| Autor: |
Teoh, Roger, Schumann, Ulrich, Gryspeerdt, Edward, Shapiro, Marc, Molloy, Jarlath, Koudis, George, Voigt, Christiane, Stettler, Marc E. J. |
| Předmět: |
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| Zdroj: |
Atmospheric Chemistry & Physics; 2022, Vol. 22 Issue 16, p10919-10935, 17p |
| Abstrakt: |
Around 5 % of anthropogenic radiative forcing (RF) is attributed to aviation CO 2 and non-CO 2 impacts. This paper quantifies aviation emissions and contrail climate forcing in the North Atlantic, one of the world's busiest air traffic corridors, over 5 years. Between 2016 and 2019, growth in CO 2 (+3.13% yr -1) and nitrogen oxide emissions (+4.5 % yr -1) outpaced increases in flight distance (+3.05 % yr -1). Over the same period, the annual mean contrail cirrus net RF (204–280 mW m -2) showed significant inter-annual variability caused by variations in meteorology. Responses to COVID-19 caused significant reductions in flight distance travelled (-66%), CO 2 emissions (-71%) and the contrail net RF (-66%) compared with the prior 1-year period. Around 12 % of all flights in this region cause 80 % of the annual contrail energy forcing, and the factors associated with strongly warming/cooling contrails include seasonal changes in meteorology and radiation, time of day, background cloud fields, and engine-specific non-volatile particulate matter (nvPM) emissions. Strongly warming contrails in this region are generally formed in wintertime, close to the tropopause, between 15:00 and 04:00 UTC, and above low-level clouds. The most strongly cooling contrails occur in the spring, in the upper troposphere, between 06:00 and 15:00 UTC, and without lower-level clouds. Uncertainty in the contrail cirrus net RF (216–238 mW m -2) arising from meteorology in 2019 is smaller than the inter-annual variability. The contrail RF estimates are most sensitive to the humidity fields, followed by nvPM emissions and aircraft mass assumptions. This longitudinal evaluation of aviation contrail impacts contributes a quantified understanding of inter-annual variability and informs strategies for contrail mitigation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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