Airborne Measurements of Aerosol Size Distributions During ACE-Asia and INDOEX
Abstract
Aerosol size distributions in outflow from Asia were measured from the NCAR C-130 aircraft during 2 field campaigns, INDOEX (Feb--Mar 1999, south of India) and ACE-Asia (Mar--May 2001, west of China). For the former, we used a Differential Mobility Analyzer (DMA) for particles 10--200 nm in diameter and a laser Optical Particle Counter (OPC) for 200--7000 nm particles. Both were equipped with heated inlets so inferences about size-dependent composition were possible. For ACE-Asia, we added a TSI Aerodynamic Particle Sizer and an MSP Flying MOUDI cascade impactor. Polluted INDOEX aerosol was much more consistent, with number, mass, and scattering all usually dominated by accumulation mode particles between 0.1 and 0.4 μ m. This relatively uniform aerosol extended from hundreds to thousands of km downwind with its basic characteristics intact. The ACE-Asia aerosol was much more heterogeneous, including frequent dust episodes (some exceeding 1 mg m-3), recent nucleation episodes superimposed on aged accumulation modes, and occasional volcanic aerosol in addition to the sub-μ m pollution. While the more complete instrumentation during ACE-Asia yielded better characterization of the aerosol, the complexity makes it more difficult to achieve closure between size distributions, chemical composition, and optical properties.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFM.A22A0109H
- Keywords:
-
- 0305 Aerosols and particles (0345;
- 4801);
- 0345 Pollution: urban and regional (0305);
- 0365 Troposphere: composition and chemistry