Hazel Jones led the analysis of contrail observations for COISC at the University of Manchester. Article is now on ACPD
A case study published by Jim Haywood and Colleagues in JGR (doi:10.1029/2009JD012650) observed and modelled a single contrail breakout event over the UK. The event had a large effect on radiative forcing. The pictures show satellite thermal images of the evolving contrail.
This meeting saw 40 stakeholders from the aviation industry, government, civil society and the media discussing the state of the science with aviation-climate scientists.  Morning presentations concentrated on the latest developments in contrail science with talks  by Bernd Kärcher and Ulrike Burkhardt from DLR in Germany, as well as Jim Haywood from the Met Office….
Rap et al. (2010)  doi:10.1029/2010GL045161estimated the climate impact of linear contrails using the UK Met Office climate model and found only a tiny effect of contrails on the daily temperature range – in contrast to the large effect suggested from 9/11 observations.