Sea ice 2

Lecture, exercises and practical by Jun.-Prof. Dr. Lars Kaleschke

• Monday 13:30-15:00
• Room ZMAW 022

Description of the course

The lecture will cover the thermodynamic coupling between the sea ice, the ocean, and the atmosphere. It is designed for master-level students with moderate knowledge in numerical methods, scientific programming, and sea ice physics. A conceptual model of the Arctic will be derived and simulation results will be analyzed. For didactical reasons the model will be developed from scratch and kept as simple as possible, but complex enough to learn about the basic principles of the thermodynamic interaction between the ocean, the ice and the atmosphere for climatic, oceanographic and meteorological studies.

Deliverable: Report (15 August 2011)

• Description of conducted experiments
• Assumptions
• Governing equations
• Model variables
• Forcing data
• Model results (graph and descriptions)
• Source code
• Discussion and conclusions

Acknowledgments

This lecture is derived from content taken from a lecture Sea ice modeling by Aike Beckmann (Univ. Hamburg, Summer 2009) and a short course on Ice-Ocean Modeling and Data Assimilation which was conducted by Frank Kauker and Michael Karcher (Univ. Bremen, 6-7 December 2006).

Project work: source code, results

/Gruppe1 /Gruppe2 /Gruppe3 /Gruppe4 /Gruppe5

Table of Contents

Lesson 1+2 - Ocean mixed layer and radiative forcing without sea ice and atmosphere

Scenario 1

• Ocean mixed layer forced by shortwave radiation only
• No atmosphere
• No exchange with deeper ocean layers, immediate mixing
• Heat balance at the sea surface: Short wave incoming radiation + long wave outgoing radiation

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• Numerics: forward-in-time integration, finite differences

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Research questions

Compute the time evolution of the ocean mixed layer temperature T_ml(t) for different h_ml, initial temperatures T_ml(t=0), and short wave insolation Q_SW.

Estimate the typical time scale for stationarity and select appropriate time step delta_t for model integration.

Change insolation after the model has reached stationarity.

Literature

References for download

Maykut, G.A. & N. Untersteiner, 1971: Some results from a time-dependent thermodynamic model of sea ice. J. Geophys. Res.,76, 1550-1575.

Semtner, A., 1976: A model for the thermodynamic growth of sea ice in numerical investigations of climate, J. Phys. Oceanogr, 6, 379-389.

Hibler III, W.D., 1979: A dynamic-thermodynamic sea ice model. J. Phys. Oceanogr., 9, 815-846.

Parkinson, C.L. & W.M. Washington, 1979: A large-scale numerical model of sea ice., J. Geophys. Res., 84, 311-337.

Sellers, W.D., 1969: A Global Climatic Model Based on the Energy Balance of the Earth-Atmosphere System, J. Appl. Met., 8(3), 392-400.