Surface and Ocean Fluxes from Ice Mass Balance Observations

Abstract:

The Arctic sea ice cover has been declining in recent decades. Data from a network of autonomous sea ice mass balance ice buoys, installed in the drifting ice cover, provide key insights into the forces driving this decline. Measurements of sea ice temperature and mass balance are used to estimate the ocean heat flux and the net surface heat budget. Ice mass balance observations collected in the Western Arctic from 2000 to 2015 show spatial and temporal variability in the fluxes. Ocean heat fluxes tend to be near zero for much of the winter, increasing in the summer. The summer ocean heat flux is typically tens of W m^-2, however it can exceed 100 W m^-2 in areas of low ice concentration due to solar heating of the upper ocean. Mass balance observations also indicate that the net surface heat budget is negative throughout much of the year and positive for a few months in summer. These observationally-derived ocean and net surface flux estimates provide an important check on reanalysis products and an evaluation tool for predictive models.