In order to simulate the large-scale structure and temporal variability of oceanic heat flux (F _w ) to the Arctic perennial ice pack, observations of heat in the mixed layer and ice dynamics are compared with parameterizations and climatologies. Long-term drifting platform observations of seawater temperature and salinity (primarily from automated buoys) are used to describe the annual cycle of temperature above freezing (ΔT _f ) in the mixed layer beneath the ice pack, which are modulated by ice-ocean friction velocities (u*) determined from the platform drifts to produce estimates of F _w between 1975 and 1998. On average, ΔT _f is not negligible in winter, especially in the Transpolar Drift, which implies a positive F _w to the ice pack by means other than solar heating. A parameterization based solely on the solar zenith angle (with a 1 month lag) is found to largely describe the observed ΔT _f (with root mean square error of 0.03°C), despite the lack of an albedo or open water term. A reconstruction of F _w from 1979 to 2002 is produced by modulating parameterized ΔT _f with u* on the basis of daily ice drift estimates from a composite satellite and in situ data set. The reconstructed estimates are corrected for regional variations and are compared to independent estimates of F _w from ice mass balance measurements, indicating annual F _w averages between 3 and 4 W m⁻² depending on the selection of under-ice roughness length in the ice-ocean stress calculations. Although the interannual variations in ΔT _f are fixed by the parameterization in the derived reconstruction, the dynamics indicate an overall positive trend (0.2 W m⁻² decade⁻¹) in Arctic F _w , with the largest variations found in the southern Beaufort Gyre.