scholarly journals Investigation of CO, C2H6 and aerosols in a boreal fire plume over eastern Canada during BORTAS 2011 using ground- and satellite-based observations and model simulations

2013 ◽  
Vol 13 (20) ◽  
pp. 10227-10241 ◽  
Author(s):  
D. Griffin ◽  
K. A. Walker ◽  
J. E. Franklin ◽  
M. Parrington ◽  
C. Whaley ◽  
...  
Keyword(s):  
Forest Fires ◽  
Transport Model ◽  
Eastern Canada ◽  
Small Shift ◽  
Smoke Plume ◽  
Northwestern Ontario ◽  
Geographical Regions ◽  
Fine Mode ◽  
The Impact ◽  
Total Column

Abstract. We present the results of total column measurements of CO, C2H6 and fine-mode aerosol optical depth (AOD) during the "Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites" (BORTAS-B) campaign over eastern Canada. Ground-based observations, using Fourier transform spectrometers (FTSs) and sun photometers, were carried out in July and August 2011. These measurements were taken in Halifax, Nova Scotia, which is an ideal location to monitor the outflow of boreal fires from North America, and also in Toronto, Ontario. Measurements of fine-mode AOD enhancements were highly correlated with enhancements in coincident trace gas (CO and C2H6) observations between 19 and 21 July 2011, which is typical for a smoke plume event. In this paper, we focus on the identification of the origin and the transport of this smoke plume. We use back trajectories calculated by the Canadian Meteorological Centre as well as FLEXPART forward trajectories to demonstrate that the enhanced CO, C2H6 and fine-mode AOD seen near Halifax and Toronto originated from forest fires in northwestern Ontario that occurred between 17 and 19 July 2011. In addition, total column measurements of CO from the satellite-borne Infrared Atmospheric Sounding Interferometer (IASI) have been used to trace the smoke plume and to confirm the origin of the CO enhancement. Furthermore, the enhancement ratio – that is, in this case equivalent to the emission ratio (ERC2H6/CO) – was estimated from these ground-based observations. These C2H6 emission results from boreal fires in northwestern Ontario agree well with C2H6 emission measurements from other boreal regions, and are relatively high compared to fires from other geographical regions. The ground-based CO and C2H6 observations were compared with outputs from the 3-D global chemical transport model GEOS-Chem, using the Fire Locating And Modeling of Burning Emissions (FLAMBE) inventory. Agreement within the stated measurement uncertainty (~3% for CO and ~8% for C2H6) was found for the magnitude of the enhancement of the CO and C2H6 total columns between the measured and modelled results. However, there is a small shift in time (of approximately 6 h) of arrival of the plume over Halifax between the results.

scholarly journals Investigation of CO, C<sub>2</sub>H<sub>6</sub> and aerosols in a boreal fire plume over eastern Canada during BORTAS 2011 using ground- and satellite-based observations, and model simulations

2013 ◽  
Vol 13 (4) ◽  
pp. 11071-11109 ◽  
Author(s):  
D. Griffin ◽  
K. A. Walker ◽  
J. E. Franklin ◽  
M. Parrington ◽  
C. Whaley ◽  
...  
Keyword(s):  
Forest Fires ◽  
Transport Model ◽  
Eastern Canada ◽  
Small Shift ◽  
Smoke Plume ◽  
Northwestern Ontario ◽  
Geographical Regions ◽  
Fine Mode ◽  
The Impact ◽  
Total Column

