get_NCEP: Obtains NCEP data required to run microclima

In ilyamaclean/microclima: microclimate modelling with R

Obtains NCEP data required to run microclima

Description

Obtains NCEP data required to run microclima

Usage

get_NCEP(lat, long, tme, reanalysis2 = FALSE)

Arguments

lat	the latitude of the location for which data are required
long	the longitude of the location for which data are required
tme	a POSIXlt object covering the duration for which data are required. Hourly data are returned irrespective of the time interval of tme.
reanalysis2	Logical. Should data be obtained from the Reanalysis II dataset (default) or from Reanalysis I (data prior to 1979).

Details

The NCEP-NCAR and NCEP–DOE Atmospheric Model Intercomparison Project (Kanamitso et al 2002) provides estimates of a range of climate and radiation data for the period 1948 to present. Data at six-hourly intervals are available at a spatial resolution of ~ 1.8 to 2.5º. The function downloads the following datasets: mean, min and max air temperature at 2m, specific humidity and 2m, surface pressure, the u and v wind vectors at 10, the downward and upward longwave radiation fluxes at the surface and the downward shortwave flux at the surface. Data for days either side of tme are downloaded to aid with interpolation by hourlyNCEP(). Requires internet connection.

Value

a dataframe with the following variables: (i) obs_time:times in YYY-MM-DD HH:MM format (UTC), (ii) Tk: mean temperatures at 2m (K), (iii) Tkmin: minimum temperatures at 2m (K) (iv) Tkmax: maximum temperatures at 2m (K), (v) sh: specific humidity at 2m (Kg / Kg), (vi) pr: surface pressure (Pa), (vii) wu u wind vector at 10m (m/s) (viii) wv: v wind vector at 10m (m/s) (ix) dlw: downward longwave radiation flux (W m^-2), (x) ulw: upward longwave radiation flux (W m^-2), (xi) dsw: downward shortwave radiation flux (W m^-2), (xii) tcdc: Total cloud cover for the entire atmosphere.

References

Kanamitsu M, Ebisuzaki W, Woollen J, Yang SK, Hnilo JJ, Fiorino M, Potter GL (2002) Ncep–doe amip-ii reanalysis (r-2). Bulletin of the American Meteorological Society 83: 1631-1644.

See Also

hourlyNCEP()

Examples

tme <- as.POSIXlt(c(1:15) * 24 * 3600, origin = "2015-01-15", tz = 'UTC')
head(get_NCEP(50, -5, tme))

ilyamaclean/microclima documentation built on Oct. 31, 2023, 11:41 p.m.