Total Energy Index

The function estimates the Total Energy Index (TEI) after Haklander & Van Delden (2003) either at 925 hPa or 850 hPa.

Usage

Total_Energy(hus, ta, pa, zg, hus500, ta500, zg500, nthreads = 1)

Arguments

hus

specific humidity [lon, lat, time] at specific pressure level (kg/kg).

ta

air temperature [lon, lat, time] at specific pressure level (K).

pa

air pressure [lon, lat, time] of hus and ta (hPa).

zg

geopotential [lon, lat, time] at specific pressure level (m^2/s^2).

hus500

specific humidity [lon, lat, time] at 500 hPa (kg/kg).

ta500

air temperature [lon, lat, time] at 500 hPa (K).

zg500

geopotential [lon, lat, time] at 500 hPa (m^2/s^2).

nthreads

an integer specifying the number of threads to use for computation (OpenMP). Default is 1.

Value

the computed TEI [lon, lat, time] (J/kg).

Details

When calculating TEI at ,e.g., 925 hPa, pa is a three dimensional array of 925 hPa.

References

• Haklander, A. J., & Van Delden, A. (2003). Thunderstorm predictors and their forecast skill for the Netherlands. Atmospheric Research, 67–68, 273–299. doi:10.1016/S0169-8095(03)00056-5 .

• Darkow, G.L., 1968. The total energy environment of severe storms. J. Appl. Meteor. 7, 199–205.

Examples

#' data("ERA5_pl")
pa <- ERA5_pl$plev / 100
hus <- ERA5_pl$hus
ta <- ERA5_pl$ta
z <- ERA5_pl$z
l500 <- which(pa == 500)
l925 <- which(pa == 925)
pa <- array(925, dim = dim(hus))
res <- Total_Energy(
  hus[, , l925, ],
  ta[, , l925, ],
  pa,
  z[, , l925, ],
  hus[, , l500, ],
  ta[, , l500, ],
  z[, , l500, ]
)