Thermo Design Document
People need to use equations to calculate thermodynamic quantities all the time. There should be a nice interface to do this.
- Easy to use interface that minimizes how much you need to memorizes
- Works on xarray dataarrays
- Takes full advantage of labeled data and automated broadcasting (e.g. for latitude-dependent calculation of absolute salinity)
- Handles units – where present in metadata or passed in by user as keyword
- Can work for atmosphere or ocean (or arbitrary set of equations)
- Scales to big data
- Can take advantage of metadata stored in DataArrays
- Clear in documentation which form of equations are being solved
- Support for custom equation of state (particularly for ocean)
- What does it calculate?
- Potential temperature
- saturation vapor pressure
- Slope of adiabats in T-P space etc
- Slope of isopycnals in T-S space
- All functions of thermodynamic state variables
- Isolate solving code into a new package, that gets used by the atmos package
- Someone can make an ocean package that does something similar to the atmos package, containing equations for ocean thermodynamics
- Have saturation vapor pressure assumption treated specially as keyword argument
- Chain numba calls when doing ocean eqns, they’re huge!
- Aim for pure Python / numba implementation
What are people doing now?
- Seawater toolkit (depractated but still widely used)
- Or using routines extraced from models
- No one rolls their own (formulas too clunky)
- Don’t have a package that can use labeled xarray data effectively
link to hackpad