Emissions relationships in western forest fire plumes – Part 1: Reducing the effect of mixing errors on emission factors

摘要: Abstract. Studies of emission factors from biomass burning using aircraft data complement the results lab studies and extend them to conditions immense hot conflagrations. We illustrate discuss relationships for 422 individual samples many forest-fire plumes in Western US. The are two NASA investigations: ARCTAS (Arctic Research Composition Troposphere Aircraft Satellites) SEAC4RS (Studies Emissions Atmospher-ic Composition, Clouds, Climate Coupling by Regional Surveys). This work provides sample-by-sample enhancement ratios (EnRs) 23 gases particulate properties. Many EnRs provide candidates (ERs, corresponding EnR at source) when origin degree transformation is understood appropriate. From these, (EFs) can be estimated fuel dry mass consumed known or carbon budget approach. analysis requires understanding interplay mixing plume with surrounding air. Some initial examples emphasize that measured Ctot = CO2 + CO a fire does not necessarily describe emissions total liberated flames, Cburn. Rather, it represents Cburn Cbkgd, which includes possibly varying background concentrations en-trained Consequently, we present simple theoretical description entrainment multiple tracers flame hundreds kilometers downwind some intrinsic linear behaviors. suggests Mixed Effects Regression Emission Technique (MERET), eliminate occasional strong biases associated commonly used normalized excess mix-ing ratio (NEMR) method. MERET splits reveal exploiting fact all respond linearly dilution, while each tracer has consistent behavior (slope concentration respect Cburn). effects separable. Two three preferably more indicators required as minimum; here ten. Limited variations incorporated co-variations analyzed. percentage yield (or modified combustion efficiency) plays role. Other co-relationships involving ni-trogen organic classes prominent; these have O3 relationship. In summary, allows fine spatial resolution (EnRs ob-servations) comparison similar distant time space. Alkene us an approximate photochemical timescale. discrimination definition, sit-uation, ERs, allowing estimate factors.