Tracking ICESat-2 Arctic Sea Ice Freeboard

Arctic sea ice coverage has changed considerably over the last few decades. Sea ice extent record minimums have been observed in recent years, the distribution of sea ice age now heavily favors younger ice, and sea ice is thinning.

To investigate the response of the ice pack to climate forcing during summertime melt, we have developed a technique to track individual Arctic sea ice parcels along with associated properties as these parcels advect through the Arctic Ocean. This sea ice parcel tracking method utilizes our sea ice motion dataset, archived at NASA's National Snow and Ice Data Center.

Tracked sea ice parcel locations coincide with other environmental products that influence sea ice growth/decay. We have recently tracked variables such as ice surface temperature, albedo, ice concentration, and ice thickness for hundreds of sea ice parcels, defined as occupying one EASE-grid cell location. These parcels can be tracked through a melt season, to determine the influence of these properties on sea ice melt, along with determining what fraction of the parcels survive or don't survive summer melt. This analysis can be applied to determine the impact of these and other properties on ice melt, in terms of their relative importance.

Here, we focus on tracking recent sea ice freeboard, produced from NASA's ICESat-2 observations. We look at the evolution of ice thickness for individual parcels through the recent ICESat-2 record, to determine the rate of ice growth over part or all of the winter, depending on product availability (as of this writing, freeboard is available through Dec 27, 2018). We determine how sea ice growth varies for hundreds of parcels, and determine how growth is affected by location and time.