| 1 | SUBROUTINE computeice_table(ngrid,nslope,nsoil_PEM,rhowatersurf_ave,rhowatersoil_ave,ice_table) |
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| 2 | !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
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| 3 | !!! |
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| 4 | !!! Purpose: Compute the ice table depth knowing the yearly average water |
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| 5 | !!! density at the surface and at depth. |
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| 6 | !!! Computations are made following the methods in Schorgofer et al., 2005 |
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| 7 | !!! |
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| 8 | !!! Author: LL |
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| 9 | !!! |
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| 10 | !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
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| 11 | |
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| 12 | #ifndef CPP_STD |
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| 13 | USE comsoil_h_PEM, only: layer_PEM ! Depth of the vertical grid |
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| 14 | implicit none |
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| 15 | |
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| 16 | integer,intent(in) :: ngrid,nslope,nsoil_PEM ! Size of the physical grid, number of subslope, number of soil layer in the PEM |
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| 17 | real,intent(in) :: rhowatersurf_ave(ngrid,nslope) ! Water density at the surface, yearly averaged [kg/m^3] |
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| 18 | real,intent(in) :: rhowatersoil_ave(ngrid,nsoil_PEM,nslope) ! Water density at depth, computed from clapeyron law's (Murchy and Koop 2005), yearly averaged [kg/m^3] |
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| 19 | real,intent(inout) :: ice_table(ngrid,nslope) ! ice table depth [m] |
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| 20 | real :: z1,z2 ! intermediate variables used when doing a linear interpolation between two depths to find the root |
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| 21 | integer ig, islope,isoil ! loop variables |
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| 22 | real :: diff_rho(nsoil_PEM) ! difference of water vapor density between the surface and at depth [kg/m^3] |
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| 23 | |
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| 24 | |
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| 25 | do ig = 1,ngrid |
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| 26 | do islope = 1,nslope |
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| 27 | ice_table(ig,islope) = -10. |
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| 28 | |
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| 29 | do isoil = 1,nsoil_PEM |
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| 30 | diff_rho(isoil) = rhowatersurf_ave(ig,islope) - rhowatersoil_ave(ig,isoil,islope) |
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| 31 | |
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| 32 | enddo |
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| 33 | |
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| 34 | if(diff_rho(1) > 0) then ! ice is at the surface |
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| 35 | ice_table(ig,islope) = 0. |
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| 36 | else |
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| 37 | do isoil = 1,nsoil_PEM -1 ! general case, we find the ice table depth by doing a linear approximation between the two depth, and then solve the first degree equation to find the root |
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| 38 | if((diff_rho(isoil).lt.0).and.(diff_rho(isoil+1).gt.0.)) then |
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| 39 | z1 = (diff_rho(isoil) - diff_rho(isoil+1))/(layer_PEM(isoil) - layer_PEM(isoil+1)) |
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| 40 | z2 = -layer_PEM(isoil+1)*z1 + diff_rho(isoil+1) |
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| 41 | ice_table(ig,islope) = -z2/z1 |
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| 42 | exit |
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| 43 | endif |
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| 44 | enddo |
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| 45 | endif |
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| 46 | enddo |
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| 47 | enddo |
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| 48 | !======================================================================= |
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| 49 | RETURN |
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| 50 | #endif |
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| 51 | END |
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