! source file: /sfs/fs6/home-geomar/smomw258/UVic_ESCM/2.9/updates/02/source/mtlm/mtlm.F subroutine MTLM (is, ie, js, je) !----------------------------------------------------------------------- ! land-surface and vegetation model ! The land model is a modified form of the MOSES and TRIFFID !********************************************************************** ! this file is based on code that may have had the following copyright: ! (c) CROWN COPYRIGHT 1997, U.K. METEOROLOGICAL OFFICE. ! Permission has been granted by the authors to the public to copy ! and use this software without charge, provided that this Notice and ! any statement of authorship are reproduced on all copies. Neither the ! Crown nor the U.K. Meteorological Office makes any warranty, express ! or implied, or assumes any liability or responsibility for the use of ! this software. !********************************************************************** !----------------------------------------------------------------------- implicit none include "size.h" include "csbc.h" include "mtlm.h" include "mtlm_data.h" include "switch.h" integer ie, is, je, js, NOTCROP(NPFT) integer I, J, L, N, KITER ! Loop counters !----------------------------------------------------------------------- ! Driving variables !----------------------------------------------------------------------- ! LW_OUT_P = WORK Surface longwave (W/m**2) ! LW_OUT_S = WORK Surface longwave (W/m**2) ! PAR = WORK Photosynthetically active ! SWN_P = WORK Net shortwave for each PFT ! SWN_S = WORK Net shortwave for bare soil ! RTSB = WORK Inverse of the timestep for burning real LW_OUT_P(POINTS,NPFT), LW_OUT_S(POINTS), PAR(POINTS) real SWN_P(POINTS,NPFT), SWN_S(POINTS) real RTSB !----------------------------------------------------------------------- ! Other variables which need to be saved between calls !----------------------------------------------------------------------- ! ALBLAND_SOIL = WORK surface albedo ! ALBLAND_VEG = WORK surface albedo real ALBLAND_SOIL(POINTS), ALBLAND_VEG(POINTS,NPFT) !----------------------------------------------------------------------- ! Work Carbon variables. !----------------------------------------------------------------------- ! FTIME_PHEN = Weighting factor for accumulations. ! GC = Canopy conductance (m/s). phenology (/yr). ! LAI_BAL = Balanced growth LAI. ! LIT_C = Carbon litter (kg C/m2/yr). ! RESP_P = Plant respiration rate (kg C/m2/s). ! RESP_W = Wood maintenance respiration rate (kg C/m2/s). real FTIME_PHEN, GC(POINTS,NPFT), LAI_BAL(POINTS,NPFT) real LIT_C(POINTS,NPFT), RESP_P(POINTS,NPFT), RESP_W(POINTS,NPFT) !----------------------------------------------------------------------- ! Work Hydrology variables !