On the potential contribution of open lead particle emissions to the central Arctic aerosol concentration 1University of Bayreuth, Bayreuth Center of Ecology and Environmental Research, 95440 Bayreuth, Germany
01 Apr 2011
2Stockholm University, Department of Meteorology, 10691 Stockholm, Sweden
3University of Leeds, School of Earth and Environment, Leeds, LS2 9JT, UK
4Bert Bolin Center for Climate Research, Stockholm University, 10691 Stockholm, Sweden
Received: 10 Sep 2010 – Published in Atmos. Chem. Phys. Discuss.: 25 Oct 2010Abstract. We present direct eddy covariance measurements of aerosol number
fluxes, dominated by sub-50 nm particles, at the edge of an ice floe
drifting in the central Arctic Ocean. The measurements were made during the
ice-breaker borne ASCOS (Arctic Summer Cloud Ocean Study)
expedition in August 2008 between 2°–10° W longitude and 87°–87.5° N latitude. The median aerosol transfer velocities over
different surface types (open water leads, ice ridges, snow and ice
surfaces) ranged from 0.27 to 0.68 mm s−1 during deposition-dominated
episodes. Emission periods were observed more frequently over the open lead,
while the snow behaved primarily as a deposition surface. Directly measured
aerosol fluxes were compared with particle deposition parameterizations in
order to estimate the emission flux from the observed net aerosol flux.
Finally, the contribution of the open lead particle source to atmospheric
variations in particle number concentration was evaluated and compared with
the observed temporal evolution of particle number. The direct emission of
aerosol particles from the open lead can explain only 5–10% of the
observed particle number variation in the mixing layer close to the surface.
Revised: 13 Mar 2011 – Accepted: 20 Mar 2011 – Published: 01 Apr 2011
Citation: Held, A., Brooks, I. M., Leck, C., and Tjernström, M.: On the potential contribution of open lead particle emissions to the central Arctic aerosol concentration, Atmos. Chem. Phys., 11, 3093-3105, doi:10.5194/acp-11-3093-2011, 2011.