Simulated radiative forcing from contrails and contrail cirrus National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000, USA
20 Dec 2013
Received: 06 Mar 2013 – Published in Atmos. Chem. Phys. Discuss.: 24 Apr 2013Abstract. A comprehensive general circulation model including ice supersaturation is
used to estimate the climate impact of aviation induced contrails. The model
uses a realistic aviation emissions inventory for 2006 to initiate contrails,
and allows them to evolve consistently with the model hydrologic cycle.
Revised: 31 Oct 2013 – Accepted: 11 Nov 2013 – Published: 20 Dec 2013
The radiative forcing from linear contrails is very sensitive to the diurnal
cycle. For linear contrails, including the diurnal cycle of air traffic
reduces the estimated radiative forcing by 29%, and for contrail cirrus
estimates, the radiative forcing is reduced by 25%. Estimated global
radiative forcing from linear contrails is 0.0031 ± 0.0005 Wm−2. The
linear contrail radiative forcing is found to exhibit a strong diurnal cycle.
The contrail cirrus radiative forcing is less sensitive to the diurnal cycle
of flights. The estimated global radiative forcing from contrail cirrus is
0.013 ± 0.01 Wm−2. Over regions with the highest air traffic, the
regional effect can be as large as 1 Wm−2.
Citation: Chen, C.-C. and Gettelman, A.: Simulated radiative forcing from contrails and contrail cirrus, Atmos. Chem. Phys., 13, 12525-12536, doi:10.5194/acp-13-12525-2013, 2013.