static void _MDRainPotETPsTaylor (int itemID) {
// Priestley and Taylor (1972) PE in mm for day
// Input
float dayLen; // daylength in fraction of day
float i0hDay; // daily potential insolation on horizontal [MJ/m2]
float albedo; // albedo
float airT; // air temperatur [degree C]
float solRad; // daily solar radiation on horizontal [MJ/m2]
float vPress; // daily average vapor pressure [kPa]
float sHeat = 0.0; // average subsurface heat storage for day [W/m2]
// Local
float solNet; // average net solar radiation for daytime [W/m2]
float lngNet; // average net longwave radiation for day [W/m2]
float aa; // available energy [W/m2]
float es; // vapor pressure at airT [kPa]
float delta; // dEsat/dTair [kPa/K]
float dd; // vapor pressure deficit [kPa]
float le; // latent heat [W/m2]
// Output
float pet;
if (MFVarTestMissingVal (_MDInDayLengthID, itemID) ||
MFVarTestMissingVal (_MDInI0HDayID, itemID) ||
MFVarTestMissingVal (_MDInCParamAlbedoID, itemID) ||
MFVarTestMissingVal (_MDInAtMeanID, itemID) ||
MFVarTestMissingVal (_MDInSolRadID, itemID) ||
MFVarTestMissingVal (_MDInVPressID, itemID)) { MFVarSetMissingVal (_MDOutPetID,itemID); return; }
dayLen = MFVarGetFloat (_MDInDayLengthID, itemID, 0.0);
i0hDay = MFVarGetFloat (_MDInI0HDayID, itemID, 0.0);
albedo = MFVarGetFloat (_MDInCParamAlbedoID, itemID, 0.0);
airT = MFVarGetFloat (_MDInAtMeanID, itemID, 0.0);
solRad = MFVarGetFloat (_MDInSolRadID, itemID, 0.0);
vPress = MFVarGetFloat (_MDInVPressID, itemID, 0.0);
solNet = (1.0 - albedo) * solRad / MDConstIGRATE;
lngNet = MDSRadNETLong (i0hDay,airT,solRad,vPress);
aa = solNet + lngNet - sHeat;
es = MDPETlibVPressSat (airT);
delta = MDPETlibVPressDelta (airT);
dd = es - vPress;
le = MDConstPTALPHA * delta * aa / (delta + MDConstPSGAMMA);
pet = MDConstEtoM * MDConstIGRATE * le;
MFVarSetFloat (_MDOutPetID,itemID,pet);
}
static void _MDRainPotETPstd (int itemID) {
// Penman (1948) PE in mm for day also given by Chidley and Pike (1970)
// Input
float dayLen; // daylength in fraction of day
float i0hDay; // daily potential insolation on horizontal [MJ/m2]
float albedo; // albedo
float airT; // air temperatur [degree C]
float solRad; // daily solar radiation on horizontal [MJ/m2]
float vPress; // daily average vapor pressure [kPa]
float wSpeed; // average wind speed for the day [m/s]
float sHeat = 0.0; // average subsurface heat storage for day [W/m2]
// Local
float solNet; // average net solar radiation for day [W/m2]
float novern; // sunshine duration fraction of daylength
float effem; // effective emissivity from clear sky
float cldCor; // cloud cover correction to net longwave under clear sky
float lngNet; // average net longwave radiation for day [W/m2]
float aa; // available energy [W/m2]
float fu; // Penman wind function, [mm d-1 kPa-1]
float es; // vapor pressure at airT [kPa]
float delta; // dEsat/dTair [kPa/K]
// Output
float pet;
if (MFVarTestMissingVal (_MDInDayLengthID, itemID) ||
MFVarTestMissingVal (_MDInI0HDayID, itemID) ||
