classification_jc {jcext}

classification_jc

Description

Calculates the classification of the main weather types for one central point that is surrounded by 16-points (grid16). Wind-flow characteristics are computed for the daily pressure field according to the rules proposed by the original Jenkinson and Collison classification (see Jones et al. 1993, Jones et al. 2016).

Usage

classification_jc(mslp, grid16, centralp, loni, lati, times, gale)

Arguments

mslp

3-Dimensional multi-array ([loni,lati,time]) with mean sea level pressure in Pa.

grid16

Data frame obtained in the main function (extended_jc) that contains the 16 grid-points defining the scheme. First row is for longitudes, while the second row is for latitudes.

centralp

Numeric that refers to the central point for which the JC classification is calculated.

loni

Array with longitude values.

lati

Array with latitude values.

times

Array with the dates used.

gale

A logical for deteriming Gale days.

Value

Daily frequencies of Weather Types and airflow indices.

References

Jones, P. D., Hulme M., Briffa K. R. (1993) A comparison of Lamb circulation types with an objective classification scheme Int. J. Climatol. 13: 655–663.

Jones, P. D., Harpham C, Briffa K. R. (2013) Lamb weather types derived from Reanalysis products Int. J. Climatol. 33: 1129–1139.

See Also

calculate_cwt

Examples

# Load data
data(press)
mslp  <- press$msl
loni  <- press$loni
lati  <- press$lati
times <- press$dates
# Define a central point
centralp <- c(10,50)
# Get the scheme for the  central point
grid16 <- get_jcpoints(10,50)[1:16]
classification_jc(mslp, grid16, centralp, loni, lati, times, gale=FALSE)