correct_prec {LWFBrook90R}

Correct rain gauge precipitation data for wind and evaporation errors after Richter (1995)

Description

Correct rain gauge precipitation data for wind and evaporation errors after Richter (1995)

Usage

correct_prec(month, tavg, prec, station.exposure = "mg", full_output = FALSE)

Arguments

month

Vector of months.

tavg

Vector of air temperature values (deg C). Same length as month.

prec

Vector of measured rainfall vales (mm). Same length as month.

station.exposure

Situation of the weather station where prec was measured: one of 'frei', 'lg', 'mg', 'sg' (corresponding to full exposure, low protected, moderate protected, strong protected situation).

full_output

Logical wether to return the full data set additionally including input data, correction coefficients.

Value

A vector of corrected rainfall data, or (if full_output == TRUE) a data.table containing the input objects, the month, the precipitation type ('N4So': liquid rain, summer; 'N4Wi' liquid rain, winter; 'N8' = sleet, 'N7' = snow), correction coefficients epsilon and b, and the corrected rainfall.

References

Richter, D. (1995) Ergebnisse methodischer Untersuchungen zur Korrektur des systematischen Messfehlers des Hellmann-Niederschlagsmessers. Berichte des Deutschen Wetterdienstes, 194, 93 pp, Offenbach, Germany

Examples

clim <- slb1_meteo[as.integer(format(slb1_meteo$dates,"%Y")) %in% 2001:2005,]
clim$month <- as.integer(format(clim$dates, "%m"))

prec_meas <- clim$prec
correct_prec_frei <- with(clim,
                       correct_prec(month, tmean, prec, station.exposure = "frei"))
correct_prec_lg <- with(clim,
                     correct_prec(month, tmean, prec, station.exposure = "lg"))
correct_prec_mg <- with(clim,
                     correct_prec(month, tmean, prec, station.exposure = "mg"))
correct_prec_sg <- with(clim,
                     correct_prec(month, tmean, prec, station.exposure = "sg"))

plot(clim$dates, cumsum(correct_prec_frei),
type = "l", col = "violet", xlab = "dates", ylab = "cum. precipitation (mm)")
lines(clim$dates, cumsum(correct_prec_lg), col = "blue")
lines(clim$dates, cumsum(correct_prec_mg), col = "green")
lines(clim$dates, cumsum(correct_prec_sg), col = "red")
lines(clim$dates, cumsum(prec_meas))
legend('bottomright', c('frei', "lg", "mg", "sg"),
       col = c("violet", "blue", "green", "red", "black"),
       lty = 1, pch = NULL )