----------------------------------------------------------------------- ! ESOIL = Soil evaporation (kg/m2/s). ! ETRAN = Transpiration (kg/m2/s). ! G_T = ground heat flux on veg tiles (W/m2). ! G = ground heat flux (W/m2). ! GSOIL = Bare soil ground heat flux (W/m2). ! SH_T = Sensible heat flux on veg tiles (W/m2 ! HSOIL = Bare soil sensible heat flux (W/m2). ! LESOIL = Latent heat of soil evaporation (W/m2). ! LETRAN = Latent heat of transpiration (W/m2). ! RADNET_T = Net radiation on veg tiles (W/m2). ! RADNET = Net Radiation (W/m2). ! RADNETSOIL = Bare soil net radiation (W/m2). ! STHU = Unfrozen soil moisture as a fraction of saturation. ! V_ROOT = Liquid volumetric soil moisture concentration in the ! rootzone (m3 H2O/m3 soil). real ESOIL(POINTS), ETRAN(POINTS,NPFT), G_T(POINTS,NPFT) real G(POINTS), GSOIL(POINTS), SH_T(POINTS,NPFT), HSOIL(POINTS) real LESOIL(POINTS), LETRAN(POINTS,NPFT), RADNET_T(POINTS,NPFT) real RADNET(POINTS), RADNETSOIL(POINTS), STHU(POINTS) real V_ROOT(POINTS) !----------------------------------------------------------------------- ! Other surface quantities !----------------------------------------------------------------------- ! RA = Aerodynamic resistance (s/m). ! RS = Surface resistance (s/m). ! RSSOIL = Surface resistance for bare soil (s/m). ! V_SAT = Volumetric soil moisture concentration at saturation ! (m3 H2O/m3 soil). ! V_WILT = Volumetric soil moisture concentration below which stomata ! close (m3 H2O/m3 soil). real RA(POINTS), RS(POINTS,NPFT), RSSOIL(POINTS), V_SAT(POINTS) real V_WILT(POINTS) !----------------------------------------------------------------------- ! Local parameters !----------------------------------------------------------------------- ! ITER_EQ = Number of TRIFFID iterations for gradient descent to ! equilibrium. integer ITER_EQ parameter (ITER_EQ=10) ! DENOM_MIN = Minimum value for the denominator of the update equation. ! Ensures that gradient descent does not lead to an ! unstable solution. ! GAMMA_EQ = Inverse timestep for gradient descent to equilibrium ! (/yr). ! CP = Specific heat of dry air at constant pressure (J/kg/K). ! EPSILON = Ratio of molecular weights of water and dry air. ! KARMAN = Von Karman's constant. ! TM = Melting point of fresh water (K). ! ZERODEGC = Zero Celsius (K). ! MSAT = Saturated soil moisture (kg/m2). ! RSS = Surface resistance for bare soil (s/m ! SATCON = Saturated hydraulic conductivity (kg/m2/s). ! V_CRIT = Volumetric soil moisture concentration above which ! stomata are not sensitive to soil water (m3 H2O/m3 soil). ! VSAT = Volumetric soil moisture concentration at saturation ! (m3 H2O/m3 soil). ! VWILT = Volumetric soil moisture concentration below which ! stomata close (m3 H2O/m3 soil). ! Z0_SOIL = Roughness length for bare soil (m). ! Z1_REF = Reference level height (m). ! DTIME_PHEN = Timestep for phenology (/yr). ! FORW = Forward timestep weighting. ! GAMMA = Inverse timestep (/yr). ! RHO_WATER = density of pure water (Kg/m3) ! PI = PI real DENOM_MIN ,GAMMA_EQ, CP, EPSILON, KARMAN, TM, ZERODEGC real MSAT, RSS, SATCON, V_CRIT, VSAT, VWILT, Z0_SOIL, Z1_REF real DTIME_PHEN, FORW, GAMMA, RHO_WATER, PI parameter (DENOM_MIN=1.0E-6, GAMMA_EQ=1.0E-1, CP=1005.0) parameter (EPSILON=0.62198, KARMAN=0.4, TM=273.15) parameter (ZERODEGC=273.15, RSS=100.0, SATCON=0.0005) parameter (V_CRIT=0.34, VSAT=0.458, VWILT=0.13) parameter (MSAT=1000*ROOTDEP*VSAT, Z0_SOIL=0.0003, Z1_REF=10.0) parameter (RHO_WATER = 1000.0, PI=3.14159265358979323846) !----------------------------------------------------------------------- ! Factors for accumulation variables !----------------------------------------------------------------------- FTIME = TIMESTEP/REAL(SEC_DAY*DAY_TRIF) FTIME_PHEN = TIMESTEP/REAL(SEC_DAY*DAY_PHEN) !----------------------------------------------------------------------- ! Calculate timestep values of the driving data. !----------------------------------------------------------------------- LAND_COUNTER = LAND_COUNTER + 1 ISTEP = mod(LAND_COUNTER-1,STEP_DAY) + 1 L_TRIF = .false. L_PHEN = .false. if (ISTEP .eq. STEP_DAY) then L = LAND_COUNTER/STEP_DAY if (INT_VEG .and. MOD(L,DAY_TRIF) .eq. 0.) L_TRIF=.true. if (MOD(L,DAY_PHEN) .eq. 0.) L_PHEN=.true. endif TIMEDAY = (REAL(ISTEP) - 0.5)*SEC_DAY/STEP_DAY do I=1,LAND_PTS L = LAND_INDEX(I) SAT_D(L) = T_C(L) + 0.5*DTEMP_DAY(L) & *COS(2*PI*(TIMEDAY-TIME_MAX(L))/SEC_DAY) LW(L) = SIGMA*T_C(L)**4*(4.0*SAT_D(L)/T_C(L)-3.0) SW(L) = SUN(L,ISTEP) enddo call QSAT (POINTS, LAND_PTS, LAND_INDEX, EPSILON, ZERODEGC &, QS, SAT_D, PSTAR) !CDIR NODEP do I=1,LAND_PTS L = LAND_INDEX(I) if (RH_C(L) .gt. 0.) then Q(L) = QS(L)*RH_C(L) else Q(L) = 0. endif !----------------------------------------------------------------------- ! Approximate PAR, assume atmosphere is neutral and setup vector fields. !----------------------------------------------------------------------- PAR(L) = 0.45 * SW(L) Z0S(L) = Z0_SOIL V_SAT(L) = VSAT V_WILT(L) = VWILT RA(L) = 0.0 enddo !----------------------------------------------------------------------- ! Calculate the water and carbon fluxes for each FT. !----------------------------------------------------------------------- do N=1,NPFT !----------------------------------------------------------------------- ! Calculate the soil moisture stress factor. !----------------------------------------------------------------------- V_ROOT(L) = M(L)*MAF(N)/(RHO_WATER*ROOTDEP) if (V_ROOT(L) .gt. V_CRIT) then FSMC(L) = 1.0 elseif (V_ROOT(L) .le. VWILT) then FSMC(L) = 0.0 else FSMC(L) = (V_ROOT(L) - VWILT) & /(V_CRIT - VWILT) endif !----------------------------------------------------------------------- ! Calculate available energy when the surface temperature is equal to ! the atmospheric temperature (AHAT). !----------------------------------------------------------------------- call SWRAD (POINTS, LAND_PTS, LAND_INDEX, ALBSNF(1,N) &, ALBSNC(1,N), LYING_SNOW, SW, TSTAR(1,N), TM &, SWN_P(1,N), ALBLAND_VEG(1,N)) !----------------------------------------------------------------------- ! Calculate the canopy resistance and the resistance factor. !----------------------------------------------------------------------- call SF_STOM (LAND_PTS, LAND_INDEX, N, CO2, FSMC &, HT(1,N), PAR, LAI(1,N), PSTAR, Q, RA, SAT_D &, ZERODEGC, EPCO2, EPSILON, GPP(1,N), NPP(1,N) &, RESP_P(1,N), RESP_W(1,N), GC(1,N)) !CDIR NODEP do I=1,LAND_PTS L = LAND_INDEX(I) RS(L,N) = 1.0 / GC(L,N) !----------------------------------------------------------------------- ! If snow assume no surface resistance !----------------------------------------------------------------------- if (LYING_SNOW(L) .gt. 50.0) RS(L,N) = 0.0 enddo !