1:3.4.2 Generated Values

The daily generated values are determined by multiplying the residual elements generated with equation 1:3.4.1 by the monthly standard deviation and adding the monthly average value.

$T_{mx}=\mu mx_{mon} + \chi_i(1)*\sigma mx_{mon}$ 1:3.4.10

$T_{mn}=\mu mn_{mon} + \chi_i(2)*\sigma mn_{mon}$ 1:3.4.11

$H_{day}=\mu rad_{mon} + \chi_i(3)*\sigma rad_{mon}$ 1:3.4.12

where $T_{mx}$ is the maximum temperature for the day (°C), $\mu mx_{mon}$ is the average daily maximum temperature for the month (°C), $\chi_i(1)$ is the residual for maximum temperature on the given day, $\sigma mx_{mon}$ is the standard deviation for daily maximum temperature during the month (°C), $T_{mn}$ is the minimum temperature for the day (°C), $\mu mn_{mon}$ is the average daily minimum temperature for the month (°C), $\chi_i(2)$ is the residual for minimum temperature on the given day, $\sigma mn_{mon}$ is the standard deviation for daily minimum temperature during the month (°C), $H_{day}$ is the solar radiation for the day (MJ m$^{-2}$), $\mu rad_{mon}$ is the average daily solar radiation for the month (MJ m$^{-2}$), $\chi_i(3)$ is the residual for solar radiation on the given day, and $\sigma rad_{mon}$ is the standard deviation for daily solar radiation during the month (MJ m$^{-2}$).

The user is required to input standard deviation for maximum and minimum temperature. For solar radiation the standard deviation is estimated as ¼ of the difference between the extreme and mean value for each month.

$\sigma rad_{mon}=\frac{H_{mx}-\mu rad_{mon}}{4}$ 1:3.4.13

where $\sigma rad_{mon}$ is the standard deviation for daily solar radiation during the month (MJ m$^{-2}$), $H_{mx}$ is the maximum solar radiation that can reach the earth’s surface on a given day (MJ m$^{-2}$), and $\mu rad_{mon}$ is the average daily solar radiation for the month (MJ m$^{-2}$).