Convective Instability (Reap)

Convective Instability (Reap)

Usage

CI_Reap(ta_s, hus_s, pa_s, ta850, hus850, ta700, hus700, nthreads = 1)

Arguments

ta_s

air temperature [lon. lat, time] at 2 meter above the surface (K).

hus_s

surface specific humidity [lon, lat, time] at 2 meter above the surface (kg/kg).

pa_s

surface pressure [lon, lat, time] (hPa).

ta850

air temperature [lon, lat, time] at 850 hPa (K).

hus850

specific humidity [lon, lat, time] at 850 hPa (kg/kg).

ta700

air temperature [lon, lat, time] at 700 hPa (K).

hus700

specific humidity [lon, lat, time] at 700 hPa (kg/kg).

nthreads

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

Value

the computed convective stability index [lon. lat, time] in K defined by Reap due to Peppler (1988).

References

• Peppler, R. A., & Lamb, P. J. (1989). Tropospheric Static Stability and Central North American Growing Season Rainfall. Monthly Weather Review, 117(6), 1156–1180. doi:10.1175/1520-0493(1989)117<1156:TSSACN>2.0.CO;2

• Reap, R. M., and M. A. Alaka, 1969: An objective quasi-lagrangian index for predicting convective weather outbreaks. Preprints. Sixth Conf. Severe Local Storms, Chicago, Amer. Meteor. S o c , 119-124.

Examples

data("ERA5_sfc")
ta_s <- ERA5_sfc$t2m
td_s <- ERA5_sfc$t2d
pa_s <- ERA5_sfc$sp / 100
hus_s <- hus_from_td(td_s, pa_s)
dim(hus_s) <- dim(td_s)

data("ERA5_pl")
ta_pl <- ERA5_pl$ta
hus_pl <- ERA5_pl$hus
pa_pl <- ERA5_pl$plev / 100
l700 <- which(pa_pl == 700)
l850 <- which(pa_pl == 850)

res <- CI_Reap(
  ta_s, hus_s, pa_s,
  ta_pl[, , l850, ], hus_pl[, , l850, ],
  ta_pl[, , l700, ], hus_pl[, , l700, ]
)