Abstract. We present the results of total column measurements of CO, C2H6 and fine mode aerosol optical depth (AOD) during the "Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites" (BORTAS-B) campaign over Eastern Canada. Ground-based observations, using Fourier transform spectrometers (FTSs) and sun photometers, were carried out in July and August 2011. These measurements were taken in Halifax, Nova Scotia, which is an ideal location to monitor the outflow of boreal fires from North America, and also in Toronto, Ontario. Measurements of fine mode AOD enhancements were highly correlated with enhancements in coincident trace gas (CO and C2H6) observations between 19 and 21 July 2011, which is typical for a smoke plume event. In this paper, we focus on the identification of the origin and the transport of this smoke plume. We use back-trajectories calculated by the Canadian Meteorological Centre as well as FLEXPART forward-trajectories to demonstrate that the enhanced CO, C2H6 and fine mode AOD seen near Halifax and Toronto originated from forest fires in Northwestern Ontario that occurred between 17 and 19 July 2011. In addition, total column measurements of CO from the satellite-borne Infrared Atmospheric Sounding Interferometer (IASI) have been used to trace the smoke plume and to confirm the origin of the CO enhancement. Furthermore, the emission ratio (ERC2H6/CO) and the emission factor (EFC2H6) of C2H6 (with respect to the CO emission) were estimated from these ground-based observations. These C2H6 emission results from boreal fires in Northwestern Ontario agree well with C2H6 emission measurements from other boreal regions, and are relatively high compared to fires from other geographical regions. The ground-based CO and C2H6 observations were compared with outputs from the 3-D global chemical transport model GEOS-Chem, using the Fire Locating And Monitoring of Burning Emissions (FLAMBE) inventory. Agreement within the stated measurement uncertainty was found for the magnitude of the enhancement of the total columns of CO (~3%) and C2H6 (~8%) between the measured and modelled results. However, there is a small shift in time (of approximately 6 h) of arrival of the plume over Halifax between the results.

scholarly journals Extending methane profiles from aircraft into the stratosphere for satellite total column validation using the ECMWF C-IFS and TOMCAT/SLIMCAT 3-D model

2017 ◽  
Vol 17 (11) ◽  
pp. 6663-6678 ◽  
Author(s):  
Shreeya Verma ◽  
Julia Marshall ◽  
Mark Parrington ◽  
Anna Agustí-Panareda ◽  
Sebastien Massart ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Transport Model ◽  
A Priori ◽  
Atmospheric Composition ◽  
Random Errors ◽  
Chemical Transport Model ◽  
Spatial Coverage ◽  
Forecasting System ◽  
The Impact ◽  
Total Column

Abstract. Airborne observations of greenhouse gases are a very useful reference for validation of satellite-based column-averaged dry air mole fraction data. However, since the aircraft data are available only up to about 9–13 km altitude, these profiles do not fully represent the depth of the atmosphere observed by satellites and therefore need to be extended synthetically into the stratosphere. In the near future, observations of CO2 and CH4 made from passenger aircraft are expected to be available through the In-Service Aircraft for a Global Observing System (IAGOS) project. In this study, we analyse three different data sources that are available for the stratospheric extension of aircraft profiles by comparing the error introduced by each of them into the total column and provide recommendations regarding the best approach. First, we analyse CH4 fields from two different models of atmospheric composition – the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System for Composition (C-IFS) and the TOMCAT/SLIMCAT 3-D chemical transport model. Secondly, we consider scenarios that simulate the effect of using CH4 climatologies such as those based on balloons or satellite limb soundings. Thirdly, we assess the impact of using a priori profiles used in the satellite retrievals for the stratospheric part of the total column. We find that the models considered in this study have a better estimation of the stratospheric CH4 as compared to the climatology-based data and the satellite a priori profiles. Both the C-IFS and TOMCAT models have a bias of about −9 ppb at the locations where tropospheric vertical profiles will be measured by IAGOS. The C-IFS model, however, has a lower random error (6.5 ppb) than TOMCAT (12.8 ppb). These values are well within the minimum desired accuracy and precision of satellite total column XCH4 retrievals (10 and 34 ppb, respectively). In comparison, the a priori profile from the University of Leicester Greenhouse Gases Observing Satellite (GOSAT) Proxy XCH4 retrieval and climatology-based data introduce larger random errors in the total column, being limited in spatial coverage and temporal variability. Furthermore, we find that the bias in the models varies with latitude and season. Therefore, applying appropriate bias correction to the model fields before using them for profile extension is expected to further decrease the error contributed by the stratospheric part of the profile to the total column.

scholarly journals Identifying the sources driving observed PM<sub>2.5</sub> variability over Halifax, Nova Scotia, during BORTAS-B

2013 ◽  
Vol 13 (2) ◽  
pp. 4491-4533 ◽  
Author(s):  
M. D. Gibson ◽  
J. R. Pierce ◽  
D. Waugh ◽  
J. S. Kuchta ◽  
L. Chisholm ◽  
...  
Keyword(s):  
Nova Scotia ◽  
Atmospheric Chemistry ◽  
Forest Fires ◽  
Back Trajectory ◽  
Valuable Insight ◽  
Eastern Canada ◽  
Average Mass ◽  
Fire Emissions ◽  
Pmf Model ◽  
The Impact

