Preparation of weather file

x-model requires two kinds of weather files: one for daily weather data and another for diurnal weather data. If the diurnal weather data is not provided the x-model will simulate diurnal weather using daily weather properties. These weather files must be prepared following a certain format.

The daily weather file must contain meteorological data such as daily wind speed (km day^-1), daily vapour pressure (mbar), daily total solar radiation (MJ m^-2 day^-1), maximum air temperature (° C), and minimum air temperature (° C). The file format for the daily weather file must follow this format:

   [dailyweather]
   :mDOY :mrfDayTmax :mrfDayTmin :mrfDayTotRad :mrfDayWind :mrfDayVP :end
   200 23.0 8.5 21.24 158.6 15.53
   201 25.9 10.6 23.89 162.4 18.39
   202 21.0 13.1 16.71 358.0 16.48
   …
   [/dailyweather]

where data in weather file is enclosed within tags "[dailyweather]" and "[/dailyweather]". The following line:

:mDOY :mrfDayTmax :mrfDayTmin :mrfDayTotRad :mrfDayWind :mrfDayVP :end

tells of the order of the meteorological data in file where data starts with mDOY and ends with mrfDayVP, and where mDOY, mrfDayWind, mrfDayVP, mrfDayTotRad, mrfDayTmax, and mrfDayTmin are day of year, daily wind speed (km day^-1), daily vapour pressure (mbar), daily total solar radiation (MJ m^-2 day^-1), maximum air temperature (° C), and minimum air temperature (° C), respectively. These order of variables must terminate with the :end tag. Consequently, the first line of data:

200 23.0 8.5 21.24 158.6 15.53

means 200 is mDOY, 23.0 is mrfDayTmax, and line ends with 15.53 that is for mrfDayVP, following the order of:

:mDOY :mrfDayTmax :mrfDayTmin :mrfDayTotRad :mrfDayWind :mrfDayVP :end

Likewise, the meteorological data in the hourly weather file must be prepared in a similar format. Here, the weather file must contain diurnal data of wind speed (m s^-1), vapour pressure (mbar), total solar radiation (W m^-2), and air temperature (° C). The file format for the diurnal weather file must follow this format:

   [diurnalweather]
   :mDOY :mHour :mrfDiuTotRad :mrfDiuWind :mrfDiuTemp :mrfDiuVP :end
   200 0.0 0 0.356 10.22 12.5
   200 0.5 0 0.282 9.63 12.0
   200 1.0 0 0.344 9.26 11.7
   …
   [/diurnalweather]

where data in diurnal weather file is enclosed within class tags "[diurnalweather]" and "[/diurnalweather]". The following line:

:mDOY :mHour :mrfDiuTotRad :mrfDiuWind :mrfDiuTemp :mrfDiuVP :end

tells of the order of meteorological data in file where data starts with mDOY and ends with mrfDiuVP, and where mDOY and mHour are day of year and hour, respectively; and mrfDiuWind, mrfDiuVP, mrfDiuTotRad, and mrfDiuTemp are wind speed (m s^-1), vapour pressure (mbar), total solar radiation (W m^-2), and air temperature (° C), respectively. These order of variables must terminate with the :end tag. Consequently, the first line of data:

200 0.0 0 0.356 10.22 12.5

means 200 is mDOY, 0.0 is mHour, and line ends with 12.5 that is for mrfDiuVP, following the order of:

:mDOY :mHour :mrfDiuTotRad :mrfDiuWind :mrfDiuTemp :mrfDiuVP :end

Finally, users must also be aware of the number of lines in the weather file that represents one day’s worth of meteorological data. This is because x-model requires the input of this information (see here). For example, if a file contains the daily weather data where one line represents one day’s data, such as:

then the number of lines that represent the weather data for one day is 1. But if there is a blank line for every 2 lines, such as:

[dailyweather]

:mDOY :mrfDayTmax :mrfDayTmin :mrfDayTotRad :mrfDayWind :mrfDayVP :end

200 23.0 8.5 21.24 158.6 15.53

201 25.9 10.6 23.89 162.4 18.39

202 21.0 13.1 16.71 358.0 16.48

…

[/dailyweather]

then the number of lines that represent the weather data for one day is 2.

Likewise, if a file contains hourly weather data, such as:

   [diurnalweather]
   :mDOY :mHour :mrfDiuTotRad :mrfDiuWind :mrfDiuTemp :mrfDiuVP :end
   200 0.0 0 0.356 10.22 12.5
   200 1.0 0 0.344 9.26 11.7
   200 2.0 …
   200 3.0 …
   …
   200 21.0 …
   200 22.0 …
   200 23.0 …
   201 0.0 …
   201 1.0 …
   …
   [/diurnalweather]

then the number of lines that represent the weather data for one day is 24 because 24 lines in file represents the data for one day. If the data was instead half-hourly (with no blank lines) the number of lines that represent the weather data for one day would be 48.

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