Sensitivity of tropospheric loads and lifetimes of short lived pollutants to fire emissions

Abstract. The capability of global chemistry and transport models (CTMs) to simulate atmospheric composition and its spatial and temporal changes highly relies on the input data used by the models, in particular the emission inventories. Biomass burning emissions show large spatial, diurnal, seasonal and year-to-year variability. In the present study, we applied a global 3-D CTM to evaluate uncertainties in the computed atmospheric composition associated with the use of different biomass burning emissions and identify areas where observational data can help to reduce these uncertainties. We find the emission inventory choice to lead to regional differences in the calculated load of aerosols up to a factor of 4. Assumptions on the injection height of the biomass burning emissions are found to produce regionally up to 30% differences in the calculated tropospheric lifetimes of pollutants. Computed changes in lifetimes point to a strong chemical feedback mechanism between emissions from biomass burning and isoprene emissions from vegetation that are linked via NOx-driven oxidant chemistry, NOx-dependent changes in isoprene oxidation products, aerosol emissions and atmospheric transport. These interactions reduce isoprene load in the presence of biomass burning emissions by 15%, calculated for the same amount of isoprene emitted into the troposphere. Thus, isoprene load and lifetime are inversely related to the quantities of pollutants emitted by biomass burning. These interactions are shown to be able to increase the global annual secondary aerosol yield from isoprene emissions, defined as the ratio of tropospheric loads of secondary aerosol from isoprene oxidation to isoprene emissions, by up to 18%.

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Sensitivity of tropospheric loads and lifetimes of short lived pollutants to fire emissions

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-22639-2014 ◽

2014 ◽

Vol 14 (16) ◽

pp. 22639-22676 ◽

Cited By ~ 2

Author(s):

N. Daskalakis ◽

S. Myriokefalitakis ◽

M. Kanakidou

Keyword(s):

Biomass Burning ◽

Regional Differences ◽

Input Data ◽

Emission Inventory ◽

Feedback Mechanism ◽

Atmospheric Composition ◽

Emission Inventories ◽

Transport Models ◽

Fire Emissions ◽

Calculated Load

Abstract. The capability of global Chemistry and Transport Models (CTMs) to simulate atmospheric composition and its spatial and temporal changes highly relies on the input data used by the models, in particular the emission inventories. Biomass burning emissions show large spatial, daily, seasonal and year-to-year variability. In the present study, we applied a global 3-D CTM to evaluate uncertainties in the computed atmospheric composition associated with the use of different biomass burning emissions and identify areas where observational data can improve in reducing these uncertainties. We find the emission inventory choice to be able to introduce regional differences in the calculated load of aerosols up to a factor of 4. Assumptions on the injection height of the biomass burning emissions are found to produce regionally up to 30% differences in the calculated tropospheric lifetimes of pollutants. Computed changes in lifetimes point to a strong chemical feedback mechanism between emissions from biomass burning and isoprene emissions from vegetation that are linked via oxidant chemistry. These interactions reduce isoprene load in the presence of biomass burning emissions by 15%, calculated for the same amount of isoprene emitted into the troposphere. Thus, isoprene load and lifetime are inversely related to the quantities of pollutants emitted by biomass burning. This feedback is shown to be able to increase the effective secondary aerosol yield from isoprene by up to 40%.

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Combining fire radiative power observations with the fire weather index improves the estimation of fire emissions

10.5194/acp-2017-790 ◽

2017 ◽

Cited By ~ 1

Author(s):

Francesca Di Giuseppe ◽

Samuel Rémy ◽

Florian Pappenberger ◽

Fredrik Wetterhall

Keyword(s):

Biomass Burning ◽

Atmospheric Composition ◽

Composition Analysis ◽

Fire Weather ◽

Atmospheric Conditions ◽

Weather Index ◽

Fire Weather Index ◽

Fire Emissions ◽

Radiative Power ◽

Fire Radiative Power

Abstract. The atmospheric composition analysis and forecast for the European Copernicus Atmosphere Monitoring Services (CAMS) relies on biomass burning fire emission estimates from the Global Fire Assimilation System (GFAS). GFAS converts fire radiative power (FRP) observations from MODIS satellites into smoke constituents. Missing observations are filled in using persistence where observed FRP from the previous day are progressed in time until a new observation is recorded. One of the consequences of this assumption is an overestimation of fire duration, which in turn translates into an overestimation of emissions from fires. In this study persistence is replaced by modelled predictions using the Canadian Fire Weather Index (FWI), which describes how atmospheric conditions affect the vegetation moisture content and ultimately fire duration. The skill in predicting emissions from biomass burning is improved with the new technique, which indicates that using an FWI-based model to infer emissions from FRP is better than persistence when observations are not available.

