Linear contrail and contrail cirrus properties determined from satellite data

Abstract

[1] The properties of contrail cirrus clouds are retrieved through analysis of Terra and Aqua Moderate Resolution Imaging Spectroradiometer data for 21 cases of spreading linear contrails. For these cases, contrail cirrus enhanced the linear contrail coverage by factors of 2.4-7.6 depending on the contrail mask sensitivity. In dense air traffic areas, linear contrail detection sensitivity is apparently reduced when older contrails overlap and thus is likely diminished during the afternoon. The mean optical depths and effective particle sizes of the contrail cirrus were 2-3 times and 20% greater, respectively, than the corresponding values retrieved for the adjacent linear contrails. When contrails form below, in, or above existing cirrus clouds, the column cloud optical depth is increased and particle size is decreased. Thus, even without increased cirrus coverage, contrails will affect the radiation balance. These results should be valuable for refining model characterizations of contrail cirrus needed to fully assess the climate impacts of contrails. Citation: Minnis, P., S.

Contrail life cycle and properties from 1 year of MSG/SEVIRI rapid-scan images

“…The recent analysis of Bedka et al (2013) gave a τ value of 0.2, with 21 % below 0.1. The study of contrail outbreaks by Minnis et al (2013) show optical thicknesses for contrail cirrus ranging from 0.32 to 0.43, consistent with our findings.…”

“…Bedka et al (2013), using a modified CDA on Aqua/MODIS, retrieved an average τ of linear contrails of 0.216. Minnis et al (2013) closely analysed 11 contrail outbreaks using Terra and Aqua MODIS data and derived τ values of contrail cirrus ranging from 0.32 to 0.43 and τ values of linear contrails between 0.13 and 0.17. The in situ measurements of τ taken by Voigt et al (2011) are also consistent with our findings.…”

“…Moreover, τ varies with the age of the contrail. In a case study of 11 contrail outbreaks, Minnis et al (2013) other properties. The mean optical depths of the contrail cirrus under study ranged from 0.32 to 0.43.…”

Dehydration effects from contrails in a coupled contrail–climate model

“…As in previous CoCiP studies, the magnitude of the computed SW / LW ratio is quite large (0.56). This SW / LW ratio varies between 0.2 and 0.8 in the literature (Haywood et al, 2009;Myhre et al, 2009;Yi et al, 2012;Minnis et al, 2013;Schumann and Graf, 2013;Vázquez-Navarro et al, 2015). The ratio may become even larger for small ice particles and higher contrail temperatures (Meerkötter et al, 1999;Zhang et al, 1999).…”

“…Contrails have been investigated in many observational and numerical studies (Schumann, 2002;Mannstein and Burkhardt et al, 2010;Heymsfield et al, 2010;Yang et al, 2010;Unterstrasser and Gierens, 2010b;Minnis et al, 2013;Lewellen, 2014;Voigt et al, 2015). Nevertheless, the dehydration effects from contrails are not well known.…”