surface_temp Struct Reference

#include <ERF_MOSTStress.H>

Collaboration diagram for surface_temp:

Public Member Functions
	surface_temp (amrex::Real Tflux, amrex::Real Qvflux, bool cons_qflux, int face_dir, bool face_is_low)
AMREX_GPU_DEVICE AMREX_FORCE_INLINE void	iterate_flux (const int &i, const int &j, const int &k, const int &max_iters, const amrex::Array4< const amrex::Real > &zref_arr, const amrex::Array4< const amrex::Real > &z0_arr, const amrex::Array4< const amrex::Real > &umm_arr, const amrex::Array4< const amrex::Real > &tm_arr, const amrex::Array4< const amrex::Real > &tvm_arr, const amrex::Array4< const amrex::Real > &qvm_arr, const amrex::Array4< amrex::Real > &u_star_arr, const amrex::Array4< amrex::Real > &w_star_arr, const amrex::Array4< amrex::Real > &t_star_arr, const amrex::Array4< amrex::Real > &q_star_arr, const amrex::Array4< amrex::Real > &t_surf_arr, const amrex::Array4< amrex::Real > &q_surf_arr, const amrex::Array4< amrex::Real > &olen_arr, const amrex::Array4< amrex::Real > &pblh_arr, const amrex::Array4< amrex::Real > &, const amrex::Array4< amrex::Real > &, const amrex::Array4< amrex::Real > &) const

Private Attributes
most_data	mdata
bool	spec_qflux {false}
similarity_funs	sfuns
int	dir
bool	is_low = true
const amrex::Real	tol = amrex::Real(1.0e-3)
const amrex::Real	alpha = myhalf
const amrex::Real	WSMIN = most_min_wind_speed

Detailed Description

Surface temperature with constant roughness

Constructor & Destructor Documentation

surface_temp()

surface_temp::surface_temp ( amrex::Real  Tflux, amrex::Real  Qvflux, bool  cons_qflux, int  face_dir, bool  face_is_low  )

inline

Construct specified-temperature, constant-roughness MOST data.

Parameters

[in]	Tflux	prescribed heat flux
[in]	Qvflux	prescribed moisture flux
[in]	cons_qflux	whether the moisture flux is specified
[in]	face_dir	face direction (x,y,z)
[in]	face_is_low	face orientation (low or high face: 0 or 1)

    {
        mdata.surf_temp_flux  = Tflux;
        mdata.surf_moist_flux = Qvflux;
        spec_qflux = cons_qflux;
        dir = face_dir;
        is_low = face_is_low;
    }

Member Function Documentation

iterate_flux()

AMREX_GPU_DEVICE AMREX_FORCE_INLINE void surface_temp::iterate_flux ( const int &  i, const int &  j, const int &  k, const int &  max_iters, const amrex::Array4< const amrex::Real > &  zref_arr, const amrex::Array4< const amrex::Real > &  z0_arr, const amrex::Array4< const amrex::Real > &  umm_arr, const amrex::Array4< const amrex::Real > &  tm_arr, const amrex::Array4< const amrex::Real > &  tvm_arr, const amrex::Array4< const amrex::Real > &  qvm_arr, const amrex::Array4< amrex::Real > &  u_star_arr, const amrex::Array4< amrex::Real > &  w_star_arr, const amrex::Array4< amrex::Real > &  t_star_arr, const amrex::Array4< amrex::Real > &  q_star_arr, const amrex::Array4< amrex::Real > &  t_surf_arr, const amrex::Array4< amrex::Real > &  q_surf_arr, const amrex::Array4< amrex::Real > &  olen_arr, const amrex::Array4< amrex::Real > &  pblh_arr, const amrex::Array4< amrex::Real > &  , const amrex::Array4< amrex::Real > &  , const amrex::Array4< amrex::Real > &    ) const

inline

Iterate MOST state for one surface point.

Calling sequence

i, j, k, max_iters, zref_arr, z0_arr, umm_arr, tm_arr, tvm_arr, qvm_arr, u_star_arr, w_star_arr, t_star_arr, q_star_arr, t_surf_arr, q_surf_arr, olen_arr, pblh_arr, Hwave_arr, Lwave_arr, eta_arr.

    {
        amrex::Real Rib      = zero;
        amrex::Real zeta     = zero;
        amrex::Real zeta_old = zero;
        amrex::Real psi_m    = zero;
        amrex::Real psi_h    = zero;
        amrex::Real CmPsim   = zero;
        amrex::Real CmPsih   = zero;
        amrex::Real zref     = zref_arr(i,j,k);
        amrex::Real z0       = z0_arr(i,j,k);
        // NOTE: umm here will be either mean x/y velocity if on a Z-face, x/z velocity if on a Y-face, or y/z velocity if on an X-face
        amrex::Real umm      = std::max(umm_arr(i,j,k), WSMIN);
        amrex::Real C        = std::log(zref / z0);
 
        // First iteration we assume neutral (L -> inf)
        if (u_star_arr(i,j,k) == bogus_large_value) { olen_arr(i,j,k) = amrex::Real(1.0e3); }
        zeta  = zref / olen_arr(i,j,k);
 
        amrex::Real t_surf   = t_surf_arr(i,j,k);
        amrex::Real t_mean   = tm_arr(i,j,k);
 
