R/GHCN_FUNCTIONS.R
get_ghcn_daily.Rd
get_ghcn_daily
returns a named list of length 2:
'spatial': A Simple Feature
of the locations of GHCN weather stations
in the template, and
'tabular': A named list of type data.frame()
with the daily weather data for each station.
The name of each list item is the station ID.
An Simple Feature
or SpatRaster
object to serve as a template for cropping.
Alternatively, a character vector providing GHCN station IDs. If missing, all stations
will be downloaded!
A character string naming the study area.
A character vector of elements to extract.
The five core elements are:
PRCP = Precipitation (tenths of mm)
SNOW = Snowfall (mm)
SNWD = Snow depth (mm)
TMAX = Maximum temperature (tenths of degrees C)
TMIN = Minimum temperature (tenths of degrees C)
The other elements are:
ACMC = Average cloudiness midnight to midnight from 30-second
ceilometer data (percent)
ACMH = Average cloudiness midnight to midnight from
manual observations (percent)
ACSC = Average cloudiness sunrise to sunset from 30-second
ceilometer data (percent)
ACSH = Average cloudiness sunrise to sunset from manual
observations (percent)
AWDR = Average daily wind direction (degrees)
AWND = Average daily wind speed (tenths of meters per second)
DAEV = Number of days included in the multiday evaporation
total (MDEV)
DAPR = Number of days included in the multiday precipitation
total (MDPR)
DASF = Number of days included in the multiday snowfall
total (MDSF)
DATN = Number of days included in the multiday minimum temperature
(MDTN)
DATX = Number of days included in the multiday maximum temperature
(MDTX)
DAWM = Number of days included in the multiday wind movement
(MDWM)
DWPR = Number of days with non-zero precipitation included in
multiday precipitation total (MDPR)
EVAP = Evaporation of water from evaporation pan (tenths of mm)
FMTM = Time of fastest mile or fastest 1-minute wind
(hours and minutes, i.e., HHMM)
FRGB = Base of frozen ground layer (cm)
FRGT = Top of frozen ground layer (cm)
FRTH = Thickness of frozen ground layer (cm)
GAHT = Difference between river and gauge height (cm)
MDEV = Multiday evaporation total (tenths of mm; use with DAEV)
MDPR = Multiday precipitation total (tenths of mm; use with DAPR and
DWPR, if available)
MDSF = Multiday snowfall total
MDTN = Multiday minimum temperature (tenths of degrees C; use with DATN)
MDTX = Multiday maximum temperature (tenths of degrees C; use with DATX)
MDWM = Multiday wind movement (km)
MNPN = Daily minimum temperature of water in an evaporation pan
(tenths of degrees C)
MXPN = Daily maximum temperature of water in an evaporation pan
(tenths of degrees C)
PGTM = Peak gust time (hours and minutes, i.e., HHMM)
PSUN = Daily percent of possible sunshine (percent)
SN*# = Minimum soil temperature (tenths of degrees C)
where * corresponds to a code
for ground cover and # corresponds to a code for soil
depth.
Ground cover codes include the following:
0 = unknown
1 = grass
2 = fallow
3 = bare ground
4 = brome grass
5 = sod
6 = straw multch
7 = grass muck
8 = bare muck
Depth codes include the following:
1 = 5 cm
2 = 10 cm
3 = 20 cm
4 = 50 cm
5 = 100 cm
6 = 150 cm
7 = 180 cm
SX*# = Maximum soil temperature (tenths of degrees C)
where * corresponds to a code for ground cover
and # corresponds to a code for soil depth.
See SN*# for ground cover and depth codes.
TAVG = Average temperature (tenths of degrees C)
(Note that TAVG from source 'S' corresponds
to an average for the period ending at
2400 UTC rather than local midnight)
THIC = Thickness of ice on water (tenths of mm)
TOBS = Temperature at the time of observation (tenths of degrees C)
TSUN = Daily total sunshine (minutes)
WDF1 = Direction of fastest 1-minute wind (degrees)
WDF2 = Direction of fastest 2-minute wind (degrees)
WDF5 = Direction of fastest 5-second wind (degrees)
WDFG = Direction of peak wind gust (degrees)
WDFI = Direction of highest instantaneous wind (degrees)
WDFM = Fastest mile wind direction (degrees)
WDMV = 24-hour wind movement (km)
WESD = Water equivalent of snow on the ground (tenths of mm)
WESF = Water equivalent of snowfall (tenths of mm)
WSF1 = Fastest 1-minute wind speed (tenths of meters per second)
WSF2 = Fastest 2-minute wind speed (tenths of meters per second)
WSF5 = Fastest 5-second wind speed (tenths of meters per second)
WSFG = Peak gust wind speed (tenths of meters per second)
WSFI = Highest instantaneous wind speed (tenths of meters per second)
WSFM = Fastest mile wind speed (tenths of meters per second)
WT** = Weather Type where ** has one of the following values:
01 = Fog, ice fog, or freezing fog (may include heavy fog)
02 = Heavy fog or heaving freezing fog (not always
distinguished from fog)
03 = Thunder
04 = Ice pellets, sleet, snow pellets, or small hail
05 = Hail (may include small hail)
06 = Glaze or rime
07 = Dust, volcanic ash, blowing dust, blowing sand, or
blowing obstruction
08 = Smoke or haze
09 = Blowing or drifting snow
10 = Tornado, waterspout, or funnel cloud
11 = High or damaging winds
12 = Blowing spray
13 = Mist
14 = Drizzle
15 = Freezing drizzle
16 = Rain (may include freezing rain, drizzle, and freezing drizzle)
17 = Freezing rain
18 = Snow, snow pellets, snow grains, or ice crystals
19 = Unknown source of precipitation
21 = Ground fog
22 = Ice fog or freezing fog
WV** = Weather in the Vicinity where ** has one of the following
values:
01 = Fog, ice fog, or freezing fog (may include heavy fog)
03 = Thunder
07 = Ash, dust, sand, or other blowing obstruction
18 = Snow or ice crystals
20 = Rain or snow shower
A numeric vector indicating which years to get.
A character string indicating where raw downloaded files should be put. The directory will be created if missing. Defaults to './RAW/GHCN/'.
A character string indicating where the extracted and cropped GHCN shapefiles should be put. The directory will be created if missing. Defaults to './EXTRACTIONS/GHCN/'.
Select only common year/month/day? Defaults to FALSE.
If an extraction for this template and label already exists, should a new one be created? Defaults to FALSE.
A named list containing the 'spatial' and 'tabular' data.
if (FALSE) {
# Get the daily GHCN data (GLOBAL)
# Returns a list: the first element is the spatial locations of stations,
# and the second is a list of the stations and their daily data
GHCN.prcp <-
get_ghcn_daily(
template = FedData::meve,
label = "meve",
elements = c("prcp")
)
# Plot the VEP polygon
plot(meve$geometry)
# Plot the spatial locations
plot(GHCN.prcp$spatial, pch = 1, add = T)
legend("bottomleft", pch = 1, legend = "GHCN Precipitation Records")
# Elements for which you require the same data
# (i.e., minimum and maximum temperature for the same days)
# can be standardized using standardize==T
GHCN.temp <- get_ghcn_daily(
template = FedData::meve,
label = "meve",
elements = c("tmin", "tmax"),
standardize = T
)
# Plot the VEP polygon
plot(meve$geometry)
# Plot the spatial locations
plot(GHCN.temp$spatial, pch = 1, add = T)
legend("bottomleft", pch = 1, legend = "GHCN Temperature Records")
}