MFVarTestMissingVal (_MDInCParamAlbedoID, itemID) ||
MFVarTestMissingVal (_MDInAtMeanID, itemID) ||
MFVarTestMissingVal (_MDInSolRadID, itemID) ||
MFVarTestMissingVal (_MDInVPressID, itemID) ||
MFVarTestMissingVal (_MDInWSpeedID, itemID)) {
MFVarSetMissingVal (_MDOutPetID,itemID);
return;
}
dayLen = MFVarGetFloat (_MDInDayLengthID, itemID, 12.0);
i0hDay = MFVarGetFloat (_MDInI0HDayID, itemID, 0.0);
albedo = MFVarGetFloat (_MDInCParamAlbedoID, itemID, 0.0);
airT = MFVarGetFloat (_MDInAtMeanID, itemID, 0.0);
solRad = MFVarGetFloat (_MDInSolRadID, itemID, 0.0);
vPress = MFVarGetFloat (_MDInVPressID, itemID, 0.0);
wSpeed = fabs (MFVarGetFloat (_MDInWSpeedID, itemID, 0.0));
if (wSpeed < 0.2) wSpeed = 0.2;
solNet = (1.0 - albedo) * solRad / MDConstIGRATE; // net solar with Penman (1948) albedo of 0.25
effem = 0.44 + 0.252 * sqrt (vPress); // Brunt method for effective emissivity with Penman (1948) coefficients
novern = ((solRad / i0hDay) - 0.18) / 0.55; // Penman's relation of SOLRAD / I0HDAY to sunshine duration n/N
if (novern > 1.0) novern = 1.0;
cldCor = 0.1 + 0.9 * novern; //Penman's (1948) longwave cloud correction coefficient
lngNet = (effem - 1.0) * cldCor * MDConstSIGMA * pow (airT + 273.15,4.0);
aa = solNet + lngNet - sHeat;
es = MDPETlibVPressSat (airT);
delta = MDPETlibVPressDelta (airT);
fu = 2.6 * (1.0 + 0.54 * wSpeed); // Penman wind function given by Brutsaert (1982) eq 10.17
// Penman equation from Brutsaert eq 10.15
pet = (delta * MDConstEtoM * MDConstIGRATE * aa + MDConstPSGAMMA * fu * (es - vPress)) / (delta + MDConstPSGAMMA);
MFVarSetFloat (_MDOutPetID,itemID,pet);
}
static void _MDRainPotETSWGday (int itemID) {
// daily Shuttleworth-Wallace-Gurney (1985, 1990) PE in mm for day
// Input
float dayLen; // daylength in fraction of day
float i0hDay; // daily potential insolation on horizontal [MJ/m2]
float albedo; // albedo
float height; // canopy height [m]
float lWidth; // average leaf width [m]
float rss; // soil surface resistance [s/m]
float r5; // solar radiation at which conductance is halved [W/m2]
float cd; // vpd at which conductance is halved [kPa]
float cr; // light extinction coefficient for projected LAI
float glMax; // maximum leaf surface conductance for all sides of leaf [m/s]
float z0g; // z0g - ground surface roughness [m]
float lai; // projected leaf area index
float sai; // projected stem area index
float airT; // air temperatur [degree C]
float airTMin; // daily minimum air temperature [degree C]
float solRad; // daily solar radiation on horizontal [MJ/m2]
float vPress; // daily average vapor pressure [kPa]
float wSpeed; // average wind speed for the day [m/s]
float sHeat = 0.0; // average subsurface heat storage for day [W/m2]
// Local
float solNet; // average net solar radiation for daytime [W/m2]
float lngNet; // average net longwave radiation [W/m2]
float z0; // roughness parameter [m]
float disp; // height of zero-plane [m]
float z0c; // roughness parameter (closed canopy)
float dispc; // zero-plane displacement (closed canopy)
