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start:hype_model_description:processes_above_ground [2018/10/02 10:30]
cpers [Input to alternative potential evaporation models]
start:hype_model_description:processes_above_ground [2019/03/19 16:12]
cpers [Evaporation]
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 |Figure 3 Soil temperature factor for reduction of soil evapotranspiration. Parameter values: //​ttrip//​=1,​ //​tredA//​=0.5,​ //​tredB//​=1.| |Figure 3 Soil temperature factor for reduction of soil evapotranspiration. Parameter values: //​ttrip//​=1,​ //​tredA//​=0.5,​ //​tredB//​=1.|
  
-The actual evaporation is set to zero for temperatures below the threshold temperature and for negative potential evaporation estimates (condensation). ​The soil evapotranspiration reduction is calculated as:+The soil temperature ​evapotranspiration reduction is calculated as:
  
 <m> factor = 1-e^( - tredA*(soiltemp-ttrig)^tredB) </m> <m> factor = 1-e^( - tredA*(soiltemp-ttrig)^tredB) </m>
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 <m> evapp = evapp*factor </m> <m> evapp = evapp*factor </m>
  
-A river with an area (is a class), flooded floodplains and lakes are assumed to evaporate at the potential rate, when the air temperature is above the threshold temperature (//ttmp//). Evaporation is limited by the water body's volume.+The actual soil evaporation is set to zero for temperatures below the threshold temperature and for negative potential evaporation estimates (condensation). 
 + 
 +A river with an area (i.e. is a class), flooded floodplains and lakes are assumed to evaporate at the potential rate, when the air temperature is above the threshold temperature (//ttmp//). Evaporation is limited by the water body's volume.
  
  
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 HYPE give the option to exchange the default potential evaporation model for another model. Only the basic potential evaporation (<​m>​epot_base</​m>​) differs between models. Models 0-2 only use air temperature forcing. Models 3-5 want shortwave radiation and minimum and maximum daily air temperature,​ although if lacking approximations are made (see section [[start:​hype_model_description:​processes_above_ground#​input_to_alternative_potential_evaporation_models|Input to alternative potential evaporation models]] below). In addition, model 5 wants relative humidity and wind speed if available. HYPE give the option to exchange the default potential evaporation model for another model. Only the basic potential evaporation (<​m>​epot_base</​m>​) differs between models. Models 0-2 only use air temperature forcing. Models 3-5 want shortwave radiation and minimum and maximum daily air temperature,​ although if lacking approximations are made (see section [[start:​hype_model_description:​processes_above_ground#​input_to_alternative_potential_evaporation_models|Input to alternative potential evaporation models]] below). In addition, model 5 wants relative humidity and wind speed if available.
 +Note, regardless of potential evaporation model, the actual evaporation is limited to temperatures above parameter //ttmp//.
  
 === Model 0 (default) ===  === Model 0 (default) === 
start/hype_model_description/processes_above_ground.txt · Last modified: 2024/02/21 08:54 by cpers