Instantaneous sea ice drift speed from TanDEM-X interferometry

Dyre Oliver Dammann,Leif E B Eriksson,Hajo Eicken,Andrew R Mahoney,Yasushi Fukamachi,Roland Romeiser,Joshua M Jones,Franz J Meyer

doi:10.5194/tc-13-1395-2019

Abstract

Abstract. The drift of sea ice is an important geophysical process with widespread implications for the ocean energy budget and ecosystems. Drifting sea ice can also threaten marine operations and present a hazard for ocean vessels and installations. Here, we evaluate single-pass along-track synthetic aperture radar (SAR) interferometry (S-ATI) as a tool to assess ice drift while discussing possible applications and inherent limitations. Initial validation shows that TanDEM-X phase-derived drift speed corresponds well with drift products from a ground-based radar at Utqiaġvik, Alaska. Joint analysis of TanDEM-X and Sentinel-1 data covering the Fram Strait demonstrates that S-ATI can help quantify the opening/closing rate of leads with possible applications for navigation. S-ATI enables an instantaneous assessment of ice drift and dynamic processes that are otherwise difficult to observe. For instance, by evaluating sea ice drift through the Vilkitsky Strait, Russia, we identified short-lived transient convergence patterns. We conclude that S-ATI enables the identification and analysis of potentially important dynamic processes (e.g., drift, rafting, and ridging). However, current limitations of S-ATI are significant (e.g., data availability and they presently only provide the cross-track vector component of the ice drift field) but may be significantly reduced with future SAR systems.

Highlights

Arctic sea ice is predominantly in a state of drift as a result of a near-continuous wind and ocean drag, which leads to redistribution and deformation
Over the past several decades, Arctic sea ice has declined at a rapid rate (Stroeve et al, 2012; Comiso and Hall, 2014; Meier et al, 2014) and in confined regions resulted in more dynamic ice (Spreen et al, 2011; Kwok et al, 2013) increasing strain and fracturing (Rampal et al, 2009a)
We have demonstrated the potential use of synthetic aperture radar (SAR) interferometry (S-ATI) for derivation of instantaneous sea ice drift

Summary

Introduction

Arctic sea ice is predominantly in a state of drift as a result of a near-continuous wind and ocean drag, which leads to redistribution and deformation. Drift processes play a large part in the sea ice thickness distribution. Differential ice motion results in the opening and closing of leads and polynyas and the formation of pressure ridges, while large-scale drift patterns control sea ice loss through export from the Arctic Ocean. Sea ice drift has major implications for the mass, heat, and momentum balance of the Arctic Ocean’s ice cover. Sea ice drift is a major concern for maritime activities (Eicken et al, 2009), and associated sea ice hazards play a prominent role in offshore resource development and associated coastal infrastructure (Eicken et al, 2011; Eicken and Mahoney, 2015)

Results

Discussion

Conclusion