Abbreviation list

Table 1 Abbreviations used within the SEBCS documentation

Feature

Unit

Description

\(a_w\)

°

Aspect

\(B\)

rel.

Spectral bands, spectral reflectance

\(C\)

const.

Constant

\(c_p\)

\(J.kg^{-1}.K^{-1}\)

Thermal heat capacity of dry air (cp = 1012 \(J.kg^{-1}.K^{-1}\))

\(d\)

m

Effective height of the canopy

\(DMT\)

m

Digital model of terrain

\(d{\epsilon}\)

unitless

Effect of natural surfaces geometry distribution and their internal reflection

\(E_a\)

kPa

Water vapour pressure of saturated air

\(e_a\)

kPa

Water vapour pressure

\(E_s\)

kPa

Water vapour pressure of saturated air at the surface

\(e_s\)

kPa

Water vapour pressure at the surface

\(F_L\)

unitless

Factor of Monin-Obukhov length

\(g\)

\(m.s^{-2}\)

Gravitational forcing

\(G\)

\(W.m^{-2}\)

Ground heat flux

\(h\)

m

Canopy height

\(H\)

\(W.m^{-2}\)

Sensible heat flux

\(H_s\)

°

Hour angle

\(h_{st}\)

m

Mean height of canopy around the meteo-station

\(I_s\)

\(W.m^{-2}\)

Incident shortwave solar radiation perpendicular to beam

\(L\)

m

Monin-Obukhov length

\(L_{dry}\)

m

Monin-Obukhow length for dry air

\(Lat\)

°

Latitude

\(Long\)

°

Longitude

\(N\)

unitless

No. of day in year

\(MSAVI\)

unitless

Modified Soil Adjusted Vegetation Index

\(NDMI\)

unitless

Normalized Difference Moisture Index

\(NDVI\)

unitless

Normalized Difference Vegetation Index

\(P\)

kPa

Atmospheric pressure

\(Pv\)

unitless

Fractional vegetation index

\(r_a\)

\(s.m^{-1}\)

Surface aerodynamic resistance for heat and momentum transfer

\(r_c\)

\(s.m^{-1}\)

Surface resistance for water vapour transfer

\(r_{cp}\)

\(s.m^{-1}\)

Surface aerodynamic resistance for water vapour transfer in case of potential evapotranspiration

\(Rh\)

%

Relative humidity of air

\(Rl_{\uparrow}\)

\(W.m^{-2}\)

Upward longwave radiation flux

\(Rl_{\downarrow}\)

\(W.m^{-2}\)

Downward longwave radiation flux

\(Rn\)

\(W.m^{-2}\)

Total net radiation

\(R_{blue}\)

\(rel.\)

Spectral reflectance in blue spectral area (BLUE band)

\(R_{green}\)

\(rel.\)

Spectral reflectance in green spectral area (GREEN band)

\(R_{red}\)

\(rel.\)

Spectral reflectance in red spectral area (RED band)

\(R_{nir}\)

\(rel.\)

Spectral reflectance in NIR spectral area (NIR band)

\(R_{swir1}\)

\(rel.\)

Spectral reflectance in SWIR spectral area at approx. 1.6 \({\mu}m\) (SWIR1 band)

\(R_{swir2}\)

\(rel.\)

Spectral reflectance in NIR spectral area at approx. 2.2 \({\mu}m\) (SWIR2 band)

\(Rs_{\uparrow}\)

\(W.m^{-2}\)

Reflected shortwave radiation flux

\(Rs_{\downarrow}\)

\(W.m^{-2}\)

Incomming shortwave radiation flux

\(Rs_{\downarrow const}\)

\(W.m^{-2}\)

Incomming shortwave radiation flux at the horizontal surface

\(S_t\)

Solar time

\(T^*\)

K

Scaling parameter of temperature in the boundary layer

\(T_a\)

˚C

Air temperature in height \(z\)

\(T_{a\_K}\)

K

Air temperature in height \(z\)

\(T_B\)

K

Surface brightness temperature (\({\varepsilon} = 1.0\))

\(T_{max}\)

˚C

Max. surface temperature in the image

\(T_s\)

