A New Unified Sea Ice Thickness Climate Data Record

We are creating a new unified sea ice thickness climate data set to better intercompare different ice thickness measurements, to better evaluate the changing state of the ice pack and to better validate sea ice models. We would greatly improve the usefulness of these valuable data for the entire polar research community. Existing observations of ice thickness span a variety of methods, accuracies, and temporal and spatial scales and are archived in a variety of different locations and in different formats. Each has its own strengths in terms of sampling or accuracy. A concerted effort to collect as many observations as possible in one place, with consistent formats, and with clear and abundant documentation will allow the community to better utilize what is now a considerable body of observations. With a variety of data in one location and format, it will be much easier to compare the different sources with each other and with model output.

We target the wealth of data from both polar regions that are now available from moored and submarine-based upward looking sonar (ULS) instruments, airborne electromagnetic (EM) induction instruments, and satellite laser altimeters (ICESat). These instruments offer adequate sampling dating from 1975 to establish the mean ice thickness and thickness distribution for scales generally appropriate for change detection and climate model validations. The proposed data set will be the best approximation to a reference data set that is possible to assemble for sea ice thickness and only by using all of the available data and analyzing all of the biases will we obtain a reliable and extensive record of how the ice pack is changing.

Sea ice thickness is perhaps, the most important climate state variable that is currently poorly observed, poorly documented, and poorly archived. We as a community can do much better and a unified sea ice thickness data set is an important step forward. The new archive will be a valuable baseline and a continuously growing resource for ongoing work by many groups in understanding, predicting, and adapting to changes in the polar regions.