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Expand a minimal meteorological set to a complete one

Source: R/expand_met.R
expand_met.Rd

Derives every variable a lake model may ask for from a small required core, filling in only what is missing: relative humidity and dew point from each other, vapour pressure, cloud cover from measured shortwave (calc_cc()), downwelling longwave (calc_in_lwr()), station and sea level pressure, wind speed/direction and u/v components, and snowfall.

Usage

expand_met(met, lat, lon, elev = 0, tz = NULL, round_to = 6)

Arguments

met

data frame with a Date column (Date or POSIXct) and the MET_* columns above. Any timestep; nothing is resampled.

lat, lon

lake position, decimal degrees.

elev

lake surface elevation, m above sea level.

tz

timezone the timestamps refer to, used for the solar geometry in calc_cc(). Default NULL, which uses the tz attribute of met when present, otherwise "UTC". Ignored when MET_cldcvr is supplied.

round_to

decimal places for the returned values, or NULL to leave unrounded.

Value

data frame with Date and MET_radswd, MET_radlwd, MET_cldcvr, MET_tmpair, MET_humrel, MET_tmpdew, MET_prvapr, MET_prsttn, MET_prmslp, MET_wndspd, MET_wnddir, MET_wnduvu, MET_wnduvv, MET_pprain, MET_ppsnow.

Details

Required: MET_radswd (W m-2), MET_tmpair (degC), MET_pprain (mm per timestep), one of MET_humrel (percent) / MET_tmpdew (degC), and wind as either MET_wndspd (m/s) or both MET_wnduvu and MET_wnduvv.

Examples

met <- data.frame(Date = seq(as.Date("2024-01-01"), by = "day", length.out = 5),
                  MET_radswd = c(300, 120, 280, 90, 310),
                  MET_tmpair = c(18, 16, 19, 15, 20),
                  MET_humrel = c(70, 85, 65, 90, 60),
                  MET_wndspd = c(3, 5, 2, 6, 3),
                  MET_pprain = c(0, 12, 0, 25, 0))
expand_met(met, lat = -38.08, lon = 176.27, elev = 280)
#>         Date MET_radswd MET_radlwd MET_cldcvr MET_tmpair MET_humrel MET_tmpdew
#> 1 2024-01-01        300   285.7138   0.622384         18         70   12.44683
#> 2 2024-01-02        120   386.8604   1.000000         16         85   13.47894
#> 3 2024-01-03        280   303.4781   0.680155         19         65   12.27193
#> 4 2024-01-04         90   381.5364   1.000000         15         90   13.37259
#> 5 2024-01-05        310   285.4573   0.587987         20         60   11.99990
#>   MET_prvapr MET_prsttn MET_prmslp MET_wndspd MET_wnddir MET_wnduvu MET_wnduvv
#> 1   14.45189   98067.55   101333.4          3        180          0          3
#> 2   15.45939   98046.63   101334.7          5        180          0          5
#> 3   14.28710   98078.32   101333.2          2        180          0          2
#> 4   15.35190   98035.30   101334.5          6        180          0          6
#> 5   14.03379   98088.91   101332.9          3        180          0          3
#>   MET_pprain MET_ppsnow
#> 1          0          0
#> 2         12          0
#> 3          0          0
#> 4         25          0
#> 5          0          0