get_weather: Easily Collection of Worldwide Daily Weather Data.

In allogamous/EnvRtype: Envirotyping Tools for Crop Research and Genetic Improvment

Easily Collection of Worldwide Daily Weather Data.

Description

Imports daily-scale weather data from the NASA-POWER GIS and geographic data from SRTM database.

Usage

get_weather(
  env.id = NULL,
  lat = NULL,
  lon = NULL,
  start.day = NULL,
  end.day = NULL,
  variables.names = NULL,
  dir.path = NULL,
  save = FALSE,
  parallel = TRUE,
  workers = NULL,
  chunk_size = 29,
  sleep = 60
)

Arguments

env.id	vector (character or level). Identifies the site/environment (e.g. Piracicaba01).
lat	vector (numeric). Latitude values of the site/environment (e.g. -13.05) in WGS84.
lon	vector (numeric). Longitude values site/environment (e.g. -56.05) in WGS84.
start.day	vector (character). First date in which weather/geographic data should be collected (e.g. "2015-02-15").
end.day	vector (character). Last date in which weather/geographic data should be collected (e.g. "2015-06-15").
variables.names	vector (character). Name of the variables. Should be "T2M","T2M_MAX","T2M_MIN","PRECTOT", etc. See Details for more information.
dir.path	character. Directory for the output. If not informed, the output will be saved in the current working directory.
save	bollean. If TRUE, save each environmental data.frame as .csv in dir.path.
parallel	bollean. If TRUE, a parallel strategy is implemented. The vectors are split into chunks with 'chunk_size' elements (30 by default) where the data is downloaded. The function then sleeps for 'sleep' seconds to ensure the available number of requests per minute. (https://github.com/ropensci/nasapower/issues/57)
workers	The number of processes in parallel. Defaults to 90 available cores.
chunk_size	The size of the chunks where the parallel strategy is implemented. Defaults to 29. Increasing this number may exceed the limit of queries per minute of the API.
sleep	The time (in seconds) to sleep the function after each chunk has been downloaded. Defaults to 60. Decreasing this number may exceed the limit of queries per minute of the API.

Details

The available variables are (from NASAPOWER & Computed):

• T2M: Temperature at 2 Meters. C

• T2M_MAX: Maximum Temperature at 2 Meters, C

• T2M_MIN: Minimum Temperature at 2 Meters, C

• PRECTOT: Precipitation (mm)

• WS2M: Wind Speed at 2 Meters, m/s

• RH2M: Relative Humidity at 2 Meters, percentage

• QV2M: Specific Humidity, the ratio of the mass of water vapor to the total mass of air at 2 meters (kg water/kg total air).

• T2MDEW: Dew/Frost Point at 2 Meters, C

• ALLSKY_SFC_LW_DWN: Downward Thermal Infrared (Longwave) Radiative Flux

• ALLSKY_SFC_SW_DWN: All Sky Insolation Incident on a Horizontal Surface

• ALLSKY_SFC_SW_DNI All Sky Surface Shortwave Downward Direct Normal Irradiance

• ALLSKY_SFC_UVA: All Sky Surface Ultraviolet A (315nm-400nm) Irradiance

• ALLSKY_SFC_UVB: All Sky Surface Ultraviolet B (280nm-315nm) Irradiance

• ALLSKY_SFC_PAR_TOT: All Sky Surface Photosynthetically Active Radiation (PAR) Total

• FROST_DAYS: If it was a frost day (temperature less than 0C or 32F)

• GWETROOT: Root Zone Soil Wetness (layer from 0 to 100cm),ranging from 0 (water-free soil) to 1 (completely saturated soil).

• GWETTOP: Surface Soil Wetness (layer from 0 to 5cm),ranging from 0 (water-free soil) to 1 (completely saturated soil).

• EVPTRNS: Evapotranspiration energy flux at the surface of the earth.

• P-ETP: Computed difference between preciptation and evapotranspiration.

• VPD: Vapour pressure deficit (kPa), computed from T2MDEW,T2M_MAX and T2M_MIN

• N: Photoperiod (in h), computed from latitude and julian day (day of the year)

• n: number of sunny hours in the day for a clear sky (no clouds)

• RTA: Radiation on the top of the atmosphere, computed from latitude and julian day (day of the year)

• TH1: Temperature-Humidity Index by NRC 1971

• TH2: Temperature-Humidity Index by Yousef 1985

• PAR_TEMP: computed ratio between ALLSKY_SFC_PAR_TOT and T2M

Value

A data.frame with selected variable.names collected from a start.day to a end.day at the informed lat and lon.

Author(s)

Germano Costa Neto and Giovanni Galli, modified by Tiago Olivoto

References

Sparks A (2018). _nasapower: NASA-POWER Data from R_. R package version 1.1.3, <URL:https://CRAN.R-project.org/package=nasapower>. Yousef M.K.(1985) _Stress Physiology in Livestock_, CRC Press, Boca Raton, FL NRC (1971) _A guide to environmental research on animals_, Natl. Acad. Sci., Washington, DC (1971)

Examples

## Not run: 
## Temperature for a single location
get_weather(env.id = "NM", lat = -13.05, lon = -56.05,
            start.day = "2015-02-15", end.day = "2015-06-15",
            variables.names = c("T2M"))

## GWETROOT (Root Zone Soil Wetness) for a single location
get_weather(env.id = "NM", lat = -13.05, lon = -56.05,
            start.day = "2015-02-15", end.day = "2015-06-15",
            variables.names = c("GWETROOT"))

## All variables for two locations
env = c("NM","SO")
lat = c(-13.05,-12.32); lon = c(-56.05,-55.42)
plant.date = c("2015-02-15",'2015-02-13')
harv.date = rep("2015-06-15", 2)
get_weather(env.id = env, lat = lat, lon = lon,
            start.day = plant.date, end.day = harv.date)

## End(Not run)

allogamous/EnvRtype documentation built on June 11, 2025, 5:57 a.m.