Abstract
Since its launch, in September 2018, ICESat-2’s Advanced Topographic
Laser Altimeter System (ATLAS) has collected high-resolution
measurements of Arctic sea ice by sampling the surface every 70 cm
along-track. We utilize the high-resolution capabilities of ATLAS with a
novel algorithm called the University of Maryland-Ridge Detection
Algorithm (UMD-RDA) to investigate sea ice topography across a range of
scales. Applying the UMD-RDA to the ATL03 Global Geolocated Photon
product we measure surface roughness and derive the frequency, height,
width, and angle of individual pressure ridge sails. Aggregating data
from multiple orbit crossings per day we investigate ridge
characteristics at length-scales varying from 1 km (individual floes) to
the pan-Arctic scale (central Arctic Ocean). Here, we present an
evaluation of pressure ridge characteristics during the winter seasons
of 2018/19, 2019/20, and 2020/21, comparing results from distinct
regions with varying ice conditions. Near-coincident, independent
observations of pressure ridges with Operation IceBridge (OIB) Airborne
Topographic Mapper (ATM) lidar data, OIB near-coincident Continuous
Airborne Mapping By Optical Translator (CAMBOT) high-resolution
(~15 cm) optical imagery, and WorldView high-resolution
(~30 cm) panchromatic satellite imagery are used to
evaluate the accuracy of our ICESat-2 ridge detection scheme. There are
many potential use-cases for a high-resolution sea ice topography data
product within the community, ranging from navigational hazard
mitigation to ecological studies of marine mammal habitats. We discuss
plans for releasing these data products and discuss the improvements
such data would make within high-resolution sea ice models.