SCM and GSM Results at the ARM Sites

Utilize a 12-hr spin-up period
Includes in-situ measured surface albedo data
SCM run duration is 24 hours (not including spin-up)
SCM runs produced every 6 hours
Ability to utilizes different forcing data sets

Rather than take only the first 6 hours of each SCM run, all 24 hours are used to compute the SCM results. Thus, the SCM value at a particular hour, say 2100, is an average of that value from four runs:
Run 1 that starts at 0000 hours
Run 2 that starts at 0600 hours
Run 3 that starts at 1200 hours
Run 4 that starts at 1800 hours

This format is used for two reasons:
1) To prevent the masking of some model errors that are strongly dependent on the diurnal cycle. As and example, assume the SCM begins to overestimate the cloud amount and that this error increases as the run progresses. If we used a single 24-hour SCM run that started at 0000GMT, the effect on the solar radiative fluxes would be much different at a site where 0000GMT is local midnight compared to another site where 0000GMT is local noon.
2) Using a run length of 24 hours generally allows for deficiencies in most model parameterizations to become evident. Of course, using a longer run length would increase the chances for parameterization deficiencies to show up, but the longer run would also increase the chances for unrealistic model temperature and humidities that would also influence the performance of the model parameterizations. The choice of a 24-hour run is a compromise between these two competing factors.

SCM Results: Comparison to ECPC GSM

SCM Results: Evaluation of Different Forcing Data Sets

SCM Results: Evaluation of Different Convection Schemes

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Last Updated: 23-Jun-2005
Comments and suggestions to: Sam Iacobellis -