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Biomass burning emission disturbances of isoprene oxidation in a tropical forest

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-12715-2018 ◽

2018 ◽

Vol 18 (17) ◽

pp. 12715-12734 ◽

Cited By ~ 4

Author(s):

Fernando Santos ◽

Karla Longo ◽

Alex Guenther ◽

Saewung Kim ◽

Dasa Gu ◽

...

Keyword(s):

Chemical Composition ◽

Biomass Burning ◽

Oxidative Capacity ◽

Oxidation Products ◽

Amazon Rainforest ◽

Amazon Forest ◽

Oxidation Reactions ◽

Smoke Plumes ◽

Isoprene Oxidation ◽

The Impact

Abstract. We present a characterization of the chemical composition of the atmosphere of the Brazilian Amazon rainforest based on trace gas measurements carried out during the South AMerican Biomass Burning Analysis (SAMBBA) airborne experiment in September 2012. We analyzed the observations of primary biomass burning emission tracers, i.e., carbon monoxide (CO), nitrogen oxides (NOx), ozone (O3), isoprene, and its main oxidation products, methyl vinyl ketone (MVK), methacrolein (MACR), and isoprene hydroxy hydroperoxide (ISOPOOH). The focus of SAMBBA was primarily on biomass burning emissions, but there were also several flights in areas of the Amazon forest not directly affected by biomass burning, revealing a background with a signature of biomass burning in the chemical composition due to long-range transport of biomass burning tracers from both Africa and the eastern part of Amazonia. We used the [MVK + MACR + ISOPOOH] ∕ [isoprene] ratio and the hydroxyl radical (OH) indirect calculation to assess the oxidative capacity of the Amazon forest atmosphere. We compared the background regions (CO < 150 ppbv), fresh and aged smoke plumes classified according to their photochemical age ([O3] ∕ [CO]), to evaluate the impact of biomass burning emissions on the oxidative capacity of the Amazon forest atmosphere. We observed that biomass burning emissions disturb the isoprene oxidation reactions, especially for fresh plumes ([MVK + MACR + ISOPOOH] ∕ [isoprene] = 7) downwind. The oxidation of isoprene is higher in fresh smoke plumes at lower altitudes (∼ 500 m) than in aged smoke plumes, anticipating near the surface a complex chain of oxidation reactions which may be related to secondary organic aerosol (SOA) formation. We proposed a refinement of the OH calculation based on the sequential reaction model, which considers vertical and horizontal transport for both biomass burning regimes and background environment. Our approach for the [OH] estimation resulted in values on the same order of magnitude of a recent observation in the Amazon rainforest [OH] ≅ 106 (molecules cm−3). During the fresh plume regime, the vertical profile of [OH] and the [MVK + MACR + ISOPOOH] ∕ [isoprene] ratio showed evidence of an increase in the oxidizing power in the transition from planetary boundary layer to cloud layer (1000–1500 m). These high values of [OH] (1.5 × 106 molecules cm−3) and [MVK + MACR + ISOPOOH] ∕ [isoprene] (7.5) indicate a significant change above and inside the cloud decks due to cloud edge effects on photolysis rates, which have a major impact on OH production rates.

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Impact of El Niño Southern Oscillation on the interannual variability of methane and tropospheric ozone

10.5194/acp-2019-222 ◽

2019 ◽

Author(s):

Matthew J. Rowlinson ◽

Alexandru Rap ◽

Stephen R. Arnold ◽

Richard J. Pope ◽

Martyn P. Chipperfield ◽

...