Abstract. The source attribution of observed variability of total PM2.5 concentrations over Halifax, Nova Scotia was investigated between 11 July–26 August 2011 using measurements of PM2.5 mass and PM2.5 chemical composition (black carbon, organic matter, anions, cations and 33 elements). This was part of the BORTAS-B (quantifying the impact of BOReal forest fires on Tropospheric oxidants using aircraft and satellites) experiment, which investigated the atmospheric chemistry and transport of seasonal boreal wild fire emissions over eastern Canada in 2011. The US EPA Positive Matrix Factorization (PMF) receptor model was used to determine the average mass (percentage) source contribution over the 45 days, which was estimated to be: Long-Range Transport (LRT) Pollution 1.75 μg m−3 (47%), LRT Pollution Marine Mixture 1.0 μg m−3 (27.9%), Vehicles 0.49 μg m−3 (13.2%), Fugitive Dust 0.23 μg m−3 (6.3%), Ship Emissions 0.13 μg m−3 (3.4%) and Refinery 0.081 μg m−3 (2.2%). The PMF model describes 87% of the observed variability in total PM2.5 mass (bias = 0.17 and RSME = 1.5 μg m−3). The factor identifications are based on chemical markers, and they are supported by air mass back trajectory analysis and local wind direction. Biomass burning plumes, found by other surface and aircraft measurements, were not significant enough to be identified in this analysis. This paper presents the results of the PMF receptor modelling, providing valuable insight into the local and upwind sources impacting surface PM2.5 in Halifax during the BORTAS-B mission.

scholarly journals Impact of spaceborne carbon monoxide observations from the S-5P platform on tropospheric composition analyses and forecasts

2017 ◽  
Vol 17 (2) ◽  
pp. 1081-1103 ◽  
Author(s):  
Rachid Abida ◽  
Jean-Luc Attié ◽  
Laaziz El Amraoui ◽  
Philippe Ricaud ◽  
William Lahoz ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Forest Fires ◽  
Weather Conditions ◽  
Emission Sources ◽  
Simulation Experiments ◽  
Northern Summer ◽  
Free Model ◽  
Comparison Of The Results ◽  
The Impact ◽  
Total Column

Abstract. We use the technique of Observing System Simulation Experiments (OSSEs) to quantify the impact of spaceborne carbon monoxide (CO) total column observations from the Sentinel-5 Precursor (S-5P) platform on tropospheric analyses and forecasts. We focus on Europe for the period of northern summer 2003, when there was a severe heat wave episode associated with extremely hot and dry weather conditions. We describe different elements of the OSSE: (i) the nature run (NR), i.e., the truth; (ii) the CO synthetic observations; (iii) the assimilation run (AR), where we assimilate the observations of interest; (iv) the control run (CR), in this study a free model run without assimilation; and (v) efforts to establish the fidelity of the OSSE results. Comparison of the results from AR and the CR, against the NR, shows that CO total column observations from S-5P provide a significant benefit (at the 99 % confidence level) at the surface, with the largest benefit occurring over land in regions far away from emission sources. Furthermore, the S-5P CO total column observations are able to capture phenomena such as the forest fires that occurred in Portugal during northern summer 2003. These results provide evidence of the benefit of S-5P observations for monitoring processes contributing to atmospheric pollution.

scholarly journals Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) experiment: design, execution and science overview

2013 ◽  
Vol 13 (13) ◽  
pp. 6239-6261 ◽  
Author(s):  
P. I. Palmer ◽  
M. Parrington ◽  
J. D. Lee ◽  
A. C. Lewis ◽  
A. R. Rickard ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Forest Fires ◽  
Atmospheric Composition ◽  
Atmospheric Measurements ◽  
Eastern Canada ◽  
Chemical Aging ◽  
Air Masses ◽  
Research Aircraft ◽  
The Uk ◽  
The Impact

Abstract. We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned July 2010 deployment of the ARA, which was postponed by 12 months due to UK-based flights related to the dispersal of material emitted by the Eyjafjallajökull volcano, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 involved the same atmospheric measurements, but included the ARA, special satellite observations and a more comprehensive ground-based measurement suite. The high-frequency aircraft data provided a comprehensive chemical snapshot of pyrogenic plumes from wildfires, corresponding to photochemical (and physical) ages ranging from < 1 day to ~

scholarly journals The 2019 Methane Budget And Uncertainties At 1 Degree Resolution And Each Country Through Bayesian Integration Of GOSAT Total Column Methane Data And A Priori Inventory Estimates

