A comparison between three-dimensional, transient, thermomechanically coupled first-order and Stokes ice flow models

• Published in: Journal of Glaciology
• Main Authors: Yan, Zhan, Leng, Wei, Wang, Yuzhe, Xiao, Cunde, Zhang, Tong
• Other Authors: State Key Laboratory of Earth Surface Processes and Resource Ecology, Fundamental Research Funds for the Central Universities, National Key Research and Development Program of China
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2022
• Subjects: Ice Sheet; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/jog.2022.77; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143022000776

Abstract In this study, we investigate the differences between two transient, three-dimensional, thermomechanically coupled ice-sheet models, namely, a first-order approximation model (FOM) and a ‘full’ Stokes ice-sheet model (FSM) under the same numerical framework. For all numerical experiments, we take the FSM outputs as the reference values and calculate the mean relative errors in the velocity and temperature fields for the FOM over 100 years. Four different boundary conditions (ice slope, geothermal heat flux, basal topography and basal sliding) are tested, and by changing these parameters, we verify the thermomechanical behavior of the FOM and discover that the velocity and temperature biases of the FOM generally increase with increases in the ice slope, geothermal heat flux, undulation amplitude of the ice base, and with the existence of basal sliding. In addition, the model difference between the FOM and FSM may accumulate over time, and the spatial distribution patterns of the relative velocity and temperature errors are in good agreement.