Keyword(s):

Growth Rate ◽

Interannual Variability ◽

Biomass Burning ◽

El Niño ◽

Atmospheric Transport ◽

El Nino ◽

Southern Oscillation ◽

Fire Emissions ◽

Tropospheric O3 ◽

Global Mean

Abstract. The growth rate of global methane (CH4) concentrations has a strong interannual variability which is believed to be driven largely by fluctuations in CH4 emissions from wetlands and wildfires, as well as changes to the atmospheric sink. The El Niño Southern Oscillation (ENSO) is known to influence fire occurrence, wetland emission and atmospheric transport, but there are still important uncertainties associated with the exact mechanism and magnitude of this influence. Here we use a modelling approach to investigate how fires and meteorology control the interannual variability of global carbon monoxide (CO), CH4 and ozone (O3) concentrations, particularly during large El Niño events. Using a three-dimensional chemical transport model (TOMCAT) coupled to a sophisticated aerosol microphysics scheme (GLOMAP) we simulate changes to CO, hydroxyl radical (OH) and O3 for the period 1997–2014. We then use an offline radiative transfer model to quantify the impact of changes to atmospheric composition as a result of specific drivers. During the El Niño event of 1997–1998, there were increased emissions from biomass burning globally. As a result, global CO concentrations increased by more than 40 %. This resulted in decreased global mass-weighted tropospheric OH concentrations of up to 9 % and a resulting 4 % increase in the CH4 atmospheric lifetime. The change in CH4 lifetime led to a 7.5 ppb yr−1 increase in global mean CH4 growth rate in 1998. Therefore biomass burning emission of CO could account for 72 % of the total effect of fire emissions on CH4 growth rate in 1998. Our simulations indicate variations in fire emissions and meteorology associated with El Niño have opposing impacts on tropospheric O3 burden. El Niño-related atmospheric transport changes decrease global tropospheric O3 concentrations leading to a −0.03 Wm−2 change in O3 radiative effect (RE). However, enhanced fire emission of precursors such as nitrous oxides (NOx) and CO increase O3 RE by 0.03 Wm−2. While globally the two mechanisms nearly cancel out, causing only a small change in global mean O3 RE, the regional changes are large up to −0.33 Wm−2 with potentially important consequences for atmospheric heating and dynamics.

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Six global biomass burning emission datasets: intercomparison and application in one global aerosol model

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-969-2020 ◽

2020 ◽

Vol 20 (2) ◽

pp. 969-994 ◽

Cited By ~ 20

Author(s):

Xiaohua Pan ◽

Charles Ichoku ◽

Mian Chin ◽

Huisheng Bian ◽

Anton Darmenov ◽

...

Keyword(s):

Southern Hemisphere ◽

Biomass Burning ◽

Satellite Observations ◽

Burned Area ◽

Aerosol Model ◽

Fire Emissions ◽

Active Fire ◽

Aerosol Emission ◽

High Level ◽

Aerosol Emissions

Abstract. Aerosols from biomass burning (BB) emissions are poorly constrained in global and regional models, resulting in a high level of uncertainty in understanding their impacts. In this study, we compared six BB aerosol emission datasets for 2008 globally as well as in 14 regions. The six BB emission datasets are (1) GFED3.1 (Global Fire Emissions Database version 3.1), (2) GFED4s (GFED version 4 with small fires), (3) FINN1.5 (FIre INventory from NCAR version 1.5), (4) GFAS1.2 (Global Fire Assimilation System version 1.2), (5) FEER1.0 (Fire Energetics and Emissions Research version 1.0), and (6) QFED2.4 (Quick Fire Emissions Dataset version 2.4). The global total emission amounts from these six BB emission datasets differed by a factor of 3.8, ranging from 13.76 to 51.93 Tg for organic carbon and from 1.65 to 5.54 Tg for black carbon. In most of the regions, QFED2.4 and FEER1.0, which are based on satellite observations of fire radiative power (FRP) and constrained by aerosol optical depth (AOD) data from the Moderate Resolution Imaging Spectroradiometer (MODIS), yielded higher BB aerosol emissions than the rest by a factor of 2–4. By comparison, the BB aerosol emissions estimated from GFED4s and GFED3.1, which are based on satellite burned-area data, without AOD constraints, were at the low end of the range. In order to examine the sensitivity of model-simulated AOD to the different BB emission datasets, we ingested these six BB emission datasets separately into the same global model, the NASA Goddard Earth Observing System (GEOS) model, and compared the simulated AOD with observed AOD from the AErosol RObotic NETwork (AERONET) and the Multiangle Imaging SpectroRadiometer (MISR) in the 14 regions during 2008. In Southern Hemisphere Africa (SHAF) and South America (SHSA), where aerosols tend to be clearly dominated by smoke in September, the simulated AOD values were underestimated in almost all experiments compared to MISR, except for the QFED2.4 run in SHSA. The model-simulated AOD values based on FEER1.0 and QFED2.4 were the closest to the corresponding AERONET data, being, respectively, about 73 % and 100 % of the AERONET observed AOD at Alta Floresta in SHSA and about 49 % and 46 % at Mongu in SHAF. The simulated AOD based on the other four BB emission datasets accounted for only ∼50 % of the AERONET AOD at Alta Floresta and ∼20 % at Mongu. Overall, during the biomass burning peak seasons, at most of the selected AERONET sites in each region, the AOD values simulated with QFED2.4 were the highest and closest to AERONET and MISR observations, followed closely by FEER1.0. However, the QFED2.4 run tends to overestimate AOD in the region of SHSA, and the QFED2.4 BB emission dataset is tuned with the GEOS model. In contrast, the FEER1.0 BB emission dataset is derived in a more model-independent fashion and is more physically based since its emission coefficients are independently derived at each grid box. Therefore, we recommend the FEER1.0 BB emission dataset for aerosol-focused hindcast experiments in the two biomass-burning-dominated regions in the Southern Hemisphere, SHAF, and SHSA (as well as in other regions but with lower confidence). The differences between these six BB emission datasets are attributable to the approaches and input data used to derive BB emissions, such as whether AOD from satellite observations is used as a constraint, whether the approaches to parameterize the fire activities are based on burned area, FRP, or active fire count, and which set of emission factors is chosen.

