Index

Rundeck: P1SoM40

Created: Fri May 10 03:30:18 EDT 2024

q_eqn

Module: SOCPBL

File: PBL.f

Summary: q_eqn integrates differential eqns for the specific humidity, Q, using tridiagonal method over npbl(=8) sublayers between the surface (sublayer 1) and the middle of the first GCM layer (sublayer npbl). The boundary condition at the bottom is: kq * dq/dz = min ( cq * usurf * (q1 - qgrnd) + cq * gusti * qprime , fr_sat * ( cq * usurf * (q1 - qgrnd) + cq * gusti * qprime ) - ( 1 - fr_sat ) * flux_max ), which includes the effects on the surface flux due to the moist convection wind gustiness and the downdraft specific humidity perturbation (Redelsperger et al. 2000; Emanuel and Zivkovic 1999), where qprime=qdns-qtop, qtop is Q at the first layer and qdns is the downdraft humidity in kg/kg, (i,j), which is calculated in subroutines CONDSE (in CLOUDS2_DRV.f) and PBL (in PBL_DRV.f). At the top, i.e., the middle of the first GCM layer, Q is prescribed.
Author : Ye Cheng/G. Hartke
Version:

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Declaration:

subroutine q_eqn(q0, q, kq, dz, dzh, cq, usurf, qgrnd, qtop, dtime, n, flux_max, fr_sat, usurf0, gusti, qprime, qdns, ddml_eq_1)

Variables:

q : real*8, dimension(n), intent(out)

z-profle of specific humidity

q0 : real*8, dimension(n), intent(in)

z-profle of q at previous time step

kq : real*8, dimension(n-1), intent(in)

z-profile of moisture diffusivity

dz : real*8, dimension(n), intent(in)

(j) zhat(j)-zhat(j-1)

dzh : real*8, dimension(n-1), intent(in)

(j) z(j+1)-z(j)

cq : real*8, intent(in)

dimensionless moisture flux at surface (dalton number)

usurf : real*8, intent(in)

effective surface velocity

qgrnd : real*8, intent(in)

specific humidity at the ground

qtop : real*8, intent(in)

specific humidity at the first GCM layer

dtime : real*8, intent(in)

time step

n : integer, intent(in)

number of vertical subgrid main layers

flux_max : real*8, intent(in)

maximal flux from the unsaturated soil

fr_sat : real*8, intent(in)

fraction of the saturated soil

sub : real*8, dimension(n)

dia : real*8, dimension(n)

sup : real*8, dimension(n)

rhs : real*8, dimension(n)

usurf0 : real*8, intent(in)

gusti : real*8, intent(in)

qprime : real*8, intent(in)

qdns : real*8, intent(in)

ddml_eq_1 : logical, intent(in)

i : integer

loop variable

factq0 : real*8

factq : real*8