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How to simulating Urban Heat Island?

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oleson

Keith Oleson
CSEG and Liaisons
Staff member
The environmental conditions of urban areas are automatically simulated in any gridcell that has non-zero urban area as specified by the surface dataset you are using. The heat island can be computed by taking the different between the urban air temperature (TSA_U) and the rural (vegetated+soil) air temperature (TSA_R). These variables are available from history output. See the following chapter in the CLM5 technical note for more details on the urban model:

 
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Eghe

Igun Eghosa
New Member
Thank you so much for the detailed reply regarding UHI simulation/computation. Actually, I have not used the CESM data and model before. I just want to ask, can I run simulate this using NCAR command language? Also I would be glad if you can point me the source of the scripts and the data and further details of how to go about the analysis. I would be so grateful for this.

Thanks in anticipation,

Igun Eghosa
 
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Eghe

Igun Eghosa
New Member
Thanks for help once again...I tried creating a case but this was the error message i got
"ERROR: Could not initialize machine object from /home/svn/CESM/cime/config/cesm/machines/config_machines.xml or /home/hp/.cime/config_machines.xml"
Please,how do I rectify this. Also I want to kindly ask for a step by step guide on running an Urban heat Island Script.

I would be so grateful for the help

 
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oleson

Keith Oleson
CSEG and Liaisons
Staff member
This sounds like a porting problem. Please see:



Post any problems you have regarding porting to:

bb.cgd.ucar.edu

Infrastructure (CIME, porting, machines, scripts)

CIME, case control system, build and configure, machines and supporting scripts.
bb.cgd.ucar.edu bb.cgd.ucar.edu

Examples of scripts and tools that can be used to process CESM history data (e.g., TSA_R and TSA_U from CLM history files) can be found here:

 
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Eghe

Igun Eghosa
New Member
This would really help me....Thank you so much for the detailed information. I am so grateful
 
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Eghe

Igun Eghosa
New Member
Please can I use TG_R and TG_U to estimate Surface urban heat island? and TSA_R and TSA_U to estimate canopy layer UHI?
 
O

oleson

Keith Oleson
CSEG and Liaisons
Staff member
The surface heat island from the model could be derived several different ways. You could use TG_R and TG_U. These are the area weighted averages of the surface temperature of the individual urban surfaces (roof, sunwall, shadewall, pervious and impervious canyon floor). You could also invert the upward longwave from the model (FIRE_U and FIRE_R) using the Stefan-Boltzmann equation and some assumption about the effective emissivity of urban and rural areas.
TSA_U and TSA_R are normally used to estimate the urban canopy air temperature in this model
 
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