Progress

In March 2023, we had our first ISSI in-person meeting in Bern.

We discussed:

– An overview of each GCM and a comparison of the “chemistry-free” results
– Discuss and decide on the chemical and radiation schemes
– Discuss the details and challenges in implementation

We have finalized the benchmark tests as follows:

Test description:

Model boundaries:
– The lowest layer needs to be at least 100 bar. Use convective adjustment.
– Use approximately 2-4 degrees or equivalents for the horizontal resolution
– Use the least damping and sponge layers that can keep the simulation stable

Test 1 (passive tracer):
0. Run the nominal GCM until the steady state
1. After the steady state has been achieved, initializing passive tracers from the dayside equatorial region below 1 bar: for the region below 1 bar, +/- 30 degree longitude and +/- 30 degree latitude, fix a uniform mixing ratio of passive tracers from.
2. Report 0, 1, 50, 100 days after the tracers are initialized
(In practice, Test 1 is embedded in Test 2 using an inert gas)

Test 2 (double-grey with mini-chem):
0. Run the nominal GCM until the steady state
1. Use the following constant opacities:
kappa_IR =  0.003, kappa_shortwave = 0.00085 (m^2 kg^-1)
2. For internal heating, relax the temperature at the bottom toward the temperature given by an adiabat with Tint = 350K. A relaxation time of 10^5 sec is used in Steinrueck 2023 but choose whatever works better. In the case that the temperature relaxation at the bottom is difficult to implement, use Tint = 350 K internal flux instead.
3. After the steady state has been achieved, include the chemical tracers.