----------------------------------------------------------------------- ! Solve the surface energy balance. !----------------------------------------------------------------------- call PENMON (POINTS, LAND_PTS, LAND_INDEX, ROOTDEP &, HCON_SOIL, RS(1,N), Z0(1,N), LW, SWN_P(1,N) &, PSTAR, Q, SAT_D, TS1, WIND, Z1_REF, LHC, LHF &, EPSILON, SIGMA, TM, ZERODEGC, ETRAN(1,N) &, LETRAN(1,N), SH_T(1,N), G_T(1,N), RADNET_T(1,N) &, TSTAR(1,N), MNEG, LW_OUT_P(1,N), LYING_SNOW) !----------------------------------------------------------------------- ! Calculate the leaf turnover rate. !----------------------------------------------------------------------- call LEAF_LIT (LAND_PTS, LAND_INDEX, N &, FSMC, TSTAR(1,N), G_LEAF(1,N)) enddo ! FT Loop !----------------------------------------------------------------------- ! Calculate the bare soil evaporation. !----------------------------------------------------------------------- call SWRAD (POINTS, LAND_PTS, LAND_INDEX ,ALBSOIL, ALBSNOW &, LYING_SNOW, SW, TSOIL, TM, SWN_S, ALBLAND_SOIL) !CDIR NODEP !----------------------------------------------------------------------- ! Calculate the soil moisture stress factor. !----------------------------------------------------------------------- do I=1,LAND_PTS L = LAND_INDEX(I) V_ROOT(L) = M(L)*MAF(SOIL)/(RHO_WATER*ROOTDEP) if (V_ROOT(L) .gt. V_CRIT) then FSMC(L) = 1.0 elseif (V_ROOT(L) .le. VWILT) then FSMC(L) = 0.0 else FSMC(L) = (V_ROOT(L) - VWILT) & /(V_CRIT - VWILT) endif if (FSMC(L) .gt. (RSS/1.0E6)) then RSSOIL(L) = RSS/FSMC(L) else RSSOIL(L) = 1.0E6 endif !----------------------------------------------------------------------- ! If snow assume no surface resistance !----------------------------------------------------------------------- if (LYING_SNOW(L) .gt. 50.0) RSSOIL(L) = 0.0 enddo !----------------------------------------------------------------------- ! Solve the soil surface energy balance. !----------------------------------------------------------------------- call PENMON (POINTS, LAND_PTS, LAND_INDEX, ROOTDEP, HCON_SOIL &, RSSOIL, Z0S, LW, SWN_S, PSTAR, Q, SAT_D, TS1, WIND &, Z1_REF, LHC, LHF, EPSILON, SIGMA, TM, ZERODEGC &, ESOIL, LESOIL, HSOIL, GSOIL, RADNETSOIL, TSOIL &, MNEG, LW_OUT_S, LYING_SNOW) !----------------------------------------------------------------------- ! Calculate gridbox mean fluxes and surface temperature. !----------------------------------------------------------------------- !! !CDIR NODEP do I=1,LAND_PTS L = LAND_INDEX(I) ET(L) = 0.0 LE(L) = 0.0 SH(L) = 0.0 RADNET(L) = 0.0 G(L) = 0.0 TSTAR_GB(L) = 0.0 ALBLAND(L) = 0.0 LW_OUT(L) = 0.0 SWN(L) = 0.0 !! !CDIR unroll=5 do N=1,NPFT ET(L) = ET(L) + FRAC(L,N)*ETRAN(L,N) LE(L) = LE(L) + FRAC(L,N)*LETRAN(L,N) TSTAR_GB(L) = TSTAR_GB(L) + FRAC(L,N)*TSTAR(L,N) SH(L) = SH(L) + FRAC(L,N)*SH_T(L,N) G(L) = G(L) + FRAC(L,N)*G_T(L,N) RADNET(L) = RADNET(L) + FRAC(L,N)*RADNET_T(L,N) ALBLAND(L) = ALBLAND(L) + FRAC(L,N)*ALBLAND_VEG(L,N) LW_OUT(L) = LW_OUT(L) + FRAC(L,N)*LW_OUT_P(L,N) SWN(L) = SWN(L) + FRAC(L,N)*SWN_P(L,N) enddo ET(L) = ET(L) + (1 - VEG_FRAC(L))*ESOIL(L) ALBLAND(L) = ALBLAND(L) + (1 - VEG_FRAC(L))*ALBLAND_SOIL(L) LW_OUT(L) = LW_OUT(L) + (1 - VEG_FRAC(L))*LW_OUT_S(L) SWN(L) = SWN(L) + (1 - VEG_FRAC(L))*SWN_S(L) ! If snow is lying assume that evapotranspiration is zero if (LYING_SNOW(L) .gt. 50.0) then ESUB(L) = ET(L) ET(L) = 0. else ESUB(L) = 0. endif LE(L) = LE(L) + (1 - VEG_FRAC(L)) * LESOIL(L) TSTAR_GB(L) = TSTAR_GB(L) + (1 - VEG_FRAC(L)) * TSOIL(L) SH(L) = SH(L) + (1 - VEG_FRAC(L)) * HSOIL(L) G(L) = G(L) + (1 - VEG_FRAC(L)) * GSOIL(L) RADNET(L) = RADNET(L) + (1 - VEG_FRAC(L)) * RADNETSOIL(L) enddo !----------------------------------------------------------------------- ! Calculate the soil respiration !----------------------------------------------------------------------- do I=1,LAND_PTS L = LAND_INDEX(I) STHU(L) = V_ROOT(L)/VSAT enddo call MICROBE (POINTS, LAND_PTS, LAND_INDEX, CS, STHU, V_SAT &, V_WILT, TS1, RESP_S) !----------------------------------------------------------------------- ! Update phenology accumulation variable. !----------------------------------------------------------------------- !! !CDIR NODEP do I=1,LAND_PTS L = LAND_INDEX(I) !! !CDIR unroll=5 do N=1,NPFT G_LEAF_DAY(L,N) = G_LEAF_DAY(L,N) + G_LEAF(L,N)*FTIME_PHEN enddo enddo !----------------------------------------------------------------------- ! Update leaf phenological state !----------------------------------------------------------------------- if (L_PHEN) then if (DAY_PHEN .gt. 1) then DTIME_PHEN = real(DAY_PHEN)*segtim/DAY_YEAR else DTIME_PHEN = real(DAY_PHEN)/DAY_YEAR endif do N=1,NPFT call PHENOL (LAND_PTS, LAND_INDEX, N, G_LEAF_DAY(1,N) &, HT(1,N), DTIME_PHEN, G_LEAF_PHEN(1,N), LAI(1,N)) do I=1,LAND_PTS L = LAND_INDEX(I) G_LEAF_DAY(L,N) = 0.0 enddo enddo endif ! End of PHENOL call !----------------------------------------------------------------------- ! Update the land surface state !----------------------------------------------------------------------- call MTLM_STATE (POINTS, LAND_PTS, LAND_INDEX, ROOTDEP, HCAP_SOIL &, SATCON, VSAT, LHF, TM, TIMESTEP*segtim, G, RAIN &, SNOW, ET, ESUB, M, LYING_SNOW, TS1, SURF_ROFF &, SNOWMELT, MNEG) !----------------------------------------------------------------------- ! Accumulate TRIFFID driving variables !----------------------------------------------------------------------- do I=1,LAND_PTS L = LAND_INDEX(I) RESP_S_DR(L) = RESP_S_DR(L)+RESP_S(L)*FTIME*SEC_YEAR do N=1,NPFT NPP_DR(L,N) = NPP_DR(L,N) + NPP(L,N)*FTIME*SEC_YEAR G_LEAF_DR(L,N) = G_LEAF_DR(L,N) + G_LEAF_PHEN(L,N)*FTIME RESP_W_DR(L,N) = RESP_W_DR(L,N) + RESP_W(L,N)*FTIME*SEC_YEAR enddo enddo !--------------------------------------------------------------------- ! Form the mean for variables given to the atmospheric and ocean model !--------------------------------------------------------------------- do j=2,jmt-1 do i=2,imt-1 L = land_map(i,j) if (L .ne. 0) then sbc(i,j,iro) = sbc(i,j,iro) + SURF_ROFF(L)*TIMESTEP*0.1 sbc(i,j,isca) = sbc(i,j,isca) + (1. - ALBLAND(L))*TIMESTEP sbc(i,j,ievap) = sbc(i,j,ievap) & + 0.1*(ET(L) + ESUB(L))*TIMESTEP sbc(i,j,ilwr) = sbc(i,j,ilwr) - 1000.*(LW_OUT(L) - SW_C(L) & + SWN(L))*TIMESTEP sbc(i,j,isens) = sbc(i,j,isens) + 1000.