ag5_extract {ag5Tools} | R Documentation |
Extract AgERA5 data stored in a local hard drive
Description
Extract data from AgERA5 data files previously downloaded from the Copernicus Climate Data Store.
These functions use package 'terra' to read *.nc files and extract the requested data for a given location
and dates. If dates is one value it extracts a single observation for the specified variable and location.
If dates is a character vector of length == 2
, it will extract a time series of the specified variable
and location, where the first dates value is the start date and the second the end date.
Usage
ag5_extract(coords, ..., path)
## S3 method for class 'numeric'
ag5_extract(
coords,
dates,
variable,
statistic = NULL,
time = NULL,
celsius = FALSE,
parallel = TRUE,
...,
path
)
## S3 method for class 'data.frame'
ag5_extract(
coords,
lon = "lon",
lat = "lat",
start_date = "start_date",
end_date = "end_date",
variable,
statistic = NULL,
time = NULL,
celsius = FALSE,
ncores = NULL,
...,
path
)
Arguments
coords |
numeric vector of length = 2 of the form (lon, lat), or a |
... |
Other parameters |
path |
|
dates |
|
variable |
|
statistic |
|
time |
Only for variable Relative-Humidity-2m, see details for valid options |
celsius |
logical Only for variables "Temperature-Air-2m" and "2m_dewpoint_temperature". |
parallel |
logical Use parallel computation to speed-up data processing |
lon |
|
lat |
|
start_date |
|
end_date |
|
ncores |
Number of cores to use with parallel. If NULL and parallel is ON, half the available cores will be used.
If |
Value
numeric
vector with length equal to the number of dates between first and
second date. The returned vecter is a named vector, with requested dates as names.
If only one date is provided the function returns a numeric
vector
with length = 1
.
If coords
is a data.frame
, the function returns a list
of
numeric
vectors, each one corresponding to the rows in the input data.frame
Valid variable values
"cloud_cover"
"liquid_precipitation_duration_fraction"
"snow_thickness_lwe"
"Solar-Radiation-Flux"
"Temperature-Air-2m"
"2m_dewpoint_temperature"
"Precipitation-Flux"
"solid_precipitation_duration_fraction"
"snow_thickness"
"vapour_pressure"
"10m_wind_speed"
"Relative-Humidity-2m"
Valid statistics for variable "Temperature-Air-2m"
Max-24h
Mean-24h
Min-24h
Max-Day-Time
Mean-Day-Time
Mean-Night-Time
Min-Night-Time
Variables that require statistic
For the following variables, only "24_hour_mean" statistic is available, but should be explicitly indicated.
cloud_cover
snow_thickness_lwe
2m_dewpoint_temperature
snow_thickness
vapour_pressure
10m_wind_speed
Valid time values for variable "Relative-Humidity-2m"
06h
09h
12h
15h
18h
References
Temperature conversion is made accordingly to: Preston-Thomas, H. (1990). The International Temperature Scale of 1990 (ITS-90). Metrologia, 27(1), 3-10. doi:10.1088/0026-1394/27/1/002
Examples
## Not run:
temp <- ag5_extract(coords = c(lon = 35.72636, lat = -2.197162),
dates = "1991-04-22",
variable = "Temperature-Air-2m",
statistic = "Max-Day-Time",
path = "C:/temperature_data/")
## End(Not run)