Table 2 Input parameters for calculating WBGT and their WRF equivalent output variables

Dew point temperature at 2 m

td_k (K)

Td_2m (K)

Calculated with the NCAR NCL script wrfout_to_cf

Air temperature at 2 m

t2_k (K)

T2 (K)

Standard wrf output

Relative humidity at 2 m

rh (%)

rh_2m (%)

Calculated with the NCAR NCL script wrfout_to_cf

Wind speed at 10 m height

va (\({{m\; s}}^{-1}\))

WS (\({{m\; s}}^{-1}\)) = \(\sqrt{({U10}^{2}+{V10}^{2})}\)

Calculated from standard WRF output U10 and V10

Cosine of solar zenith angle

cossza \(({{\circ}\atop})\)

COSZEN

cos of solar zenith angle

Standard wrf output

Solar elevation angle

\(\gamma\) \(({{\circ}\atop})\) = 90-cossza

-

-

Total sky direct solar radiation at surface (downward on a horizontal plane)

fdir (\({{W\; m}}^{-2}\))

SWDDIR

Shortwave surface downward direct irradiance (\({{W\; m}}^{-2}\))

Not a standard WRF output, added in myoutfields.txt

Surface solar radiation downwards

ssrd (\({{W\; m}}^{-2}\))

SWDOWN (\({{W\; m}}^{-2}\))

downward shortwave flux at ground surface

Standard wrf output

Surface thermal radiation downwards

strd (\({{W\; m}}^{-2}\))

GLW (\({{W\; m}}^{-2}\))

downward longwave flux at ground surface

Standard wrf output

Surface solar radiation upwards

rsw = ssrd-ssr

SWUPB (\({{W\; m}}^{-2}\)) instantaneous upwelling shortwave flux at bottom

Standard wrf output

Surface thermal radiation upwards

lur = strd-strr

LWUPB (\({{W\; m}}^{-2}\))

instantaneous upwelling longwave flux at bottom

Standard wrf output

Surface net solar radiation

ssr (\({{W\; m}}^{-2}\))

SWDOWN-SWUPB

Required for calculating mean radiant temperature

Surface net thermal radiation

strr (\({{W\; m}}^{-2}\))

GLW-LWUPB

Required for calculating mean radiant temperature

Direct solar radiation (at surface) on a plane perpendicular to the direction of the Sun

dsrp (\({{W\; m}}^{-2}\))

SWDDNI

Shortwave surface downward direct normal irradiance (\({{W\; m}}^{-2}\))

Not a standard WRF output, added in myoutfields.txt

Diffuse solar radiation

dsw = ssrd-fdir

SWDDIF

Shortwave surface downward diffuse irradiance (\({{W\; m}}^{-2}\))

Not a standard WRF output, added in myoutfields.txt