2021 ◽  
Author(s):  
John Worden ◽  
Daniel Cusworth ◽  
Zhen Qu ◽  
Yi Yin ◽  
Yuzhong Zhang ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Transport Model ◽  
Systematic Errors ◽  
Top Down ◽  
Bayesian Algorithm ◽  
Bottom Up ◽  
Fire Emissions ◽  
Bayesian Integration ◽  
The Impact ◽  
Total Column

Abstract. We present 2019 global methane (CH4) emissions and uncertainties, by sector, at 1-degree and country-scale resolution based on a Bayesian integration of satellite data and inventories. Globally, we find that agricultural and fire emissions are 227 +/− 19 Tg CH4/yr, waste is 50 +/− 7 Tg CH4/yr , anthropogenic fossil emissions are 82 +/− 12 Tg CH4/yr, and natural wetland/aquatic emissions are 180 +/− 10 Tg CH4/yr. These estimates are intended as a pilot dataset for the Global Stock Take in support of the Paris Agreement. However, differences between the emissions reported here and widely-used bottom-up inventories should be used as a starting point for further research because of potential systematic errors of these satellite based emissions estimates. Calculation of emissions and uncertainties: We first apply a standard optimal estimation (OE) approach to quantify CH4 fluxes using Greenhouse Gases Observing Satellite (GOSAT) total column CH4 concentrations and the GEOS-Chem global chemistry transport model. Second, we use a new Bayesian algorithm that projects these posterior fluxes to emissions by sector to 1 degree and country-scale resolution. This algorithm can also quantify uncertainties from measurement as well as smoothing error, which is due to the spatial resolution of the top-down estimate combined with the assumed structure in the prior emission uncertainties. Detailed Results: We find that total emissions for approximately 58 countries can be resolved with this observing system based on the degrees-of-freedom for signal (DOFS) metric that can be calculated with our Bayesian flux estimation approach. We find the top five emitting countries (Brazil, China, India, Russia, USA) emit about half of the global anthropogenic budget, similar to our choice of prior emissions. However, posterior emissions for these countries are mostly from agriculture, waste and fires (~129 Tg CH4/yr) with ~45 Tg CH4/yr from fossil emissions, as compared to prior inventory estimates of ~88 and 60 Tg CH4/yr respectively, primarily because the satellite observed concentrations are larger than expected in regions with substantive livestock activity. Differences are outside of 1-sigma uncertainties between prior and posterior for Brazil, India, and Russia but are consistent for China and the USA. The new Bayesian algorithm to quantify emissions from fluxes also allows us to “swap priors” if better informed or alternative priors and/or their covariances are available for testing. For example, recent bottom-up literature supposes greatly increased values for wetland/aquatic as well as fossil emissions. Swapping in priors that reflect these increased emissions results in posterior wetland emissions or fossil emissions that are inconsistent (differences greater than calculated uncertainties) with these increased bottom-up estimates, primarily because constraints related to the methane sink only allow total emissions across all sectors of ~560 Tg CH4/yr and because the satellite based estimate well constrains the spatially distinct fossil and wetland emissions. Given that this observing system consisting of GOSAT data and the GEOS-Chem model can resolve much of the different sectoral and country-wide emissions, with ~402 DOFS for the whole globe, our results indicate additional research is needed to identify the causes of discrepancies between these top-down and bottom-up results for many of the emission sectors reported here. In particular, the impact of systematic errors in the methane retrievals and transport model employed should be assessed where differences exist. However, our results also suggest that significant attention must be provided to the location and magnitude of emissions used for priors in top-down inversions; for example, poorly characterized prior emissions in one region and/or sector can affect top-down estimates in another because of the limited spatial resolution of these top-down estimates. Satellites such as the Tropospheric Monitoring Instrument (TROPOMI) and those in formulation such as the Copernicus CO2M, Methane-Sat, or Carbon Mapper offer the promise of much higher resolution fluxes relative to GOSAT assuming they can provide data with comparable or better accuracy, thus potentially reducing this uncertainty from poorly characterized emissions. These higher resolution estimates can therefore greatly improve the accuracy of emissions by reducing smoothing error. Fluxes calculated from other sources can also in principal be incorporated in the Bayesian estimation framework demonstrated here for the purpose of reducing uncertainty and improving the spatial resolution and sectoral attribution of subsequent methane emissions estimates.