float aa; // available energy [W/m2]
float asubs; // available energy at ground [W/m2]
float es; // vapor pressure at airT [kPa]
float delta; // dEsat/dTair [kPa/K]
float dd; // vapor pressure deficit [kPa]
float rsc; // canopy resistance [s/m]
float le; // latent heat [W/m2]
float rn; // net radiation [W/m2]
float rns; // net radiation at ground [W/m2]
float raa; // aerodynamic resistance [s/m]
float rac; // leaf boundary layer resistance [s/m]
float ras; // ground aerodynamic resistance [s/m]
// Output
float pet;
if (MFVarTestMissingVal (_MDInDayLengthID, itemID) ||
MFVarTestMissingVal (_MDInI0HDayID, itemID) ||
MFVarTestMissingVal (_MDInCParamAlbedoID, itemID) ||
MFVarTestMissingVal (_MDInCParamCHeightID,itemID) ||
MFVarTestMissingVal (_MDInCParamLWidthID, itemID) ||
MFVarTestMissingVal (_MDInCParamRSSID, itemID) ||
MFVarTestMissingVal (_MDInCParamR5ID, itemID) ||
MFVarTestMissingVal (_MDInCParamCDID, itemID) ||
MFVarTestMissingVal (_MDInCParamCRID, itemID) ||
MFVarTestMissingVal (_MDInCParamGLMaxID, itemID) ||
MFVarTestMissingVal (_MDInCParamZ0gID, itemID) ||
MFVarTestMissingVal (_MDInLeafAreaIndexID,itemID) ||
MFVarTestMissingVal (_MDInStemAreaIndexID,itemID) ||
MFVarTestMissingVal (_MDInAtMeanID, itemID) ||
MFVarTestMissingVal (_MDInAtMinID, itemID) ||
MFVarTestMissingVal (_MDInSolRadID, itemID) ||
MFVarTestMissingVal (_MDInVPressID, itemID) ||
MFVarTestMissingVal (_MDInWSpeedID, itemID)) { MFVarSetMissingVal (_MDOutPetID,itemID); return; }
dayLen = MFVarGetFloat (_MDInDayLengthID, itemID, 0.1);
i0hDay = MFVarGetFloat (_MDInI0HDayID, itemID, 0.0);
albedo = MFVarGetFloat (_MDInCParamAlbedoID, itemID, 0.0);
height = MFVarGetFloat (_MDInCParamCHeightID, itemID, 0.0);
lWidth = MFVarGetFloat (_MDInCParamLWidthID, itemID, 0.0);
rss = MFVarGetFloat (_MDInCParamRSSID, itemID, 0.0);
r5 = MFVarGetFloat (_MDInCParamR5ID, itemID, 0.0);
cd = MFVarGetFloat (_MDInCParamCDID, itemID, 0.0);
cr = MFVarGetFloat (_MDInCParamCRID, itemID, 0.0);
glMax = MFVarGetFloat (_MDInCParamGLMaxID, itemID, 0.0);
z0g = MFVarGetFloat (_MDInCParamZ0gID, itemID, 0.0);
lai = MFVarGetFloat (_MDInLeafAreaIndexID, itemID, 0.0);
sai = MFVarGetFloat (_MDInStemAreaIndexID, itemID, 0.0);
airT = MFVarGetFloat (_MDInAtMeanID, itemID, 0.0);
airTMin = MFVarGetFloat (_MDInAtMinID, itemID, 0.0);
solRad = MFVarGetFloat (_MDInSolRadID, itemID, 0.0);
vPress = MFVarGetFloat (_MDInVPressID, itemID, 0.0);
wSpeed = fabs (MFVarGetFloat (_MDInWSpeedID, itemID, 0.0));
if (wSpeed < 0.2) wSpeed = 0.2;
solNet = (1.0 - albedo) * solRad / MDConstIGRATE;
z0c = MDPETlibRoughnessClosed (height,z0g);
dispc = height - z0c / 0.3;
disp = MDPETlibZPDisplacement (height,lai,sai,z0g);
z0 = MDPETlibRoughness (disp,height,lai,sai,z0g);
lngNet = MDSRadNETLong (i0hDay,airT,solRad,vPress);
rn = solNet + lngNet;
aa = rn - sHeat;
rns = rn * exp (-cr * (lai + sai));
asubs = rns - sHeat;
es = MDPETlibVPressSat (airT);
delta = MDPETlibVPressDelta (airT);
dd = es - vPress;
rsc = MDPETlibCanopySurfResistance (airTMin,solRad,dd,lai,sai,r5,cd,cr,glMax);
