Simulating smoke transport from wildland fires with a regional-scale air quality model: Sensitivity to spatiotemporal allocation of fire emissions

Abstract. Through the comparison of several regional-scale chemistry transport modelling systems that simulate meteorology and air quality over the European and American continents, this study aims at i) apportioning the error to the responsible processes using time-scale analysis, ii) helping to detect causes of models error, and iii) identifying the processes and scales most urgently requiring dedicated investigations. The analysis is conducted within the framework of the third phase of the Air Quality Model Evaluation International Initiative (AQMEII) and tackles model performance gauging through measurement-to-model comparison, error decomposition and time series analysis of the models biases for several fields (ozone, CO, SO2, NO, NO2, PM10, PM2.5, wind speed, and temperature). The operational metrics (magnitude of the error, sign of the bias, associativity) provide an overall sense of model strengths and deficiencies, while apportioning the error to its constituent parts (bias, variance and covariance) can help to assess the nature and quality of the error. Each of the error components is analysed independently and apportioned to specific processes based on the corresponding timescale (long scale, synoptic, diurnal, and intra-day) using the error apportionment technique devised in the former phases of AQMEII. The application of the error apportionment method to the AQMEII Phase 3 simulations provides several key insights. In addition to reaffirming the strong impact of model inputs (emissions and boundary conditions) and poor representation of the stable boundary layer on model bias, results also highlighted the high inter-dependencies among meteorological and chemical variables, as well as among their errors. This indicates that the evaluation of air quality model performance for individual pollutants needs to be supported by complementary analysis of meteorological fields and chemical precursors to provide results that are more insightful from a model development perspective. The error embedded in the emissions is dominant for primary species (CO, PM, NO) and largely outweighs the error from any other source. The uncertainty in meteorological fields is most relevant to ozone. Some further aspects emerged whose interpretation requires additional consideration, such as, among others, the uniformity of the synoptic error being region and model-independent, observed for several pollutants; the source of unexplained variance for the diurnal component; and the type of error caused by deposition and at which scale.

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Evaluation of gas-particle partitioning in a regional air quality model for organic pollutants

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-15327-2016 ◽

2016 ◽

Vol 16 (23) ◽

pp. 15327-15345 ◽

Cited By ~ 8

Author(s):

Christos I. Efstathiou ◽

Jana Matejovičová ◽

Johannes Bieser ◽

Gerhard Lammel

Keyword(s):

Air Quality ◽

Organic Pollutants ◽

Heterogeneous Reaction ◽

Regional Scale ◽

Fate And Transport ◽

Heterogeneous Reactions ◽

Absorption Model ◽

Air Quality Model ◽

Adsorption Model ◽

Quality Model

Abstract. Persistent organic pollutants (POPs) are of considerable concern due to their well-recognized toxicity and their potential to bioaccumulate and engage in long-range transport. These compounds are semi-volatile and, therefore, create a partition between vapour and condensed phases in the atmosphere, while both phases can undergo chemical reactions. This work describes the extension of the Community Multiscale Air Quality (CMAQ) modelling system to POPs with a focus on establishing an adaptable framework that accounts for gaseous chemistry, heterogeneous reactions, and gas-particle partitioning (GPP). The effect of GPP is assessed by implementing a set of independent parameterizations within the CMAQ aerosol module, including the Junge–Pankow (JP) adsorption model, the Harner–Bidleman (HB) organic matter (OM) absorption model, and the dual Dachs–Eisenreich (DE) black carbon (BC) adsorption and OM absorption model. Use of these descriptors in a modified version of CMAQ for benzo[a]pyrene (BaP) results in different fate and transport patterns as demonstrated by regional-scale simulations performed for a European domain during 2006. The dual DE model predicted 24.1 % higher average domain concentrations compared to the HB model, which was in turn predicting 119.2 % higher levels compared to the baseline JP model. Evaluation with measurements from the European Monitoring and Evaluation Programme (EMEP) reveals the capability of the more extensive DE model to better capture the ambient levels and seasonal behaviour of BaP. It is found that the heterogeneous reaction of BaP with O3 may decrease its atmospheric lifetime by 25.2 % (domain and annual average) and near-ground concentrations by 18.8 %. Marginally better model performance was found for one of the six EMEP stations (Košetice) when heterogeneous BaP reactivity was included. Further analysis shows that, for the rest of the EMEP locations, the model continues to underestimate BaP levels, an observation that can be attributed to low emission estimates for such remote areas. These findings suggest that, when modelling the fate and transport of organic pollutants on large spatio-temporal scales, the selection and parameterization of GPP can be as important as degradation (reactivity).