        // Water vapor in the atmosphere and at the surface
        const amrex::Real qv_a_raw = qvm_arr(i,j,k);
        const amrex::Real qv_s_raw = q_surf_arr(i,j,k);
        amrex::Real qv_s, qv_a;
        if (qv_s_raw > zero) {
            qv_s = qv_s_raw;
        } else {
            // First iteration and no qv_surf was specified
            // Use mean since there will be no flux
            qv_s = qv_a_raw;
        }
        qv_a = qv_a_raw;
 
        amrex::Real thv_s = t_surf_arr(i,j,k) * (one + epsv*qv_s);
        amrex::Real thv_a =     tm_arr(i,j,k) * (one + epsv*qv_a);
 
        if (dir == 2 && !is_low) {
            // On the hi-Z face, swap surf and mean values to force unstable condition
            thv_a = thv_s;
            thv_s = tm_arr(i,j,k) * (one + epsv*qv_a);
            t_mean = t_surf;
            t_surf = tm_arr(i,j,k);
            qv_a = qv_s;
            qv_s = qv_a_raw;
        }
 
        // update w* and Umagmean from Beljaars (1995)
        if (w_star_arr) {
            // NOTE: Thv flux is lagged, similar to WRF
            psi_m = sfuns.calc_psi_m2(zeta);
            psi_h = sfuns.calc_psi_h2(zeta);
            amrex::Real ustar = mdata.kappa * umm / most_bracket(C, psi_m);
            amrex::Real tstar = mdata.kappa * (tm_arr(i,j,k) - t_surf_arr(i,j,k)) / most_bracket(C, psi_h);
            amrex::Real qflux = (spec_qflux) ? mdata.surf_moist_flux :
                                 -ustar * mdata.kappa * (qv_a - qv_s) / most_bracket(C, psi_h);
            amrex::Real tflux = -ustar*tstar*(one + epsv*qvm_arr(i,j,k)) + epsv*tm_arr(i,j,k)*qflux;
            w_star_arr(i,j,k) = calc_wstar(tflux, pblh_arr(i,j,k), tvm_arr(i,j,k));
            amrex::Real wstar = mdata.Bjr_beta * w_star_arr(i,j,k);
            umm = std::sqrt(umm_arr(i,j,k)*umm_arr(i,j,k) + wstar*wstar);
            umm = std::max(umm, WSMIN);
        }
 
        // Bulk Richardson number w/ moisture
        Rib = ( (mdata.gravity * zref) / t_mean ) *
              ( (thv_a - thv_s) / (umm * umm) );
        Rib = std::min(std::max(Rib,-amrex::Real(4.0)),amrex::Real(4.0));
 
        // Fixed point iteration on zeta
        const amrex::Real zeta_start = zeta;
        int iter = 0;
        do {
            // Transfer curr to old
            zeta_old = zeta;
 
            // Stability functions
            psi_m = sfuns.calc_psi_m2(zeta_old);
            psi_h = sfuns.calc_psi_h2(zeta_old);
 
            // Limiting
            CmPsim = most_bracket(C, psi_m);
            CmPsih = most_bracket(C, psi_h);
 
            // Update with under relaxation
            zeta = (one - alpha) * zeta_old + alpha * Rib * CmPsim * CmPsim / CmPsih;
 
            ++iter;
        } while ( (std::abs(zeta - zeta_old) > tol) && (iter <= max_iters) );
        if (iter > max_iters ||
            !most_rib_zeta_is_root(sfuns, C, Rib, zeta, amrex::Real(10.0) * tol)) {
            // The relaxed iteration stalls, or stops where no root is near, where its residual
            // nearly touches zero (z0 comparable to zref); solve the same equation by bracketing
            zeta   = most_rib_zeta_bracketed(sfuns, C, Rib, zeta_start, tol);
            CmPsim = most_bracket(C, sfuns.calc_psi_m2(zeta));
            CmPsih = most_bracket(C, sfuns.calc_psi_h2(zeta));
        }
 
        // Populate the stored MOST arrays
        olen_arr(i,j,k)   = zref / zeta;
        u_star_arr(i,j,k) = mdata.kappa * umm / CmPsim;
        t_star_arr(i,j,k) = mdata.kappa * (t_mean - t_surf) / CmPsih;
        if (spec_qflux) {
            q_surf_arr(i,j,k) = mdata.surf_moist_flux * CmPsih /
                                (u_star_arr(i,j,k) * mdata.kappa) + qv_a_raw;
            q_star_arr(i,j,k) = -mdata.surf_moist_flux / u_star_arr(i,j,k);
        } else {
            // q_star follows the raw atmospheric/surface contrast.  The
            // existing high-z orientation reverses this contrast, matching
            // the corresponding thermodynamic and flux calculations above.
            const amrex::Real qv_delta = (dir == 2 && !is_low)
                ? (qv_s_raw - qv_a_raw)
                : (qv_a_raw - qv_s_raw);
            q_star_arr(i,j,k) = mdata.kappa * qv_delta / CmPsih;
        }
    }

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Member Data Documentation

alpha

const amrex::Real surface_temp::alpha = myhalf

private

Referenced by iterate_flux().

dir

int surface_temp::dir

private

Referenced by iterate_flux(), and surface_temp().

is_low

bool surface_temp::is_low = true

private

Referenced by iterate_flux(), and surface_temp().

mdata

most_data surface_temp::mdata

private

Referenced by iterate_flux(), and surface_temp().

sfuns

similarity_funs surface_temp::sfuns

private

Referenced by iterate_flux().

spec_qflux

bool surface_temp::spec_qflux {false}

private

Referenced by iterate_flux(), and surface_temp().

tol

const amrex::Real surface_temp::tol = amrex::Real(1.0e-3)

private

Referenced by iterate_flux().

WSMIN

const amrex::Real surface_temp::WSMIN = most_min_wind_speed

private

Referenced by iterate_flux().

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The documentation for this struct was generated from the following file:

• Source/BoundaryConditions/ERF_MOSTStress.H