N., Vogt M., Dauge F. R., Lahoz W. A., and Bartonova A., 2017. Mapping urban air quality in near real-time using observations from low-cost sensors and model information. Environment international, 106, 234-247.</p>

scholarly journals Seasonal ozone vertical profiles over North America using the AQMEII3 group of air quality models: model inter-comparison and stratospheric intrusions

2018 ◽  
Vol 18 (19) ◽  
pp. 13925-13945 ◽  
Author(s):  
Marina Astitha ◽  
Ioannis Kioutsioukis ◽  
Ghezae Araya Fisseha ◽  
Roberto Bianconi ◽  
Johannes Bieser ◽  
...  
Keyword(s):  
United States ◽  
Air Quality ◽  
North America ◽  
Vertical Profiles ◽  
Lateral Boundary ◽  
Air Quality Model ◽  
Quality Model ◽  
Mixing Ratios ◽  
Lateral Boundary Conditions ◽  
Stratospheric Intrusions

Abstract. This study evaluates simulated vertical ozone profiles produced in the framework of the third phase of the Air Quality Model Evaluation International Initiative (AQMEII3) against ozonesonde observations in North America for the year 2010. Four research groups from the United States (US) and Europe have provided modeled ozone vertical profiles to conduct this analysis. Because some of the modeling systems differ in their meteorological drivers, wind speed and temperature are also included in the analysis. In addition to the seasonal ozone profile evaluation for 2010, we also analyze chemically inert tracers designed to track the influence of lateral boundary conditions on simulated ozone profiles within the modeling domain. Finally, cases of stratospheric ozone intrusions during May–June 2010 are investigated by analyzing ozonesonde measurements and the corresponding model simulations at Intercontinental Chemical Transport Experiment Ozonesonde Network Study (IONS) experiment sites in the western United States. The evaluation of the seasonal ozone profiles reveals that, at a majority of the stations, ozone mixing ratios are underestimated in the 1–6 km range. The seasonal change noted in the errors follows the one seen in the variance of ozone mixing ratios, with the majority of the models exhibiting less variability than the observations. The analysis of chemically inert tracers highlights the importance of lateral boundary conditions up to 250 hPa for the lower-tropospheric ozone mixing ratios (0–2 km). Finally, for the stratospheric intrusions, the models are generally able to reproduce the location and timing of most intrusions but underestimate the magnitude of the maximum mixing ratios in the 2–6 km range and overestimate ozone up to the first kilometer possibly due to marine air influences that are not accurately described by the models. The choice of meteorological driver appears to be a greater predictor of model skill in this altitude range than the choice of air quality model.

Modelling aerosol–cloud–meteorology interaction: A case study with a fully coupled air quality model (GEM-MACH)

2015 ◽  
Vol 115 ◽  
pp. 695-715 ◽  
Author(s):  
W. Gong ◽  
P.A. Makar ◽  
J. Zhang ◽  
J. Milbrandt ◽  
S. Gravel ◽  
...  
Keyword(s):  
Air Quality ◽  
Air Quality Model ◽  
Quality Model ◽  
Aerosol Cloud ◽  
Fully Coupled

scholarly journals The effect of climate change and emission scenarios on ozone concentrations over Belgium: a high resolution model study for policy support

2014 ◽  
Vol 14 (2) ◽  
pp. 1761-1790
Author(s):  
D. Lauwaet ◽  
P. Viaene ◽  
E. Brisson ◽  
T. van Noije ◽  
A. Strunk ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Quality ◽  
High Resolution ◽  
Emission Scenario ◽  
Emission Scenarios ◽  
Air Quality Model ◽  
Quality Model ◽  
Near Surface ◽  
Near Future ◽  
Surface O3

Abstract. Belgium is one of the areas within Europe experiencing the highest levels of air pollution. To provide insight to policy makers about expected changes in the air quality towards the near future (2026–2035), a high resolution (3 km) modelling experiment is set up. The regional air quality model AURORA (Air quality modelling in Urban Regions using an Optimal Resolution Approach), driven by output from a regional climate model, is used to simulate several 10-yr time slices to investigate the impact of climatic changes and different emission scenarios on near-surface O3 concentrations, one of the key indices for air quality. Model evaluation against measurements from 34 observation stations shows that the AURORA model is capable of reproducing 10-yr mean concentrations, daily cycles and spatial patterns. The results for the RCP4.5 emission scenario indicate that the mean surface O3 concentrations are expected to increase significantly in the near future due to less O3 titration by reduced NOx emissions. Applying an alternative emission scenario for Europe is found to have only a minor impact on the overall concentrations, which are dominated by the background changes. Climate change alone has a much smaller effect on the near-surface O3 concentrations over Belgium than the projected emission changes. The very high horizontal resolution that is used in this study results in much improved spatial correlations and simulated peak concentrations compared to a standard 25 km simulation. This allows to investigate the number of peak episodes during summer, which are found to be reduced with 25% by the emission reductions in RCP4.5.

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