Comprehensive analysis of particle growth rates from nucleation mode to cloud condensation nuclei in Boreal forest

Abstract. Growth of aerosol particles to sizes at which they can act as cloud condensation nuclei (CCN) is a crucial factor in estimating the current and future impacts of aerosol cloud climate interactions. Growth rates are typically determined for particles with diameters (dP) smaller than 40 nm immediately after a regional new particle formation (NPF) event. These growth rates are often taken as representatives for the particle growth until CCN sizes (dP > 50–100 nm). In modelling frameworks, the concentration of the condensable vapours causing the growth is typically calculated with steady state assumptions, where the condensation sink is the only loss term for the vapours. Additionally, the growth to CCN sizes is represented with the condensation of extremely low-volatile vapours and gas-particle partitioning of semi-volatile vapours. Here, we use a novel automatic method to determine growth rates (GR) from below 10 nm to hundreds of nanometres from a 20-years long particle size distribution data set in Boreal forest. With this method, we are able to detect growth rates also at other times than immediately after a NPF event. We show that the GR increases with an increasing oxidation rate of monoterpenes, which is closely coupled with the ambient temperature. Based on our analysis, the oxidation reactions of monoterpenes with ozone, hydroxyl radical and nitrate radical all are capable of producing vapours that contribute to the particle growth in the studied size ranges. We find that GR increases with particle diameter, resulting in up to three-fold GRs for particles with dP ~ 100 nm in comparison to those with dP ~ 10 nm. We use a single particle model to show that this increase in GR can be explained with aerosol-phase reactions, in which semi-volatile vapours form non-volatile dimers. Finally, our analysis reveals that the GR of particles with dP

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Comprehensive analysis of particle growth rates from nucleation mode to cloud condensation nuclei in boreal forest

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-12085-2018 ◽

2018 ◽

Vol 18 (16) ◽

pp. 12085-12103 ◽

Cited By ~ 9

Author(s):

Pauli Paasonen ◽

Maija Peltola ◽

Jenni Kontkanen ◽

Heikki Junninen ◽

Veli-Matti Kerminen ◽

...

Keyword(s):

Boreal Forest ◽

Growth Rates ◽

Cloud Condensation Nuclei ◽

Particle Diameter ◽

Particle Growth ◽

Particle Model ◽

Oxidation Reactions ◽

Condensation Nuclei ◽

Data Set ◽

Condensation Sink

Abstract. Growth of aerosol particles to sizes at which they can act as cloud condensation nuclei (CCN) is a crucial factor in estimating the current and future impacts of aerosol–cloud–climate interactions. Growth rates (GRs) are typically determined for particles with diameters (dP) smaller than 40 nm immediately after a regional new particle formation (NPF) event. These growth rates are often taken as representatives for the particle growth to CCN sizes (dP > 50–100 nm). In modelling frameworks, the concentration of the condensable vapours causing the growth is typically calculated with steady state assumptions, where the condensation sink (CS) is the only loss term for the vapours. Additionally, the growth to CCN sizes is represented with the condensation of extremely low-volatility vapours and gas–particle partitioning of semi-volatile vapours. Here, we use a novel automatic method to determine growth rates from below 10 nm to hundreds of nanometres from a 20-year-long particle size distribution (PSD) data set in boreal forest. With this method, we are able to detect growth rates also at times other than immediately after a NPF event. We show that the GR increases with an increasing oxidation rate of monoterpenes, which is closely coupled with the ambient temperature. Based on our analysis, the oxidation reactions of monoterpenes with ozone, hydroxyl radical and nitrate radical all are capable of producing vapours that contribute to the particle growth in the studied size ranges. We find that GR increases with particle diameter, resulting in up to 3-fold increases in GRs for particles with dP ∼ 100 nm in comparison to those with dP ∼ 10 nm. We use a single particle model to show that this increase in GR can be explained with aerosol-phase reactions, in which semi-volatile vapours form non-volatile dimers. Finally, our analysis reveals that the GR of particles with dP < 100 nm is not limited by the condensation sink, even though the GR of larger particles is. Our findings suggest that in the boreal continental environment, the formation of CCN from NPF or sub-100 nm emissions is more effective than previously thought and that the formation of CCN is not as strongly self-limiting a process as the previous estimates have suggested.

