:py:mod:`exo_k.two_stream.two_stream_lmdz`
==========================================

.. py:module:: exo_k.two_stream.two_stream_lmdz

.. autoapi-nested-parse::

   Created in Jan 2021

   @author: jeremy leconte



Module Contents
---------------

.. py:function:: solve_2stream_nu_xsec(source_nu, dtau_nu, omega0_nu, g_asym_nu, flux_top_dw_nu, alb_surf_nu, mu0=0.5, flux_at_level=False)

   Deals with the spectral axis



.. py:function:: solve_2stream_nu_corrk(source_nu, dtau_nu, omega0_nu, g_asym_nu, flux_top_dw_nu, alb_surf_nu, mu0=0.5, flux_at_level=False)

   Deals with the spectral axis



.. py:function:: solve_2stream(source, dtau, omega0, g_asym, mu0=0.5, flux_top_dw=0.0, alb_surf=0.0, flux_at_level=False)

   Based on gfluxi in LMDZ code
   ##-----------------------------------------------------------------------
   ##  THIS SUBROUTINE TAKES THE OPTICAL CONSTANTS AND BOUNDARY CONDITIONS
   ##  FOR THE INFRARED FLUX AT ONE WAVELENGTH AND SOLVES FOR THE FLUXES AT
   ##  THE LEVELS.  THIS VERSION IS SET UP TO WORK WITH LAYER OPTICAL DEPTHS
   ##  MEASURED FROM THE TOP OF EACH LAYER.  THE TOP OF EACH LAYER HAS
   ##  OPTICAL DEPTH ZERO.  IN THIS SUB LEVEL N IS ABOVE LAYER N. THAT IS LAYER N
   ##  HAS LEVEL N ON TOP AND LEVEL N+1 ON BOTTOM. OPTICAL DEPTH INCREASES
   ##  FROM TOP TO BOTTOM.  SEE C.P. MCKAY, TGM NOTES.
   ##  THE TRI-DIAGONAL MATRIX SOLVER IS DSOLVER AND IS DOUBLE PRECISION SO MANY
   ##  VARIABLES ARE PASSED AS SINGLE THEN BECOME DOUBLE IN DSOLVER
   ##
   ## NLL            = NUMBER OF LEVELS (NLAYERS + 1) MUST BE LESS THAT NL (101)
   ## TLEV(L_LEVELS) = ARRAY OF TEMPERATURES AT GCM LEVELS
   ## WAVEN          = WAVELENGTH FOR THE COMPUTATION
   ## DW             = WAVENUMBER INTERVAL
   ## dtau(NLAYER)   = ARRAY OPTICAL DEPTH OF THE LAYERS
   ## omega0(NLEVEL)     = SINGLE SCATTERING ALBEDO
   ## g_asym(NLEVEL) = ASYMMETRY FACTORS, 0=ISOTROPIC
   ## mu0          = AVERAGE ANGLE, MUST BE EQUAL TO 0.5 IN IR
   ## alb_surf            = SURFACE REFLECTANCE
   ## BTOP           = UPPER BOUNDARY CONDITION ON IR INTENSITY (NOT FLUX)
   ## BSURF          = SURFACE EMISSION = (1-RSFI)*PLANCK, INTENSITY (NOT FLUX)
   ## FP(NLEVEL)     = UPWARD FLUX AT LEVELS
   ## FM(NLEVEL)     = DOWNWARD FLUX AT LEVELS
   ## FMIDP(NLAYER)  = UPWARD FLUX AT LAYER MIDPOINTS
   ## FMIDM(NLAYER)  = DOWNWARD FLUX AT LAYER MIDPOINTS
   ##-----------------------------------------------------------------------


.. py:function:: DSOLVER(NL, GAMA, CP, CM, CPM1, CMM1, E1, E2, E3, E4, BTOP, BSURF, alb_surf)

   #  GCM2.0  Feb 2003
   #
   # DOUBLE PRECISION VERSION OF SOLVER

   #*********************************************************
   #* THIS SUBROUTINE SOLVES FOR THE COEFFICIENTS OF THE    *
   #* TWO STREAM SOLUTION FOR GENERAL BOUNDARY CONDITIONS   *
   #* NO ASSUMPTION OF THE DEPENDENCE ON OPTICAL DEPTH OF   *
   #* C-PLUS OR C-MINUS HAS BEEN MADE.                      *
   #* NL     = NUMBER OF LAYERS IN THE MODEL                *
   #* CP     = C-PLUS EVALUATED AT TAO=0 (TOP)              *
   #* CM     = C-MINUS EVALUATED AT TAO=0 (TOP)             *
   #* CPM1   = C-PLUS  EVALUATED AT TAOSTAR (BOTTOM)        *
   #* CMM1   = C-MINUS EVALUATED AT TAOSTAR (BOTTOM)        *
   #* EP     = EXP(LAMDA*dtau)                              *
   #* EM     = 1/EP                                         *
   #* E1     = EP + GAMA *EM                                *
   #* E2     = EP - GAMA *EM                                *
   #* E3     = GAMA*EP + EM                                 *
   #* E4     = GAMA*EP - EM                                 *
   #* BTOP   = THE DIFFUSE RADIATION INTO THE MODEL AT TOP  *
   #* BSURF  = THE DIFFUSE RADIATION INTO THE MODEL AT      *
   #*          THE BOTTOM: INCLUDES EMMISION AND REFLECTION *
   #*          OF THE UNATTENUATED PORTION OF THE DIRECT    *
   #*          BEAM. BSTAR+alb_surf*FO*EXP(-TAOSTAR/U0)          *
   #* alb_surf    = REFLECTIVITY OF THE SURFACE                  *
   #* XK1    = COEFFICIENT OF THE POSITIVE EXP TERM         *
   #* XK2    = COEFFICIENT OF THE NEGATIVE EXP TERM         *
   #*********************************************************


.. py:function:: DTRIDGL(L, AF, BF, CF, DF)

   !  GCM2.0  Feb 2003

   !     DOUBLE PRECISION VERSION OF TRIDGL

         DIMENSION AF(L),BF(L),CF(L),DF(L),XK(L)
         DIMENSION AS(2*L),DS(2*L)

   !*    THIS SUBROUTINE SOLVES A SYSTEM OF TRIDIAGIONAL MATRIX
   !*    EQUATIONS. THE FORM OF THE EQUATIONS ARE:
   !*    A(I)*X(I-1) + B(I)*X(I) + C(I)*X(I+1) = D(I)

   !======================================================================!