lambWT: Calculation of Lamb Weather types (WT).

In SantanderMetGroup/transformeR: A climate4R package for general climate data manipulation and transformation

Calculation of Lamb Weather types (WT).

Description

Calculate automated Lamb WT as defined in Trigo and daCamara (2000), Int J Climatol

Usage

lambWT(grid, center.point = c(-5, 55), typeU = FALSE)

Arguments

grid	A grid (gridded or station dataset), or multimember grid object of MSLP values.
center.point	A two value vector that must include lon and lat from a location that will work as center point for the Lamb WT. See details.
typeU	Logical. Should "Unclassified" type be included in the output. Default to FALSE, so the closest is assigned.

Details

According to Trigo and daCamara (2000), Int J Climatol, Lamb WT is only applied on North Atlantic domain. The input grid units must be Pa, not hPa/mbar. If it is not in Pa, the units must be converted. A center location point must be specified by the user. Then, the function calculates from left to right and from first to 16st the rest of the location point from the grid specified by Trigo and daCamara (2000):

						01			02
			03			04			05			06
			07			08			09			10
			11			12			13			14
						15			16

where the north-south distance is 5º and the west-east distance is 10º. 26 different WTs are defined, 10 pure types (NE, E, SE, S, SW, W, NW, N, C and A) and 16 hybrid types (8 for each C and A hybrid).

Value

The Lamb WT circulation index (and members, if applicable) with:

• index: vector with the corresponding weather type from each point of the series, that is defined as follows:

  	purely anticyclonic:	1	"A"
  	anticyclonic northeasterly:	2	"ANE"
  	anticyclonic easterly:	3	"AE"
  	anticyclonic southeasterly:	4	"ASE"
  	anticyclonic southerly:	5	"AS"
  	anticyclonic southwesterly:	6	"ASW"
  	anticyclonic westerly:	7	"AW"
  	anticyclonic northwesterly:	8	"ANW"
  	anticyclonic northerly:	9	"AN"
  	northeasterly:	10	"NE"
  	easterly:	11	"E"
  	southeasterly:	12	"SE"
  	southerly:	13	"S"
  	southwesterly:	14	"SW"
  	westerly:	15	"W"
  	northwesterly:	16	"NW"
  	northerly:	17	"N"
  	purely cyclonic:	18	"C"
  	cyclonic northeasterly:	19	"CNE"
  	cyclonic easterly:	20	"CE"
  	cyclonic southeasterly:	21	"CSE"
  	cyclonic southerly:	22	"CS"
  	cyclonic southwesterly:	23	"CSW"
  	cyclonic westerly:	24	"CW"
  	cyclonic northwesterly:	25	"CNW"
  	cyclonic northerly:	26	"CN"

• pattern: Array with the spatial pattern of the 26 weather types obtained.

• dates and coordinates.

• further arguments related to the Lamb WT index.

Examples

## Not run: 
require(climate4R.indices)
data(NCEP_slp_2001_2010)
lamb.wt <- lambWT(grid = NCEP_slp_2001_2010)

## End(Not run)

SantanderMetGroup/transformeR documentation built on Nov. 25, 2024, 1:25 p.m.