Sea Surface Height Anomalies of the Arctic Ocean From ICESat‐2: A First Examination and Comparisons With CryoSat‐2

Abstract

AbstractAccurately 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 2 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 estimates from ESA's CryoSat‐2 mission, including semisynchronous along‐track measurements from the recent CRYO2ICE orbit alignment campaign. There are documented residual centimeter‐scale range biases between the ICESat‐2 beams (in release‐003 data) and we opted for a single‐beam approach in our comparisons. We find good agreement in the along‐track estimates (spatial correlation coefficient >0.8 and mean differences <0.03 m) as well as in the gridded monthly SSHA estimates (temporal correlation coefficient of 0.76 and a mean difference of 0.01 m) from the two altimeters, suggesting ICESat‐2 adds to the CryoSat‐2 SSHA estimates.