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Nancy Marley Argonne National Laboratory 9700 S. Cass Avenue Argonne, IL 60439 Tel: 630-252-5014 Fax: 630-252-7420 email: namarley@anl.gov Determining the overall impact of atmospheric aerosols on radiative balance requires measurement of the relative amounts of scattering aerosols (e.g., ammonium nitrate, ammonium sulfate) and absorbing aerosols (e.g., carbon), their distributions, and their chemical properties. A suite of state-of-the-art instrumentation is essential for characterizing aerosol formation, loadings, and life cycles in Atmospheric Science Program (ASP) field studies. We are developing and deploying such a suite of instrumentation for measurements including (1) aerosol absorption as a function of wavelength, measured continuously with a seven-channel aethalometer, with simultaneous determination of fine-aerosol particle scattering with a three-wavelength ephelometer; (2) collection of size-fractionated aerosol samples, followed by water extraction to evaluate contributions of highly colored “humic-like” substances; (3) laboratory characterization of submicron aerosol samples with multiple spectroscopy methods in the ultraviolet-visible and infrared regions; (4) determination of the relative contributions of absorbing and scattering aerosols as a function of wavelength with a continuous-wavelength nephelometer developed for direct comparison with the aethalometer measurements; and (5) field measurements of ammonia with a near-infrared tunable diode laser instrument tested in Mexico City in 2003. All of these data are made available to the ASP community. Key Words: aerosol optical characterization, aerosol radiative effects, atmospheric aerosols, humic-like substances, particulate matter, precursor gases. [back to ASP ST Membership] |