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Natural new particle formation at the coastal Antarctic site Neumayer

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-15655-2015 ◽

2015 ◽

Vol 15 (11) ◽

pp. 15655-15681

Author(s):

R. Weller ◽

K. Schmidt ◽

K. Teinilä ◽

R. Hillamo

Keyword(s):

Growth Rates ◽

Cloud Condensation Nuclei ◽

Particle Diameter ◽

Particle Growth ◽

Particle Formation ◽

New Particle Formation ◽

Particle Size Distributions ◽

Polar Night ◽

Volatile Precursor ◽

Simple Estimation

Abstract. We measured condensation particle (CP) concentrations and particle size distributions at the coastal Antarctic station Neumayer (70°39' S, 8°15' W) during two summer campaigns (from 20 January to 26 March 2012 and 1 February to 30 April 2014) and during polar night between 12 August and 27 September 2014 in the particle diameter (Dp) range from 2.94 to 60.4 nm (2012) and from 6.26 to 212.9 nm (2014). During both summer campaigns we identified all in all 44 new particle formation (NPF) events. From 10 NPF events, particle growth rates could be determined to be around 0.90 ± 0.46 nm h−1 (mean ± SD; range: 0.4 to 1.9 nm h−1). With the exception of one case, particle growth was generally restricted to the nucleation mode (Dp < 25 nm) and the duration of NPF events was typically around 6.0 ± 1.5 h (mean ± SD; range: 4 to 9 h). Thus in the main, particles did not grow up to sizes required for acting as cloud condensation nuclei. NPF during summer usually occurred in the afternoon in coherence with local photochemistry. During winter, two NPF events could be detected, though showing no ascertainable particle growth. A simple estimation indicated that apart from sulfuric acid, the derived growth rates required other low volatile precursor vapours.

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Natural new particle formation at the coastal Antarctic site Neumayer

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-11399-2015 ◽

2015 ◽

Vol 15 (19) ◽

pp. 11399-11410 ◽

Cited By ~ 21

Author(s):

R. Weller ◽

K. Schmidt ◽

K. Teinilä ◽

R. Hillamo

Keyword(s):

Growth Rates ◽

Cloud Condensation Nuclei ◽

Particle Diameter ◽

Particle Growth ◽

Particle Formation ◽

New Particle Formation ◽

Particle Size Distributions ◽

Polar Night ◽

Volatile Precursor ◽

Simple Estimation

Abstract. We measured condensation particle (CP) concentrations and particle size distributions at the coastal Antarctic station Neumayer (70°39´ S, 8°15´ W) during two summer campaigns (from 20 January to 26 March 2012 and 1 February to 30 April 2014) and during the polar night between 12 August and 27 September 2014 in the particle diameter (Dp) range from 2.94 to 60.4 nm (2012) and from 6.26 to 212.9 nm (2014). During both summer campaigns we identified all in all 44 new particle formation (NPF) events. From 10 NPF events, particle growth rates could be determined to be around 0.90 ± 0.46 nm h−1 (mean ± SD; range: 0.4–1.9 nm h−1). With the exception of one case, particle growth was generally restricted to the nucleation mode (Dp < 25 nm) and the duration of NPF events was typically around 6.0 ± 1.5 h (mean ± SD; range: 4–9 h). Thus, in the surrounding area of Neumayer, particles did not grow up to sizes required for acting as cloud condensation nuclei. NPF during summer usually occurred in the afternoon in coherence with local photochemistry. During winter, two NPF events could be detected, though showing no ascertainable particle growth. A simple estimation indicated that apart from sulfuric acid, the derived growth rates required other low volatile precursor vapours.

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Summertime observations of ultrafine particles and cloud condensation nuclei from the boundary layer to the free troposphere in the Arctic

10.5194/acp-2016-701 ◽

2016 ◽

Cited By ~ 2

Author(s):

Julia Burkart ◽

Megan D. Willis ◽

Heiko Bozem ◽

Jennie L. Thomas ◽

Kathy Law ◽

...

Keyword(s):

Boundary Layer ◽

Ultrafine Particles ◽

Cloud Condensation Nuclei ◽

Particle Diameter ◽

Open Ocean ◽

The Arctic ◽

Condensation Nuclei ◽

Aerosol Composition ◽

Low Level ◽

20 Nm

Abstract. The Arctic is extremely sensitive to climate change. Shrinking sea ice extent increases the area covered by open ocean during Arctic summer, which impacts the surface albedo and aerosol and cloud properties among many things. In this context extensive aerosol measurements (aerosol composition, particle number and size, cloud condensation nuclei, and trace gases) were made during 11 flights of the NETCARE July, 2014 airborne campaign conducted from Resolute Bay, Nunavut (74N, 94W). Flights routinely included vertical profiles from about 60 to 3000 m a.g.l. as well as several low-level horizontal transects over open ocean, fast ice, melt ponds, and polynyas. Here we discuss the vertical distribution of ultrafine particles (UFP, particle diameter, dp: 5–20 nm), size distributions of larger particles (dp: 20 nm to 1 μm), and cloud condensation nuclei (CCN, supersaturation = 0.6 %) in relation to meteorological conditions and underlying surfaces. UFPs were observed predominantly within the boundary layer, where concentrations were often several hundreds to a few thousand particles per cubic centimeter. Occasionally, particle concentrations below 10 cm−3 were found. The highest UFP concentrations were observed above open ocean and at the top of low-level clouds, whereas numbers over ice-covered regions were substantially lower. Overall, UFP formation events were frequent in a clean boundary layer with a low condensation sink. In a few cases this ultrafine mode extended to sizes larger than 40 nm, suggesting that these UFP can grow into a size range where they can impact clouds and therefore climate.

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Intercomparison of modal and sectional aerosol microphysics representations within the same 3-D global chemical transport model

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-623-2012 ◽

2012 ◽

Vol 12 (1) ◽

pp. 623-689 ◽

Cited By ~ 2

Author(s):

G. W. Mann ◽

K. S. Carslaw ◽

D. A. Ridley ◽

D. V. Spracklen ◽

K. J. Pringle ◽

...

Keyword(s):

Size Distribution ◽

Transport Model ◽

Cloud Condensation Nuclei ◽

Particle Growth ◽

Free Troposphere ◽

Chemical Transport Model ◽

Condensation Nuclei ◽

Chemistry Transport Model ◽

Surface Mass ◽

Cloud Processing

Abstract. A global modal aerosol microphysics module (GLOMAP-mode) is evaluated and improved by comparing against a sectional version (GLOMAP-bin) and observations in the same 3-D global offline chemistry transport model. With both schemes, the model captures the main features of the global particle size distribution, with sub-micron aerosol approximately unimodal in continental regions and bi-modal in marine regions. Initial bin-mode comparisons showed that various size distribution parameter settings (mode widths and inter-modal separation sizes) resulted in clear biases compared to the sectional scheme. By adjusting these parameters in the modal scheme, much better agreement is achieved against the bin scheme and observations. Surface mass of sulphate, sea-salt, black carbon (BC) and organic carbon (OC) are, on the annual mean, within 25 % in the two schemes in nearly all regions. On the annual mean, surface level concentrations of condensation nuclei (CN), cloud condensation nuclei (CCN), surface area density and condensation sink also compare within 25 % in most regions. However, marine CCN concentrations between 30° N and 30° S are systematically higher in the modal scheme, by 25–60 %, which we attribute to differences in size-resolved particle growth or cloud-processing. Larger differences also exist in regions or seasons dominated by biomass burning and in free-troposphere and high-latitude regions. Indeed, in the free-troposphere, GLOMAP-mode BC is a factor 2–4 higher than GLOMAP-bin, likely due to differences in size-resolved scavenging. Nevertheless, in most parts of the atmosphere, we conclude that bin-mode differences are much less than model-observation differences, although some processes are missing in these runs which may pose a bigger challenge to modal schemes (e.g. boundary layer nucleation, ultra-fine sea-spray). The findings here underline the need for a spectrum of complexity in global models, with size-resolved aerosol properties predicted by modal schemes needing to be continually benchmarked and improved against freely evolving sectional schemes and observations.

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Investigating three patterns of new particles growing to the size of cloud condensation nuclei in Beijing's urban atmosphere

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-183-2021 ◽

2021 ◽

Vol 21 (1) ◽

pp. 183-200

Author(s):

Liya Ma ◽

Yujiao Zhu ◽

Mei Zheng ◽

Yele Sun ◽

Lei Huang ◽

...

