Re-analyses represent global model data calculated back over a definite time period, in which monitoring data is assimilated. The data normally covers a long-standing, climatologically relevant time period from 1979 to the present day. Re-analysis data for diverse application purposes is available to us:
MERRA stands for Modern Era Retrospective Analysis for Research and Applications. The MERRA re-analysis data has been developed by NASA with a 6-hourly assimilation of monitoring data. The spatial resolution is 1/2° in a North-South direction and 2/3° in a West-East direction with 72 vertical layers. The data is provided in an hourly resolution.
ERA-Interim has been developed by ECMWF. The re-analysis data is assimilated with monitoring data every 12 hours and has a spatial resolution of 0.75 ° x 0.75° (~ 80 km) and 60 vertical layers. The temporal resolution is 3 hours.
The NCEP Climate Forecast System Re-analyses (CFSR) developed by NOAA have a coupled atmosphere/ocean/polar-ice system and are available with a spatial resolution of 0.5° x 0.5° (~ 38 km) and 64 vertical layers. The data is resolved hourly.
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