HR: 17:30h
AN: A52G-07    [PDF]
TI: Using SAGE III PSC observations to derive solid particle nucleation rates in the Arctic
AU: * Ridley, D
EM: dar10@leicester.ac.uk
AF: University of Leeds, Woodhouse Lane, Leeds, LS2 9JT United Kingdom
AU: Carslaw, K S
EM: carslaw@env.leeds.ac.uk
AF: University of Leeds, Woodhouse Lane, Leeds, LS2 9JT United Kingdom
AU: Mann, G
EM: gmann@env.leeds.ac.uk
AF: University of Leeds, Woodhouse Lane, Leeds, LS2 9JT United Kingdom
AU: Davies, S
EM: stewart@env.leeds.ac.uk
AF: University of Leeds, Woodhouse Lane, Leeds, LS2 9JT United Kingdom
AU: Poole, L R
EM: l.r.poole@nasa.gov
AF: NASA Langley Research Center, NASA, Hampton, VA 23681-0001 United States
AU: Luo, B
EM: luo
AF: ETH-Zurich, ETH Hoenggerberg HPP, Zurich, CH 8093 Switzerland
AU: Peter, T
EM: thomas.peter@ethz.ch
AF: ETH-Zurich, ETH Hoenggerberg HPP, Zurich, CH 8093 Switzerland
AB: Stratospheric Aerosol and Gas Experiment (SAGE) III aerosol extinction data from the Arctic in December 2002 are used to evaluate and refine a 3-D model of large NAT particles (NAT rocks). The observations and model results are used in a unique iterative procedure to determine the optimum NAT nucleation rate as a function of NAT supersaturation. We use the DLAPSE model (Denitrification by Lagrangian Particle Sedimentation). DLAPSE generates 3-D fields of solid PSCs by simulating the nucleation, growth and sedimentation of several thousand individual NAT particles in the Arctic vortex. These particles evolve by interacting with the nitric acid field in a chemical transport model, causing denitrification. In DLAPSE each model particle stands for a particular number of real particles, and this number can be adjusted to simulate any nucleation mechanism. The unique feature of DLAPSE is that after a model run each particle can be traced back to its point of formation and the effective number of particles adjusted (according to the physical conditions and the chosen nucleation model) to optimise agreement with the SAGE PSC extinctions. The optimum choice of rates can then be used in a second model run and the procedure repeated until optimum agreement between SAGE and model is obtained. In this paper we demonstrate the potential of SAGE III observations to quantify NAT nucleation rates in this way.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0320 Cloud physics and chemistry
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting