radiation

radiation solves for radiation due to the enviorment for a particular datetime and altitude.

class radiation.Radiation[source]
__init__()[source]
getTempForecast(coord)[source]

Looks up the forecast temperature at the current coordinate and altitude

Important

TODO. This function is not operational yet.

Parameters:

coord (dict) – current coordinate

Returns:

atmospheric temperature (k)

Return type:

float

get_SI0()[source]

Incident solar radiation above Earth’s atmosphere (W/m^2)

\[I_{sun,0}= I_0 \cdot [1+0.5(\frac{1+e}{1-e})^2-1) \cdot cos(f)]\]
Returns:

The incident solar radiation above Earths atm (W/m^2)

Return type:

float

get_air_mass(zen, el)[source]

Air Mass at elevation

\[AM = 1229+(614cos(\zeta)^2)^{\frac{1}{2}}-614cos(\zeta)\]
Parameters:
  • zen (float) – Solar Angle (rad)

  • el (float) – Elevation (m)

Returns:

The approximate air mass (unitless)

Return type:

float

get_diffuse_SI(zen, el)[source]

Calculates Diffuse Solar Radiation from sky

Parameters:
  • zen (float) – Solar Angle (rad)

  • el (float) – Elevation (m)

Returns:

The intensity of the diffuse solar radiation from the sky (W/m^2)

Return type:

float

get_direct_SI(zen, el)[source]

Calculates Direct Solar Radiation

Parameters:
  • zen (float) – Solar Angle (rad)

  • el (float) – Elevation (m)

Returns:

Tntensity of the direct solar radiation (W/m^2)

Return type:

float

get_earth_IR(el)[source]

Calculates Infared Radiation emitted from Earth’s surface

Parameters:

el (float) – Elevation (m)

Returns:

Intensity of IR radiation emitted from earth (W/m^2)

Return type:

float

get_rad_total(datetime, coord)[source]

Calculates total radiation sources as a function of altitude, time, and balloon surface area.

The figure below shows how different altitudes effects the radiation sources on a particular date and coordinate for Tucson Arizona (at sruface level and 25 km altitudes)

../_images/Tucson_Radiation_Comparison.png
get_reflected_SI(zen, el)[source]

Calculates Reflected Solar Radiation from from the Earth’s Surface

Parameters:
  • zen (float) – Solar Angle (rad)

  • el (float) – Elevation (m)

Returns:

The intensity solar radiation reflected by the Earth (W/m^2)

Return type:

float

get_sky_IR(el)[source]

Calculates Infared Radiation emitted the from Sky

Parameters:

el (float) – Elevation (m)

Returns:

Intensity of IR radiation emitted from sky (W/m^2)

Return type:

float

get_trans_atm(zen, el)[source]

The amount of solar radiation that permeates through the atmosphere at a certain altitude, I_{sun} is driven by the atmospheric transmittance.

\[\tau_{atm}= \frac{1}{2}(e^{-0.65AM}+e^{-0.095AM})\]
Parameters:
  • zen (float) – Solar Angle (rad)

  • el (float) – Elevation (m)

Returns:

The atmospheric trasmittance (unitless)

Return type:

float

get_zenith(t, coord)[source]

Calculates adjusted solar zenith angle at elevation

Parameters:
  • t (Datetime) – Lattitude (rad)

  • coord (dict) – Solar Hour Angle (rad)

Returns:

The approximate solar zenith angle (rad)

Return type:

float