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icepack_therm_vertical.F90
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icepack_therm_vertical.F90
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!=========================================================================
!
! Update ice and snow internal temperatures and compute
! thermodynamic growth rates and atmospheric fluxes.
!
! NOTE: The thermodynamic calculation is split in two for load balancing.
! First icepack_therm_vertical computes vertical growth rates and coupler
! fluxes. Then icepack_therm_itd does thermodynamic calculations not
! needed for coupling.
!
! authors: William H. Lipscomb, LANL
! C. M. Bitz, UW
! Elizabeth C. Hunke, LANL
!
! 2003: Vectorized by Clifford Chen (Fujitsu) and William Lipscomb
! 2004: Block structure added by William Lipscomb
! 2006: Streamlined for efficiency by Elizabeth Hunke
! Converted to free source form (F90)
module icepack_therm_vertical
use icepack_kinds
use icepack_parameters, only: c0, c1, p001, p5, puny
use icepack_parameters, only: pi, depressT, Lvap, hs_min, cp_ice, min_salin
use icepack_parameters, only: cp_ocn, rhow, rhoi, rhos, Lfresh, rhofresh, ice_ref_salinity
use icepack_parameters, only: ktherm, calc_Tsfc, rsnw_fall, rsnw_tmax
use icepack_parameters, only: ustar_min, fbot_xfer_type, formdrag, calc_strair
use icepack_parameters, only: rfracmin, rfracmax, dpscale, frzpnd, snwgrain, snwlvlfac
use icepack_parameters, only: phi_i_mushy, floeshape, floediam, use_smliq_pnd, snwredist
use icepack_parameters, only: saltflux_option
use icepack_parameters, only: icepack_chkoptargflag
use icepack_tracers, only: tr_iage, tr_FY, tr_aero, tr_pond, tr_fsd, tr_iso
use icepack_tracers, only: tr_pond_lvl, tr_pond_topo
use icepack_tracers, only: n_aero, n_iso
use icepack_therm_shared, only: ferrmax, l_brine
use icepack_therm_shared, only: calculate_tin_from_qin, Tmin
use icepack_therm_shared, only: hi_min
use icepack_therm_shared, only: adjust_enthalpy
use icepack_therm_bl99, only: temperature_changes
use icepack_therm_mushy, only: temperature_changes_salinity
use icepack_warnings, only: warnstr, icepack_warnings_add
use icepack_warnings, only: icepack_warnings_setabort, icepack_warnings_aborted
use icepack_mushy_physics, only: icepack_mushy_temperature_mush
use icepack_mushy_physics, only: liquidus_temperature_mush
use icepack_mushy_physics, only: enthalpy_mush, enthalpy_of_melting
use icepack_aerosol, only: update_aerosol
use icepack_isotope, only: update_isotope
use icepack_atmo, only: neutral_drag_coeffs, icepack_atm_boundary
use icepack_age, only: increment_age
use icepack_firstyear, only: update_FYarea
use icepack_flux, only: set_sfcflux, merge_fluxes
use icepack_meltpond_lvl, only: compute_ponds_lvl
use icepack_meltpond_topo, only: compute_ponds_topo
use icepack_snow, only: drain_snow
implicit none
private
public :: icepack_step_therm1
!=======================================================================
contains
!=======================================================================
!
! Driver for updating ice and snow internal temperatures and
! computing thermodynamic growth rates and atmospheric fluxes.
!
