Constraining Arctic and Antarctic sea ice projections with new observational estimates of freeboard and thickness
Alek
Petty
University of Maryland
Poster
Future projections of Arctic and Antarctic sea ice remain poorly constrained, due in large-part to the significant inter-model spread across the CMIP6 archive. Various recent studies have explored novel calibration approaches to better constrain future sea ice conditions of concern, especially the potential timing of an ice-free Arctic, but can come to different conclusions depending on the calibration approach taken. Sea ice exhibits significant variability across interannual and decadal time-scales, the causes of which can be challenging for models to correctly predict and simulate. The lack of long-term and reliable observations of sea ice thickness, especially in the Antarctic, have also meant that the more limited concentration/area observations have been the primary tool used for the needed calibration attempts.
Our project team is engaged with new NASA funded efforts to utilize the multi-year record of sea ice freeboard and thickness from ICESat-2 together with freeboard/thickness data collected from the original ICESat mission and ESA’s CryoSat-2 in an attempt to better calibrate model projections of polar sea ice change and reduce future model uncertainty. This data is more limited in space and time but can offer advantages over the longer-term area record; freeboard for example can be very accurately measured by laser altimetry satellites and is now output by some of the CMIP6 models enabling direct comparisons between the model sea ice state and satellite observations. Freeboard also exhibits higher variability/information within the pack ice, which we hope to better exploit for assessing current model performance (mean state and trends).
In this presentation I aim to provide a synthesis of recent approaches and conclusions from studies exploring sea ice projections/calibrations together with our efforts to better constrain polar sea ice projections with more novel satellite data and calibration methods.
Our project team is engaged with new NASA funded efforts to utilize the multi-year record of sea ice freeboard and thickness from ICESat-2 together with freeboard/thickness data collected from the original ICESat mission and ESA’s CryoSat-2 in an attempt to better calibrate model projections of polar sea ice change and reduce future model uncertainty. This data is more limited in space and time but can offer advantages over the longer-term area record; freeboard for example can be very accurately measured by laser altimetry satellites and is now output by some of the CMIP6 models enabling direct comparisons between the model sea ice state and satellite observations. Freeboard also exhibits higher variability/information within the pack ice, which we hope to better exploit for assessing current model performance (mean state and trends).
In this presentation I aim to provide a synthesis of recent approaches and conclusions from studies exploring sea ice projections/calibrations together with our efforts to better constrain polar sea ice projections with more novel satellite data and calibration methods.
Poster file
petty-alek-confronting-poster.pdf
(18.36 MB)