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2.0.0b10
catchment modelling framework
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2.0.0b10
catchment modelling framework
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A meteorological station holding timeseries to create Weather records. More...
Collaboration diagram for MeteoStation:A meteorological station holding timeseries to create Weather records.
In order to calculate ETpot with cmf a big amount of meteorological data is needed, more data than usually available. The MeteoStation class can estimate missing data from a minimal set. As more data, as one provides, the better the calculation of ETpot becomes. The minimal data needed is Tmin and Tmax (daily) and precipitation. To calculate the global radiation (although measured global radiation could be inserted), the position of meteorological station in geographic coordinates has to be set.
A meteorological station is created by cmf::atmosphere::MeteoStationList::add_station . Usage from python:
There are two modes for the meteorology: daily=true and daily=false. If daily=true, Radiation is given as a daily mean value. If daily=false, Radiation is given as an hourly mean value, which shows the dial ETpot variation but results in erronous results if the timestep is daily.
Public Types | |
| typedef std::shared_ptr< MeteoStation > | ptr |
| shared pointer | |
Public Member Functions | |
Data access methods | |
| cmf::atmosphere::Weather | get_data (cmf::math::Time t, double height) const |
| Returns the current Atmosphere state. Uses default values for missing timeseries. | |
| void | use_for_cell (cmf::upslope::Cell &c) |
| Connects this meteostation as a meteo data provider with the cell. | |
| void | SetSunshineFraction (cmf::math::timeseries sunshine_duration) |
| Calculates a timeseries of the sunshine fraction (to put into Sunshine) from a timeseries of absolute sunshine duration. | |
Public Attributes | |
Timeseries of meteorological data | |
| cmf::math::timeseries | T |
| Timeseries of Temperature \( T\left[^\circ C\right] \) Optional, can be calculated from \( T=\frac{T_{max} + T_{min}} 2 \). | |
| cmf::math::timeseries | Tmax |
| Timeseries of daily maximum Temperature \( T_{max} \left[^\circ C\right] \) Required, but it can be generated from T | |
| cmf::math::timeseries | Tmin |
| Timeseries of daily minimum Temperature \( T_{min}\left[^\circ C\right] \) Required, but it can generate from T | |
| cmf::math::timeseries | Tground |
| Timeseries of upper soil temperature \( T_{ground}\left[^\circ C\right] \) Optional, if missing \( T_{ground} = T \). | |
| cmf::math::timeseries | Windspeed |
| Timeseries of windspeed at instrument height (default 2m) in \(m/s\). | |
| cmf::math::timeseries | rHmean |
| Timeseries of relative mean Humidity \( rH_{mean} \left[\%\right] \) Optional, not used if rHmax or Tdew is available | |
| cmf::math::timeseries | rHmin |
| Timeseries of daily minimum relative Humidity \( rH_{min} \left[\%\right] \) Optional, only used if rHmax is used | |
| cmf::math::timeseries | rHmax |
| Timeseries of daily maximum relative Humidity \( rH_{max} \left[\%\right] \)Optional, not used if Tdew is available | |
| cmf::math::timeseries | Tdew |
| Timeseries of dew point temperature \( T_{dew}\left[^\circ C\right]\) Optional, if neither Tdew, rHmax or rHmean is available then Tdew = Tmin | |
| cmf::math::timeseries | Sunshine |
| Fractional sunshine \(\frac{n}{N}\). | |
| cmf::math::timeseries | Rs |
| Global Radiation in \( \frac{MJ}{m^2 day} \) Optional, if not available cmf::atmosphere::global_radiation is used | |
| cmf::math::timeseries | T_lapse |
| Temperature lapse, the slope of the temperature / height regression. Typical values are \( -0.0004 .. -0.001 \frac{^\circ C}{m} \), default is \( 0\frac{^\circ C}{m} \) (no temperature adjusting) | |
Location and behaviour properties | |
| double | Latitude |
| Latitude in dec. deg. | |
| double | Longitude |
| Longitude in dec. deg. | |
| double | Timezone |
| Time zone, 1 Germany, 0 UK, -8 Pacific U.S. | |
| double | z |
| position of the station in m | |
| std::string | Name |
| Name of the Station. | |
| bool | daily |
| If true, the global radiation is calculated for daily averages (no day-night cycle), if false the hourly average is calculated. | |
| real | InstrumentHeight |
| The height of the meteorological instruments above the surface in m. | |
| MeteoStation (const cmf::atmosphere::MeteoStation &other) | |
| Copy c'tor. | |
| void SetSunshineFraction | ( | cmf::math::timeseries | sunshine_duration | ) |
Calculates a timeseries of the sunshine fraction (to put into Sunshine) from a timeseries of absolute sunshine duration.
see http://www.fao.org/docrep/X0490E/x0490e07.htm#radiation
\begin{eqnarray*} \phi &=& \frac{(\mbox{geogr. Latitude})^\circ \pi}{180^\circ} \mbox{ Latitude in }rad \\ \delta &=& 0.409 \sin\left(\frac{2\pi}{365}DOY - 1.39\right) \mbox{ Declination, DOY is day of year}\\ \omega_s &=& \arccos(-\tan\phi\tan\delta) \mbox{ Sunset angle in }rad \\ N &=& \frac{24}{\pi}\omega_s \mbox{ potential duration of sunshine in }h \\ \frac n N &=& n\mbox{ absolute sunshine duration in }h \end{eqnarray*}
| real InstrumentHeight |
The height of the meteorological instruments above the surface in m.
Defaults to 2m.
This can effect temperature and wind speed.
| cmf::math::timeseries Sunshine |
Fractional sunshine \(\frac{n}{N}\).
Sunshine duration per potential sunshine durationOptional, if not present 0.5 If you have the total duration of sunshine, use cmf::atmosphere::MeteoStation::SetSunshineFraction. If you have cloud coverage instead of total sunshine duration you may assume that the fractional sunshine duration equals 1-cloudfraction
Timeseries of daily maximum Temperature \( T_{max} \left[^\circ C\right] \) Required, but it can be generated from T
If you have a high resolution timeseries for Temperature, Tmax can be generated as follows:
Timeseries of daily minimum Temperature \( T_{min}\left[^\circ C\right] \) Required, but it can generate from T
If you have a high resolution timeseries for Temperature, Tmin can be generated as follows:
| cmf::math::timeseries Windspeed |
Timeseries of windspeed at instrument height (default 2m) in \(m/s\).
Optional, if not available the wind speed defaults to 2 m/s
