Hello to all, How do I know at what level the values of z correspond? For example z = 1 is at 1000 hPa but if I want to plot at 700 and 500 hpa, what value corresponds to z? best JP. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://gradsusr.org/pipermail/gradsusr/attachments/20171022/fd323977/attachment.html