surface_temp_charnock Struct Reference

#include <ERF_MOSTStress.H>

Collaboration diagram for surface_temp_charnock:

Public Member Functions
	surface_temp_charnock (amrex::Real Tflux, amrex::Real Qvflux, amrex::Real cnk_a, bool cnk_visc, bool cons_qflux)
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< 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
similarity_funs	sfuns
const amrex::Real	tol = amrex::Real(1.0e-3)
const amrex::Real	tol_z = amrex::Real(1.0e-10)
const amrex::Real	alpha = myhalf
const amrex::Real	WSMIN = amrex::Real(0.1)

Detailed Description

Surface temperature with charnock roughness

Constructor & Destructor Documentation

surface_temp_charnock()

surface_temp_charnock::surface_temp_charnock ( amrex::Real  Tflux, amrex::Real  Qvflux, amrex::Real  cnk_a, bool  cnk_visc, bool  cons_qflux  )

inline

Construct specified-temperature, Charnock-roughness MOST data.

Parameters

[in]	Tflux	prescribed heat flux
[in]	Qvflux	prescribed moisture flux
[in]	cnk_a	Charnock parameter
[in]	cnk_visc	whether to include viscous roughness
[in]	cons_qflux	whether the moisture flux is specified

    {
        mdata.surf_temp_flux  = Tflux;
        mdata.surf_moist_flux = Qvflux;
        mdata.Cnk_a = cnk_a;
        mdata.visc  = cnk_visc;
        spec_qflux  = cons_qflux;
    }

Member Function Documentation

iterate_flux()

AMREX_GPU_DEVICE AMREX_FORCE_INLINE void surface_temp_charnock::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< 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 num      = zero;
        amrex::Real den      = zero;
        amrex::Real z0       = z0_arr(i,j,k);
        amrex::Real z0_old   = z0;
        amrex::Real ustar    = zero;
        amrex::Real zref     = zref_arr(i,j,k);
        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);
 
        // Water vapor in atmos and surface
        amrex::Real qv_s, qv_a;
        if (q_surf_arr(i,j,k) > zero) {
            qv_s = q_surf_arr(i,j,k);
        } else {
            // First iteration and no qv_surf was specified
            // Use mean since there will be no flux
            qv_s = qvm_arr(i,j,k);
        }
        qv_a = qvm_arr(i,j,k);
 
        // 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);
                        ustar = mdata.kappa * umm / (C - psi_m);
            amrex::Real tstar = mdata.kappa * (tm_arr(i,j,k) - t_surf_arr(i,j,k)) / (C - psi_h);
            amrex::Real qflux = (spec_qflux) ? mdata.surf_moist_flux :
                                 -ustar * mdata.kappa * (qv_a - qv_s) / (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
        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);
        Rib = ( (mdata.gravity * zref) / tm_arr(i,j,k) ) *
              ( (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
        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);
 
            // Fixed point iteration on roughness
            int iter_z = 0;
            do {
                // Transfer curr to old
                z0_old = z0;
 
                // Update
                C = std::log(zref / z0_old);
                ustar = mdata.kappa * umm / (C - psi_m);
                if (mdata.Cnk_a > 0) {
                    z0 = (mdata.Cnk_a / mdata.gravity) * ustar * ustar;
                    if (mdata.visc) {
                        z0 += air_viscosity(tm_arr(i,j,k)) / std::max(ustar, amrex::Real(0.05));
                    }
                } else {
                    z0 = COARE3_roughness(zref, umm, ustar);
                }
 
                ++iter_z;
            } while ( (std::abs(z0 - z0_old) > tol_z) && (iter_z <= max_iters) );
            AMREX_ALWAYS_ASSERT_WITH_MESSAGE(iter_z < max_iters,
                                             "Maximum number of MOST roughness iterations reached.");
            C = std::log(zref / z0);
 
            // Limiting
            num = std::max(C - psi_m, amrex::Real(1.0));
            den = std::max(C - psi_h, amrex::Real(1.0));
 
            // Update with under relaxation
            zeta = (amrex::Real(1.0) - alpha) * zeta_old + alpha * Rib * num * num / den;
 
            ++iter;
        } while ( (std::abs(zeta - zeta_old) > tol) && (iter <= max_iters) );
        AMREX_ALWAYS_ASSERT_WITH_MESSAGE(iter < max_iters,
                                         "Maximum number of MOST iterations reached.");
 
        // Populate the stored MOST arrays
        z0_arr(i,j,k)     = z0;
        olen_arr(i,j,k)   = zref / zeta;
        u_star_arr(i,j,k) = mdata.kappa * umm / (C - psi_m);
        t_star_arr(i,j,k) = mdata.kappa * (tm_arr(i,j,k) - t_surf_arr(i,j,k)) / (C - psi_h);
        if (spec_qflux) {
            q_surf_arr(i,j,k) = mdata.surf_moist_flux * (C - psi_h) /
                                (u_star_arr(i,j,k) * mdata.kappa) + qvm_arr(i,j,k);
            q_star_arr(i,j,k) = -mdata.surf_moist_flux / u_star_arr(i,j,k);
        } else {
            q_star_arr(i,j,k) = mdata.kappa * (qvm_arr(i,j,k) - q_surf_arr(i,j,k)) / (C - psi_h);
        }
    }

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Member Data Documentation

alpha

const amrex::Real surface_temp_charnock::alpha = myhalf

private

Referenced by iterate_flux().

mdata

most_data surface_temp_charnock::mdata

private

Referenced by iterate_flux(), and surface_temp_charnock().

sfuns

similarity_funs surface_temp_charnock::sfuns

private

Referenced by iterate_flux().

spec_qflux

bool surface_temp_charnock::spec_qflux

private

Referenced by iterate_flux(), and surface_temp_charnock().

tol

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

private

Referenced by iterate_flux().

tol_z

const amrex::Real surface_temp_charnock::tol_z = amrex::Real(1.0e-10)

private

Referenced by iterate_flux().

WSMIN

const amrex::Real surface_temp_charnock::WSMIN = amrex::Real(0.1)

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