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apps:biomet_utci [2015/12/22 22:27] enviadminapps:biomet_utci [2021/12/12 19:37] (current) – [Final Remarks] enviadmin
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 ====== UTCI ====== ====== UTCI ======
  
-The calculation of UTCI is based on a 6th order polynomial regression function estimating UTCI from wind speed, air temperature, mean radiant temperature and air vapour pressure (see [[http://www.utci.org/utci_doku.php|COST 730 Webpage]]). Due to that approach, there is almost nothing that can be changed in the personal settings such as clothing, activity etc.+The UTCI was first integrated in EnvimetV4 in 2013. The calculation of UTCI is based on a 6th order polynomial regression function estimating UTCI from wind speed, air temperature, mean radiant temperature and air vapour pressure (see [[http://www.utci.org/utci_doku.php|COST 730 Webpage]]). Due to that approach, there is almost nothing that can be changed in the personal settings such as clothing, activity etc. 
  
  
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-As the UTCI calculation expects the wind given at the 10 m level, ENVI-met BioMet uses the calculated local wind speed in the model domain related to the pedestrian level ($zlevel$) and scales it up to the  10 m level equivalent using the logarithmic wind power profile +As the UTCI calculation expects the wind given at the 10 m level, ENVI-met BioMet uses the calculated local wind speed $Wind_{zlevel}$ in the model domain related to the pedestrian level ($zlevel$) and scales it up to the  10 m level equivalent using the logarithmic wind power profile 
 $$ Wind_{10m} = \frac{ln(10 / z0)}{ln(zlevel / z0)} \cdot Wind_{zlevel}$$ $$ Wind_{10m} = \frac{ln(10 / z0)}{ln(zlevel / z0)} \cdot Wind_{zlevel}$$
  
-In other word, if you calculate UTCI at some point for zlevel= 1.6 m, all ENVI-met data such as air temperature or radiative temperature will be used from this level, except of the wind speed which will be extrapolated to the 10 m level value.+In other words, if you calculate UTCI at some point for zlevel= 1.6 m, all ENVI-met data such as air temperature or radiative temperature will be used from this level, except of the wind speed which will be extrapolated to the 10 m level value.
  
 Obviously, that doesn't make much sense as the $z0$ roughness value is unknown for most sites, but ENVI-met provides detailed and calculated wind flow data for all levels.  Obviously, that doesn't make much sense as the $z0$ roughness value is unknown for most sites, but ENVI-met provides detailed and calculated wind flow data for all levels. 
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-**Please Note**:  Due to these restrictions, areas outside the official bounds of UTCI will not be calculated by BioMet. These areas are marked with "No Data". Especially in urban areas, the lower limit of 0.5 m/s can create a number of white "No Data" areas in the maps. In future versions of BioMet, will add an option to ignore these UTCI boundsBUT: Remember that UTCI is not a part of ENVI-metUsing this option your maps might look better and  more completeBut scientifically, you are leaving the "official" and pre-calcuated UTCI range.+**Please Note**:  Due to these restrictions, areas outside the official bounds of UTCI will not be calculated by BioMet. These areas are marked with "No Data". Especially in urban areas, the lower limit of 0.5 m/s can create a number of white "No Data" areas in the maps. 
 + 
 +From Version 5.0.1 (Dec 2021) onthe 0.5 m/s limit is ignored when calculating UTCI.
  
 **References** **References**
  
 Link to the original source code and to the EU COST Action 730 Homepage: [[http://www.utci.org/utci_doku.php]] Link to the original source code and to the EU COST Action 730 Homepage: [[http://www.utci.org/utci_doku.php]]