RESUMO
Mercury emissions from biomass burning contribute significantly to the atmospheric mercury budget and the interannual variation of mercury concentrations in the troposphere. This study developed a high-resolution (0.1°â¯×â¯0.1°) monthly inventory of mercury emissions from biomass burning across five land types in the tropical continents (Central and South America, Africa, and South and Southeast Asia) during 2001-2017. The inventory estimates of mercury emissions from biomass burning are based on the newly released MCD64A1 Version 6 Burned Area data product, satellite and observational data of biomass density, and spatial and temporal variable combustion factors. Results from the inventory demonstrated that during 2001-2017, the average annual mercury emissions from biomass burning in tropical continents was 497â¯Mg and ranged from 289â¯Mg to 681â¯Mg. Forest fires were the largest contributor, accounting for 61% (300â¯Mg) of the total mercury emissions from biomass burning, followed by fires in woody savanna/shrubland (30%, 151â¯Mg), savanna/grassland (7%, 35â¯Mg), peatland (1%, 6â¯Mg), and cropland (1%, 5â¯Mg). However, these proportions varied between the continents; in the Americas and Asia, the largest biomass burning emissions came from forest fires, and in Africa the largest emissions were from fires woody savanna/shrubland. Between the three continents, Africa released 41% of the mercury emissions from biomass burning (202â¯Mgâ¯year-1), Asia released 31% (154â¯Mgâ¯year-1), and the Americas released 28% (141â¯Mgâ¯year-1). The total mercury emissions from biomass burning in these tropical continents exhibited strong interannual variations from 2001 to 2017, with peak emissions in March and August to September, and forest fires were the primary land type controlling the interannual variations.
Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Mercúrio/análise , Clima Tropical , Incêndios Florestais , Madeira/química , África , Ásia , América Central , Florestas , Pradaria , Modelos Teóricos , Estações do Ano , América do Sul , Incêndios Florestais/estatística & dados numéricosRESUMO
This study compared five widely used globally gridded biomass burning emissions inventories for the 2002-2011 period (Global Fire Emissions Database 3 (GFED3), Global Fire Emissions Database 4 (GFED4), Global Fire Assimilation System 1.0 (GFAS1.0), Fire INventory from NCAR 1.0 (FINN1.0) and Global Inventory for Chemistry-Climate studies-GFED4 (G-G)). Average annual CO2 emissions range from 6521.3 to 9661.5 Tg year(-1) for five inventories, with extensive amounts in Africa, South America and Southeast Asia. Coefficient of Variation for Southern America, Northern and Southern Africa are 30%, 39% and 48%. Globally, the majority of CO2 emissions are released from savanna burnings, followed by forest and cropland burnings. The largest differences among the five inventories are mainly attributable to the overestimation of CO2 emissions by FINN1.0 in Southeast Asia savanna and cropland burning, and underestimation in Southern Africa savanna and Amazon forest burning. The overestimation in Africa by G-G also contributes to the differences.
Assuntos
Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , África , Sudeste Asiático , Clima , Incêndios , Incineração , América do Sul , AstronaveRESUMO
Biomass burning in tropical regions plays a significant role in atmospheric pollution and climate change. This study quantified a comprehensive monthly biomass burning emissions inventory with 1 km high spatial resolution, which included the burning of vegetation, human waste, and fuelwood for 2010 in three tropical regions. The estimations were based on the available burned area product MCD64A1 and statistical data. The total emissions of all gases and aerosols were 17382 Tg of CO2, 719 Tg of CO, 30 Tg of CH4, 29 Tg of NOx, 114 Tg of NMOC (nonmethane organic compounds), 7 Tg of SO2, 10 Tg of NH3, 79 Tg of PM2.5 (particulate matter), 45 Tg of OC (organic carbon), and 6 Tg of BC (black carbon). Taking CO as an example, vegetation burning accounted for 74% (530 Tg) of the total CO emissions, followed by fuelwood combustion and human waste burning. Africa was the biggest emitter (440 Tg), larger than Central and South America (113 Tg) and South and Southeast Asia (166 Tg). We also noticed that the dominant fire types in vegetation burning of these three regions were woody savanna/shrubland, savanna/grassland, and forest, respectively. Although there were some slight overestimations, our results are supported by comparisons with previously published data.