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What's the impact of increased sea level pressure on surface temperature?

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zeyuxue

New member
Hi all,

I have conducted WRF runs with and without increased sea level pressure (about 0.1 mb) and found that in the run with increased sea level pressure, the surface temperature (T2) is much less (more than 1 K) than in the run without increased sea level pressure. Also, the underestimation of temperature only exists at low levels (below about 900 mb).

In both runs, the sea level pressure instead of surface pressure is provided so that the surface pressure in WRF should be calculated based on terrain height, temperature, moisture and sea level pressure. According to the hypsometric equation, I can imagine that an increased sea level pressure will bring a decreased surface pressure. But I don't how does WPS or WRF make such an adjustment and why the adjustment only exists at low levels.

Could you please help me figure it out? It would be great if there are some references to cite.

Thank you so much for your kind help!

Bests,
Zeyu
 
Hi Zeyu,
This is probably dependent on the physics options you are using. Have you tried using different options to see if the results differ?
 
Hi Kelly,

Very sorry that I missed your reply, previously we thought this might come from the spectral nudging we used; however, the same problems still exist in the run without any nudging. Currently, we used the physics options as attached (most of them are used in CESM). It sounds reasonable that a different parameterization might solve the problem. Do you have any recommendations for us to test?

Thank you so much for your kind help!

Bests,
Zeyu
 

Attachments

  • parameterization.png
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Zeyu,
I'm not a physics expert, but we do have two physics suites that are highly tested and show the best results, in general. One is the CONUS suite, which is often tested over the CONUS (Continental United States), but is reasonable to use over any large continental area at mid-latitudes. The other is the tropical suite, which is more suitable for the tropics, and perhaps subtropics. You can read more about those in chapter 5 of our WRF Users' Guide. If your domains are not suitable for either of these suites, you can read brief descriptions of all the physics options in the Users' Guide, or for more details, see the literature for each scheme, linked from this page.
 
Hi Kelly,

Thank you so much for the information. I will have a test with the CONUS suite then. Thanks again for your help!

Bests,
Zeyu
 
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