*SH(L)*TIMESTEP do N=1,NPFT sbc(i,j,inpp) = sbc(i,j,inpp) & + NPP(L,N)*FRAC(L,N)*TIMESTEP enddo sbc(i,j,isr) = sbc(i,j,isr) + RESP_S(L)*TIMESTEP endif enddo enddo atlnd = atlnd + TIMESTEP !---------------------------------------------------------------------- ! Update the vegetation areal coverages, structural parameters, ! and soil carbon. !---------------------------------------------------------------------- if (L_TRIF) then if (VEG_EQUIL) then FORW = 1.0 GAMMA = GAMMA_EQ KITER = ITER_EQ else FORW = 0.0 if (DAY_TRIF .gt. 1) then GAMMA = DAY_YEAR/(segtim*real(DAY_TRIF)) else GAMMA = DAY_YEAR/real(DAY_TRIF) endif KITER = 1 endif ! diagnose the total land carbon before triffid do j=2,jmt-1 do i=2,imt-1 L = land_map(i,j) if (L .ne. 0) then sbc(i,j,iburn) = CS(L) - RESP_S_DR(L)/GAMMA do N=1,NPFT sbc(i,j,iburn) = sbc(i,j,iburn) + FRAC(L,N)*C_VEG(L,N) & + FRAC(L,N)*NPP_DR(L,N)/GAMMA enddo endif enddo enddo do I=1,KITER call TRIFFID (LAND_PTS, LAND_INDEX, FORW, GAMMA, FRAC_VS &, FRACA, FRAC_MIN, FRAC_SEED, DENOM_MIN, BF &, G_LEAF_DR, NPP_DR, RESP_S_DR, RESP_W_DR, CS &, FRAC, HT, LAI, C_VEG, CV, LIT_C, LIT_C_T) enddo LAND_COUNTER = 0. !---------------------------------------------------------------------- ! Diagnose the amount of vegetation burnt (land use change emissions) !---------------------------------------------------------------------- RTSB = 1./(DAY_TRIF*segtim*SEC_DAY) do j=2,jmt-1 do i=2,imt-1 L = land_map(i,j) if (L .ne. 0) then sbc(i,j,iburn) = sbc(i,j,iburn) - CS(L) do N=1,NPFT sbc(i,j,iburn) = sbc(i,j,iburn) - FRAC(L,N)*C_VEG(L,N) enddo sbc(i,j,iburn) = sbc(i,j,iburn)*RTSB else sbc(i,j,iburn) = 0. endif enddo enddo !---------------------------------------------------------------------- ! Zero the accumulated driving variables !---------------------------------------------------------------------- do I=1,LAND_PTS L = LAND_INDEX(I) RESP_S_DR(L) = 0.0 do N=1,NPFT NPP_DR(L,N) = 0.0 G_LEAF_DR(L,N) = 0.0 RESP_W_DR(L,N) = 0.0 enddo enddo !---------------------------------------------------------------------- ! Derive vegetation parameters from the new areal fractions and ! structural properties. !---------------------------------------------------------------------- do N=1,NPFT call PFT_SPARM (LAND_PTS, LAND_INDEX, N, ALBSOIL &, HT(1,N), LAI(1,N), ALBSNC(1,N), ALBSNF(1,N) &, CATCH(1,N), Z0(1,N)) enddo !---------------------------------------------------------------------- ! Define other vegetation parameters !---------------------------------------------------------------------- do I=1,LAND_PTS L = LAND_INDEX(I) VEG_FRAC(L) = 0.0 do N=1,NPFT VEG_FRAC(L) = VEG_FRAC(L) + FRAC(L,N) enddo FRAC_VS(L) = VEG_FRAC(L) + FRAC(L,SOIL) enddo endif !----------------------------------------------------------------------- ! accumulate time averages !----------------------------------------------------------------------- call ta_mtlm_tavg (is, ie, js, je, 1) !----------------------------------------------------------------------- ! accumulate time step integrals !----------------------------------------------------------------------- call ta_mtlm_tsi (is, ie, js, je, 1) return end