CAM5 coupled to SOM in Radiative Convective Equilibrium Setting

[simchan_yook@colostate_edu]

Hi all,

I'm trying to run a simulation with CAM5 coupled to a slab ocean in RCE setting.

I'm using QSC5 compset in cesm2_1_2 with resolution of f09_f09_mg17.

To run a preindustrial like RCE simulation following Popke et al. (2013), I've made changes on the CAM namelist:
omega=0
seasalt_emis_scale = 0.0
ch4vmr = 650.0e-9
co2vmr = 278.0e-6
f11vmr = 0.0
f12vmr = 0.0
flbc_list = ' '
n2ovmr = 270.0e-9


I also set the solar zenith angle to be spatially uniform but temporally varying with repeated diurnal cycle:
src/share/util/shr_orb_mod.F90
shr_orb_cosz = -cos((jday-floor(jday))*2.0_SHR_KIND_R8*pi)


I set the insolation to 1069.3W/m2 to make the global average of daily insolation to be 340 W/m2.
I did that via making alteration in the variable SOLIN from /src/physics/rrtmg/radsw.F90
solin(i) = sum(sfac(:)*solar_band_irrad(:)) * eccf * coszrs(i) * 1069.3_r8/1365.0_r8

And I set the global Q-flux to be zero.



Then, my model crashed or showed unrealistically high surface temperature values (>315 K) probably due to a runaway greenhouse effect.
(I've checked global average of FSNT and it was around 340 W/m^2, although it varied throughout the simulation).

Is this "too warm" atmosphere caused by the zero Q-flux? If so, how should I set the Q-flux to prevent the model from the "crash"?
Or are there any other factors that I should modify?

Thank you in advance
Shim

 

[simchan_yook@colostate_edu]

Firstly, I've confused some of my results while testing my RCE/SOM setting on both CAM6 and CAM5.

Some of my results using CAM6 has shown the extremely warm surface temperature, but I think I might made some mistakes in the model setting.
So please neglect below part from my previous post:
Then, my model crashed or showed unrealistically high surface temperature values (>315 K) probably due to a runaway greenhouse effect.
(I've checked global average of FSNT and it was around 340 W/m^2, although it varied throughout the simulation).

Is this "too warm" atmosphere caused by the zero Q-flux? If so, how should I set the Q-flux to prevent the model from the "crash"?
Or are there any other factors that I should modify?

In CAM5 RCE coupled to SOM setting, the model doesn't show extremely warm surface temperature, however, it shows a single convection cell and global surface temperature ~ 284 K (after 2 simulated years, and is keep decreasing).

I was wondering whether there are any scientifically validated RCE simulations run on CAM5/CAM6 coupled to the slab ocean?

 

[simchan_yook@colostate_edu]

Sorry this was my mistake.
I didn't know that SOLIN is diagnostic output, not the actual insolation used in the model.

It works very well after I've changed the "total solar irradiance" input values in "solar_irrad_data_file" to the required values (1069 w/m^2).