raa = MDPETlibBoundaryResistance (wSpeed,height,z0g,z0c,dispc,z0,disp);
rac = MDPETlibLeafResistance (wSpeed,height,lWidth,z0g,lai,sai,z0c,dispc);
ras = MDPETlibGroundResistance (wSpeed,height,z0g,z0c,dispc,z0,disp);
// ras=70;
// raa=50;
rsc=70;
le = MDPETlibShuttleworthWallace (rss,aa,asubs,dd,raa,rac,ras,rsc,delta);
pet = MDConstEtoM * MDConstIGRATE * le;
// float pet1 = MFVarGetFloat (_MDInRefETPIDDEBUG, itemID, 0.0);
// printf ("height %f lWidth %f rss %f r4 %f cd %f cr %f glMax %f z0g %f lai %f sai %f \n",height , lWidth ,rss, r5 ,cd ,cr, glMax ,z0g ,lai , sai );
// printf ("pet BMF %f pet FAO %f albedo %f\n",pet,pet1,albedo);
MFVarSetFloat (_MDOutPetID,itemID,pet);
}
static void _MDIrrRefEvapotransFAO (int itemID) {
/* day-night Penman-Monteith PE in mm for day */
// Input
// float dayLen; // daylength in fraction of day
float i0hDay; // daily potential insolation on horizontal [MJ/m2]
float airT; // air temperatur [degree C]
float airTMin; // daily minimum air temperature [degree C]
float airTMax; // daily maximum air temperature [degree C]
float solRad; // daily solar radiation on horizontal [MJ/m2]
float vPress; // daily average vapor pressure [kPa]
float wSpeed; // average wind speed for the day [m/s]
// Local
float solNet; // average net solar radiation for daytime [W/m2]
float es; // vapor pressure at airT [kPa]
float es_min; // vapor pressure at airT [kPa]
float es_max; // vapor pressure at airT [kPa]
float delta; // dEsat/dTair [kPa/K]
float psychometricConstant;
float FAOEtp;
float solNet_MJm2d;
float nom;
float denom;
float meanAirTemp;
float atmosPressure;
float elevation;
float nen;
float temp;
// dayLen = MFVarGetFloat (_MDInDayLengthID, itemID,0);
i0hDay = MFVarGetFloat (_MDInI0HDayID, itemID,0);
elevation = MFVarGetFloat (_MDInElevationID, itemID,0);
airT = MFVarGetFloat (_MDInAtMeanID, itemID,0);
solRad = MFVarGetFloat (_MDInSolRadID, itemID,0);
vPress = MFVarGetFloat (_MDInVPressID, itemID,0);
wSpeed = fabs (MFVarGetFloat (_MDInWSpeedID, itemID,0));
if (wSpeed < 0.2) wSpeed = 0.2;
airTMin = MFVarGetFloat (_MDInAtMinID, itemID, 0.0);
airTMax = MFVarGetFloat (_MDInAtMaxID, itemID, 0.0);
atmosPressure = (293.0 - 0.0065 * elevation) / 293.0;
atmosPressure = pow (atmosPressure, 5.26);
atmosPressure = atmosPressure * 101.3;
psychometricConstant = 0.665 * atmosPressure / 1000.0;
meanAirTemp = (airTMin + airTMax) / 2.0;
solNet = (1.0 - 0.23) * solRad ;// in MJ/m2
es_min = MDPETlibVPressSat (airTMin);
es_max = MDPETlibVPressSat (airTMax);
es = (es_min + es_max) / 2.0;
solNet_MJm2d = solNet; // 0.0864; FAO equation wants SolNet in MJ/m2.
nen = 4098 * (0.6108 * exp (17.27 * airT / (airT + 237.3)));
delta = nen / ((airT + 237.3)*(airT + 237.3));
temp = es-vPress;
nom = 0.408 * delta * solNet_MJm2d + psychometricConstant * 900 / (273.3 + airT) * wSpeed * temp;
//FBM nimmt vapor pressure in kPA!
denom = delta + psychometricConstant*(1+0.34 * wSpeed);
FAOEtp = nom / denom;
MFVarSetFloat (_MDOutIrrRefEvapotransID,itemID,FAOEtp);
}