SWAT - atmosphere.radiation¶

Used constants in this module

EARTH_ROTATION_VELOCITY = 0.2618 \(\frac{rad}{h}\)
SOLAR_CONSTANT = 4.921 \(\frac{MJ}{m^2\cdot h}\)
BOLTZMANN_CONSTANT = 4.903 \(\frac{MJ}{m^2\cdot ^\circ K^4\cdot day}\)
CC_A, CC_B = 1.2, -0.2 - coefficients for cloud cover adjustment - [R1] (general values from table 1:1-3)
EM_A, EM_B = 0.39, -0.158 - coefficients for net emittence computation - [R1] (general values from table 1:1-3)

mef_agri.models.atmosphere.radiation.model_swat.eccentricity_correction(doy)¶

According to [R1] (equ. 1:1.1.1)

Parameters:: doy (int) – n-th day of the year
Returns:: eccentricity correction [ ]
Return type:: float

mef_agri.models.atmosphere.radiation.model_swat.extraterrestrial_radiation(exc_corr, dayl, sd, lat)¶

According to [R1] (equ. 1:1.2.5)

Parameters:

exc_corr (float) – eccentricity correction [ ]
dayl (float) – daylength [h]
sd (float) – solar declination [rad]
lat (float) – site latitude [rad]

Returns:

extraterrestrial radiation \(\frac{MJ}{m^2\cdot day}\)

Return type:

float

class mef_agri.models.atmosphere.radiation.model_swat.Radiation_V2009(**kwargs)¶

Model to compute radiation-related quantities.

kwargs \(\rightarrow\) mef_agri.models.base.Model

albedo()¶

RQ - from model with id 'zone.soil.surface'

\(s_{\textrm{alb},s,k}\ [\ ]\)

Returns:: albedo at current day (considering crops)
Return type:: Requirement

daylength()¶

RQ - from model with id 'zone.atmosphere.daylength'

\(a_{\textrm{dl},k}\)

Returns:: daylength
Return type:: Requirement

eccentricity_correction()¶

MQ - Deterministic Output

\(a_{\textrm{ecorr},k}\ [\ ]\) - [R1] (equ. 1:1.1.1)

Returns:: eccentricity correction due to elliptic orbit of earth
Return type:: float

extraterrestrial_radiation()¶

MQ - Deterministic Output

\(a_{\textrm{exrad},k}\ [\frac{MJ}{m^2\cdot day}]\) - [R1] (equ. 1:1.2.5)

Returns:: extraterrestrial radiation (i.e. before atmosphere influence)
Return type:: float

initialize(epoch)¶

Get the site latitude.

Parameters:: epoch (datetime.date) – initialzation epoch

net_longwave_radiation()¶

MQ - Random Output

\(a_{\textrm{nlrad},k}\ [\frac{MJ}{m^2\cdot day}]\) - [R1] (equ. 1:1.2.18)

Returns:: net longwave radiation
Return type:: numpy.ndarray

net_radiation()¶

MQ - Random Output

\(a_{\textrm{nrad},k}\ [\frac{MJ}{m^2\cdot day}]\) - [R1] (equ. 1:1.2.11)

Returns:: daily net radiation
Return type:: numpy.ndarray

net_shortwave_radiation()¶

MQ - Random Output

\(a_{\textrm{nsrad},k}\ [\frac{MJ}{m^2\cdot day}]\) - [R1] (equ. 1:1.2.12)

Returns:: net shortwave radiation is a fraction of the observed daily incoming radiation
Return type:: numpy.ndarray

radiation()¶

RQ - from model with id 'zone.atmosphere.weather'

\(a_{\textrm{rad},k}\ [\frac{MJ}{m^2\cdot day}]\)

Returns:: observed daily incoming radiation
Return type:: Requirement

solar_declination()¶

RQ - from model with id 'zone.atmosphere.daylength'

\(a_{\textrm{sd},k}\ [rad]\)

Returns:: solar declination
Return type:: Requirement

temperature()¶

RQ - from model with id 'zone.atmosphere.weather'

\(a_{\textrm{temp},k}\ [^\circ K]\)

Returns:: mean air temperature
Return type:: Requirement

update(epoch)¶

The following computations are performed

Radiation_V2009.eccentricity_correction()
Radiation_V2009.extraterrestrial_radiation()
net_shortwave_radiation()
cloud cover adjustment factor - [R1] (equ. 1:1.2.19)
net emittance - [R1] (equ. 1:1.2.20)
net_longwave_radiation()
net_radiation()

Parameters:: epoch (_type_) – _description_

vapor_pressure()¶

RQ - from model with id 'zone.atmosphere.weather'

\(a_{\textrm{vpr},k}\ [kPa]\)

Returns:: current vapor pressure
Return type:: Requirement