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A procedure for inter-comparing the skill of regional-scale air quality model simulations of daily maximum 8-h ozone concentrations

Atmospheric Environment ◽

10.1016/j.atmosenv.2008.02.046 ◽

2008 ◽

Vol 42 (21) ◽

pp. 5403-5412 ◽

Cited By ~ 4

Author(s):

John S. Irwin ◽

Kevin Civerolo ◽

Christian Hogrefe ◽

Wyat Appel ◽

Kristen Foley ◽

...

Keyword(s):

Air Quality ◽

Regional Scale ◽

Daily Maximum ◽

Air Quality Model ◽

Quality Model ◽

Model Simulations ◽

Ozone Concentrations

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New Categorical Metrics for Air Quality Model Evaluation

Journal of Applied Meteorology and Climatology ◽

10.1175/jam2479.1 ◽

2007 ◽

Vol 46 (4) ◽

pp. 549-555 ◽

Cited By ~ 11

Author(s):

Daiwen Kang ◽

Rohit Mathur ◽

Kenneth Schere ◽

Shaocai Yu ◽

Brian Eder

Keyword(s):

Air Quality ◽

False Alarm ◽

Regional Scale ◽

Central Line ◽

Threshold Concentration ◽

Air Quality Model ◽

Quality Model ◽

False Alarm Ratio ◽

Air Quality Forecast ◽

Success Index

Abstract Traditional categorical metrics used in model evaluations are “clear cut” measures in that the model’s ability to predict an “exceedance” is defined by a fixed threshold concentration and the metrics are defined by observation–forecast sets that are paired both in space and time. These metrics are informative but limited in evaluating the performance of air quality forecast (AQF) systems because AQF generally examines exceedances on a regional scale rather than a single monitor. New categorical metrics—the weighted success index (WSI), area hit (aH), and area false-alarm ratio (aFAR)—are developed. In the calculation of WSI, credits are given to the observation–forecast pairs within the observed exceedance region (missed forecast) or the forecast exceedance region (false alarm), depending on the distance of the points from the central line (perfect observation–forecast match line or 1:1 line on scatterplot). The aH and aFAR are defined by matching observed and forecast exceedances within an area (i.e., model grid cells) surrounding the observation location. The concept of aH and aFAR resembles the manner in which forecasts are usually issued. In practice, a warning is issued for a region of interest, such as a metropolitan area, if an exceedance is forecast to occur anywhere within the region. The application of these new categorical metrics, which are supplemental to the traditional counterparts (critical success index, hit rate, and false-alarm ratio), to the Eta Model–Community Multiscale Air Quality (CMAQ) forecast system has demonstrated further insight into evaluating the forecasting capability of the system (e.g., the new metrics can provide information about how the AQF system captures the spatial variations of pollutant concentrations).

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A 3d Regional Scale Photochemical Air Quality Model. Application to a 3 Day Summertime Episode over Paris

Revue de l Institut Français du Pétrole ◽

10.2516/ogst:1998021 ◽

1998 ◽

Vol 53 (2) ◽

pp. 225-237 ◽

Cited By ~ 3

Author(s):

B. Carissimo ◽

E. Dupont ◽

L. Musson-Genon ◽

P. M. Riboud ◽

A. Jaecker-Voirol ◽

...

