Height-based Deep Hot Jupiter Forcing

[Thomas Bendall (tommbendall)]

PR Summary

Sci/Tech Reviewer:
Code Reviewer:

This PR is an attempt to improve the stability of the deep hot Jupiter test case, through some setting tweaks and also through a change to the temperature forcing. The temperature forcing is written as a function of height rather than pressure, which removes a potential feedback in the dynamics as the pressure evolves (and thus the forcing with it).

Details

• I have changed the deep hot Jupiter temperature forcing to be specified as a function of height, rather than pressure
• the coefficients have been derived in offline code (see below)
• changed two settings for the deep hot Jupiter test to improve stability
• edited the corresponding unit-test, which has involved updating a hard-coded answer

Derivation of coefficients

The relaxation frequency, day-time and night-time temperatures are all defined through a polynomial expansion of log(sigma) -- essentially a scaled log(pressure) variable. The initial Exner pressure field for the deep hot Jupiter test does not depend on longitude or latitude, so it is possible to translate between log(sigma) and a log(height) coordinate. The relaxation frequency, day-time and night-time temperatures can then be written as a polynomial expansion of log(height) instead.

The attached python code computes these coefficients:
forcing_coeffs.py

The following plots show that the new coefficients ensure that the vertical profiles match:

Code Quality Checklist

• I have performed a self-review of my own code
• My code follows the project's style guidelines
• Comments have been included that aid understanding and enhance the readability of the code
• My changes generate no new warnings
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Testing

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trac.log

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Performance Impact

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Documentation

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Sci/Tech Review

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Code Review

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