en:hydro:shortwave-radiation

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# Incoming short-wave radiation

The incoming short wave radiation can be estimated based on several formulae. If the solar radiation at the exterior of the atmosphere $I_o$ is known, the incoming short wave radiation can be estimated based on an empirical formula of Black et al 1954:

$$ Q_s = I_o*(0.803-0.340*C-0.458*C^2)$$

where $C$ is the mean monthly cloudiness as decimal fraction and $I_o$ is the extraterrestrial-radiation for the whole month in cal/cm²/day.

Another method of estimating $Q_s$ is by means of the equation:

$$ Q_s = I_o * \left (a+b* \frac{n } {N } \right )$$

where $a,b$ are empirical constants, $n$ are observed duration of sunshine hours per day and $N$ are maximum possible duration of sunshine hours.

Location | a | b | Source |
---|---|---|---|

World | 0.23 | 0.48 | Black et al. 1954 |

World | 0.23*cos $\lambda$ | 0.52 | Glover and McCulloch 1958 |

S.E. England | 0.18 | 0.55 | Penman 1948 |

Virgina U.S.A | 0.22 | 0.54 | in Penman 1948 |

Canberra Australia | 0.25 | 0.54 | in Penman 1948 |

Brisbane Australia | 0.23 to 0.35 | 0.38 to 0.54 | Cartledge 1973 |

West Africa | -0.12 to 0.26 | 0.99 to 0.50 | Davies 1966 |

/usr/www/users/uhydro/doku/data/pages/en/hydro/shortwave-radiation.txt · Last modified: 2024/04/10 10:02 by 127.0.0.1