Comparison of Arctic Sea Ice Thickness from Satellites, Aircraft, and PIOMAS Data

Xuanji Wang,Ron Kwok,Jinlun Zhang,Jeffrey Key

doi:10.3390/rs8090713

Abstract

In this study, six Arctic sea ice thickness products are compared: the AVHRR Polar Pathfinder-extended (APP-x), ICESat, CryoSat-2, SMOS, NASA IceBridge aircraft flights, and the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS). The satellite products are based on three different retrieval methods: an energy budget approach, measurements of ice freeboard, and the relationship between passive microwave brightness temperatures and thin ice thickness. Inter-comparisons are done for the periods of overlap from 2003 to 2013. Results show that ICESat sea ice is thicker than APP-x and PIOMAS overall, particularly along the north coast of Greenland and Canadian Archipelago. The relative differences of APP-x and PIOMAS with ICESat are −0.48 m and −0.31 m, respectively. APP-x underestimates thickness relative to CryoSat-2, with a mean difference of −0.19 m. The biases for APP-x, PIOMAS, and CryoSat-2 relative to IceBridge thicknesses are 0.18 m, 0.18 m, and 0.29 m. The mean difference between SMOS and CryoSat-2 for 0~1 m thick ice is 0.13 m in March and −0.24 m in October. All satellite-retrieved ice thickness products and PIOMAS overestimate the thickness of thin ice (1 m or less) compared to IceBridge for which SMOS has the smallest bias (0.26 m). The spatial correlation between the datasets indicates that APP-x and PIOMAS are the most similar, followed by APP-x and CryoSat-2.

Highlights

Sea ice affects the exchange of heat, energy, mass, and momentum between the atmosphere and ocean, and has a significant impact on society in terms of marine transportation, security, fisheries, hazards, recreation, and hunting
Generally reported as extent or area, has been monitored from space for decades and it is commonly used in assessing changes in the Arctic climate system
Sea ice thickness can be estimated as a bulk average quantity at instrument specified resolutions from space using laser and radar altimeters to measure ice elevation, visible and infrared data to model the ice thickness that balances the surface energy budget, and passive microwave data with

Summary

Introduction

Sea ice affects the exchange of heat, energy, mass, and momentum between the atmosphere and ocean, and has a significant impact on society in terms of marine transportation, security, fisheries, hazards, recreation, and hunting. Observing Strategy Cryosphere Theme Report [6], “Adequate knowledge of the sea ice mass is important for weather and climate prediction, assessment and prediction of navigation, shipping, fishing, mineral resource exploration and exploitation, and in many other practical applications. The sea ice provides indicators of climate change, yet it may be the most under-sampled domain in the climate system”. Generally reported as extent or area, has been monitored from space for decades and it is commonly used in assessing changes in the Arctic climate system.

Methods

Results

Discussion

Conclusion