#include <ERF_BaseStateParams.H>

Collaboration diagram for BaseStateParams:

Public Member Functions
void	set_layer_interfaces ()

bool	same_params_as (const BaseStateParams &bsp) const

Public Attributes
amrex::Real	T00 = amrex::Real(290.0)

amrex::Real	P00 = p_0

amrex::Real	TLP = amrex::Real(50.0)

amrex::Real	TISO = amrex::Real(200.0)

amrex::Real	TLP_STRAT = amrex::Real(-11.0)

amrex::Real	P_STRAT = zero

amrex::Real	P_iso = zero

amrex::Real	z_iso = zero

amrex::Real	z_strat = zero

bool	use_strat = false

bool	is_set = false

Detailed Description

Parameters defining the WRF reference (base) state, along with the layer interface heights derived from them.

The base state is piecewise in log-pressure: (1) troposphere T = T00 + TLP * ln(p/P00) p > P_iso (2) isothermal layer T = TISO P_STRAT < p <= P_iso (3) stratosphere T = TISO + TLP_STRAT * ln(p/P_STRAT) p <= P_STRAT Each piece inverts to p(z) in closed form under dp/dz = -rho g, so the two interface heights are precomputed once and the inversion branches on z.

Because the resulting profile is a pure function of height, it can be evaluated on any subset of a column – it does not require a box that spans the domain in the vertical.

NOTE: The defaults are the WRF namelist defaults for base_temp, base_pres, base_lapse, iso_temp, base_lapse_strat and base_pres_strat. metgrid files do not carry these parameters at all; wrfinput files usually do, and are read by read_base_state_params_from_wrfinput.

Member Function Documentation

◆ same_params_as()

bool BaseStateParams::same_params_as ( const BaseStateParams & bsp ) const

inline

     {
         return (T00       == bsp.T00 ) && (P00     == bsp.P00 ) &&
                (TLP       == bsp.TLP ) && (TISO    == bsp.TISO) &&
                (TLP_STRAT == bsp.TLP_STRAT) && (P_STRAT == bsp.P_STRAT);
     }

◆ set_layer_interfaces()

void BaseStateParams::set_layer_interfaces ( )

inline

     {
         // The troposphere inverts p(z) as sqrt((T00/TLP)^2 - 2*g*z/(TLP*R_d)), which
         // folds 1/TLP inside the square root and so discards the sign of TLP. A
         // non-positive lapse parameter, or an isothermal temperature at or above the
         // surface temperature, would silently select the wrong root instead of failing.
         AMREX_ALWAYS_ASSERT_WITH_MESSAGE(TLP > zero,
                                          "Base state TLP must be positive");
         AMREX_ALWAYS_ASSERT_WITH_MESSAGE(TISO < T00,
                                          "Base state TISO must be less than T00");
  
         const amrex::Real x_iso = (TISO - T00) / TLP;
         P_iso = P00 * std::exp(x_iso);
         z_iso = -(R_d/CONST_GRAV) * (T00*x_iso + myhalf*TLP*x_iso*x_iso);
  
         // The upper stratospheric layer is optional (P_STRAT == 0 or TLP_STRAT == 0
         // disables it) and is only meaningful if it begins above the isothermal layer,
         // i.e. if P_STRAT is below the pressure at which the isothermal layer starts.
         const bool want_strat = ((P_STRAT > zero) && (TLP_STRAT != zero));
         use_strat = (want_strat && (P_STRAT < P_iso));
         z_strat   = (use_strat) ? z_iso + (R_d*TISO/CONST_GRAV)*std::log(P_iso/P_STRAT)
                                 : z_iso;
  
         // A configured stratospheric layer that lies at or below the isothermal
         // transition cannot be represented, so say so rather than dropping it quietly.
         if (want_strat && !use_strat) {
             amrex::Print() << "WARNING: the base stratospheric layer is being ignored: P_STRAT = "
                            << P_STRAT << " Pa is not below the pressure at the base of the "
                            << "isothermal layer, P_iso = " << P_iso << " Pa.\n";
             amrex::Print() << "         TLP_STRAT = " << TLP_STRAT << " will have no effect and "
                            << "the atmosphere above z_iso will be isothermal at TISO = "
                            << TISO << " K.\n";
         }
  
         amrex::Print() << "Base state layer interfaces: z_iso = " << z_iso << " m";
         if (use_strat) amrex::Print() << ", z_strat = " << z_strat << " m";
         amrex::Print() << "\n";
  
         is_set = true;
     }