Good morning
I've been running some OpenIFS experiments at Tco95 L91. As usual OpenIFS reads soil temp at level 1 (STL1), sea ice fraction (CI) etc from the ICMCL file.
My question is: Should the soil temp at level 1 (STL1), skin temperature (SKT) and sea-surface temp (SST) be equal at all times over the ocean?
I have made a plot of monthly mean STL1 from the ICMCL file and SKT from the output. Both variables are very similar, but not identical.
On a map plot of SKT - STL1 it is clear that SKT - STL1 is around -0.1 K almost everywhere over the ocean.
Could this be the "cool-skin" parametrisation mentioned in the IFS documentation, or is this a known bias, or could there be an error somewhere?
Note: The ICMCL data was interpolated to regular grid using CDO (bi-linear) and the OpenIFS output on regular grid comes from XIOS (also bi-linear, I think...). So both STL1 and SKT are interpolated variables.
Cheers
Joakim
Hi Joakim
A quick check would be to see if you have the cold ocean /warm layer parametrisations on
LEOCCO
LEOCWA
If they are then skt can vary from STL1
Hi Sarah
I've got:
LEOCWA = T LEOCCO = T
in my NODE file, so I guess both cool skin and warm layer are activated.
Thanks for the help!
/Joakim
Hi Sarah,
I have been analyzing the sea surface temperature diurnal cycle using ERA5, GHRSST, and outputs from a coupled model.
The diurnal variability in ERA5 sea surface skin temperature (SKT) shows very good consistency with GHRSST. Meanwhile, the diurnal signal in the coupled model bulk SST and GLORYS analysis appears to be weaker, which raises some questions on the calculation of air-sea heat fluxes.
May I ask whether the cool skin / warm layer parameterizations are activated in the operational IFS for surface flux calculations?
Thanks very much for your time, and I would appreciate any guidance.
Best regards,
Biao
Biao Zhao, Ph.D.
Postdoctoral Research Associate
Atmospheric and Oceanic Sciences Program, Princeton University
300 Forrestal Road, Princeton, NJ 08540
