Mapped Variables for the ET project

 

VariableSymbolDescriptionMonths per year1Maps per month2Total mapsAvailable For DownloadIncluded in Interactive Map
Clear sky radiation Kclear-sky

Solar radiation estimated for clear sky (no clouds) condition

12

15

180

x

x
Cloud frequency CF

Frequency of occurrence of cloud cover

12

24

288

x

x
Solar radiation Kd

Solar radiation estimated with effects of clouds included

12

15

180

x

x
Diffuse radiation Kdiffuse

Solar radiation that reaches surface after reflection

12

15

180

x

 
Albedo α

Proportion of incident solar radiation reflected by the surface

12

1

12

x

x
Downwelling longwave radiation Ld

Longwave radiation from atmosphere and clouds reaching surface

12

24

288

x

 
Upwelling longwave radiation Lu

Longwave radiation emitted by the surface

12

24

288

x

 
Net radiation Rnet

The difference between incoming and outgoing radiation

12

24

288

x

x
Soil heat flux G

Sensible heat conducting into or out of the soil

12

24

288

x

 
Biomass heat storage Qb

Sensible heat conducting into or out of the biomass

12

24

288

x

 
Air layer heat storage Qa

Increase or decrease in sensible and latent heat stored in air layer

12

24

288

x

 
Air Temperature T

Air temperature

12

24

288

x

x
Relative Humidity RH

Relative Humidity

12

24

288

x

x
Surface Temperature Ts

Temperature of the exposed surface (canopy and/or soil)

12

24

288

x

 
Vapor pressure e

Partial pressure of water vapor in the air

12

24

288

 

 
Saturation vapor pressure esat

Maximum vapor pressure at a given air temperature

12

24

288

 

 
Vapor pressure deficit VPD

Saturation vapor pressure minus Vapor pressure

12

24

288

x

x
Wind speed U

Wind speed at reference level of vegetation height plus 2 m

12

24

288

x

x
Land cover type LCT

Land cover type

1

1

1

x

x
Vegetation height h

Vegetation height

1

1

1

x

 
Leaf area index LAI

Leaf area (one-sided) divided by ground area

12

1

12

x

 
Vegetation cover fraction fc

Fraction of ground area covered by vegetation

12

1

12

x

 
Canopy wetness fraction fw

Fraction time vegetation is wet from rain, fog, or dew

12

24

288

x

 
Soil moisture constraint factor (transpiration) fΘ-transp

Factor representing the effects of soil moisture on transpiration

12

1

12

 

 
Soil moisture constraint factor (soil evaporation) fΘ-soil

Factor representing the effects of soil moisture on soil evaporation

12

1

12

 

 
Potential ET - Priestley Taylor PETP-T

Potential evapotranspiration based on the Priestley-Taylor model

12

24

288

x

x
Potential ET - Penman-Monteith PETP-M

Potential evapotranspiration based on the Penman-Monteith model

12

24

288

x

x
Potential ET - Grass reference surface PET0

Potential evapotranspiration based on the FAO grass reference surface model

12

24

288

x

x
Wet canopy evaporation Ewet-canopy

Evaporation of water from vegetation wetted by rain and/or fog

12

24

288

x

x
Transpiration Etransp

Transpiration

12

24

288

x

x
Soil evaporation Esoil

Evaporation of water from soil

12

24

288

x

x
Evapotranspiration ET

Sum of wet canopy evaporation, transpiration, and soil evaporation

12

24

288

x

x
Latent energy flux LE

Energy equivalent of evapotranspiration

12

24

288

x

x

1For variables with different maps for each month, annual maps were also created by averaging (or summing) the monthly values at each grid location. 2For variables with different maps for each hour, monthly maps were also created by averaging (or summing) the hourly values at each grid location.