Investigation of dynamic sea ice processes in the Weddell Sea during 1992

Through a series of case studies, signal processing and statistical tools, analyses of dynamic sea ice processes of drift, deformation, and ice pack expansion and decay are investigated for the Weddell Sea region during 1992. Cavitating fluid (CAV) and viscous-plastic (VP) models are the most widely used ice models in sea ice, ocean and climate communities. Examination of these and observations are presented in order to identify the external (air/ocean) and internal (ice) forces that affect specific processes. Inconsistencies between processes in models and observations are isolated and examined with suggestions given for the next generation of ice models.; Key findings are as follows. Observationally, from ISW 1992, ice velocity in Western Weddell is found to be driven by low frequency forcing ({dollar}>{dollar} one day), while subdaily frequencies drive ice deformation. Mechanistic studies increase understanding in simulated ice performance under idealized conditions. In the models, annual expansion during winter months is dominated by air temperature at the ice edge and storms in the interior where sensible/latent heat fluxes are large, especially in leads. Coupled with this is divergent advection towards open water regimes which works to expand the ice pack. Thermodynamic processes dominate ice edge retreat in summer, specifically daily/subdaily thermal variations, relative humidity/latent heat and ocean heat flux. Interior thickness and deformation are respectively more sensitive than ice edge extent and velocity. Relative humidity and ocean heat flux are critical climatological variables having their greatest impact near the Antarctic Peninsula. Increased ocean heat flux reduces overall thickness with little effect to the ice edge, leading to catastrophic melting scenarios. Cross-spectral analyses show significant coherence between simulated and 30 hour low pass filter observed velocity and strain rates. Shear is significantly better modeled than divergence. Suggestions for next generation models include a reformulation of the boundary layer and incorporation of high frequency tidal forcing.