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Wildfires in Northern Eurasia affect the budget of black carbon in the Arctic. A 12-year retrospective synopsis (2002–2013).

10.5194/acp-2015-994 ◽

2016 ◽

Cited By ~ 1

Author(s):

N. Evangeliou ◽

Y. Balkanski ◽

W. M. Hao ◽

A. Petkov ◽

R. P. Silverstein ◽

...

Keyword(s):

Black Carbon ◽

Northern Hemisphere ◽

Biomass Burning ◽

Emission Inventory ◽

Atmospheric Composition ◽

Anthropogenic Sources ◽

The Arctic ◽

Northern Eurasia ◽

Fire Emissions ◽

Vegetation Fires

Abstract. In recent decades much attention has been given to the Arctic environment, where climate change is happening rapidly. Black carbon (BC) has been shown to be a major component of Arctic pollution that also affects the radiative balance. In the present study, we focused on how vegetation fires that occurred in Northern Eurasia during the period of 2002–2013 influenced the budget of BC in the Arctic. For simulating the transport of fire emissions from Northern Eurasia to the Arctic, we adopted BC fire emission estimates developed independently by GFED3 (Global Fire Emissions Database) and FEI-NE (Fire Emission Inventory – Northern Eurasia). Both datasets were based on fire locations and burned areas detected by MODIS (MODerate resolution Imaging Spectroradiometer) instruments on NASA's (National Aeronautics and Space Administration) Terra and Aqua satellites. Anthropogenic sources of BC were estimated using the MACCity (Monitoring Atmospheric Composition & Climate/megaCITY – Zoom for the ENvironment) emission inventory. During the 12-year period, an average area of 250,000 km2 yr−1 was burned in Northern Eurasia and the global emissions of BC ranged between 8.0 and 9.5 Tg yr−1. For the BC emitted in the Northern Hemisphere, about 70 % originated from anthropogenic sources and the rest from biomass burning (BB). Using the FEI-NE inventory, we found that 102 ± 29 kt yr−1 BC from biomass burning was deposited on the Arctic (defined here as the area north of 67º N) during the 12 years simulated, which was twice as much as when using MACCity inventory (56 ± 8 kt yr−1). The annual mass of BC deposited in the Arctic from all sources (FEI-NE in Northern Eurasia, MACCity elsewhere) is significantly higher by about 37 % in 2009 to 181 % in 2012, compared to the BC deposited using just the MACCity emission inventory. Deposition of BC in the Arctic from BB sources in the Northern Hemisphere thus represents 68 % of the BC deposited from all BC sources (the remaining being due to anthropogenic sources). Northern Eurasian vegetation fires (FEI-NE) contributed 85 % (79–91 %) to the BC deposited over the Arctic from all BB sources in the Northern Hemisphere. Arctic total BC burden showed strong seasonal variations, with highest values during the Arctic Haze season. High winter–spring values of BC burden were caused by transport of BC mainly from anthropogenic sources in Europe, whereas the peak in summer was mainly due to the fire emissions in Northern Eurasia. BC particles emitted from fires in lower latitudes (35° N–40° N) were found to remain the longest in the atmosphere due to the high release altitudes of smoke plumes, exhibit tropospheric transport resulting in a high summer peak of burden, and grow by condensation processes. In regards to the geographic contribution on the deposition of BC, we estimated that about 46 % of the BC deposited over the Arctic from vegetation fires in Northern Eurasia originated from Siberia, 6 % from Kazakhstan, 5 % from Europe, and about 1 % from Mongolia. The remaining 42 % originated from other areas in Northern Eurasia. For spring and summer, we computed that 42 % of the BC released from Northern Eurasian vegetation fires was deposited over the Arctic (annual average: 17 %). Vegetation fires in Northern Eurasia contributed to 14 % to 57 % of BC surface concentrations at the Arctic stations (Alert, Barrow, Zeppelin, Villum, and Tiksi), with fires in Siberia contributing the largest share. However, anthropogenic sources in the Northern Hemisphere remain essential, contributing 29 % to 54 % to the surface concentrations at the Arctic monitoring stations. The rest originated from North American fires.

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Biomass burning emissions disturbances on the isoprene oxidation in a tropical forest

10.5194/acp-2017-1083 ◽

2017 ◽

Author(s):

Fernando C. Santos ◽

Karla M. Longo ◽

Alex B. Guenther ◽

Saewung Kim ◽

Dasa Gu ◽

...

Keyword(s):

Chemical Composition ◽

Biomass Burning ◽

Oxidative Capacity ◽

Oxidation Products ◽

Amazon Forest ◽

South American ◽

Range Transport ◽

Isoprene Oxidation ◽

Emission Tracers

Abstract. We present a characterization of the chemical composition of the atmosphere of the Brazilian Amazon rainforest based on trace gases measurements carried out during the South American Biomass Burning Analysis (SAMBBA) airborne experiment in September 2012. We analyzed the observations of primary biomass burning emission tracers, i.e., carbon monoxide (CO) and nitrogen oxides (NOx), ozone (O3), isoprene, and its main oxidation products, methyl vinyl ketone (MVK), methacrolein (MACR), and hydroxyhydroperoxides (ISOPOOH). The focus of SAMBBA was primarily on biomass burning emissions, but there were also several flights in areas of the Amazon forest not directly affected by biomass burning, revealing a background with a signature of biomass burning in the chemical composition due to long-range transport of biomass burning tracers from both Africa and the eastern part of Amazonia. We used the [MVK + MACR + ISOPOOH] / [Isoprene] ratio and the hydroxyl radical (OH) indirect calculation to assess the oxidative capacity of the Amazon forest atmosphere. We compared the background regions (CO

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Using the Fire Weather Index (FWI) to improve the estimation of fire emissions from fire radiative power (FRP) observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-5359-2018 ◽

2018 ◽

Vol 18 (8) ◽

pp. 5359-5370 ◽

Cited By ~ 11

Author(s):

Francesca Di Giuseppe ◽

Samuel Rémy ◽

Florian Pappenberger ◽

Fredrik Wetterhall

Keyword(s):

Biomass Burning ◽

Atmospheric Composition ◽

Composition Analysis ◽

Fire Weather ◽

Atmospheric Conditions ◽

Weather Index ◽

Fire Weather Index ◽

Fire Emissions ◽

Radiative Power ◽

Fire Radiative Power

Abstract. The atmospheric composition analysis and forecast for the European Copernicus Atmosphere Monitoring Services (CAMS) relies on biomass-burning fire emission estimates from the Global Fire Assimilation System (GFAS). The GFAS is a global system and converts fire radiative power (FRP) observations from MODIS satellites into smoke constituents. Missing observations are filled in using persistence, whereby observed FRP values from the previous day are progressed in time until a new observation is recorded. One of the consequences of this assumption is an increase of fire duration, which in turn translates into an increase of emissions estimated from fires compared to what is available from observations. In this study persistence is replaced by modelled predictions using the Canadian Fire Weather Index (FWI), which describes how atmospheric conditions affect the vegetation moisture content and ultimately fire duration. The skill in predicting emissions from biomass burning is improved with the new technique, which indicates that using an FWI-based model to infer emissions from FRP is better than persistence when observations are not available.

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Historic global biomass burning emissions based on merging satellite observations with proxies and fire models (1750–2015)

10.5194/gmd-2017-32 ◽

2017 ◽

Cited By ~ 4

Author(s):

Margreet J. E. van Marle ◽

Silvia Kloster ◽

Brian I. Magi ◽

Jennifer R. Marlon ◽

Anne-Laure Daniau ◽

...

Keyword(s):

Biomass Burning ◽

Satellite Data ◽

Carbon Emissions ◽

Data Representation ◽

Atmospheric Composition ◽

Full Time ◽

Fire Emissions ◽

Fire Models ◽

Time Period ◽

In Fire

Abstract. Fires have influenced atmospheric composition and climate since the rise of vascular plants, and satellite data has shown the overall global extent of fires. Our knowledge of historic fire emissions has progressively improved over the past decades due mostly to the development of new proxies and the improvement of fire models. Currently there is a suite of proxies including sedimentary charcoal records, measurements of fire-emitted trace gases and black carbon stored in ice and firn, and visibility observations. These proxies provide opportunities to extrapolate emissions estimates based on satellite data starting in 1997 back in time, but each proxy has strengths and weaknesses regarding, for example, the spatial and temporal extents over which they are representative. We developed a new historic biomass burning emissions dataset starting in 1750 that merges the satellite record with several existing proxies, and uses the average of six models from the Fire Model Intercomparison Project (FireMIP) protocol to estimate emissions when the available proxies had limited coverage. According to our approach, global biomass burning emissions were relatively constant with 10-year averages varying between 1.8 and 2.3 Pg C year−1. Carbon emissions increased only slightly over the full time period and peaked during the 1990s after which they decreased gradually. There is substantial uncertainty in these estimates and patterns varied depending on choices regarding data representation, especially on regional scales. The observed pattern in fire carbon emissions is for a large part driven by African fires, which accounted for 58 % of global fire carbon emissions. African fire emissions declined since about 1950 due to conversion of savanna to cropland, and this decrease is partially compensated for by increasing emissions in deforestation zones of South America and Asia. These global fire emissions estimates are mostly suited for global analyses and will be used in the IPCC CMIP simulations.

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Coupling interactive fire with atmospheric composition and climate in the UK Earth System Model

Geoscientific Model Development ◽

10.5194/gmd-14-6515-2021 ◽

2021 ◽

Vol 14 (10) ◽

pp. 6515-6539

Author(s):

João C. Teixeira ◽

Gerd A. Folberth ◽

Fiona M. O'Connor ◽

Nadine Unger ◽

Apostolos Voulgarakis

Keyword(s):

Biomass Burning ◽

Prescribed Fire ◽

Radiative Forcing ◽

Regional Scale ◽

Earth System Model ◽

System Model ◽

Atmospheric Composition ◽

Earth System ◽

Fire Emissions ◽

Similar Performance

Abstract. Fire constitutes a key process in the Earth system (ES), being driven by climate as well as affecting the climate by changing atmospheric composition and impacting the terrestrial carbon cycle. However, studies on the effects of fires on atmospheric composition, radiative forcing and climate have been limited to date, as the current generation of ES models (ESMs) does not include fully atmosphere–composition–vegetation coupled fires feedbacks. The aim of this work is to develop and evaluate a fully coupled fire–composition–climate ES model. For this, the INteractive Fires and Emissions algoRithm for Natural envirOnments (INFERNO) fire model is coupled to the atmosphere-only configuration of the UK's Earth System Model (UKESM1). This fire–atmosphere interaction through atmospheric chemistry and aerosols allows for fire emissions to influence radiation, clouds and generally weather, which can consequently influence the meteorological drivers of fire. Additionally, INFERNO is updated based on recent developments in the literature to improve the representation of human and/or economic factors in the anthropogenic ignition and suppression of fire. This work presents an assessment of the effects of interactive fire coupling on atmospheric composition and climate compared to the standard UKESM1 configuration that uses prescribed fire emissions. Results show a similar performance when using the fire–atmosphere coupling (the “online” version of the model) when compared to the offline UKESM1 that uses prescribed fire. The model can reproduce observed present-day global fire emissions of carbon monoxide (CO) and aerosols, despite underestimating the global average burnt area. However, at a regional scale, there is an overestimation of fire emissions over Africa due to the misrepresentation of the underlying vegetation types and an underestimation over equatorial Asia due to a lack of representation of peat fires. Despite this, comparing model results with observations of CO column mixing ratio and aerosol optical depth (AOD) show that the fire–atmosphere coupled configuration has a similar performance when compared to UKESM1. In fact, including the interactive biomass burning emissions improves the interannual CO atmospheric column variability and consequently its seasonality over the main biomass burning regions – Africa and South America. Similarly, for aerosols, the AOD results broadly agree with the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Aerosol Robotic Network (AERONET) observations.

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