˚C

Surface temperature

\(T_{s\_K}\)

K

Surface temperature

\(T_{st}\)

°C

Air temperature measured at meteostation in height \(z_{st}\)

\(T_{s\_dry}\)

K

Calculated maximal surface temperature

\(T_{s\_wet}\)

K

Calculated minimal surface temperature

\(U\)

\(m.s^{-1}\)

Wind speed in height \(z\)

\(u^*\)

\(m.s^{-1}\)

Friction velocity of the wind

\(U_{st}\)

\(m.s^{-1}\)

Wind speed measured at meteostation in height \(z_{st}\)

\(VPD\)

kPa

Water vapour pressure deficit

\(W\)

mm

Amount of water for rain in atmosphere

\(w_b\)

const.

Constants for spectral bands

\(x\)

unitless

Constant

\(z\)

m

Height of the mixing layer (\(z=200\))

\(z_{0h}\)

m

Aerodynamic roughness for heat and water vapour transfer

:math:`z_{0m}

m

Aerodynamic roughness for momentum transfer

\(z_{st}\)

m

Height of measurement at the meteostation

\(\alpha\)

rel.

Albedo

\(\alpha_{PT}\)

unitless

Priestley-Taylor alpha (\(\alpha_{PT}=1.26\))

\(\alpha_z\)

°

Solar height angle

\(\beta\)

unitless

Bowen ratio

\(\beta_s\)

°

Slope gradient

\(\Gamma\)

\(°C.m^{-1}\)

Adiabatic lapse rate (\({\Gamma=0.0065}\ °C.m^{-1}\))

\(\gamma\)

\(kPa.˚C^{-1}\)

Psychrometric constant

\(\gamma^*\)

\(kPa.˚C^{-1}\)

Modified psychrometric constant according to Jackson et al. (1981)

\(\delta_s\)

°

Solar declination

\(\delta T\)

K

Temperature gradient calculated according to Bastiaanssen et al. (1998)

\(\delta T_{dry}\)

K

Temperature gradient for the dry areas

\(\Delta\)

\(kPa.˚C^{-1}\)

The slope of the saturated water vapour pressure\ to temperature gradient

\(\varepsilon\)

rel.

Surface emissivity

\(\varepsilon_a\)

rel.

Atmospheric emissivity

\(\varepsilon_s\)

rel.

Soil emissivity

\(\varepsilon_v\)

rel.

Vegetation emissivity

\(\kappa\)

unitless

Kármán constant (\(\kappa=0.41\))

\(\lambda\)

\(J.g^{-1}\)

Latent heat of evaporation

\(\lambda E\)

\(W.m^{-2}\)

Latent heat flux

\(\lambda E_{max}\)

\(W.m^{-2}\)

Latent heat flux equal to \(Rn-G\)

\(\lambda E_p\)

\(W.m^{-2}\)

Potential latent heat flux

\(\lambda E_{PT}\)

\(W.m^{-2}\)

Priestley-Taylor potential latent heat flux

\(\pi\)

unitless

Ludolf number

\(\rho\)

\(kg.m^{-3}\)

Dry air density

\(\rho_{s\_b}\)

rel.

Surface spectral reflectance for optical bands

\(\rho_{t\_b}\)

rel.

TOA spectral reflectance for optical bands

\(\varsigma\)

unitless

Monin-Obukhov stability parameter

\(\sigma\)

\(W.m^{-2}.K^{-4}\)

Stefan-Boltzmann constant (\(\sigma=5.6703\cdot 10^{-8}\ W.m^{-2}.K^{-4}\))

\(\Psi_h {(\varsigma)}\)

unitless

Stability parameter for heat transfer

\(\Psi_m {(\varsigma)}\)

unitless

Stability parameter for momentum transfer

\(\Omega\)

rel.

Decoupling coefficient (Omega factor)

\(\eta\)

°

Satellite inclination angle to nadir

\(\theta\)

°

Solar zenith angle

\(\tau_{in\_b}\)

rel.

Atmospheric transmittance for spectral bands for direct radiation

\(\tau_{out\_b}\)

rel.

Atmospheric transmittance for spectral bands for diffuse radiation