[Ncep.list.emc.monsoondesk] Discripancy in the actual Ocean Surface temperatue and Surface temperature Seen by the Atmosphere (GFS)

[Shrinivas Moorthi]

Prajeesh,
     I have not looked at the code and not sure how MOM treats sea ice, 
but where sea ice exists, it is treated like land and
the atmosphere sees sea ice skin temperature.  I assume that sst in the 
sea ice region should be the ice bottom temperature
(or the sea surface temperature under sea ice.  (I am not sure if this 
is what is done, but I am not a MOM4 expert).
Moorthi
On 09/25/2014 12:42 AM, Prajeesh A.G. wrote:
>
> Hi all,
>
> I find that, over the Sea-Ice regions, there is a large discrepancy in 
> the Surface temperature calculated by the Ocean Model and the one 
> which is seen by the Atmospheric model.
>
> The attached figure is from a free run of our ESMv1 model (Which has 
> MOM4p1 in place of MOM4p0 in CFSv2). In the figure left panel is the 
> Sea Surface temperature from Ocean Model and the right panel is 
> Surface temperature from Atmospheric (GFS) Model. The Color scales are 
> same. It can be seen that over the Polar region the surface 
> temperature are largely different. In the Ocean model it is between -1 
> to 1 degree, where as in the atmosphere it is below -4 degree (Sea-Ice 
> region over the north pole) . We also confirmed that this discrepancy 
> exist in our CFSv2 simulations too.
>
> I think that, this discrepancy is due to the Sea-Ice thermodynamics 
> model in the GFS. The atmospheric model see the Ocean calculated 
> surface temperature only where there is no Sea-Ice, and where there is 
> Sea-Ice it takes the Sea-Ice fraction and Sea-Ice depth from Ocean 
> model and calculates the surface temperature using a Sea-Ice 
> thermodynamics model in the GFS. I conjecture that this might account 
> some part of the TOA energy Imbalance.
>
> We would be like to hear from other users of CFSv2 on this issue.
>
> *Regards..*
>
> Prajeesh
> CCCR
> IITM, Pune
> India
>


-- 
Dr. Shrinivas Moorthi
Research Meteorologist
Global Climate and Weather Modeling Branch
Environmental Modeling Center / National Centers for Environmental Prediction
5830 University Research Court - (W/NP23), College Park MD 20740 USA
Tel:(301)683-3718

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