Poster's note : This is a game-changing piece of research. Finding we have up to 0.8 W/m2 of previously 'hidden' warming is a spectacular result. It also suggests a possible contradiction with Kravitz' result on the use of soot, albeit his paper was analysing stratospheric (not tropospheric) soot injections.
NB Link is to abstract only. Paper will hopefully be in PNAS http://www.daca-13.org/wsl/daca13/program/DACA-13_Abstract_Proceedings.pdf Radiative forcing by aircraft: effects of soot on large-scale clouds Joyce Penneret al Radiative forcing by aircraft soot in large-scale clouds has been estimated to be both positive and negative, while forcing by contrails and contrail cirrus (i.e. spreading contrails) is positive. Here we use an improved model to estimate the forcing in large-scale clouds. We assume that the fraction of soot particles that have been processed through contrails are good heterogeneous ice nuclei (IN) and use the average fraction determined from the CoCiP model. The calculated total all-sky radiative climate forcing ranges between -0.2 and -0.8 Wm-2 , with the range determined by whether sulfate on soot decreases their ability to act as IN as well as the treatment used for precipitation scavenging. We discuss what is needed to narrow the range. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
