Sea surface height anomalies of the Arctic Ocean from ICESat-2: a first
examination and comparisons with CryoSat-2
Abstract
Accurately resolving spatio-temporal variations in sea surface height
across the polar oceans is key to improving our understanding of ocean
circulation variability and change. Here, we examine the first two years
(2018-2020) of Arctic Ocean sea surface height anomalies (SSHA) from the
photon-counting laser altimeter onboard NASA’s ICE, Cloud, and Land
Elevation Satellite-2 (ICESat-2). ICESat-2 SSHA estimates are compared
to independent estimates from the CryoSat-2 mission, including available
semi-synchronous along-track measurements from the recent CRYO2ICE orbit
alignment campaign. There are documented residual centimeter-scale range
biases between the ICESat-2 beams (in the current data release, r003)
and we opted for a single-beam approach in our comparisons. We find good
agreements in the along-track estimates (correlations > 0.8
and differences < 0.03 m) as well as in the gridded monthly
SSHA estimates (correlation 0.76 and mean difference 0.01 m) from the
two altimeters, suggesting ICESat-2 adds to the SSHA estimates from
CryoSat-2.