Keyword(s):

Air Quality ◽

Regional Scale ◽

Air Quality Model ◽

Quality Model ◽

Model Application

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Wildfire Smoke Transport and Air Quality Impacts in Different Regions of China

Atmosphere ◽

10.3390/atmos11090941 ◽

2020 ◽

Vol 11 (9) ◽

pp. 941

Author(s):

Fengjun Zhao ◽

Yongqiang Liu ◽

Lifu Shu ◽

Qi Zhang

Keyword(s):

Air Quality ◽

Human Health ◽

Northeast China ◽

Southwest China ◽

Regional Scale ◽

Health Impacts ◽

Fire Emissions ◽

Wildfire Smoke ◽

Human Health Impacts ◽

Smoke Transport

The air quality and human health impacts of wildfires depend on fire, meteorology, and demography. These properties vary substantially from one region to another in China. This study compared smoke from more than a dozen wildfires in Northeast, North, and Southwest China to understand the regional differences in smoke transport and the air quality and human health impacts. Smoke was simulated using the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) with fire emissions obtained from the Global Fire Emission Database (GFED). Although the simulated PM2.5 concentrations reached unhealthy or more severe levels at regional scale for some largest fires in Northeast China, smoke from only one fire was transported to densely populated areas (population density greater than 100 people/km2). In comparison, the PM2.5 concentrations reached unhealthy level in local densely populated areas for a few fires in North and Southwest China, though they were very low at regional scale. Thus, individual fires with very large sizes in Northeast China had a large amount of emissions but with a small chance to affect air quality in densely populated areas, while those in North and Southwest China had a small amount of emissions but with a certain chance to affect local densely populated areas. The results suggest that the fire and air quality management should focus on the regional air quality and human health impacts of very large fires under southward/southeastward winds toward densely populated areas in Northeast China and local air pollution near fire sites in North and Southwest China.

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Using SEVIRI fire observations to drive smoke plumes in the CMAQ air quality model: a case study over Antalya in 2008

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-8539-2015 ◽

2015 ◽

Vol 15 (14) ◽

pp. 8539-8558 ◽

Cited By ~ 13

Author(s):

G. Baldassarre ◽

L. Pozzoli ◽

C. C. Schmidt ◽

A. Unal ◽

T. Kindap ◽

...

Keyword(s):

Air Quality ◽

Land Surface ◽

Wrf Model ◽

Accurate Information ◽

Spatial And Temporal Variability ◽

Air Quality Model ◽

Quality Model ◽

Diurnal Variability ◽

Fire Emissions ◽

Smoke Plumes

Abstract. Among the atmospheric emission sources, wildfires are episodic events characterized by large spatial and temporal variability. Therefore, accurate information on gaseous and aerosol emissions from fires for specific regions and seasons is critical for air quality forecasts. The Spinning Enhanced Visible and Infrared Imager (SEVIRI) in geostationary orbit provides fire observations over Africa and the Mediterranean with a temporal resolution of 15 min. It thus resolves the complete fire life cycle and captures the fires' peak intensities, which is not possible in Moderate Resolution Imaging Spectroradiometer (MODIS) fire emission inventories like the Global Fire Assimilation System (GFAS). We evaluate two different operational fire radiative power (FRP) products derived from SEVIRI, by studying a large forest fire in Antalya, Turkey, in July–August 2008. The EUMETSAT Land Surface Analysis Satellite Applications Facility (LSA SAF) has higher FRP values during the fire episode than the Wildfire Automated Biomass Burning Algorithm (WF_ABBA). It is also in better agreement with the co-located, gridded MODIS FRP. Both products miss small fires that frequently occur in the region and are detected by MODIS. Emissions are derived from the FRP products. They are used along-side GFAS emissions in smoke plume simulations with the Weather Research and Forecasting (WRF) model and the Community Multiscale Air Quality (CMAQ) model. In comparisons with MODIS aerosol optical thickness (AOT) and Infrared Atmospheric Sounding Interferometer (IASI), CO and NH3 observations show that including the diurnal variability of fire emissions improves the spatial distribution and peak concentrations of the simulated smoke plumes associated with this large fire. They also show a large discrepancy between the currently available operational FRP products, with the LSA SAF being the most appropriate.

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

10.5194/acp-2020-938 ◽

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.

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