Keyword(s):

Cloud Condensation Nuclei ◽

Chemical Species ◽

Particle Growth ◽

Growth Patterns ◽

Urban Atmosphere ◽

Condensation Nuclei ◽

Two Stage ◽

Continuous Increase ◽

One Stage ◽

New Particles

Abstract. The growth of newly formed particles with diameters from ∼ 10 nm to larger sizes was investigated in Beijing's urban atmosphere during 10–23 December 2011, 12–27 April 2012, and June–August 2014. In 11 out of 27 new particle formation (NPF) events during June–August, the maximum geometric median diameter (Dpgmax) of newly formed particles exceeded 75 nm, and the grown new particles may contribute to the population of cloud condensation nuclei. In contrast, no apparent growth in new particles with Dpgmax < 20 nm was observed in all of the events in December, in approximately half of the NPF events in April, and in only two events during June–August. New particles observed in the latter NPF events were too small to be activated as cloud condensation nuclei. Apparent new particle growth with Dpgmax ≤ 50 nm was observed in the remaining 18 NPF events. The 11 NPF events during June–August with Dpgmax exceeding 75 nm were analyzed in detail. The particle growth patterns can be clearly classified into three types: one-stage growth and two-stage growth-A and growth-B patterns. The one-stage growth pattern is characterized by a continuous increase in Dpg with Dpgmax ≥ 80 nm (4 out of 11 NPF events), and the two-stage growth-A and growth-B patterns are characterized by no apparent growth and shrinkage of particles, respectively, in the middle 2–4 h of the growth period (7 out of 11 NPF events). Combining the observations of gaseous pollutants and measured (or modeled) concentrations of particulate chemical species, the three growth patterns were discussed in terms of the spatial heterogeneity of NPF, formation of secondary aerosols, and evaporation of semivolatile particulates. Secondary organic species and NH4NO3 were argued to be two major contributors to the growth of new particles, but NH4NO3 likely contributed to growth only in the late afternoon and/or at nighttime.

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Organic acids as cloud condensation nuclei: Laboratory studies of highly soluble and insoluble species

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-3-949-2003 ◽

2003 ◽

Vol 3 (1) ◽

pp. 949-982 ◽

Cited By ~ 3

Author(s):

P. Pradeep Kumar ◽

K. Broekhuizen ◽

J. P. D. Abbatt

Keyword(s):

Organic Acids ◽

Room Temperature ◽

Cloud Condensation Nuclei ◽

Particle Diameter ◽

Diffusion Chamber ◽

Laboratory Studies ◽

Condensation Nuclei ◽

Gradient Diffusion ◽

Kohler Theory ◽

Good Agreement

Abstract. The ability of sub-micron-sized organic acid particles to act as cloud condensation nuclei (CCN) has been examined at room temperature using a newly constructed continuous-flow, thermal-gradient diffusion chamber (TGDC). The organic acids studied were: oxalic, malonic, glutaric, oleic and stearic. The CCN properties of the highly soluble acids – oxalic, malonic and glutaric – match very closely Kohler theory predictions which assume full dissolution of the dry particle and a surface tension of the growing droplet equal to that of water. In particular, for supersaturations between 0.3 and 0.6, agreement between the dry particle diameter which gives 50% activation and that calculated from Kohler theory is to within 3 nm on average. In the course of the experiments, considerable instability of glutaric acid particles was observed as a function of time and there is evidence that they fragment to some degree to smaller particles. Stearic acid and oleic acid, which are both highly insoluble in water, did not activate at supersaturations of 0.6% with dry diameters up to 140 nm. Finally, to validate the performance of the TGDC, we present results for the activation of ammonium sulfate particles that demonstrate good agreement with Kohler theory if solution non-ideality is considered. Our findings support earlier studies in the literature that showed highly soluble organics to be CCN active but insoluble species to be largely inactive.

