See Brief request syntax to understand each keyword.
CAMS real-time surface forecast
Total aerosol optical depth at 550 nm, 120 steps 11 first days of June 2016, see also ECMWF Public Dataset web interface
#!/usr/bin/env python from ecmwfapi import ECMWFDataServer server = ECMWFDataServer() server.retrieve({ 'stream' : "oper", 'levtype' : "sfc", 'param' : "aod550", 'dataset' : "cams_nrealtime", 'step' : "0/3/6/9/12/15/18/21/24/27/30/33/36/39/42/45/48/51/54/57/60/63/66/69/72/75/78/81/84/87/90/93/96/99/102/105/108/111/114/117/120", 'expver' : "0001", 'time' : "00", 'date' : "2016-06-01/to/2016-06-11", 'type' : "fc", 'class' : "mc", 'target' : "cams_nrealtime.grib" })