Emission and dry deposition of accumulation mode particles in the Amazon Basin

Ahlm, Lars; Krejci, Radovan; Nilsson, E. Douglas; Mårtensson, E. M.; Vogt, Matthias; Artaxo, Paulo

doi:10.5194/acp-10-10237-2010

Cited by 27 publications

(35 citation statements)

References 57 publications

(69 reference statements)

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“…Lamaud et al (1994) found that particle deposition velocity (V d ) is related to friction velocity (u * ) and atmospheric stability. This was also supported by the studies of Grönholm et al (2007), Pryor (2006), Pryor et al (2007), and Ahlm et al (2009Ahlm et al ( , 2010. Many studies found fluxes were often upward (negative "deposition"), with frequency ranging from near 20 % to over 40 % (Pryor et al, 2008c) of the total number of flux measurements.…”

Section: Introductionsupporting

confidence: 48%

“…Forest types and locations include: mixed deciduous in eastern Tennessee (Hicks et al, 1989) and southern Indiana, USA (Pryor et al, 2009); pine in Hyytiälä, Finland (e.g. Buzorius et al, 1998;Grönholm et al, 2007); maritime pine in Les Landes, France (Lamaud et al, 1994); douglas fir in Northern Holland (Gallagher et al, 1997); spruce in Germany, at Solling (Bleyl, 2001) and near Münchberg (Held and Klemm, 2006); beech in Soro, Denmark (Pryor, 2006); and Amazonian rain forest near Manaus, Brazil (Ahlm et al, 2010). The majority of these studies measured aerosol fluxes using the eddy covariance (EC) technique with Condensational Particle Counters (CPCs), which measure the total particle number concentration over a particle size range typically between 10 nm and 1 µm.…”

Section: Introductionmentioning

confidence: 99%

“…The majority of these studies measured aerosol fluxes using the eddy covariance (EC) technique with Condensational Particle Counters (CPCs), which measure the total particle number concentration over a particle size range typically between 10 nm and 1 µm. Size-resolved fluxes have been measured using optical particle counters (Gallagher et al, 1997;Ahlm et al, 2010), relaxed Eddy Accumulation (REA) with a Differential Mobility Particle Sizer (DMPS; Grönholm et al, 2007), and EC with a Fast Mobility Particle Sizer (FMPS; Pryor et al, 2009). Lamaud et al (1994) found that particle deposition velocity (V d ) is related to friction velocity (u * ) and atmospheric stability.…”

Section: Introductionmentioning

confidence: 99%

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Aerosol flux measurements above a mixed forest at Borden, Ontario

et al. 2011

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Abstract. Aerosol fluxes were measured above a mixed forest by Eddy Covariance (EC) with a Fast Mobility Particle Sizer (FMPS) at the Borden Forest Research Station in Ontario, Canada between 13 July and 12 August 2009. Chemically speciated flux measurements were made at a height of 29 m at the same location between 19 July and 2 August, 2006 using a Quadrupole Aerosol Mass Spectrometer (Q-AMS). The Q-AMS measured an average sulphate deposition velocity of 0.3 mm s −1 and an average nitrate deposition velocity of 4.8 mm s −1 . The FMPS, mounted at a height of 33 m (approximately 10 m above the canopy top) and housed in a temperature controlled enclosure, measured sizeresolved particle concentrations from 3 to 410 nm diameter at a rate of 1 Hz. For the size range 18 < D < 452 nm, 60 % of fluxes were upward. The exchange velocity was between −0.5 and 2.0 mm s −1 , with median values near 0.5 mm s −1 for all sizes between 22 and 310 nm. The size distribution of the apparent production rate of particles at 33 m peaked at a diameter of 75 nm. Results indicate a decoupling of the above and below canopy spaces, whereby particles are stored in the canopy space at night, and are then diluted with cleaner air above during the day.

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Section: Introductionsupporting

confidence: 48%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Aerosol flux measurements above a mixed forest at Borden, Ontario

et al. 2011

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“…In the past, only a few attempts were made to directly measure the flux of bacteria from plant canopies (Lindemann et al, 1982;Lindemann and Upper, 1985;Lighthart and Shaffer, 1994;Crawford et al, 2014). Direct eddy covariance measurements of aerosol exchange in tropical forests, where PBAs represent a significant fraction of the airborne particulate matter (Graham et al, 2003), were also performed by Ahlm et al (2010) and , potentially giving a proxy for microbial emission in tropical ecosystems. The mass of PBAs that is actually released by different land use types under different conditions and, more importantly, the specific composition of such fluxes and their quantification remains so far mostly unresolved.…”

