calc_cc: Calculate cloud cover

In aemon-j/gotmtools: Tools to work with GOTM input data and also process the output data

Calculate cloud cover

Description

Calculate cloud cover using latitude, air temperature, relative humidity (or dewpoint temperature) and short wave radiation using the calculations from Martin and McCutcheon (1999).

Usage

calc_cc(date, airt, relh = NULL, dewt = NULL, swr, lat, lon, elev, daily = F)

Arguments

date	vector; Dates in as.POSixct class
airt	vector; Air temperature values which correspond to the vector of dates
relh	vector; Relative humidity values which correspond to the vector of dates
dewt	vector; Dewpoint temperature values which correspond to the vector of dates. Used instead of relative humidity
swr	vector; Short-wave radiation values which correspond to the vector of dates
lat	numeric; Latitude position (in decimal)
lon	numeric; Longitude position (in decimal)
elev	numeric; elevation in metres above sea level
daily	deprecated; logical; Is the data on a daily timestep. Defaults to FALSE

Value

vector of cloud cover values which correspond to the vector of dates supplied

Examples

 met_file <- system.file('extdata/met_file.dat', package = 'GOTMr')
 swr_file <- system.file('extdata/swr_input_file.dat', package = 'GOTMr')
 met <- read.delim(met_file)
 met[,1] <- as.POSIXct(met[,1], tz = 'UTC')
 swr <- read.delim(swr_file)
 swr[,1] <- as.POSIXct(swr[,1], tz = 'UTC')
 met <- merge(met, swr, by = 1)
 cc <- calc_cc(date = met[,1], airt = met$AirT, dewt = met$DewT, swr = met$SWR, lat = 53, lon = -9.5, elev = 14, daily = F)
 plot(cc)

aemon-j/gotmtools documentation built on April 12, 2024, 4:35 p.m.