Articles | Volume 11, issue 1
Atmos. Chem. Phys., 11, 165–173, 2011

Special issue: Arctic Summer Cloud Ocean Study (ASCOS) (ACP/AMT/OS inter-journal...

Atmos. Chem. Phys., 11, 165–173, 2011

Research article 10 Jan 2011

Research article | 10 Jan 2011

An Arctic CCN-limited cloud-aerosol regime

T. Mauritsen1, J. Sedlar2,3, M. Tjernström2,3, C. Leck2,3, M. Martin4, M. Shupe5, S. Sjogren6, B. Sierau4, P. O. G. Persson5, I. M. Brooks7, and E. Swietlicki6 T. Mauritsen et al.
  • 1Max Planck Institute for Meteorology, Hamburg, Germany
  • 2Bert Bolin Center for Climate Research, Stockholm, Sweden
  • 3Stockholm University, Stockholm, Sweden
  • 4Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
  • 5University of Colorado and NOAA-ESRL, Boulder, Colorado, USA
  • 6Lund University, Lund, Sweden
  • 7University of Leeds, Leeds, UK

Abstract. On average, airborne aerosol particles cool the Earth's surface directly by absorbing and scattering sunlight and indirectly by influencing cloud reflectivity, life time, thickness or extent. Here we show that over the central Arctic Ocean, where there is frequently a lack of aerosol particles upon which clouds may form, a small increase in aerosol loading may enhance cloudiness thereby likely causing a climatologically significant warming at the ice-covered Arctic surface. Under these low concentration conditions cloud droplets grow to drizzle sizes and fall, even in the absence of collisions and coalescence, thereby diminishing cloud water. Evidence from a case study suggests that interactions between aerosol, clouds and precipitation could be responsible for attaining the observed low aerosol concentrations.

Final-revised paper