@InProceedings{HerdiesBresFigu:2023:DeSoAm,
author = "Herdies, Dirceu Luis and Bresciani, Caroline and Figueroa, Silvio
Nilo",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)}",
title = "The detection of the South America Tropopause Aerosol Layer over
the Amazon region",
year = "2023",
organization = "International TOVS Study Conferences, 24.",
abstract = "The Amazon is one of the most important tropical forests in the
world because it is a key in the regulation of the global climate.
It is the world's largest rainforest, where interactions between
the forest and the atmosphere are fundamental to rainfall
throughout South America and have an indirect effect on all the
regions around the world. Furthermore, the Amazon region may be a
source of aerosol that will act as cloud condensation nuclei
(CCN). During the rainy season over the Amazon region, in which
intense convective activity associated with the South America
Monsoon System (SAMS) prevents fires, the primary sources of
aerosols include biogenic emissions, dust from the Sahara Desert,
and emissions from burning biomass transported from Africa.
Besides that, the downward transport of aerosols from the upper
troposphere (UT) has been considered a source of particles to the
lower troposphere. The particles in the UT over the tropics region
have been one of the largest aerosol reservoirs in the atmosphere,
which could be from primary aerosols, such as dust, organic carbon
and black carbon or secondary aerosol formed by trace gases in the
free troposphere. The existence of an aerosol layer at the
tropopause level has been observed during June, July, and August
in Asia and North America (Asian Tropopause Aerosol Layer - ATAL
and North American Tropopause Aerosol Layer - NATAL, respectively)
associated with the deep convection of the Monsoons System.
Therefore, the aerosol enhancement in the UT and lower
stratosphere (LS) and the formation of an aerosol layer over the
Amazon region associated with the deep convection of the SAMS
during the austral summer are investigated. In the past, field
campaigns over South America (SA) (GoAmazon2014/5 experiment)
showed aerosol enhancement in the UT. They suggested that new
aerosol particles are formed in the UT from biogenic volatile
organic material that goes up by upward transport associated with
the deep convection. The enhancement of aerosol backscatter values
over SA is observed from October to January; it gradually
decreases during the following months. The aerosol backscatter
inferred from MERRA-2 Reanalysis showed a maximum value of the
2.24x10-5 km-2sr-1 over the Amazon during November and December.
The results showed the first evidence of the existence of the
South American Tropopause Aerosol Layer (SATAL) that covers the
tropical SA and vertically extends up to 80hPa (approximately 18
km), similar to ATAL, and NATAL. The aerosol backscatter inferred
from MERRA-2 reanalysis was validated using the attenuated
backscatter by CALIOP from CALIPSO satellite. However, field
campaigns such as the CAFE-BRAZIL campaign (Chemistry of the
Atmosphere: Field Experiment in Brazil), which will be during
December/2022 and January/2023 using the HALO (High Altitude Long
Range Aircraft) aircraft, are necessary to study the formation of
SATAL.",
conference-location = "Tromso, Norway",
conference-year = "16-22 Mar. 2023",
language = "en",
urlaccessdate = "01 maio 2024"
}