The Tropical Forest and Fire Emissions Experiment: overview and airborne fire emission factor measurements

Abstract

Abstract. The Tropical Forest and Fire Emissions Experiment (TROFFEE) used laboratory measurements followed by airborne and ground based field campaigns during the 2004 Amazon dry season to quantify the emissions from pristine tropical forest and several plantations as well as the emissions, fuel consumption, and fire ecology of tropical deforestation fires. The airborne campaign used an Embraer 110B aircraft outfitted with whole air sampling in canisters, mass-calibrated nephelometry, ozone by UV absorbance, Fourier transform infrared spectroscopy (FTIR), and proton-transfer mass spectrometry (PTR-MS) to measure PM 10 , O 3 , CO 2 , CO, NO, NO 2 , HONO, HCN, NH 3 , OCS, DMS, CH 4 , and up to 48 non-methane organic compounds (NMOC). The Brazilian smoke/haze layers extended to 2-3 km altitude, which is much lower than the 5-6 km observed at the same latitude, time of year, and local time in Africa in 2000. Emission factors (EF) were computed for the 19 tropical deforestation fires sampled and they largely compare well to previous work. However, the TROFFEE EF are mostly based on a much larger number of samples than previously available and they also include results for significant emissions not previously reported such as: nitrous acid, acrylonitrile, pyrrole, methylvinylketone, methacrolein, crotonaldehyde, methylethylketone, methylpropanal, "acetol plus methylacetate," furaldehydes, dimethylsulfide, and C 1 -C 4 alkyl nitrates. Thus, we recommend these EF for all tropical deforestation fires. The NMOC emissions were ∼80% reactive, oxygenated volatile organic compounds (OVOC).

Emissions from forest fires near Mexico City

“…This analysis rests on several assumptions: (1) that the study-average mix of fire emissions we sampled resembled the real, average fire-emissions mix -on the days of the downwind measurements, (2) that other types of biomass burning in the study area may be ignored, and (3) that our airborne measurements of the fire ER HCN/CO are also valid for any initially-unlofted smoldering fire emissions . The third assumption is supported by the fact that EFHCN are not strongly dependent on MCE in this work (or in Africa or Brazil (Yokelson et al, 2007)). …”

Pre-Harvest Sugarcane Burning: Determination of Emission Factors through Laboratory Measurements

“…Some studies have shown that emission factors (EF) for ground-based measurements of smoldering compounds were higher than the EF measured for the same compounds from an aircraft above the same fires. This could be due to weakly lofted smoldering emissions collected by flight measurements, as occurred in the Babbitt et al [40] study, for example [23]. This fact could result in higher values for smoldering compounds from laboratory and field measurements.…”

“…Some limitations of the available measurements are mentioned as follows. Flight measurements such as the Le Canut et al [34] study in Africa tend to sample emissions that are associated with more intense and flaming combustion [23,24]. On the other hand, laboratory measurements could provide higher emission factors (EF) in relation to the previous method and be influenced by some factors as well as the types of instruments and calibrations.…”

“…Andreae and Merlet [21] presented a literature review of the available information about emissions from fires for various biomass types. This knowledge has been updated in more recent studies, such as Christian et al [22] which is concerned with savanna fires, Yokelson et al [23,24] and Soares Neto et al [25,26] which assemble information about fire emissions in tropical vegetation associated with pasture maintenance and deforestation, based on laboratory experiments and field campaigns, and Akagi et al [27] which present emission factors, among other information, for fourteen types of vegetation. Although some studies have treated different aspects of sugarcane straw burning [28][29][30][31][32], specific information about emission factors for species emitted during pre-harvest burning is still scarce, especially specific to Brazil.…”

ACE-FTS measurements of trace species in the characterization of biomass burning plumes

“…Yokelson et al (1997) measured the emission from the smoldering combustion of biomass with a Fourier transform infrared spectrometer (FT-IR) coupled to an open multipass cell. Numerous field campaigns have also been conducted in an effort to quantify and characterize emissions from biomass burning from different ecosystems such as the the work done by Yokelson et al (2003) to study the emissions from nascent and aged plumes from the African savannah and the tropical forests of Amazonia in Brazil during the TROFFEE campaign during the 2004 dry season (Yokelson et al, 2007b); but given the highly variable emissions inherent to biomass burning, particularly between lofted and unlofted emissions, even from within a single fire type Burling et al, 2011), it is uncertain whether this type of detailed characterization can be carried out with space-borne measurements and has yet to be confirmed.…”