TY  - JOUR
A1  - Kärcher, Bernd
A1  - Mahrt, Fabian
A1  - Marcolli, Claudia
T1  - Process-oriented analysis of aircraft soot-cirrus interactions constrains the climate impact of aviation
Y1  - 2021-06-17
VL  - 2
IS  - 1
JF  - Communications Earth & Environment
DO  - 10.1038/s43247-021-00175-x
PB  - Nature Publishing Group UK
N2  - Fully accounting for the climate impact of aviation requires a process-level understanding of the impact of aircraft soot particle emissions on the formation of ice clouds. Assessing this impact with the help of global climate models remains elusive and direct observations are lacking. Here we use a high-resolution cirrus column model to investigate how aircraft-emitted soot particles, released after ice crystals sublimate at the end of the lifetime of contrails and contrail cirrus, perturb the formation of cirrus. By allying cloud simulations with a measurement-based description of soot-induced ice formation, we find that only a small fraction (<1%) of the soot particles succeeds in forming cloud ice alongside homogeneous freezing of liquid aerosol droplets. Thus, soot-perturbed and homogeneously-formed cirrus fundamentally do not differ in optical depth. Our results imply that climate model estimates of global radiative forcing from interactions between aircraft soot and large-scale cirrus may be overestimates. The improved scientific understanding reported here provides a process-based underpinning for improved climate model parametrizations and targeted field observations.
N2  - Only a small part of aircraft-soot–cirrus interactions succeeds in forming cloud ice, according to simulations with a numerical cirrus cloud model. This suggests that radiative forcing from aircraft soot may have been overestimated.
UR  - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11344
ER  -