Aerosols in the Amazon, Particle Formation

New Particle Formation in Amazonia

Prepared for the February 2008 meeting on Aerosols in the Amazon.

Contacts

Peter McMurry (mcmurry (at) me.umn.edu)

Dominick Spracklen (dominick (at) env.leeds.ac.uk)

Observations from the Amazon

Zhou et al., (2002). Submicrometer aerosol particle size distribution and hygroscopic growth measured in the Amazon rain forest during the wet season, J. Geophys. Res., 107 (D20), 8055, doi:10.1029/2000JD000203, 2002.

This paper reports the first number-size distribution of sub-micrometre aerosol (3-850 nm) over the Amazon. Observations were made during the wet season (March-April 1998) in a remote environment (125 km from Manaus). An ultrafine mode (24 nm diameter, number concentration 92 cm-3) occurred ~30% of the time. No particle formation events (growth of 3 nm particles) were observed. The authors suggest that the ultrafine mode is formed above and mixed downward to the surface.

Rissler et al., (2004). 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. Atmos. Chem. Phys., 4, 2119-2143.

Sub-micrometre aerosol observations in remote location (125 km from Manaus) during the wet-to-dry transition (July 2001). An ultrafine mode (13 nm diameter, number concentration ~310 cm-3) was observed about ~70% of the time. No particle formation events (growth of 3 nm particles) observed. Ultrafine mode present during inversion breakup in the morning, during inversion buildup at night and during periods of heavy rain.

Rissler et al., (2006). Size distribution and hygroscopic properties of aerosol particles from dry-season biomass burning in Amazonia. Atmos. Chem. Phys., 6, 471-491.

Sub-micrometer aerosol observations in SW Amazonia during the dry season and transition to wet (Sep-Nov 2002). Observation of biomass burning aerosol. Greater number concentrations of ultrafine particles observed than previous observations (12 nm diameter, ~800-1000 cm-3). Observations of a diel pattern similar to that observed by Rissler et al., 2004 - suggesting that this is a characteristic feature of the Amazon. Ultrafine particles observed around sunrise and sunset and present until around midnight. Observations of ultrafine particles in morning (before onset of convection) not consistent with the theory of nucleation at higher levels and mixing to the surface. Suggestion that nucleation events in the Amazon are associated with micro- and not regional-scale meteorology.

Krejci et al., (2005). Spatial and temporal distribution of atmospheric aerosols in the lowermost troposphere over the Amazonian tropical rainforest, Atmos. Chem. Phys., 5, 1527-1543.

Airbone observations over French Guyana and Suriname during March 1998. Vertical profiles.

Background

Kulmala et al., (2004). Formation and growth rates of ultrafine atmospheric particles:a review of observations. Journal of Aerosol Science, 35, 143-176.

A review of particle formation events observed around the world. The paper reports particle formation and growth rates and observations of particles down to 3 nm size. There is no observational evidence for the formation and growth of 3 nm particles at the surface in the Amazon.

Additional Background

Kulmala, M. et al. (2007), Toward Direct Measurement of Atmospheric Nucleation, Science, 318, 89-92.
McMurry, P. H., et al. (2005), A criterion for new particle formation in the sulfur-rich Atlanta atmosphere, J. Geophys. Res., 110, D22S02, doi:10.1029/2005JD005901.
Lee, S.H., et al. (2003). Particle formation by ion nucleation in the upper troposphere and lower stratosphere, Science, 301, 1886-1889.
Yu, F.Q. and Turco, R.P. (2006), Effect of ammonia on new particle formation: A kinetic H2SO4-H2O-NH3 nucleation model constrained by laboratory experiments, J. Geophys. Res., 111, D01204, doi:10.1029/2005JD005968.
Nilsson, E.D., M. Kulmala, The potential for atmospheric mixing processes to enhance the binary nucleation rate, J. Geophys. Res., 103(D1), 1381-1390, 10.1029/97JD02629, 1998.
Kulmala M., et al. (2006), Deep convective clouds as aerosol production engines: Role of insoluble organics, J. Geophys. Res., 111, D17202, doi:10.1029/2005JD006963
Kulmala M, et al. (2000), Stable sulphate clusters as a source of new atmospheric particles, Nature 404 (6773), 66-69.
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Lehtinen, et al. (2007), Estimating nucleation rates from apparent particle formation rates and vice versa: Revised formulation of the Kerminen- Kulmala equation, Journal of Aerosol Science 38(9), 988-994.
McMurry, P. H. (1983), New Particle Formation in the Presence of an Aerosol: Rates, Time Scales and sub-0.01 m Size Distributions., J. Colloid Interface Sci. 95(1), 72-80.
McMurry, P. H. and S. K. Friedlander (1979), New particle formation in the presence of an aerosol,Atmos. Environ. 13, 1635-1651.
Spracklen, D.V., et al. (2006), The contribution of boundary layer nucleation events to total particle concentrations on regional and global scales, Atmospheric Chemistry and Physics, Vol. 6, pp 5631-5648.
Kerminen, V. M. and M. Kulmala (2002), Analytical formulae connecting the "real" and the "apparent" nucleation rate and the nuclei number concentration for atmospheric nucleation events, Journal of Aerosol Science 33(4), 609-622.
Smith, J. N., et al. (2005), Chemical composition of atmospheric nanoparticles during nucleation events in Atlanta, Journal of Geophysical Research-Atmospheres 110(D22): S2203.
Stolzenburg, et al. (2005). Growth rates of freshly nucleated atmospheric particles in Atlanta, Journal of Geophysical Research-Atmospheres 110(D22): S2205.
Voisin, D., et al. (2003), Thermal desorption chemical ionization mass spectrometer for ultrafine particle chemical composition, Aerosol Sci. Technol. 37, 471-475.