For example, CRM 1.x will not use any user supplied information about CH4 abundance or longitude or year. Note however, that doing this will confuse CRM 2.x if it reads the same input file with a non-zero longitude. CRM 1.x is no longer supported and it highly recommended that users upgrad to CRM 2.x to avoid this confusion. For example, 1.5 is Greenwich noon on January 1st, 2.0 is Greenwich midnight of January 2nd. 31.5 and 32.5 are GMT noontimes for January 31st and February 1st, respectively.
Longitude is specified in degrees east of Greenwich.
The CRM uses the specified year, latitude, longitude and GMT to compute the correct Sun-Earth distance and solar zenith angle. This can lead to instantaneous biases of up to 17 minutes of time, or 4 degrees in angle, or 50 W m-2 in TOA insolation. However, the diurnal average of this error is 0.0 W m-2. This mode of operation will not reproduce CCM answers, but will make CRM more useful at analyzing field experiments and in intercomparison studies. Whether the CCM will change to include the equation of time is unknown.