Mixed Layer CAPE
CAPE_ml.RdThe function calculates the Convective Available Potential Energy (CAPE) for a mixed layer from the surface with a certain pressure thickness (e.g., 50 hPa, or 100 hPa). It returns a list containing CAPE, convective inhibition (CIN), pressure at lifted condensation level (LCL), and at level of free convection (LFC).
Arguments
- ta_s
parcel temperature [lon, lat, time] at 2 meter above the surface (K).
- hus_s
parcel specific humidity [lon, lat, time] at 2 meter above the surface (kg/kg).
- pa_s
surface pressure [lon, lat, time] (hPa).
- ta_pl
air temperature [lon, lat, lev, time] on pressure level (K).
- hus_pl
specific humidity [lon, lat, lev, time] on pressure level (kg/kg).
- pa_pl
pressure profile [lev] in descending manner (hPa).
- dp
thickness of the mixed layer (hPa).
- vtc
logical refers to virtual temperature correction due to Doswell and Rasmussen (1994).
- nthreads
an integer specifying the number of threads to use for computation (OpenMP). Default is 1.
References
Doswell III, C. A., & Rasmussen, E. N. (1994). The effect of neglecting the virtual temperature correction on CAPE calculations. Weather and forecasting, 9(4), 625-629 doi:10.1175/1520-0434(1994)009<0625:TEONTV>2.0.CO;2 .
Examples
data("ERA5_pl")
data("ERA5_sfc")
ta_s <- ERA5_sfc$t2m
td_s <- ERA5_sfc$t2d
pa_s <- ERA5_sfc$sp / 100
hus_s <- hus_from_td(td_s, pa_s)
dim(hus_s) <- dim(ta_s)
ta_pl <- ERA5_pl$ta
hus_pl <- ERA5_pl$hus
pa_pl <- ERA5_pl$plev / 100
# Mixed layer 50 hPa
res <- CAPE_ml(ta_s, hus_s, pa_s,
ta_pl, hus_pl, pa_pl,
dp = 50,
vtc = TRUE, nthreads = 1
)
str(res)
#> List of 4
#> $ CAPE : num [1:9, 1:13, 1:2] 0 0 0 0 0 0 0 0 0 0 ...
#> $ CIN : num [1:9, 1:13, 1:2] NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN ...
#> $ p_LCL: num [1:9, 1:13, 1:2] 600 600 550 600 600 600 600 600 600 550 ...
#> $ p_LFC: num [1:9, 1:13, 1:2] NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN ...