Spin-up time for CAM with Slab ocean?

[ginah@udel_edu]

Hi,

I was wondering if anyone has recently used CAM with the slab ocean for any research and if so typically how long (years?) has it taken to spin up before it reaches any sort of equlibrium? The manual is pretty vague on this topic.

Gina.

 

[rneale]

It depends on which initial conditions you use. If it is the final output state from the
fixed SST run you used to generate the SOM QFLUX data the nit should spin-up pretty quickly (a few years), but if your initial state is significantly out of balance (like if you are spinning the land up from scratch) then it will take at least 10 years, and probably close to 20 to look like it is in equilibrium.

 

[suvarchal_kumar@gmail_com]

hi,
i am intrested in knowing different metrics for evaluating spin-up phase and why?

 

[suvarchal_kumar@gmail_com]

Can some one please point me to any reference or so ..explaining metrics for evaluating spin up?

 

[rneale]

Spin up in the slab ocean model depends mostly on how close to zero the top of atmosphere energy balance is (short wave minus long wave). If the balance is near zero for the fixed SST run from which you calculated the QFLUXES then the climate should stabilize pretty quickly (within 10 years). If you are perturbing the forcing by increasing CO2 for example then spin-up will take longer.

 

[suvarchal_kumar@gmail_com]

Than you Neale,but by what metrics will i know if my climate is stabilized? i mean is it by tempertures , moist static energy ?

Spin up in the slab ocean model depends mostly on how close to zero the top of atmosphere energy balance is (short wave minus long wave). If the balance is near zero for the fixed SST run from which you calculated the QFLUXES then the climate should stabilize pretty quickly (within 10 years). If you are perturbing the forcing by increasing CO2 for example then spin-up will take longer.