net_irradiance

Estimate net radiation balance expressed as a flux in W/m2. If
<code>lw.down.irradiance</code> is passed a value in W / m2 the difference is
computed directly and if not an approximate value is estimated, using
<code>R_rel = 0.75</code> which corresponds to clear sky, i.e., uncorrected for
cloudiness. This is the approach to estimation is that recommended by FAO for
hourly estimates while here we use it for instantaneous or mean flux rates.

Definitions of classes, methods, operators and functions for use
in photobiology and radiation meteorology and climatology. Calculation of
effective (weighted) and not-weighted irradiances/doses, fluence rates,
transmittance, reflectance, absorptance, absorbance and diverse ratios and
other derived quantities from spectral data. Local maxima and minima: peaks,
valleys and spikes. Conversion between energy-and photon-based units.
Wavelength interpolation. Astronomical calculations related solar angles and
day length. Colours and vision. This package is part of the 'r4photobiology'
suite, Aphalo, P. J. (2015) <doi:10.19232/uv4pb.2015.1.14>.

Pedro Aphalo

photobiology

Photobiological Calculations

Pedro J. Aphalo

Titta K. Kotilainen

Glenn Davis

Agnese Fazio

net_irradiance function

<dl><dt>temperature</dt>
<dd>numeric vector of air temperatures (C) at 2 m height.</dd>
<dt>sw.down.irradiance, lw.down.irradiance</dt>
<dd>numeric Down-welling short wave
and long wave radiation radiation (W/m2).</dd>
<dt>sw.albedo</dt>
<dd>numeric Albedo as a fraction of one (/1).</dd>
<dt>lw.emissivity</dt>
<dd>numeric Emissivity of the surface (ground or vegetation)
for long wave radiation.</dd>
<dt>water.vp</dt>
<dd>numeric vector of water vapour pressure in air (Pa), ignored
if <code>lw.down.irradiance</code> is available.</dd>
<dt>R_rel</dt>
<dd>numeric The ratio of actual and clear sky short wave irradiance
(/1).</dd></dl>

Arguments

Net radiation flux — net_irradiance

<dl>

<dt>temperature</dt>
<dd>numeric vector of air temperatures (C) at 2 m height.</dd>


<dt>sw.down.irradiance, lw.down.irradiance</dt>
<dd>numeric Down-welling short wave
and long wave radiation radiation (W/m2).</dd>


<dt>sw.albedo</dt>
<dd>numeric Albedo as a fraction of one (/1).</dd>


<dt>lw.emissivity</dt>
<dd>numeric Emissivity of the surface (ground or vegetation)
for long wave radiation.</dd>


<dt>water.vp</dt>
<dd>numeric vector of water vapour pressure in air (Pa), ignored
if <code>lw.down.irradiance</code> is available.</dd>


<dt>R_rel</dt>
<dd>numeric The ratio of actual and clear sky short wave irradiance
(/1).</dd>

</dl>

net_irradiance: Net radiation flux

Description

Usage

Value

Arguments

See Also