DOI: 10.5281/zenodo.11520803
title: Sea ice deformation and rotation rates (SIDRR) from the ECCC-ASITS

description: Description:

This dataset offers pan-Arctic sea ice deformation and rotation rates (SIDRR) computed from Sentinel1 (S1) and the Radarsat Constellation Mission (RCM) Synthetic Aperture Radar (SAR) imagery, based on Sea Ice Motion (SIM) vector outputs from the Environment and Climate Change Canada Automated Sea Ice tracking System (ECCC-ASITS, Howell et al., 2022). 

The ASITS produces lists of sea ice motion vectors derived by tracking recognizable features in overlapping pairs of SAR images (Komarov and Barber, 2014). The tracked features from each SAR image pair are triangulated, and the SIDRRs computed using a line integral method (Bouchat et al., 2020, 2022) based on the velocity and start location of each vertex. 

 

Format:

The raw SIDRR data from multiple SAR images are stacked in daily netcdf output files, based on the acquisition time of the earliest image in the pair. The netcdf files thus include data from variable time and space resolutions depending on the triangulation and images acquisition time, in the ranges of 4 - 20 km and 12 h - 6 days. Each file is named with the convention “SIDRR_YYYYMMDD.nc”. For example, “SIDRR_20210101.nc” contains data from pairs with the first image acquisition time on January 1st, 2021.

Dimension and variable names:

Dimensions:         n                         triangle ID number

Variables:             idpair (n)             SAR scene pair ID number

                             ids1 (n)               ID of triangle vertex 1

                             ids2 (n)               ID of triangle vertex 2

                             ids3 (n)               ID of triangle vertex 3

                             start_time            Acquisition time, SAR image #1                              (hrs since ref. time)

                             end_time             Acquisition time, SAR image #2                              (hrs since ref. time)

                             start_lat1             Start latitude, tracked vertex 1                               (ºN)

                             start_lat2             Start latitude, tracked vertex 2                               (ºN)

                             start_lat3             Start latitude, tracked vertex 3                               (ºN)

                             start_lon1           Start longitude, tracked vertex 1                              (ºE)

                             start_lon2            Start longitude, tracked vertex 2                              (ºE)

                             start_lon3            Start longitude, tracked vertex 3                              (ºE)

                             end_lat1              End latitude, tracked vertex 1                                 (ºN)

                             end_lat2              End latitude, tracked vertex 2                                 (ºN)

                             end_lat3              End latitude, tracked vertex 3                                 (ºN)

                             end_lon1             End longitude, tracked vertex 1                               (ºE)

                             end_lon2             End longitude, tracked vertex 2                               (ºE)

                             end_lon3             End longitude, tracked vertex 3                               (ºE)

                             A                         Start triangle Area                                            (m2)

                             errA                     Propagation of tracking error on A                             (m2)

                             dudx                    x-direction divergence rate                                    (day-1)

                             dvdy                    y-direction divergence rate                                    (day-1)

                             dvdx                    x-direction shear rate                                         (day-1)

                             dudy                    y-direction shear rate                                         (day-1)

                             vrt                       vorticity                                                      (day-1)

                             err_vrt                 Propagation of tracking error on vrt                                 (day-1)

                             div                       Divergent deformation rate                                     (day-1)

                             err_div                Propagation of tracking error on div                              (day-1)

                             shr                      Shear deformation rate                                         (day-1)

                             err_shr                Propagation of tracking error on shr                             (day-1)

                             s2n                     Total deformation’s signal to noise ratio