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theta perturbation

Initial potential-temperature perturbation added to the base state (gravity-wave and bubble benchmarks)

kindrequired amplituderequired centre half width half height depth

kindrequired

required

inertia gravity wave: A sin(pi z/H) / (1 + ((x - xc)/a)^2) (Skamarock & Klemp 1994); bubble: A cos^2(pi r/2) inside the ellipse r = |((x - xc)/rx, (z - zc)/rz)| <= 1; random: position-hashed +/-A turbulence seed below 'depth' (GABLS1)

Options

Value	What it does	When to use it
inertia gravity wave	$\theta' = A \sin(\pi z/H) / (1 + ((x-x_c)/a)^2)$ (Skamarock & Klemp 1994).
bubble	$\theta' = A \cos^2(\pi r/2)$ inside the ellipse $r = \|((x-x_c)/r_x, (z-z_c)/r_z)\| \le 1$ , zero outside.
random	A pseudo-random $\theta'$ of up to `amplitude` either side of zero, hashed from each cell's position and applied only below `depth`. The seed is reproducible and independent of the partitioning.	Seeding turbulence in a stable boundary layer, as in GABLS1.

Used inatmosphere

amplituderequired

float·required·in K

A; negative for a cold bubble

Used inatmosphere

centre

list of float·default [0, 0]·in m

[xc, zc]; zc is used by the bubble only

Used inatmosphere

half width

float·default 5000·> 0.0 m

a for the gravity wave, or the bubble x radius rx

Used inatmosphere

half height

float·default 2000·> 0.0 m

Bubble z radius rz

depth

float·default 10000·> 0.0 m

H in sin(pi z/H) for the gravity wave

Used inatmosphere