CICE-Consortium/Icepack version 1.0.0

The CICE Consortium’s new sea ice column physics code includes all physical parameterizations from the CICE sea ice model that are limited to single grid-cell columns or Lagrangian elements, independent of the grid and other sea ice model infrastructure. Many aspects of the physics and biogeochemistry that were previously embedded in CICE version 5 now reside within Icepack, and new features have also been added. In addition to the column physics modules from CICE, this software package includes a stand-alone driver and automated testing using a comprehensive test suite.

Enhancements:

• Full vertical biogeochemistry code, including particulate iron, humic material, modal aerosols, proteins, stationary and mobile phases
• Biogeochemical feedback on sea ice physics through the shortwave formulation
• Optional inclusion of ice velocity in the calculation of wind stress
• Multiple options for column forcing, including CFS model output, Arctic and Antarctic physical and biogeochemical measurements, and an Arctic climatology
• A warning package that captures diagnostic and error information from within the column physics, for printing by the driver
• A comprehensive test suite of various configuration options for full code coverage
• Automated testing using Travis CI
• Automated test reporting organized by hash, version, machine and branch, for both the primary Consortium repository and user forks
• Online documentation
• A flexible, extensible, robust interface between the column physics modules and the driver

Bug fixes:

• limit exponential arguments to avoid underflows in shortwave, mechanical redistribution, brine height (PR #127 #132 #158 #169)
• Use vvel instead of uvel for y-component of atmosphere-ice stress with high-frequency option (PR #142)
• Use net shortwave sum instead of cosine of the zenith angle to limit shortwave calculation for low-/no-light conditions
• Correct roundoff errors in the delta-Eddington shortwave calculation
• Define interface temperature in the brine height parameterization
• Provide flexibility for tracking frazil ice salt/water in the ice or ocean model component
• When ponds are very thin, ignore them in the radiation calculation
• Ensure fractions of snow, ponds and bare ice sum to 1
• Wrap pond tracers in conditional blocks in mushy thermodynamics and form drag parameterization
• Miscellaneous bug fixes for biogeochemistry and brine height tracer (hbrine)