HR: 1400h
AN: A43A-15    [Abstracts]
TI: Monitoring ultrafine particulate material in Santiago de Chile
AU: * Gramsch, E
EM: egramsch@lauca.usach.cl
AF: Universidad de Santiago, Physics Department, Santiago, Chile
AU: Gidhagen, L
AF: Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
AU: Oyola, P
AF: Centro Mario Molina Chile, Avda del Valle 662, Santiago, Chile
AU: Artaxo, P
AF: University of Sao Paulo, Physics Faculty, Brazil
AU: Wahlin, P
AF: National Environmental Research Institute, Roskilde, Denmark
AB: A monitoring campaign was performed in Santiago de Chile during a winter month of 2003 and 2006 (July) using several instruments to measure particulate material. For the first time, the size distribution of ultrafine particles was measured in Santiago, and an estimation of its sources was done by analyzing its temporal variation. The study was performed in three sites; one of them is located in the eastern part of Santiago, a sector with low particle concentration and about 100 m from a busy street. The other site is located in the western part, which is the sector that has the highest concentration of fine and coarse particle matter during winter, also located far from a street. The third site is located less than 5 m from the busiest street in Santiago. In all stations traffic is the dominating source for fine and ultrafine particles, however the size distribution in site near the street is peaked towards lower sizes. The size distribution measurements presented here indicate that aerosol dynamics play a more important role for the Santiago case as compared to cleaner cities in Europe. The size distribution in the sites far from streets during most of the day is peaked around 70 nm, indicating that there is a dominance of the soot mode over the nuclei mode. Changes in the particle size during different hours of the day reflect both variations in meteorological mixing conditions as well as effects of aerosol dynamic processes such as coagulation, condensation and dry deposition. A relative increase in the number of large particles (d > 70 nm), as compared to the number of smaller particles (d < 70 nm) is an indication of pollution transport with aged particles from other parts of the city.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0478 Pollution: urban, regional and global (0345, 4251)
DE: 4251 Marine pollution (0345, 0478)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly