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mio::AllSkyLWGenerator Class Reference

Detailed Description

ILWR all sky parametrization Using air temperature (TA) and relative humidity (RH) and optionnally cloud transmissivity (TAU_CLD), this offers the choice of several all-sky parametrizations:

  • OMSTEDT – from Omstedt, "A coupled one-dimensional sea ice-ocean model applied to a semi-enclosed basin", Tellus, 42 A, 568-582, 1990, DOI:10.1034/j.1600-0870.1990.t01-3-00007.
  • KONZELMANN – from Konzelmann et al., "Parameterization of global and longwave incoming radiation for the Greenland Ice Sheet." Global and Planetary change 9.1 (1994): 143-164.
  • UNSWORTH – from Unsworth and Monteith, "Long-wave radiation at the ground", Q. J. R. Meteorolo. Soc., Vol. 101, 1975, pp 13-24 coupled with a clear sky emissivity following (Dilley, 1998).
  • CRAWFORD – from Crawford and Duchon, "An Improved Parametrization for Estimating Effective Atmospheric Emissivity for Use in Calculating Daytime Downwelling Longwave Radiation", Journal of Applied Meteorology, 38, 1999, pp 474-480

If no cloud transmissivity is provided in the data, it is calculated from the solar index (ratio of measured iswr to potential iswr, therefore using the current location (lat, lon, altitude) and ISWR to parametrize the cloud cover). This relies on (Kasten and Czeplak, 1980) except for Crawford that provides its own parametrization. The last evaluation of cloud transmissivity is used all along during the times when no ISWR is available if such ratio is not too old (ie. no more than 1 day old). If only RSWR is measured, the measured snow height is used to determine if there is snow on the ground or not. In case of snow, a snow albedo of 0.85 is used while in the abscence of snow, a grass albedo of 0.23 is used in order to compute ISWR from RSWR. Finally, it is recommended to also use a clear sky generator (declared after this one) for the case of no available short wave measurement (by declaring the ClearSky generator after AllSky).

ILWR::generators = allsky_LW
ILWR::allsky_lw = Omstedt

#include <AllSkyLWGenerator.h>

Public Member Functions

 AllSkyLWGenerator (const std::vector< std::string > &vecArgs, const std::string &i_algo)
 
bool generate (const size_t &param, MeteoData &md)
 
bool create (const size_t &param, std::vector< MeteoData > &vecMeteo)
 
- Public Member Functions inherited from mio::GeneratorAlgorithm
 GeneratorAlgorithm (const std::vector< std::string > &, const std::string &i_algo)
 
virtual ~GeneratorAlgorithm ()
 
std::string getAlgo () const
 

Additional Inherited Members

- Protected Attributes inherited from mio::GeneratorAlgorithm
const std::string algo
 
- Static Protected Attributes inherited from mio::GeneratorAlgorithm
static const double soil_albedo = .23
 
static const double snow_albedo = .85
 
static const double snow_thresh = .1
 

Constructor & Destructor Documentation

mio::AllSkyLWGenerator::AllSkyLWGenerator ( const std::vector< std::string > &  vecArgs,
const std::string &  i_algo 
)
inline

Member Function Documentation

bool mio::AllSkyLWGenerator::create ( const size_t &  param,
std::vector< MeteoData > &  vecMeteo 
)
virtual
bool mio::AllSkyLWGenerator::generate ( const size_t &  param,
MeteoData md 
)
virtual

The documentation for this class was generated from the following files: