EnvirEnergy: The Surface Net Energy Budget

Description Usage Arguments Value Author(s) Examples

View source: R/EnvirEnergy.R

Description

Net Energy=S+La-Lt+S+E+R+G, where S is the net incident solar radiation, La is the atmospheric long wave radiation, Lt is the terrestrial long wave radiation, H is the sensible heat exchange, E is the energy flux associated with the latent heats of vaporization and condensation, G is ground heat conduction, P is heat added by precipitation

Usage

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EnvirEnergy(lat, Jday, Tx, Tn, wind, rain, relativehumidity,
 albedo=0.2, cloudiness=NULL, forest=0, slope=0, aspect=0, 
 surftemp=(Tx+Tn)/2, surfemissivity=0.97)

Arguments

lat

latitdue [rad]

Jday

Julian day / day of the year, 1-365 [day]

Tx

Maximum daily temperature [C]

Tn

Minimum daily temperature [C]

wind

Average daily windspeed [m/s]

rain

precipitation [mm/day]

relativehumidity

Relative humidity; if negative, air vapor density will be approximated [-]

albedo

#albedo: surface albedo or reflectivity [-]

cloudiness

Fraction of the sky covered in clouds,if no value provided, cloudiness will be approximated [-]

forest

Forest or vegeation cover [-]

slope

Slope of the ground [rad]

aspect

Ground aspect [rad from north]

surftemp

surface temperature [C]

surfemissivity

surfice emissivity: [-]

Value

NetEnergy

Surface net energy

.

Author(s)

Walter, M.T.,Fuka, D.R. Maintainer: Daniel Fuka <drf28@cornell.edu>

Examples

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## The function is currently defined as
function(lat,Jday,Tx,Tn,wind,relativehumidity,cloudiness,albedo,forest,
slope,aspect,surftemp,surfemissivity){
if(cloudiness<0){cloudiness<-EstCloudiness(lat,Jday,Tx,Tn)}

airtemp<-(Tx+Tn)/2 #average daily air temperature [C]

return(Solar(lat,Jday,Tx,Tn,albedo,forest,slope,aspect)+
Longwave(AtmosphericEmissivity(airtemp,cloudiness),airtemp)-
Longwave(surfemissivity,surftemp)+SensibleHeat(surftemp,airtemp,wind)+
EvapHeat(surftemp,airtemp,relativehumidity,Tn,wind)+
RainHeat(airtemp,rain)+GroundHeat())
  }

Example output

Loading required package: operators

Attaching package: 'operators'

The following objects are masked from 'package:base':

    options, strrep

Loading required package: topmodel
Loading required package: DEoptim
Loading required package: parallel

DEoptim package
Differential Evolution algorithm in R
Authors: D. Ardia, K. Mullen, B. Peterson and J. Ulrich

Loading required package: XML
function (lat, Jday, Tx, Tn, wind, relativehumidity, cloudiness, 
    albedo, forest, slope, aspect, surftemp, surfemissivity) 
{
    if (cloudiness < 0) {
        cloudiness <- EstCloudiness(lat, Jday, Tx, Tn)
    }
    airtemp <- (Tx + Tn)/2
    return(Solar(lat, Jday, Tx, Tn, albedo, forest, slope, aspect) + 
        Longwave(AtmosphericEmissivity(airtemp, cloudiness), 
            airtemp) - Longwave(surfemissivity, surftemp) + SensibleHeat(surftemp, 
        airtemp, wind) + EvapHeat(surftemp, airtemp, relativehumidity, 
        Tn, wind) + RainHeat(airtemp, rain) + GroundHeat())
}

EcoHydRology documentation built on May 2, 2019, 8:28 a.m.