Sea Ice Modeling

Overview

Teaching: min
Exercises: min

Questions

• How Does Sea Ice Modeling work?

Objectives

Why is it important to model sea ice?

• Arctic sea ice extent is known to be decreasing due to Arctic Amplification, the effect that the poles are warming faster than the rest of the globe.
• Sea ice feeds back to other components of the climate system
• It has high albedo which has an impact on the Earth’s radiation budget
• It insulates the ocean from the atmosphere which impacts the exhanges of heat and moisture
• Can modify ocean circulation: Ice formation leads to salt flux to ocean; ice melt freshens the oceans

Sea Ice Models

The CESM2 sea ice component is called Community Ice CodE (CICE). Sea ice models have two primary components, some models have a 3rd component:

Dynamics

• Force balance to determine the motion of the sea ice
• Wind stress, water stress, internal ice stress, Coriolis, and stress associated with sea surface slope
• Resistance to converence and shear

Thermodynamics and Radiative Properties

• Solves the vertical ice temperature profile: 8 sea ice thickness categories; 3 snow layers
• Determines the Vertical/lateral melt and growth rates
• Albedo
• Radiation
• Aerosol Depositing and cycling

Ice Thickness Distribution

Sub-gridscale parameterization to represent the spatial hterogeneity in ice

• Five ice categories
• PDF of the ice thickness evolution is solved
• Convergence, ice growth

Key Points