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In situ observations and model calculations of black carbon emission by aircraft at cruise altitude
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Titel: |
In situ observations and model calculations of black carbon emission by aircraft at cruise altitude |
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In: | Journal of Geophysical Research: Atmospheres, 104, 1999, D18, S. 22171-22181 |
veröffentlicht: |
American Geophysical Union (AGU)
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Umfang: | 22171-22181 |
ISSN: |
0148-0227 |
DOI: | 10.1029/1999jd900460 |
Zusammenfassung: | <jats:p>The exhaust aerosol of two aircraft at cruise was extensively characterized in the size range from 0.003 to 2 μm for plume ages ≤2 s. The black carbon (BC) exhaust aerosol of an older technology engine (Rolls‐Royce/Snecma M45H Mk501) consisted of a primary BC mode with a modal diameter of 0.035 μm and a mode of coagulated BC particles with a peak near 0.15–0.16 μm in diameter. The total number density at the nozzle exit plane was 3×10<jats:sup>7</jats:sup> cm<jats:sup>−3</jats:sup>. In contrast, a modern technology engine (CFM International CFM56‐3B1) emitted far smaller BC particles with a primary mode at 0.025 μm and a coagulated mode at 0.15 μm, as well as fewer particles by number with a concentration of 9×10<jats:sup>6</jats:sup> cm<jats:sup>−3</jats:sup>. The single‐scattering albedo of the jet exhaust aerosol was 0.035 ± 0.02 inside the plume, indicating a dominant contribution of ultrafine (<jats:italic>D</jats:italic><0.1 μm) BC particles to light extinction. Black carbon number emission indices <jats:italic>EI(N)</jats:italic> varied from 3.5×10<jats:sup>14</jats:sup> (CFM56‐3B1) to 1.7×10<jats:sup>15</jats:sup> kg<jats:sup>−1</jats:sup> (M45H Mk501) with corresponding mass emission indices <jats:italic>EI(BC)</jats:italic> of 0.011 and 0.1 g kg<jats:sup>−1</jats:sup>. Previously reported corresponding values for a CF6‐80C2A2 engine were 6×10<jats:sup>14</jats:sup> kg<jats:sup>−1</jats:sup> and 0.023 g kg<jats:sup>−1</jats:sup>, respectively. A comparison between <jats:italic>EI(BC)</jats:italic> values calculated by a new correlation method and measured data shows an excellent agreement, with deviations <10% at cruise conditions. By extending the <jats:italic>EI(BC)</jats:italic> calculation method to a globally operating aircraft fleet, a fleet‐averaged emission index <jats:italic>EI(BC)</jats:italic> = 0.038 g kg<jats:sup>−1</jats:sup> is calculated.</jats:p> |
Format: | E-Article |
Quelle: | American Geophysical Union (AGU) (CrossRef) |
Sprache: | Englisch |