Section: Introductionmentioning

confidence: 99%

Measurements and modeling of surface–atmosphere exchange of microorganisms in Mediterranean grassland

et al. 2017

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Abstract. Microbial aerosols (mainly composed of bacterial and fungal cells) may constitute up to 74 % of the total aerosol volume. These biological aerosols are not only relevant to the dispersion of pathogens, but they also have geochemical implications. Some bacteria and fungi may, in fact, serve as cloud condensation or ice nuclei, potentially affecting cloud formation and precipitation and are active at higher temperatures compared to their inorganic counterparts. Simulations of the impact of microbial aerosols on climate are still hindered by the lack of information regarding their emissions from ground sources. This present work tackles this knowledge gap by (i) applying a rigorous micrometeorological approach to the estimation of microbial net fluxes above a Mediterranean grassland and (ii) developing a deterministic model (the PLAnET model) to estimate these emissions on the basis of a few meteorological parameters that are easy to obtain. The grassland is characterized by an abundance of positive net microbial fluxes and the model proves to be a promising tool capable of capturing the day-to-day variability in microbial fluxes with a relatively small bias and sufficient accuracy. PLAnET is still in its infancy and will benefit from future campaigns extending the available training dataset as well as the inclusion of ever more complex and critical phenomena triggering the emission of microbial aerosol (such as rainfall). The model itself is also adaptable as an emission module for dispersion and chemical transport models, allowing further exploration of the impact of landcover-driven microbial aerosols on the atmosphere and climate.

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“…Particle number fluxes over the tropical forest typically correspond to net deposition, with potential forest sources of PBAP in the coarse mode (>1 μm) just after sunrise (Ahlm et al 2009;Ahlm et al 2010;Rizzo et al 2010). The observation of net deposition of NR-PM 1 aerosol mass with an exchange velocity of −0.1 mm s −1 is consistent with particle number flux measurements at a nearby tower site with a modal exchange velocity of −0.3 mm s −1 (Ahlm et al 2009) (see the online supplemental information for comparison of particle number versus mass fluxes).…”

Section: Amaze-08 Diel Patternsmentioning

confidence: 99%

Chemically Resolved Particle Fluxes Over Tropical and Temperate Forests

Farmer

Chen

Kimmel

et al. 2013

Aerosol Science and Technology

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Chemically resolved submicron (PM 1 ) particle mass fluxes were measured by eddy covariance with a high resolution time-of-flight aerosol mass spectrometer over temperate and tropical forests during the BEARPEX-07 and AMAZE-08 campaigns. Fluxes during AMAZE-08 were small and close to the detection limit (<1 ng m −2 s −1 ) due to low particle mass concentrations (<1 µg m −3). During BEARPEX-07, concentrations were five times larger, with mean mid-day deposition fluxes of −4.8 ng m Address correspondence to Jose L. Jimenez, CIRES and Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, USA. E-mail: jose.jimenez@colorado.edu; or to Delphine K. Farmer, Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA. E-mail: delphine.farmer@colostate. edu partitioning due to canopy temperature gradients, emission of primary biological aerosol particles, and wet and dry deposition. As a result of these competing processes, individual chemical components had fluxes of varying magnitude and direction during both campaigns. Oxygenated organic components representing regionally aged aerosol deposited, while components of fresh secondary organic aerosol (SOA) emitted. During BEARPEX-07, rapid incanopy oxidation caused rapid SOA growth on the timescale of biosphere-atmosphere exchange. In-canopy SOA mass yields were 0.5-4%. During AMAZE-08, the net organic aerosol flux was influenced by deposition, in-canopy SOA formation, and thermal shifts in gas-particle partitioning. Wet deposition was estimated to be an order of magnitude larger than dry deposition during AMAZE-08. Small shifts in organic aerosol concentrations from anthropogenic sources such as urban pollution or biomass burning alters the balance between flux terms. The semivolatile nature of the Amazonian organic aerosol suggests a feedback in which warmer temperatures will partition SOA to the gas-phase, reducing their light scattering and thus potential to cool the region.

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Emission and dry deposition of accumulation mode particles in the Amazon Basin

Cited by 27 publications

References 57 publications

Aerosol flux measurements above a mixed forest at Borden, Ontario

Aerosol flux measurements above a mixed forest at Borden, Ontario

Measurements and modeling of surface–atmosphere exchange of microorganisms in Mediterranean grassland

Chemically Resolved Particle Fluxes Over Tropical and Temperate Forests

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