All referees are agreed that the paper has significantly improved in revision. Referees 2 and 3 have made very minor comments on the revised version. Referee 1 has made more substantial comments which I think are worth considering further. Therefore, please can you provide a revised version of the paper which addresses the comments of all Referees and if changes are not made in response to particular comments, please provide an accompanying response which gives reasons why that is the case. I will then consider the paper again myself without sending to Referees again and expect to accept it for publication.

Given the generally positive reports on the first revised version of your paper and your most recent revisions I am pleased to accept this paper for publication in ACP. (You noted in your replies that some of the minor comments were arising from figures that had not been properly updated -- you might wish to check once again that the final version of the paper is as you intend.)