# 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