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Climatology of new particle formation at Izaña mountain GAW observatory in the subtropical North Atlantic

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-3865-2014 ◽

2014 ◽

Vol 14 (8) ◽

pp. 3865-3881 ◽

Cited By ~ 21

Author(s):

M. I. García ◽

S. Rodríguez ◽

Y. González ◽

R. D. García

Keyword(s):

Sulfuric Acid ◽

North Atlantic ◽

Growth Rates ◽

Particle Growth ◽

Particle Formation ◽

Dust Particles ◽

New Particle Formation ◽

Data Set ◽

Mean Values ◽

Condensation Sink

Abstract. A climatology of new particle formation (NPF) events at high altitude in the subtropical North Atlantic is presented. A 4-year data set (June 2008–June 2012), which includes number size distributions (10–600 nm), reactive gases (SO2, NOx, and O3), several components of solar radiation and meteorological parameters, measured at Izaña Global Atmosphere Watch (GAW) observatory (2373 m above sea level; Tenerife, Canary Islands) was analysed. NPF is associated with the transport of gaseous precursors from the boundary layer by orographic buoyant upward flows that perturb the low free troposphere during daytime. On average, 30% of the days contained an NPF event. Mean values of the formation and growth rates during the study period were 0.46 cm−3 s−1 and 0.42 nm h−1, correspondingly. There is a clearly marked NPF season (May–August), when these events account for 50–60% of the days per month. Monthly mean values of the formation and growth rates exhibit higher values in this season, 0.49–0.92 cm−3 s−1 and 0.48–0.58 nm h−1, respectively. During NPF events, SO2, UV radiation and upslope winds showed higher values than during non-events. The overall data set indicates that SO2 plays a key role as precursor, although other species seem to contribute during some periods. Condensation of sulfuric acid vapour accounts for most of the measured particle growth during most of the year (~70%), except for some periods. In May, the highest mean growth rates (~0.6 nm h−1) and the lowest contribution of sulfuric acid (~13%) were measured, suggesting a significant involvement of other condensing vapours. The SO2 availability seems also to be the most influencing parameter in the year-to-year variability in the frequency of NPF events. The condensation sink showed similar features to other mountain sites, showing high values during NPF events. Summertime observations, when Izaña is within the Saharan Air Layer, suggest that dust particles may play a significant role acting as coagulation sink of freshly formed nucleation particles. The contribution of dust particles to the condensation sink of sulfuric acid vapours seems to be modest (~8% as average). Finally, we identified a set of NPF events in which two nucleation modes, which may evolve at different rates, occur simultaneously and for which further investigations are necessary.

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Physical properties of the sub-micrometer aerosol over the Amazon rain forest during the wet-to-dry season transition - comparison of modeled and measured CCN concentrations

Atmospheric Chemistry and Physics ◽

10.5194/acp-4-2119-2004 ◽

2004 ◽

Vol 4 (8) ◽

pp. 2119-2143 ◽

Cited By ~ 123

Author(s):

J. Rissler ◽

E. Swietlicki ◽

J. Zhou ◽

G. Roberts ◽

M. O. Andreae ◽

...

Keyword(s):

Size Distribution ◽

Biomass Burning ◽

Time Resolution ◽

Large Scale ◽

Transition Period ◽

Cloud Condensation Nuclei ◽

Particle Diameter ◽

Hygroscopic Growth ◽

Condensation Nuclei ◽

Number Size Distribution

Abstract. Sub-micrometer atmospheric aerosol particles were studied in the Amazon region, 125 km northeast of Manaus, Brazil (-1°55.2'S, 59°28.1'W). The measurements were performed during the wet-to-dry transition period, 4-28 July 2001 as part of the LBA (Large-Scale Biosphere Atmosphere Experiment in Amazonia) CLAIRE-2001 (Cooperative LBA Airborne Regional Experiment) experiment. The number size distribution was measured with two parallel differential mobility analyzers, the hygroscopic growth at 90% RH with a Hygroscopic Tandem Mobility Analyzer (H-TDMA) and the concentrations of cloud condensation nuclei (CCN) with a cloud condensation nuclei counter. A model was developed that uses the H-TDMA data to predict the number of soluble molecules or ions in the individual particles and the corresponding minimum particle diameter for activation into a cloud droplet at a certain supersaturation. Integrating the number size distribution above this diameter, CCN concentrations were predicted with a time resolution of 10 min and compared to the measured concentrations. During the study period, three different air masses were identified and compared: clean background, air influenced by aged biomass burning, and moderately polluted air from recent local biomass burning. For the clean period 2001, similar number size distributions and hygroscopic behavior were observed as during the wet season at the same site in 1998, with mostly internally mixed particles of low diameter growth factor (~1.3 taken from dry to 90% RH). During the periods influenced by biomass burning the hygroscopic growth changed slightly, but the largest difference was seen in the number size distribution. The CCN model was found to be successful in predicting the measured CCN concentrations, typically within 25%. A sensitivity study showed relatively small dependence on the assumption of which model salt that was used to predict CCN concentrations from H-TDMA data. One strength of using H-TDMA data to predict CCN concentrations is that the model can also take into account soluble organic compounds, insofar as they go into solution at 90% RH. Another advantage is the higher time resolution compared to using size-resolved chemical composition data.

