Temperature formulas (Heat Overlay): Difference between revisions
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Two temperature formulas are used in the calculation of the PET value: | Two temperature formulas are used in the calculation of the PET value: | ||
* The atmospheric temperature T<sub>a</sub> | * The atmospheric temperature [[#Atmospheric Temperature formula|T<sub>a</sub>]] | ||
* The wet-bulb | * The wet-bulb temperature<ref name="bulb" /> [[#Wet-bulb Temperature formula|T<sub>w</sub>]] | ||
==Atmospheric Temperature formula== | ==Atmospheric Temperature formula== | ||
<math>T_{a,t} = T_{station,t} + UHI_{max,t} \cdot f_{sun,t}</math> | |||
where | where | ||
* | * <math>T_{a,t}</math> is the calculated [[Temperature_atmosphere_result_type_(Heat_Overlay)|atmospheric temperature]] at time t; | ||
* | * <math>T_{station,t}</math> is the [[Hourly_temperature_(Heat_Overlay)|temperature]] measured at a weather station 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== | ==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: | 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== | ==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:
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
- ↑ Wikipedia • Wet-bulb temperature • https://en.wikipedia.org/wiki/Wet-bulb_temperature • Last visited: 20-12-2019