scholarly journals A case study of aerosol depletion in a biomass burning plume over Eastern Canada during the 2011 BORTAS field experiment

2014 ◽  
Vol 14 (3) ◽  
pp. 3395-3426 ◽  
Author(s):  
J. E. Franklin ◽  
J. R. Drummond ◽  
D. Griffin ◽  
J. R. Pierce ◽  
D. L. Waugh ◽  
...  
Keyword(s):  
Long Range ◽  
Biomass Burning ◽  
Forest Fires ◽  
Particulate Material ◽  
Trace Gas ◽  
Eastern Canada ◽  
Air Masses ◽  
Chemical Behaviour ◽  
Physical And Chemical ◽  
The Impact

Abstract. We present measurements of a long range smoke transport event recorded on 20–21 July 2011 over Halifax, Nova Scotia, Canada, during the Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS-B) campaign. Ground-based Fourier transform spectrometers and photometers detected air masses associated with large wildland fires burning in eastern Manitoba and western Ontario. We investigate a plume with high trace gas amounts but low amounts of particles that preceded and overlapped at the Halifax site with a second plume with high trace gas loadings and significant amounts of particulate material. We show that the first plume experienced a meteorological scavenging event but the second plume had not been similarly scavenged. This points to the necessity to account carefully for the plume history when considering long range transport since simultaneous or near-simultaneous times of arrival are not necessarily indicative of either similar trajectories or meteorological history. We investigate the origin of the scavenged plume, and the possibility of an aerosol wet deposition event occurring in the plume ~24 h prior to the measurements over Halifax. The region of lofting and scavenging is only monitored on an intermittent basis by the present observing network, and thus we must consider many different pieces of evidence in an effort to understand the early dynamics of the plume. Through this discussion we also demonstrate the value of having many simultaneous remote-sensing measurements in order to understand the physical and chemical behaviour of biomass burning plumes.

scholarly journals Constraining fossil fuel CO<sub>2</sub> emissions from urban area using OCO-2 observations of total column CO<sub>2</sub>

2017 ◽  
Author(s):  
Xinxin Ye ◽  
Thomas Lauvaux ◽  
Eric A. Kort ◽  
Tomohiro Oda ◽  
Sha Feng ◽  
...  
Keyword(s):  
Los Angeles ◽  
Urban Area ◽  
Fossil Fuel ◽  
Transport Model ◽  
Careful Consideration ◽  
Metropolitan Region ◽  
Model Errors ◽  
The Impact ◽  
Pseudo Data ◽  
Total Column

Abstract. Expanding urban populations and the significant contribution of cities to global fossil-fuel CO2 (CO2ff) emissions emphasize the necessity of achieving independent and accurate quantifications of the emissions from urban area. In this paper, we assess the utility of total column dry air CO2 mole fraction (XCO2) data retrieved from NASA's Orbiting Carbon Observatory 2 (OCO-2) observations to quantify CO2ff emissions from cities. Observing System Simulation Experiments (OSSEs) are implemented by forward modeling of meteorological fields and column XCO2. The impact of transport model errors on the inverse emissions estimates is examined for two “plume cities” (Riyadh, Cairo) and a “basin city” (Los Angeles metropolitan region, LA). The pseudo data experiments indicate convergence of emission uncertainties related to transport model errors with increasing amount of observations. The 1-σ uncertainty of emission estimates is constrained to approximately 15 %/5 % with about 10 pseudo tracks for plume city/basin city. The systematic wind speed biases in simulated wind fields for LA lead to overestimations in total CO2ff emission, which require data assimilation to improve high-resolution atmospheric transport. The contribution of biogenic fluxes gradients in urban and rural area of Pearl River Delta metropolitan region in China are examined by simulations with biospheric fluxes imposed by the Net Ecosystem Exchange (NEE) from multiple terrestrial biosphere models, which show about 24 ± 21 % (1σ) and 19 ± 15 % (1σ) contributions to the total XCO2 enhancements for the two cases examined. The representations of transport model errors for the emission optimization are examined for Riyadh, Cairo and LA ¬in real cases. The determination of background XCO2 is discussed for LA by using constant and simulated background with biospheric fluxes included, demonstrating the need of careful consideration of the variations in background XCO2 for identifying concentration enhancements due to fossil fuel emissions.

