Artigo de peri??dico
The relationship between aerosol particles chemical composition and optical properties to identify the biomass burning contribution to fine particles concentration: a case study for S??o Paulo city, Brazil
Registro en:
0167-6369
6
189
10.1007/s10661-016-5659-7
44.008
Autor
MIRANDA, REGINA M. de
LOPES, FABIO
ROSARIO, NILTON E. do
YAMASOE, MARCIA A.
LANDULFO, EDUARDO
ANDRADE, MARIA de F.
Resumen
The air quality in the Metropolitan Area of
S??o Paulo (MASP) is primarily determined by the local
pollution source contribution, mainly the vehicular fleet,
but there is a concern about the role of remote sources to
the fine mode particles (PM2.5) concentration and composition.
One of the most important remote sources of
atmospheric aerosol is the biomass burning emissions
from S??o Paulo state???s inland and from the central and
north portions of Brazil. This study presents a synergy
of different measurements of atmospheric aerosol chemistry
and optical properties in the MASP in order to
show how they can be used as a tool to identify particles
from local and remote sources. For the clear identification
of the local and remote source contribution, aerosol
properties measurements at surface level were combined
with vertical profiles information. Over 15 days in the
austral winter of 2012, particulate matter (PM) was
collected using a cascade impactor and a Partisol sampler
in S??o Paulo City. Mass concentrations were determined
by gravimetry, black carbon concentrations by
reflectance, and trace element concentrations by X-ray
fluorescence. Aerosol optical properties were studied
using a multifilter rotating shadowband radiometer
(MFRSR), a Lidar system and satellite data. Optical
properties, concentrations, size distributions, and elemental
composition of atmospheric particles were
strongly related and varied according to meteorological
conditions. During the sampling period, PM mean mass
concentrations were 17.4 ?? 10.1 and 15.3 ?? 6.9 ??g/m3
for the fine and coarse fractions, respectively. The mean
aerosol optical depths at 415 nm and ??ngstr??m exponent
(AE) over the whole period were 0.29 ?? 0.14 and
1.35 ?? 0.11, respectively. Lidar ratios reached values of
75 sr. The analyses of the impacts of an event of biomass
burning smoke transport to the S??o Paulo city revealed
significant changing on local aerosol concentrations and
optical parameters. The identification of the source contributions,
local and remote, to the fine particles in
MASP can be more precisely achieved when particle
size composition and distribution, vertical profile of
aerosols, and air mass trajectories are analyzed in
combination. Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) FAPESP: 08/58104-8; 11/14365-5; 12/24689-5