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

• Published in: Atmospheric Measurement Techniques
• Main Authors: R. B. Chatfield, M. O. Andreae, ARCTAS Science Team
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2020
• Subjects: Environmental engineering; TA170-171; Earthwork. Foundations; TA715-787; Arctic
• Online Access: https://doi.org/10.5194/amt-13-7069-2020; https://doaj.org/article/ab662f3832a3473498267c4dfe749449

Studies of emission factors from biomass burning using aircraft data complement the results of lab studies and extend them to conditions of immense hot conflagrations. A new theoretical development of plume theory for multiple tracers is developed after examining aircraft samples. We illustrate and discuss emissions relationships for 422 individual samples from many forest fire plumes in the Western USA. Samples are from two NASA investigations: ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) and SEAC4RS (Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys). This work provides sample-by-sample enhancement ratios (EnRs) for 23 gases and particulate properties. Many EnRs provide candidates for emission ratios (ERs, corresponding to the EnR at the source) when the origin and degree of transformation is understood. From these, emission factors (EFs) can be estimated, provided the fuel dry mass consumed is known or can be estimated using the carbon mass budget approach. This analysis requires understanding the interplay of mixing of the plume with surrounding air. Some initial examples emphasize that measured <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>C</mi><mi mathvariant="normal">tot</mi></msub><mo>=</mo><mrow class="chem"><msub><mi mathvariant="normal">CO</mi><mn mathvariant="normal">2</mn></msub></mrow><mo>+</mo><mrow class="chem"><mi mathvariant="normal">CO</mi></mrow></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="81pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="84305589fa4e90cbb65d6f0136852b6c"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-13-7069-2020-ie00001.svg" width="81pt" height="13pt" ...