Arctic-HYPE (v3.0.26) hindcasts are deterministic simulations for historical periods, forced with daily precipitation and temperature (mean, minimum and maximum) derived from meteorological re-analysis and forecast products and observational data sets:
GFD (Global Forcing Data) is a global data set developed by SMHI with daily precipitation and temperature data on a 0.5x0.5° grid. It is based on the ECMWF ERA-Interim re-analysis and a compilation of saved first day forecasts from the deterministic ECWMF system 4. ERA-interim ends 3 months back in time from the current date, and the saved forecasts are used to fill up the time series until the end of the previous month. The re-analysis and forecast data are bias corrected using global observational based data sets with a similar method as the WATCH Forcing Data (WFDEI). For periods until 2013-12-31, the bias correction is based on GPCCv7 and CRU ts3.22, and from 2014-01-01 it is based on the GPCC MONITOR the GHCN-CAMS temperature data.
Arctic-HYPE (v3.0.26) forecasts are deterministic simulations for the next 10 days forced with the deterministic 10 day forecast from ECMWF (system 4). Initial states for the forecasts are generated by daily hindcast simulations for the last 35 days using forcing data as described above.