Abbreviation list¶
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 |