Pan-Arctic Land Surface (PALS) model drivers and outputs

All models were forced with European Centre for Medium-Range Weather Forecasts (ECMWF) 40 Year Re-analysis (ERA-40) data for the period 1979-2002. The forcing fields comprise precipitation, 2-m air temperature, incoming solar and longwave radiation at the surface, 10-m winds and specific humidity at the lowest model level, the latter calculated from dewpoint, temperature and pressure.

These are available every 6 h on a grid with an approximate 125 km spacing (the so-called N80 reduced Gaussian grid). Precipitation and radiation fluxes are provided as 6-h accumulations from 6-hr forecasts. Temperature, 10-m winds, pressure and dewpoint represent instantaneous values at the 6-h analysis time.