Add power spectra calculation capability to the Grid-Diag tool in MET

[gsketefian]

Describe the New Feature

• Provide a capability within grid_diag to calculate a power spectrum from a given field, usually a velocity component or the whole wind field.
• Capability should allow calculation of spectrum on either a regional grid (using Fourier transforms) or a global grid (using spherical harmonics transform).
• Not sure if time-averaging of power spectra (e.g. for seasonal applications) should be included in grid_diag or another MET tool.

Acceptance Testing

• Given an idealized field with a known (analytic) power spectrum, ensure that the code generates the known spectrum.
• At least two tests -- one on a regional grid and another on a global grid.
• Input data for these tests can be generated analytically. Not sure about the format of the input data (netcdf?).
• Output data -- not sure what format this should be in.

Time Estimate

• Two months.
• A set of python scripts is already available that calculates power spectra. These will have to be adapted for incorporation into MET. Scripts can be found in the DTC AIWP project's folder here.
• Also see updated version in https://github.com/CPKalb/KE_Spectra_Calculation_Plot

Sub-Issues

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Relevant Deadlines

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Funding Source

PRJ014254 NOAA BENCHMARKING TNE

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Define Related Issue(s)

Consider the impact to the other METplus components.

• METplus, MET, METdataio, METviewer, METexpress, METcalcpy, METplotpy

New Feature Checklist

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@JohnHalleyGotway @KathrynNewman @michelleharrold @CPKalb