Cold Bias over Mauritius

[RobWaters]

Hi all,

I'm currently running a WRF hindcast over Mauritius and have got a significant cold bias in the results. If any of you can help with ideas on potential causes that would be a massive help.

We have access to measurements at 5 locations: 2 from Integrated Surface Database (ISD) and the other 3 hourly are from the island and only available at daily averaged.

Below shows the initial quantile-qunatile plots from the initial model runs (v3.8), with met stations on the X and WRF results on the Y:





We are driving the model with ERA5 but believe that is not responsible (but am planning to run the model with MERRA2 in the coming weeks). The plot below shows why i don't believe the reanalysis is responsible:







Since then we have:
- upgraded to the latest WRF;
- changed the static geog data;
- tested PBL physic schemes;
- changed the SST input from reanalysis to directly from satellite observations;
- tried nudging the model in the outer domains;
- changed model heights;

Some of the above has had some effect but nothing on the level to account for all the observed bias...

I've also attached the namelist.

I've got a plethora of plots showing the issue in more depth. Let me know if there is anything specific you want to see etc.

Thanks in advance,

Rob

 

[RobWaters]

Forgot to attach an example namelist :roll:

 

[kwerner]

Hi Rob,
I was just combing through posts to make sure things haven't gone unanswered and I stumbled across this one, which clearly has been overlooked. I apologize for the long delay in response to this. As it's been over a month now, have you been able to figure this out and move past it yet, or is the original question still valid?

 

[RobWaters]

Hi kwerner,

Sorry missed this and its been a long time. Still no solution. We've had to just accept it. I've got some test to run regarding the land surface model which we are hopeful for. But at this stage the bias is still there unfortunately.

Rob

 

[kwerner]

Hi Rob,
I know that you likely need to use V3.8, but out of curiosity, have you tried a newer version (the latest is V4.1.3) to see if the problem is resolved? If that's the case, it could help us to narrow down the modifications that caused the change.