PET formulas (Heat Overlay): Difference between revisions

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==PET Shade and Night formula==
==PET Shade and Night formula==
The PET sun formula is as followed:<br>
The PET sun formula is as followed:<br>
PET<sub>sun</sub> = -13.26 + 1.25 · T<sub>a,t</sub> + 0.011 · Q<sub>gl,t</sub> - 3.37 · ln(u<sub>t</sub>) + 0.078 · T<sub>w,t</sub> + 0.0055 · Q<sub>gl,t</sub> · ln(u) + 5.56 · sin(ϕ<sub>t</sub>) - 0.0103 · Q<sub>gl,t</sub> · ln(u) · sin(ϕ<sub>t</sub>) + 0.546 · B<sub>b,t</sub> + 1.94 · S<sub>vf</sub><br>
PET<sub>shade,night,t</sub> = -12.14 + 1.25T<sub>a</sub> 0 1.47 ln(u<sub>t</sub>) + 0.060 T<sub>w</sub> + 0.015S<sub>vf</sub>Q<sub>d</sub> + 0.0060 (1-S<sub>vf</sub>) σ (T<sub>a</sub>+273.15)<sup>4</sup>
where,
where,
* T<sub>a,t</sub> is the calculated [[Temperature_formulas_(Heat_Overlay)#Atmospheric_Temperature_formula |atmospheric temperature]] at time t;
* T<sub>a,t</sub> is the calculated [[Temperature_formulas_(Heat_Overlay)#Atmospheric_Temperature_formula |atmospheric temperature]] at time t;

Revision as of 11:57, 12 September 2019

The physiological equivalent temperature PET is calculated for two possible options based on the situation:

  • A cell is in the shade or it is night at time t: PETshade, night;
  • A cell is in the sun during the day: PETsun;

PET Sun formula

The PET sun formula is as followed:
PETsun = -13.26 + 1.25 · Ta,t + 0.011 · Qgl,t - 3.37 · ln(ut) + 0.078 · Tw,t + 0.0055 · Qgl,t · ln(u) + 5.56 · sin(ϕt) - 0.0103 · Qgl,t · ln(u) · sin(ϕt) + 0.546 · Bb,t + 1.94 · Svf
where,

PET Shade and Night formula

The PET sun formula is as followed:
PETshade,night,t = -12.14 + 1.25Ta 0 1.47 ln(ut) + 0.060 Tw + 0.015SvfQd + 0.0060 (1-Svf) σ (Ta+273.15)4 where,