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Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-13393-2015 ◽

2015 ◽

Vol 15 (23) ◽

pp. 13393-13411 ◽

Cited By ~ 15

Author(s):

S. J. Lawson ◽

M. D. Keywood ◽

I. E. Galbally ◽

J. L. Gras ◽

J. M. Cainey ◽

...

Keyword(s):

Particle Size ◽

Biomass Burning ◽

Cloud Condensation Nuclei ◽

Trace Gases ◽

Particle Growth ◽

Dominant Mode ◽

Condensation Nuclei ◽

Substantial Impact ◽

Marine Air ◽

Cape Grim

Abstract. Biomass burning (BB) plumes were measured at the Cape Grim Baseline Air Pollution Station during the 2006 Precursors to Particles campaign, when emissions from a fire on nearby Robbins Island impacted the station. Measurements made included non-methane organic compounds (NMOCs) (PTR-MS), particle number size distribution, condensation nuclei (CN) > 3 nm, black carbon (BC) concentration, cloud condensation nuclei (CCN) number, ozone (O3), methane (CH4), carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), nitrous oxide (N2O), halocarbons and meteorology. During the first plume strike event (BB1), a 4 h enhancement of CO (max ~ 2100 ppb), BC (~ 1400 ng m-3) and particles > 3 nm (~ 13 000 cm-3) with dominant particle mode of 120 nm were observed overnight. A wind direction change lead to a dramatic reduction in BB tracers and a drop in the dominant particle mode to 50 nm. The dominant mode increased in size to 80 nm over 5 h in calm sunny conditions, accompanied by an increase in ozone. Due to an enhancement in BC but not CO during particle growth, the presence of BB emissions during this period could not be confirmed. The ability of particles > 80 nm (CN80) to act as CCN at 0.5 % supersaturation was investigated. The ΔCCN / ΔCN80 ratio was lowest during the fresh BB plume (56 ± 8 %), higher during the particle growth period (77 ± 4 %) and higher still (104 ± 3 %) in background marine air. Particle size distributions indicate that changes to particle chemical composition, rather than particle size, are driving these changes. Hourly average CCN during both BB events were between 2000 and 5000 CCN cm-3, which were enhanced above typical background levels by a factor of 6–34, highlighting the dramatic impact BB plumes can have on CCN number in clean marine regions. During the 29 h of the second plume strike event (BB2) CO, BC and a range of NMOCs including acetonitrile and hydrogen cyanide (HCN) were clearly enhanced and some enhancements in O3 were observed (ΔO3 / ΔCO 0.001–0.074). A short-lived increase in NMOCs by a factor of 10 corresponded with a large CO enhancement, an increase of the NMOC / CO emission ratio (ER) by a factor of 2–4 and a halving of the BC / CO ratio. Rainfall on Robbins Island was observed by radar during this period which likely resulted in a lower fire combustion efficiency, and higher emission of compounds associated with smouldering. This highlights the importance of relatively minor meteorological events on BB emission ratios. Emission factors (EFs) were derived for a range of trace gases, some never before reported for Australian fires, (including hydrogen, phenol and toluene) using the carbon mass balance method. This provides a unique set of EFs for Australian coastal heathland fires. Methyl halide EFs were higher than EFs reported from other studies in Australia and the Northern Hemisphere which is likely due to high halogen content in vegetation on Robbins Island. This work demonstrates the substantial impact that BB plumes can have on the composition of marine air, and the significant changes that can occur as the plume interacts with terrestrial, aged urban and marine emission sources.

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