Temperature formulas (Heat Overlay): Difference between revisions

From Tygron Support wiki
Jump to navigation Jump to search
No edit summary
No edit summary
 
(26 intermediate revisions by 3 users not shown)
Line 1: Line 1:
Two temperature formulas are used in the calculation of the PET value:
* The atmospheric temperature [[#Atmospheric Temperature formula|T<sub>a</sub>]]
* The wet-bulb temperature<ref name="bulb" /> [[#Wet-bulb Temperature formula|T<sub>w</sub>]]
==Atmospheric Temperature formula==
==Atmospheric Temperature formula==
T<sub>a,t</sub> = T<sub>station,t</sub> + UHI<sub>max,t</sub> * f<sub>sun,t</sub><br>
<math>T_{a,t} = T_{station,t} + UHI_{max,t} \cdot f_{sun,t}</math>
where,
 
* T<sub>a,t</sub> is the calculated [[Temperature_atmosphere_result_type_(Heat_Overlay)|atmospheric temperature]] at time t;
where
* T<sub>station,t</sub> is the temperature measured at a weather station at time t;
* <math>T_{a,t}</math> is the calculated [[Temperature_atmosphere_result_type_(Heat_Overlay)|atmospheric temperature]] at time t;
* UHI<sub>max,t</sub> is the calculated [[UHI_formula_(Heat_Overlay)|Urban Heat Island]] effect at time t;
* <math>T_{station,t}</math> is the [[Hourly_temperature_(Heat_Overlay)|temperature]] measured at a weather station at time t;
* f<sub>sun,t</sub> is the [[Sun_daily_motion_(Heat_Overlay)|sun daily motion factor]] at time t;
* <math>UHI_{max,t}</math> is the calculated [[UHI_formula_(Heat_Overlay)|Urban Heat Island]] effect at time t;
* <math>f_{sun,t}</math> is the [[Sun_daily_motion_(Heat_Overlay)|sun daily motion factor]] at time t;
 
==Wet-bulb Temperature formula==
<math>T_{w,t} = T_{a,t} \cdot \arctan( 0.151977 \cdot \sqrt{\phi + 8.313659})+ \arctan (T_{a} + \phi) - \arctan(\phi - 1.676331) + 0.00391838 \cdot \phi^{\frac{3}{2}}  \arctan(0.023101 \cdot \phi) - 4.686935</math>
 
where:
* <math>T_{w,t}</math> is the calculated wet-bulb temperature;
* <math>T_{a,t}</math> is the calculated atmospheric temperature;
* <math>\phi</math> is the [[Sun_altitude_(Heat_Overlay)|sun altitude angle]];
* Constant values are sourced from the {{Heat DPRA Report}};
 
==See also==
<references>
<ref name="bulb">Wikipedia • Wet-bulb temperature • https://en.wikipedia.org/wiki/Wet-bulb_temperature • Last visited: 20-12-2019</ref>
</references>
{{Template:HeatOverlay_formula_nav}}

Latest revision as of 11:53, 13 September 2021

Two temperature formulas are used in the calculation of the PET value:

  • The atmospheric temperature Ta
  • The wet-bulb temperature[1] Tw

Atmospheric Temperature formula

where

  • is the calculated atmospheric temperature at time t;
  • is the temperature measured at a weather station at time t;
  • is the calculated Urban Heat Island effect at time t;
  • is the sun daily motion factor at time t;

Wet-bulb Temperature formula

where:

  • is the calculated wet-bulb temperature;
  • is the calculated atmospheric temperature;
  • is the sun altitude angle;
  • Constant values are sourced from the DPRA Heat stress report;

See also

  1. ↑ Wikipedia • Wet-bulb temperature • https://en.wikipedia.org/wiki/Wet-bulb_temperature • Last visited: 20-12-2019
Heat Module
Benchmarks button.png
Heat introduction button.png
Heat Module
Benchmarks button.png
Getting started button.png
Tutorials
Benchmarks button.png
Overview button.png
Overview
Benchmarks button.png
Theory button.png
Theory
Benchmarks button.png
Benchmarks button.png
Benchmarks
Group
Formulas
UHI • Temperatures • Diffuse radiation • PET
Calculation models
Foliage height • Sky view factor • Shade • Average vegetation and sky view factor
Related
Calculation models and formulas • Feature attributes • Model attributes • Result types


Retrieved from "https://support.tygron.com/w/index.php?title=Temperature_formulas_(Heat_Overlay)&oldid=43532"