ERF_Ebert_curry.H

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#ifndef ERF_EBERT_CURRY_H_
#define ERF_EBERT_CURRY_H_
using yakl::fortran::parallel_for;
using yakl::fortran::SimpleBounds;
 
class EbertCurry {
  public:
   static constexpr real scalefactor = 1.;  //500._r8/917._r8
 
   static void ec_ice_optics_sw (int ncol, int nlev, int nswbands,
                                 const real2d& cldn, const real2d& cicewp, const real2d& rei,
                                 const real3d& ice_tau, const real3d& ice_tau_w,
                                 const real3d& ice_tau_w_g, const real3d& ice_tau_w_f)
    {
        real1d wavmin("wavmin", nswbands);
        real1d wavmax("wavmax", nswbands);
 
        // ice water coefficients (Ebert and Curry,1992, JGR, 97, 3831-3836)
        real1d abari("abari", 4);      // a coefficient for extinction optical depth
        real1d bbari("bbari", 4);     // b coefficient for extinction optical depth
        real1d cbari("cbari", 4);      // c coefficient for single scat albedo
        real1d dbari("dbari", 4);      // d coefficient for single scat albedo
        real1d ebari("ebari", 4);      // e coefficient for asymmetry parameter
        real1d fbari("fbari", 4);     // f coefficient for asymmetry parameter
 
        parallel_for(SimpleBounds<1>(1), YAKL_LAMBDA (int i)
        {
            abari(1) = 3.448e-03;
            abari(2) = 3.448e-03;
            abari(3) = 3.448e-03;
            abari(4) = 3.448e-03;
            bbari(1) = 2.431;
            bbari(2) = 2.431;
            bbari(3) = 2.431;
            bbari(4) = 2.431;
            cbari(1) = 1.00e-05;
            cbari(2) = 1.10e-04;
            cbari(3) = 1.861e-02;
            cbari(4) = 0.46658;
            dbari(1) = 0.0;
            dbari(2) = 1.405e-05;
            dbari(3) = 8.328e-04;
            dbari(4) = 2.05e-05;
            ebari(1) = 0.7661;
            ebari(2) = 0.7730;
            ebari(3) = 0.794;
            ebari(4) = 0.9595;
            fbari(1) = 5.851e-04;
            fbari(2) = 5.665e-04;
            fbari(3) = 7.267e-04;
            fbari(4) = 1.076e-04;
        });
 
        // Minimum cloud amount (as a fraction of the grid-box area) to
        // distinguish from clear sky
        constexpr real cldmin = 1.0e-80;
 
        // Decimal precision of cloud amount (0 -> preserve full resolution;
        // 10^-n -> preserve n digits of cloud amount)
        constexpr real cldeps = 0.0;
 
        // Optical properties for ice are valid only in the range of
        // 13 < rei < 130 micron (Ebert and Curry 92)
        constexpr real rei_min = 13.;
        constexpr real rei_max = 130.;
 
        //  integer :: ns, i, k, indxsl
        int indxsl;
 
        RadConstants::get_sw_spectral_boundaries(wavmin,wavmax,RadConstants::micrometer);
 
        for (auto ns=0; ns<nswbands; ++ns) {
            if(wavmax(ns) <= 0.7) {
                indxsl = 1;
            } else if(wavmax(ns) <= 1.25) {
                indxsl = 2;
            } else if(wavmax(ns) <= 2.38) {
                indxsl = 3;
            } else if(wavmax(ns) > 2.38) {
                indxsl = 4;
            }
            parallel_for(SimpleBounds<2>(nlev, ncol), YAKL_LAMBDA (int k, int i)
            {
                real tmp1i, tmp2i, tmp3i, g;
                auto abarii = abari(indxsl);
                auto bbarii = bbari(indxsl);
                auto cbarii = cbari(indxsl);
                auto dbarii = dbari(indxsl);
                auto ebarii = ebari(indxsl);
                auto fbarii = fbari(indxsl);
 
                // note that optical properties for ice valid only
                // in range of 13 > rei > 130 micron (Ebert and Curry 92)
                if (cldn(i,k) >= cldmin && cldn(i,k) >= cldeps) {
                    tmp1i = abarii + bbarii/std::max(rei_min,std::min(scalefactor*rei(i,k),rei_max));
                    ice_tau(ns,i,k) = 1000. * cicewp(i,k) * tmp1i;
                } else {
                    ice_tau(ns,i,k) = 0.0;
                }
 
                tmp2i = 1. - cbarii - dbarii*std::min(std::max(rei_min,scalefactor*rei(i,k)),rei_max);
                tmp3i = fbarii*std::min(std::max(rei_min,scalefactor*rei(i,k)),rei_max);
                // Do not let single scatter albedo be 1.  Delta-eddington solution
                // for non-conservative case has different analytic form from solution
                // for conservative case, and raddedmx is written for non-conservative case.
                ice_tau_w(ns,i,k) = ice_tau(ns,i,k) * std::min(tmp2i,.999999);
                g = ebarii + tmp3i;
                ice_tau_w_g(ns,i,k) = ice_tau_w(ns,i,k) * g;
                ice_tau_w_f(ns,i,k) = ice_tau_w(ns,i,k) * g * g;
            });
        } // nswbands
    }
 
 
    static void ec_ice_optics_lw (int ncol, int nlev, int nlwbands,
                                  const real2d& cldn, const real2d& iclwpth,
                                  const real2d& iciwpth, const real2d& rei, const real3d& abs_od)
    {
        real2d ficemr("ficemr",ncol,nlev);
        real2d cwp("cwp",ncol,nlev);
        real2d cldtau("cldtau",ncol,nlev);
 
        // longwave liquid absorption coeff (m**2/g)
        //const real kabsl = 0.090361;
 
        // Optical properties for ice are valid only in the range of
        // 13 < rei < 130 micron (Ebert and Curry 92)
        const real rei_min = 13.;
        const real rei_max = 130.;
 
        parallel_for(SimpleBounds<2>(nlev, ncol), YAKL_LAMBDA (int k, int i)
        {
            cwp(i,k) = 1000.0 *iciwpth(i,k) + 1000.0 *iclwpth(i,k);
            ficemr(i,k) = 1000.0*iciwpth(i,k)/(std::max(1.e-18,cwp(i,k)));
        });
 
        parallel_for(SimpleBounds<2>(nlev, ncol), YAKL_LAMBDA (int k, int i)
        {
            // Note from Andrew Conley:
            //  Optics for RK no longer supported, This is constructed to get
            //  close to bit for bit.  Otherwise we could simply use ice water path
            //  note that optical properties for ice valid only
            //  in range of 13 > rei > 130 micron (Ebert and Curry 92)
            auto kabsi = 0.005 + 1./std::min(std::max(rei_min,scalefactor*rei(i,k)),rei_max);
            auto kabs =  kabsi*ficemr(i,k); // kabsl*(1.-ficemr(i,k)) + kabsi*ficemr(i,k);
            cldtau(i,k) = kabs*cwp(i,k);
        });
 
        parallel_for(SimpleBounds<3>(nlwbands, ncol, nlev), YAKL_LAMBDA (int lwband, int icol, int ilev)
        {
            abs_od(lwband,icol,ilev)=cldtau(icol,ilev);
        });
    }
};
#endif