scholarly journals A case study of aerosol scavenging in a biomass burning plume over eastern Canada during the 2011 BORTAS field experiment

2014 ◽  
Vol 14 (16) ◽  
pp. 8449-8460 ◽  
Author(s):  
J. E. Franklin ◽  
J. R. Drummond ◽  
D. Griffin ◽  
J. R. Pierce ◽  
D. L. Waugh ◽  
...  
Keyword(s):  
Long Range ◽  
Biomass Burning ◽  
Forest Fires ◽  
Particulate Material ◽  
Trace Gas ◽  
Eastern Canada ◽  
Air Masses ◽  
Chemical Behaviour ◽  
Physical And Chemical ◽  
The Impact

Abstract. We present measurements of a long-range smoke transport event recorded on 20–21 July 2011 over Halifax, Nova Scotia, Canada, during the Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS-B) campaign. Ground-based Fourier transform spectrometers and photometers detected air masses associated with large wildland fires burning in eastern Manitoba and western Ontario. We investigate a plume with high trace gas amounts but low amounts of particles that preceded and overlapped at the Halifax site with a second plume with high trace gas loadings and significant amounts of particulate material. We show that the first plume experienced a meteorological scavenging event, but the second plume had not been similarly scavenged. This points to the necessity to account carefully for the plume history when considering long-range transport since simultaneous or near-simultaneous times of arrival are not necessarily indicative of either similar trajectories or meteorological history. We investigate the origin of the scavenged plume, and the possibility of an aerosol wet deposition event occurring in the plume ~ 24 h prior to the measurements over Halifax. The region of lofting and scavenging is only monitored on an intermittent basis by the present observing network, and thus we must consider many different pieces of evidence in an effort to understand the early dynamics of the plume. Through this discussion we also demonstrate the value of having many simultaneous remote-sensing measurements in order to understand the physical and chemical behaviour of biomass burning plumes.

scholarly journals Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) experiment: design, execution and science overview

2013 ◽  
Vol 13 (2) ◽  
pp. 4127-4181 ◽  
Author(s):  
P. I. Palmer ◽  
M. Parrington ◽  
J. D. Lee ◽  
A. C. Lewis ◽  
A. R. Rickard ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Atmospheric Chemistry ◽  
Forest Fires ◽  
Atmospheric Transport ◽  
Chemical Mechanism ◽  
Atmospheric Composition ◽  
Limited Information ◽  
Eastern Canada ◽  
The Impact ◽  
Aircraft Data

Abstract. We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of airmasses that contain the emission products from seasonal boreal wildfires and how these airmasses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada. The planned July 2010 deployment of the ARA was postponed by 12 months because of activities related to the dispersal of material emitted by the Eyjafjallajökull volcano. However, most other planned model and measurement activities, including ground-based measurements at the Dalhousie University Ground Station (DGS), enhanced ozonesonde launches, and measurements at the Pico Atmospheric Observatory in the Azores, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 included the same measurements, but included the ARA, special satellite observations and a more comprehensive measurement suite at the DGS. The high-frequency aircraft data provided a comprehensive snapshot of the pyrogenic plumes from wildfires. The coordinated ground-based and sonde data provided detailed but spatially-limited information that put the aircraft data into context of the longer burning season. We coordinated aircraft vertical profiles and overpasses of the NASA Tropospheric Emission Spectrometer and the Canadian Atmospheric Chemistry Experiment. These space-borne data, while less precise than other data, helped to relate the two-week measurement campaign to larger geographical and longer temporal scales. We interpret these data using a range of chemistry models: from a near-explicit gas-phase chemical mechanism, which tests out understanding of the underlying chemical mechanism, to regional and global 3-D models of atmospheric transport and lumped chemistry, which helps to assess the performance of the simplified chemical mechanism and effectively act as intermediaries between different measurement types. We also present an overview of some of the new science that has originated from this project from the mission planning and execution to the analysis of the ground-based, aircraft, and space-borne data.

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