Cloud Condensation Nuclei and aerosol properties at two forest sites in South America

HR: 0800h
AN: A41D-0740 [Abstracts]
TI: Cloud Condensation Nuclei and aerosol properties at two forest sites in South America
AU: * Artaxo, P
EM: artaxo@if.usp.br
AF: Paulo Artaxo, Instituto de Física Universidade de Sao Paulo Rua do Matao, Travessa R, 187, Sao Paulo, S.P 05508-900, Brazil
AU: Lara, L
EM: luciene@if.usp.br
AF: Paulo Artaxo, Instituto de Física Universidade de Sao Paulo Rua do Matao, Travessa R, 187, Sao Paulo, S.P 05508-900, Brazil
AU: Oliveira, P
EM: pauloh@if.usp.br
AF: Paulo Artaxo, Instituto de Física Universidade de Sao Paulo Rua do Matao, Travessa R, 187, Sao Paulo, S.P 05508-900, Brazil
AB: Cloud condensation nuclei and aerosol properties were measured at two forest sites in South America. The first site is the LBA tower North of Manaus in Amazonia and the second site is at the Atlantic Forest in Southeast Brazil. Both sites are located in primary forest. Aerosol concentration is about 12 ug/mł for PM10 and 2-4 ug/mł for PM2.5. Most of the aerosol mass is at the coarse mode, loaded with natural biogenic aerosol. Aerosol particle number is at 300-700 particles per cc. It is remarkable the similar values for light scattering and absorption at both sites. The CCN concentrations at various supersaturations are similar for both forest site, as well as the ratio between CCN and total aerosol particle number measured using a TSI CPC. Aerosol size distributions measured using an TSI SMPS shows that no new particle formation events were observed in both sites. Aerosol composition is dominated by organic components at both sites, with potassium indicating that biogenic aerosol dominates the sources. Very low soil dust was observed in both sites. Also sulfate and nitrate concentrations are low. We will discuss the diurnal variability of measured properties and a detailed comparison of tropical and subtropical aerosol properties.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0320 Cloud physics and chemistry
DE: 0321 Cloud/radiation interaction
DE: 0330 Geochemical cycles (1030)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting