New Intercampaign Bias Estimates for ICESat Elevation Data Over Dome A in Antarctica

The fidelity of intercampaign biases (ICBs) estimates for Ice, Cloud, and land Elevation Satellite (ICESat) ice elevation products is critical for ice sheet mass balance research. Prior studies have confirmed that ICBs are significantly dependent on data products, released versions, and surface types, leading to the hypothesis that ICBs for Level 2 Geosciences Laser Altimeter (GLA12) newly released products remain poorly determined. Here, we propose a new method to estimate ICBs using altimetry crossovers relative to a known stable ice surface, Dome A summit, East Antarctica, and a multitime reference framework, which maximizes the number of crossovers. The ICBs of GLA12 release 634 product range from -8.1 +/- 1.1 cm (L3A) to 19.3 +/- 0.8 cm (L2C), and most of them range from -5 to 10 cm. However, the ICBs for a few campaigns show significant campaign-dependent variations (L2B and L3D). They exhibit insignificant trend (-0.9 +/- 0.8 cm/yr) during entire ICESat mission, but there is a clear trend at -3.0 +/- 0.3 cm/yr since February 2006 (L3E). We conclude that the time-variable ICBs should be carefully considered on ice sheet mass balance estimate, especially for specific campaigns.

Automated summary

A new method is proposed to estimate the measurement biases of glacier elevation products using altimetry crossovers relative to a known stable ice surface. The results show that the measurement biases vary depending on the measurement methods and specific campaigns.