PET formulas (Heat Overlay): Difference between revisions

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* <math>\phi_{t}</math> is the [[Sun_altitude_(Heat_Overlay)|sun altitude]] at time t;
* <math>\phi_{t}</math> is the [[Sun_altitude_(Heat_Overlay)|sun altitude]] at time t;
* <math>B_{b,t}</math> is the [[Bowen_ratio_(Heat_Overlay)|bowen ratio]] at time t;
* <math>B_{b,t}</math> is the [[Bowen_ratio_(Heat_Overlay)|bowen ratio]] at time t;
* <math>S_{vf}</math> is the calculated [[Sky_view_factor_formula_(Heat_Overlay)|sky view factor]].
* <math>S_{vf}</math> is the calculated [[Sky_view_factor_calculation_model_(Heat_Overlay)|sky view factor]].


==PET Shade and Night formula==
==PET Shade and Night formula==

Revision as of 11:50, 20 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:

where,

PET Shade and Night formula

The PET shade and night formula is as followed:

where,

  • is the calculated atmospheric temperature at time t;
  • is the calculated wind speed at 1.2 meters above ground time t;
  • is the calculated wet-bulb temperature at time t;
  • is the calculated sky view factor;
  • is the calculated diffusive radiation at time t;
  • is the Stefan Boltzmann constant, which is .