Global top-down smoke-aerosol emissions estimation using satellite fire radiative power measurements
Fire emissions estimates have long been based on bottom-up approaches that are not only complex, but also fraught with compounding uncertainties. We present the development of a global gridded (1° × 1°) emission coefficients (<i>C</i><sub>e</sub>) product for smoke total part...
Main Authors: | , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2014-07-01
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Series: | Atmospheric Chemistry and Physics |
Online Access: | http://www.atmos-chem-phys.net/14/6643/2014/acp-14-6643-2014.pdf |
Summary: | Fire emissions estimates have long been based on bottom-up approaches that
are not only complex, but also fraught with compounding uncertainties. We
present the development of a global gridded
(1° × 1°) emission coefficients (<i>C</i><sub>e</sub>)
product for smoke total particulate matter (TPM) based on a top-down approach
using coincident measurements of fire radiative power (FRP) and aerosol
optical thickness (AOT) from the Moderate-resolution Imaging
Spectro-radiometer (MODIS) sensors aboard the Terra and Aqua satellites. This
new Fire Energetics and Emissions Research version 1.0 (FEER.v1) <i>C</i><sub>e</sub>
product has now been released to the community and can be obtained from
<a href="http://feer.gsfc.nasa.gov/"target=_blank">http://feer.gsfc.nasa.gov/</a>, along with the corresponding 1-to-1 mapping
of their quality assurance (QA) flags that will enable the <i>C</i><sub>e</sub>
values to be filtered by quality for use in various applications. The
regional averages of <i>C</i><sub>e</sub> values for different ecosystem types were
found to be in the ranges of 16–21 g MJ<sup>−1</sup> for savanna and
grasslands, 15–32 g MJ<sup>−1</sup> for tropical forest, 9–12 g MJ<sup>−1</sup> for
North American boreal forest, and 18–26 g MJ<sup>−1</sup> for Russian boreal
forest, croplands and natural vegetation. The FEER.v1 <i>C</i><sub>e</sub> product
was multiplied by time-integrated FRP data to calculate regional smoke TPM
emissions, which were compared with equivalent emissions products from three
existing inventories. FEER.v1 showed higher and more reasonable smoke TPM
estimates than two other emissions inventories that are based on bottom-up
approaches and already reported in the literature to be too low, but
portrayed an overall reasonable agreement with another top-down approach.
This suggests that top-down approaches may hold better promise and need to be
further developed to accelerate the reduction of uncertainty associated with
fire emissions estimation in air-quality and climate research and
applications. Results of the analysis of FEER.v1 data for 2004–2011 show
that 65–85 Tg yr<sup>−1</sup> of TPM is emitted globally from open biomass
burning, with a generally decreasing trend over this short time period. The
FEER.v1 <i>C</i><sub>e</sub> product is the first global gridded product in the
family of "emission factors", that is based essentially on satellite
measurements, and requires only direct satellite FRP measurements of an
actively burning fire anywhere to evaluate its emission rate in near-real
time, which is essential for operational activities, such as the monitoring
and forecasting of smoke emission impacts on air quality. |
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ISSN: | 1680-7316 1680-7324 |