@Article{DarbyshireMALFDOLSMJBHBALC:2019:VeDiBi,
author = "Darbyshire, Eoghan and Morgan, Willian T. and Allan, James D. and
Liu, Dantong and Flynn, Michael J. and Dorsey, James R. and
O'Shea, Sebastian J. and Lowe, Douglas and Szpek, Kate and
Marenco, Franco and Johnson, Ben T. and Bauguitte, Stephane and
Haywood, Jim M. and Brito, Joel F. and Artaxo, Paulo and Longo,
Karla Maria and Coe, Hugh",
affiliation = "{University of Manchester} and {University of Manchester} and
{University of Manchester} and {University of Manchester} and
{University of Manchester} and {University of Manchester} and
{University of Manchester} and {University of Manchester} and {Met
Office} and {Met Office} and {Met Office} and , University of
Cranfield and {Met Office} and {Universidade de S{\~a}o Paulo
(USP)} and {Universidade de S{\~a}o Paulo (USP)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {University of
Manchester}",
title = "The vertical distribution of biomass burning pollution over
tropical South America from aircraft in situ measurements during
SAMBBA",
journal = "Atmospheric Chemistry and Physics",
year = "2019",
volume = "19",
number = "9",
pages = "5771--5790",
month = "May",
abstract = "We examine processes driving the vertical distribution of biomass
burning pollution following an integrated analysis of over 200
pollutant and meteorological profiles measured in situ during the
South AMerican Biomass Burning Analysis (SAMBBA) field experiment.
This study will aid future work examining the impact of biomass
burning on weather, climate and air quality.</p> During the dry
season there were significant contrasts in the composition and
vertical distribution of haze between western and eastern regions
of tropical South America. Owing to an active or residual
convective mixing layer, the aerosol abundance was similar from
the surface to <span classCombining double low
line{"}inline-formula{"}>\ĝ1/41.5</span>\ <span
classCombining double low line{"}inline-formula{"}>km</span> in
the west and <span classCombining double low
line{"}inline-formula{"}>\ĝ1/43</span>\ <span
classCombining double low line{"}inline-formula{"}>km</span> in
the east. Black carbon mass loadings were double as much in the
east (1.7\ <span classCombining double low
line{"}inline-formula{"}>\μg m\ĝ'3</span>) than the
west (0.85\ <span classCombining double low
line{"}inline-formula{"}>\μg m\ĝ'3</span>), but
aerosol scattering coefficients at 550\ <span
classCombining double low line{"}inline-formula{"}>nm</span> were
similar (<span classCombining double low
line{"}inline-formula{"}>\ĝ1/4120</span>\ <span
classCombining double low
line{"}inline-formula{"}>Mm\ĝ'1</span>), as too were CO
near-surface concentrations (310-340\ <span classCombining
double low line{"}inline-formula{"}>ppb</span>). We attribute
these contrasts to the more flaming combustion of Cerrado fires in
the east and more smouldering combustion of deforestation and
pasture fires in the west. Horizontal wind shear was important in
inhibiting mixed layer growth and plume rise, in addition to
advecting pollutants from the Cerrado regions into the remote
tropical forest of central Amazonia. Thin layers above the mixing
layer indicate the roles of both plume injection and shallow moist
convection in delivering pollution to the lower free troposphere.
However, detrainment of large smoke plumes into the upper free
troposphere was very infrequently observed. Our results reiterate
that thermodynamics control the pollutant vertical distribution
and thus point to the need for correct model representation so
that the spatial distribution and vertical structure of biomass
burning smoke is captured.</p> We observed an increase of aerosol
abundance relative to CO with altitude both in the background haze
and plume enhancement ratios. It is unlikely associated with
thermodynamic partitioning, aerosol deposition or local non-fire
sources. We speculate it may be linked to long-range transport
from West Africa or fire combustion efficiency coupled to plume
injection height. Further enquiry is required to explain the
phenomenon and explore impacts on regional climate and air
quality.",
doi = "10.5194/acp-19-5771-2019",
url = "http://dx.doi.org/10.5194/acp-19-5771-2019",
issn = "1680-7316 and 1680-7324",
language = "en",
targetfile = "darbyshire_vertical.pdf",
urlaccessdate = "27 abr. 2024"
}