! authors: William H. Lipscomb, LANL
! C. M. Bitz, UW
subroutine thermo_vertical (nilyr, nslyr, &
dt, aicen, &
vicen, vsnon, &
Tsf, zSin, &
zqin, zqsn, &
apond, hpond, &
flw, potT, &
Qa, rhoa, &
fsnow, fpond, &
fbot, Tbot, &
Tsnice, sss, &
rsnw, &
lhcoef, shcoef, &
fswsfc, fswint, &
Sswabs, Iswabs, &
fsurfn, fcondtopn, &
fcondbotn, &
fsensn, flatn, &
flwoutn, evapn, &
evapsn, evapin, &
freshn, fsaltn, &
fhocnn, frain, &
meltt, melts, &
meltb, meltsliq, &
smice, massice, &
smliq, massliq, &
congel, snoice, &
mlt_onset, frz_onset, &
yday, dsnow, &
prescribed_ice)
integer (kind=int_kind), intent(in) :: &
nilyr , & ! number of ice layers
nslyr ! number of snow layers
real (kind=dbl_kind), intent(in) :: &
dt , & ! time step
frain ! rainfall rate (kg/m2/s)
! ice state variables
real (kind=dbl_kind), intent(inout) :: &
aicen , & ! concentration of ice
vicen , & ! volume per unit area of ice (m)
vsnon ! volume per unit area of snow (m)
! tracers
real (kind=dbl_kind), intent(inout) :: &
Tsf , & ! ice/snow top surface temp, same as Tsfcn (deg C)
apond , & ! melt pond area fraction
hpond ! melt pond depth (m)
! iage ! ice age (s)
logical (kind=log_kind), intent(in), optional :: &
prescribed_ice ! if .true., use prescribed ice instead of computed
real (kind=dbl_kind), dimension (:), intent(inout) :: &
zqsn , & ! snow layer enthalpy, zqsn < 0 (J m-3)
zqin , & ! ice layer enthalpy, zqin < 0 (J m-3)
zSin , & ! internal ice layer salinities
rsnw , & ! snow grain radius (10^-6 m)
smice , & ! ice mass tracer in snow (kg/m^3)
smliq ! liquid water mass tracer in snow (kg/m^3)
real (kind=dbl_kind), dimension (:), intent(out) :: &
massice , & ! ice mass in snow (kg/m^2)
massliq ! liquid water mass in snow (kg/m^2)
! input from atmosphere
real (kind=dbl_kind), intent(in) :: &
flw , & ! incoming longwave radiation (W/m^2)
potT , & ! air potential temperature (K)
Qa , & ! specific humidity (kg/kg)
rhoa , & ! air density (kg/m^3)
fsnow , & ! snowfall rate (kg m-2 s-1)
shcoef , & ! transfer coefficient for sensible heat
lhcoef ! transfer coefficient for latent heat
real (kind=dbl_kind), intent(inout) :: &
fswsfc , & ! SW absorbed at ice/snow surface (W m-2)
fswint , & ! SW absorbed in ice interior, below surface (W m-2)
fpond ! fresh water flux to ponds (kg/m^2/s)
real (kind=dbl_kind), dimension (:), intent(inout) :: &
Sswabs , & ! SW radiation absorbed in snow layers (W m-2)
Iswabs ! SW radiation absorbed in ice layers (W m-2)
! input from ocean
real (kind=dbl_kind), intent(in) :: &
fbot , & ! ice-ocean heat flux at bottom surface (W/m^2)
Tbot , & ! ice bottom surface temperature (deg C)
sss ! ocean salinity
! coupler fluxes to atmosphere
real (kind=dbl_kind), intent(out):: &
flwoutn , & ! outgoing longwave radiation (W/m^2)
evapn , & ! evaporative water flux (kg/m^2/s)
evapsn , & ! evaporative water flux over snow (kg/m^2/s)
evapin ! evaporative water flux over ice (kg/m^2/s)
! Note: these are intent out if calc_Tsfc = T, otherwise intent in
real (kind=dbl_kind), intent(inout):: &
fsensn , & ! sensible heat flux (W/m^2)
flatn , & ! latent heat flux (W/m^2)
fsurfn , & ! net flux to top surface, excluding fcondtopn
fcondtopn, & ! downward cond flux at top surface (W m-2)
fcondbotn ! downward cond flux at bottom surface (W m-2)
! coupler fluxes to ocean
real (kind=dbl_kind), intent(out):: &
freshn , & ! fresh water flux to ocean (kg/m^2/s)
fsaltn , & ! salt flux to ocean (kg/m^2/s)
fhocnn ! net heat flux to ocean (W/m^2)
! diagnostic fields
real (kind=dbl_kind), intent(inout):: &
Tsnice , & ! snow ice interface temperature (deg C)
meltt , & ! top ice melt (m/step-->cm/day)
melts , & ! snow melt (m/step-->cm/day)
meltsliq , & ! snow melt mass (kg/m^2/step-->kg/m^2/day)
meltb , & ! basal ice melt (m/step-->cm/day)
congel , & ! basal ice growth (m/step-->cm/day)
snoice , & ! snow-ice formation (m/step-->cm/day)
dsnow , & ! change in snow thickness (m/step-->cm/day)
mlt_onset, & ! day of year that sfc melting begins
frz_onset ! day of year that freezing begins (congel or frazil)
real (kind=dbl_kind), intent(in) :: &
yday ! day of year
! local variables
integer (kind=int_kind) :: &
k ! ice layer index
real (kind=dbl_kind) :: &
dhi , & ! change in ice thickness
dhs ! change in snow thickness
! 2D state variables (thickness, temperature)
real (kind=dbl_kind) :: &
hilyr , & ! ice layer thickness
hslyr , & ! snow layer thickness
hin , & ! ice thickness (m)
hsn , & ! snow thickness (m)
hsn_new , & ! thickness of new snow (m)
worki , & ! local work array
works ! local work array
real (kind=dbl_kind), dimension (nilyr) :: &
zTin ! internal ice layer temperatures
real (kind=dbl_kind), dimension (nslyr) :: &
zTsn ! internal snow layer temperatures
! other 2D flux and energy variables
real (kind=dbl_kind) :: &
einit , & ! initial energy of melting (J m-2)
efinal , & ! final energy of melting (J m-2)
einter ! intermediate energy
real (kind=dbl_kind) :: &
fadvocn, saltvol, dfsalt ! advective heat flux to ocean
character(len=*),parameter :: subname='(thermo_vertical)'
!-----------------------------------------------------------------
! Initialize
!-----------------------------------------------------------------
flwoutn = c0
evapn = c0
evapsn = c0
evapin = c0
freshn = c0
fsaltn = c0
fhocnn = c0
fadvocn = c0
meltt = c0
meltb = c0
melts = c0
congel = c0
snoice = c0
dsnow = c0
zTsn(:) = c0
zTin(:) = c0
meltsliq= c0
massice(:) = c0
massliq(:) = c0
if (calc_Tsfc) then
fsensn = c0
flatn = c0
fsurfn = c0
fcondtopn = c0
endif
!-----------------------------------------------------------------
! Compute variables needed for vertical thermo calculation
!-----------------------------------------------------------------
call init_vertical_profile (nilyr, nslyr, &
aicen, &
vicen, vsnon, &
hin, hilyr, &
hsn, hslyr, &
zqin, zTin, &
zqsn, zTsn, &
zSin, &
einit )
if (icepack_warnings_aborted(subname)) return
! Save initial ice and snow thickness (for fresh and fsalt)
worki = hin
works = hsn
! Save initial salt volume for prognostic flux
if (saltflux_option == 'prognostic') then
saltvol = c0
do k=1,nilyr
saltvol = saltvol + rhoi*zSin(k)*hin*p001 / real(nilyr,kind=dbl_kind)
enddo
endif
!-----------------------------------------------------------------
! Compute new surface temperature and internal ice and snow
! temperatures.
!-----------------------------------------------------------------
if (ktherm == 2) then
call temperature_changes_salinity(dt, &
nilyr, nslyr, &
rhoa, flw, &
potT, Qa, &
shcoef, lhcoef, &
fswsfc, fswint, &
Sswabs, Iswabs, &
hilyr, hslyr, &
apond, hpond, &
zqin, zTin, &
zqsn, zTsn, &
zSin, &
Tsf, Tbot, &
sss, &
fsensn, flatn, &
flwoutn, fsurfn, &
fcondtopn, fcondbotn, &
fadvocn, snoice, &
smice, smliq)
if (icepack_warnings_aborted(subname)) return
else ! ktherm
call temperature_changes(dt, &
nilyr, nslyr, &
rhoa, flw, &
potT, Qa, &
shcoef, lhcoef, &
fswsfc, fswint, &
Sswabs, Iswabs, &
hilyr, hslyr, &
zqin, zTin, &
zqsn, zTsn, &
zSin, &
Tsf, Tbot, &
fsensn, flatn, &
flwoutn, fsurfn, &
fcondtopn, fcondbotn, &
einit )
if (icepack_warnings_aborted(subname)) return
endif ! ktherm
! mass of ice and liquid water in snow
if (snwgrain) then
massice(:) = smice(:) * hslyr
massliq(:) = smliq(:) * hslyr
endif
! intermediate energy for error check
einter = c0
do k = 1, nslyr
einter = einter + hslyr * zqsn(k)
enddo ! k
do k = 1, nilyr
einter = einter + hilyr * zqin(k)
enddo ! k
Tsnice = c0
if ((hslyr+hilyr) > puny) then
if (hslyr > puny) then
Tsnice = (hslyr*zTsn(nslyr) + hilyr*zTin(1)) / (hslyr+hilyr)
else
Tsnice = Tsf
endif
endif
if (icepack_warnings_aborted(subname)) return
!-----------------------------------------------------------------
! Compute growth and/or melting at the top and bottom surfaces.
! Add new snowfall.
! Repartition ice into equal-thickness layers, conserving energy.
!-----------------------------------------------------------------
call thickness_changes(nilyr, nslyr, &
dt, yday, &
efinal, &
hin, hilyr, &
hsn, hslyr, &
zqin, zqsn, &
smice, massice, &
smliq, massliq, &
fbot, Tbot, &
flatn, fsurfn, &
fcondtopn, fcondbotn, &
fsnow, hsn_new, &
fhocnn, evapn, &
evapsn, evapin, &
meltt, melts, &
meltsliq, frain, &
meltb, &
congel, snoice, &
mlt_onset, frz_onset, &
zSin, sss, &
dsnow, rsnw)
if (icepack_warnings_aborted(subname)) return
!-----------------------------------------------------------------
! Check for energy conservation by comparing the change in energy
! to the net energy input
!-----------------------------------------------------------------
call conservation_check_vthermo(dt, &
fsurfn, flatn, &
fhocnn, fswint, &
fsnow, einit, &
einter, efinal, &
fcondtopn, fcondbotn, &
fadvocn, fbot )
if (icepack_warnings_aborted(subname)) return
!-----------------------------------------------------------------
! If prescribed ice, set hi back to old values
!-----------------------------------------------------------------
#ifdef CESMCOUPLED
if (present(prescribed_ice)) then
if (prescribed_ice) then
hin = worki
fhocnn = c0 ! for diagnostics
endif
endif
#endif
!-----------------------------------------------------------------
! Compute fluxes of water and salt from ice to ocean.
! evapn < 0 => sublimation, evapn > 0 => condensation
! aerosol flux is accounted for in icepack_aerosol.F90
!-----------------------------------------------------------------
dhi = hin - worki
dhs = hsn - works - hsn_new
freshn = freshn + evapn - (rhoi*dhi + rhos*dhs) / dt
if (saltflux_option == 'prognostic') then
dfsalt = c0
do k=1,nilyr
dfsalt = dfsalt + rhoi*zSin(k)*hin*p001 / real(nilyr,kind=dbl_kind)
enddo
fsaltn = fsaltn - (dfsalt - saltvol) / dt
else
fsaltn = fsaltn - rhoi*dhi*ice_ref_salinity*p001/dt
endif
fhocnn = fhocnn + fadvocn ! for ktherm=2
if (hin == c0) then
if (tr_pond_topo) fpond = fpond - aicen * apond * hpond
endif
!-----------------------------------------------------------------
! Given the vertical thermo state variables, compute the new ice
! state variables.
!-----------------------------------------------------------------
call update_state_vthermo(nilyr, nslyr, &
Tbot, Tsf, &
hin, hsn, &
zqin, zSin, &
zqsn, &
aicen, &
vicen, vsnon)
if (icepack_warnings_aborted(subname)) return
end subroutine thermo_vertical
!=======================================================================
!
! Compute heat flux to bottom surface.
! Compute fraction of ice that melts laterally.
!
! authors C. M. Bitz, UW
! William H. Lipscomb, LANL
! Elizabeth C. Hunke, LANL
subroutine frzmlt_bottom_lateral (dt, ncat, &
nilyr, nslyr, &
aice, frzmlt, &
vicen, vsnon, &
qicen, qsnon, &
sst, Tf, &
ustar_min, &
fbot_xfer_type, &
strocnxT, strocnyT, &
Tbot, fbot, &
rside, Cdn_ocn, &
fside, wlat)
integer (kind=int_kind), intent(in) :: &
ncat , & ! number of thickness categories
nilyr , & ! number of ice layers
nslyr ! number of snow layers
real (kind=dbl_kind), intent(in) :: &
dt ! time step
real (kind=dbl_kind), intent(in) :: &
aice , & ! ice concentration
frzmlt , & ! freezing/melting potential (W/m^2)
sst , & ! sea surface temperature (C)
Tf , & ! freezing temperature (C)
ustar_min,& ! minimum friction velocity for ice-ocean heat flux
Cdn_ocn , & ! ocean-ice neutral drag coefficient
strocnxT, & ! ice-ocean stress, x-direction
strocnyT ! ice-ocean stress, y-direction
character (char_len), intent(in) :: &
fbot_xfer_type ! transfer coefficient type for ice-ocean heat flux
real (kind=dbl_kind), dimension(:), intent(in) :: &
vicen , & ! ice volume (m)
vsnon ! snow volume (m)
real (kind=dbl_kind), dimension(:,:), intent(in) :: &
qicen , & ! ice layer enthalpy (J m-3)
qsnon ! snow layer enthalpy (J m-3)
real (kind=dbl_kind), intent(out) :: &
Tbot , & ! ice bottom surface temperature (deg C)
fbot , & ! heat flux to ice bottom (W/m^2)
rside , & ! fraction of ice that melts laterally
fside ! lateral heat flux (W/m^2)
real (kind=dbl_kind), intent(out), optional :: &
wlat ! lateral melt rate (m/s)
! local variables
integer (kind=int_kind) :: &
n , & ! thickness category index
k ! layer index
real (kind=dbl_kind) :: &
etot , & ! total energy in column
wlat_loc, & ! lateral melt rate (m/s)
qavg ! average enthalpy in column (approximate)
real (kind=dbl_kind) :: &
deltaT , & ! SST - Tbot >= 0
ustar , & ! skin friction velocity for fbot (m/s)
xtmp ! temporary variable
! Parameters for bottom melting
real (kind=dbl_kind) :: &
cpchr ! -cp_ocn*rhow*exchange coefficient
! Parameters for lateral melting
real (kind=dbl_kind), parameter :: &
m1 = 1.6e-6_dbl_kind , & ! constant from Maykut & Perovich
! (m/s/deg^(-m2))
m2 = 1.36_dbl_kind ! constant from Maykut & Perovich
! (unitless)
character(len=*),parameter :: subname='(frzmlt_bottom_lateral)'
!-----------------------------------------------------------------
! Identify grid cells where ice can melt.
!-----------------------------------------------------------------
rside = c0
fside = c0
Tbot = Tf
fbot = c0
wlat_loc = c0
if (aice > puny .and. frzmlt < c0) then ! ice can melt
!-----------------------------------------------------------------
! Use boundary layer theory for fbot.
! See Maykut and McPhee (1995): JGR, 100, 24,691-24,703.
!-----------------------------------------------------------------
deltaT = max((sst-Tbot),c0)
! strocnx has units N/m^2 so strocnx/rho has units m^2/s^2
ustar = sqrt (sqrt(strocnxT**2+strocnyT**2)/rhow)
ustar = max (ustar,ustar_min)
if (trim(fbot_xfer_type) == 'Cdn_ocn') then
! Note: Cdn_ocn has already been used for calculating ustar
! (formdrag only) --- David Schroeder (CPOM)
cpchr = -cp_ocn*rhow*Cdn_ocn
else ! fbot_xfer_type == 'constant'
! 0.006 = unitless param for basal heat flx ala McPhee and Maykut
cpchr = -cp_ocn*rhow*0.006_dbl_kind
endif
fbot = cpchr * deltaT * ustar ! < 0
fbot = max (fbot, frzmlt) ! frzmlt < fbot < 0
!!! uncomment to use all frzmlt for standalone runs
! fbot = min (c0, frzmlt)
!-----------------------------------------------------------------
! Compute rside. See these references:
! Maykut and Perovich (1987): JGR, 92, 7032-7044
! Steele (1992): JGR, 97, 17,729-17,738
!-----------------------------------------------------------------
wlat_loc = m1 * deltaT**m2 ! Maykut & Perovich
rside = wlat_loc*dt*pi/(floeshape*floediam) ! Steele
rside = max(c0,min(rside,c1))
!-----------------------------------------------------------------
! Compute heat flux associated with this value of rside.
!-----------------------------------------------------------------
do n = 1, ncat
etot = c0
! melting energy/unit area in each column, etot < 0
do k = 1, nslyr
etot = etot + qsnon(k,n) * vsnon(n)/real(nslyr,kind=dbl_kind)
enddo
do k = 1, nilyr
etot = etot + qicen(k,n) * vicen(n)/real(nilyr,kind=dbl_kind)
enddo ! nilyr
! lateral heat flux, fside < 0
fside = fside + rside*etot/dt
enddo ! n
!-----------------------------------------------------------------
! Limit bottom and lateral heat fluxes if necessary.
! FYI: fside is not yet correct for fsd, may need to adjust fbot further
!-----------------------------------------------------------------
xtmp = frzmlt/(fbot + fside + puny)
xtmp = min(xtmp, c1)
fbot = fbot * xtmp
rside = rside * xtmp
fside = fside * xtmp
endif
if (present(wlat)) wlat=wlat_loc
end subroutine frzmlt_bottom_lateral
!=======================================================================
!
! Given the state variables (vicen, vsnon, zqin, etc.),
! compute variables needed for the vertical thermodynamics
! (hin, hsn, zTin, etc.)
!
! authors William H. Lipscomb, LANL
! C. M. Bitz, UW
subroutine init_vertical_profile(nilyr, nslyr, &
aicen, vicen, &
vsnon, &
hin, hilyr, &
hsn, hslyr, &
zqin, zTin, &
zqsn, zTsn, &
zSin, &
einit )
integer (kind=int_kind), intent(in) :: &
nilyr , & ! number of ice layers
nslyr ! number of snow layers
real (kind=dbl_kind), intent(in) :: &
aicen , & ! concentration of ice
vicen , & ! volume per unit area of ice (m)
vsnon ! volume per unit area of snow (m)
real (kind=dbl_kind), intent(out):: &
hilyr , & ! ice layer thickness
hslyr , & ! snow layer thickness
einit ! initial energy of melting (J m-2)
real (kind=dbl_kind), intent(out):: &
hin , & ! ice thickness (m)
hsn ! snow thickness (m)
real (kind=dbl_kind), dimension (:), intent(inout) :: &
zqin , & ! ice layer enthalpy (J m-3)
zTin ! internal ice layer temperatures
real (kind=dbl_kind), dimension (:), intent(in) :: &
zSin ! internal ice layer salinities
real (kind=dbl_kind), dimension (:), intent(inout) :: &
zqsn , & ! snow enthalpy
zTsn ! snow temperature
! local variables
real (kind=dbl_kind), dimension(nilyr) :: &
Tmlts ! melting temperature
integer (kind=int_kind) :: &
k ! ice layer index
real (kind=dbl_kind) :: &
rnslyr, & ! real(nslyr)
Tmax ! maximum allowed snow/ice temperature (deg C)
logical (kind=log_kind) :: & ! for vector-friendly error checks
tsno_high , & ! flag for zTsn > Tmax
tice_high , & ! flag for zTin > Tmlt
tsno_low , & ! flag for zTsn < Tmin
tice_low ! flag for zTin < Tmin
character(len=*),parameter :: subname='(init_vertical_profile)'
!-----------------------------------------------------------------
! Initialize
!-----------------------------------------------------------------
rnslyr = real(nslyr,kind=dbl_kind)
tsno_high = .false.
tice_high = .false.
tsno_low = .false.
tice_low = .false.
einit = c0
!-----------------------------------------------------------------
! Surface temperature, ice and snow thickness
! Initialize internal energy
!-----------------------------------------------------------------
hin = vicen / aicen
hsn = vsnon / aicen
hilyr = hin / real(nilyr,kind=dbl_kind)
hslyr = hsn / rnslyr
!-----------------------------------------------------------------
! Snow enthalpy and maximum allowed snow temperature
!-----------------------------------------------------------------
do k = 1, nslyr
!-----------------------------------------------------------------
! Tmax based on the idea that dT ~ dq / (rhos*cp_ice)
! dq ~ q dv / v
! dv ~ puny = eps11
! where 'd' denotes an error due to roundoff.
!-----------------------------------------------------------------
if (hslyr > hs_min/rnslyr) then
! zqsn < 0
Tmax = -zqsn(k)*puny*rnslyr / &
(rhos*cp_ice*vsnon)
else
zqsn (k) = -rhos * Lfresh
Tmax = puny
endif
!-----------------------------------------------------------------
! Compute snow temperatures from enthalpies.
! Note: zqsn <= -rhos*Lfresh, so zTsn <= 0.
!-----------------------------------------------------------------
zTsn(k) = (Lfresh + zqsn(k)/rhos)/cp_ice
!-----------------------------------------------------------------
! Check for zTsn > Tmax (allowing for roundoff error) and zTsn < Tmin.
!-----------------------------------------------------------------
if (zTsn(k) > Tmax) then
tsno_high = .true.
elseif (zTsn(k) < Tmin) then
tsno_low = .true.
endif
enddo ! nslyr
!-----------------------------------------------------------------
! If zTsn is out of bounds, print diagnostics and exit.
!-----------------------------------------------------------------
if (tsno_high) then
do k = 1, nslyr
if (hslyr > hs_min/rnslyr) then
Tmax = -zqsn(k)*puny*rnslyr / &
(rhos*cp_ice*vsnon)
else
Tmax = puny
endif
if (zTsn(k) > Tmax) then
write(warnstr,*) ' '
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Starting thermo, zTsn > Tmax'
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zTsn=',zTsn(k)
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Tmax=',Tmax
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zqsn',zqsn(k),-Lfresh*rhos,zqsn(k)+Lfresh*rhos
call icepack_warnings_add(warnstr)
call icepack_warnings_setabort(.true.,__FILE__,__LINE__)
call icepack_warnings_add(subname//" init_vertical_profile: Starting thermo, zTsn > Tmax" )
return
endif
enddo ! nslyr
endif ! tsno_high
if (tsno_low) then
do k = 1, nslyr
if (zTsn(k) < Tmin) then ! allowing for roundoff error
write(warnstr,*) ' '
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Starting thermo, zTsn < Tmin'
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zTsn=', zTsn(k)
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Tmin=', Tmin
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zqsn', zqsn(k)
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, hin
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, hsn
call icepack_warnings_add(warnstr)
call icepack_warnings_setabort(.true.,__FILE__,__LINE__)
call icepack_warnings_add(subname//" init_vertical_profile: Starting thermo, zTsn < Tmin" )
return
endif
enddo ! nslyr
endif ! tsno_low
do k = 1, nslyr
if (zTsn(k) > c0) then ! correct roundoff error
zTsn(k) = c0
zqsn(k) = -rhos*Lfresh
endif
!-----------------------------------------------------------------
! initial energy per unit area of ice/snow, relative to 0 C
!-----------------------------------------------------------------
einit = einit + hslyr*zqsn(k)
enddo ! nslyr
do k = 1, nilyr
!---------------------------------------------------------------------
! Use initial salinity profile for thin ice
!---------------------------------------------------------------------
if (ktherm == 1 .and. zSin(k) < min_salin-puny) then
write(warnstr,*) ' '
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Starting zSin < min_salin, layer', k
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zSin =', zSin(k)
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'min_salin =', min_salin
call icepack_warnings_add(warnstr)
call icepack_warnings_setabort(.true.,__FILE__,__LINE__)
call icepack_warnings_add(subname//" init_vertical_profile: Starting zSin < min_salin, layer" )
return
endif
if (ktherm == 2) then
Tmlts(k) = liquidus_temperature_mush(zSin(k))
else
Tmlts(k) = -zSin(k) * depressT
endif
!-----------------------------------------------------------------
! Compute ice temperatures from enthalpies using quadratic formula
!-----------------------------------------------------------------
if (ktherm == 2) then
zTin(k) = icepack_mushy_temperature_mush(zqin(k),zSin(k))
else
zTin(k) = calculate_Tin_from_qin(zqin(k),Tmlts(k))
endif
if (l_brine) then
Tmax = Tmlts(k)
else ! fresh ice
Tmax = -zqin(k)*puny/(rhos*cp_ice*vicen)
endif
!-----------------------------------------------------------------
! Check for zTin > Tmax and zTin < Tmin
!-----------------------------------------------------------------
if (zTin(k) > Tmax) then
tice_high = .true.
elseif (zTin(k) < Tmin) then
tice_low = .true.
endif
!-----------------------------------------------------------------
! If zTin is out of bounds, print diagnostics and exit.
!-----------------------------------------------------------------
if (tice_high) then
write(warnstr,*) ' '
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Starting thermo, zTin > Tmax, layer', k
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'k:', k
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zTin =',zTin(k),', Tmax=',Tmax
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zSin =',zSin(k)
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'hin =',hin
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zqin =',zqin(k)
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'qmlt=',enthalpy_of_melting(zSin(k))
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Tmlt=',Tmlts(k)
call icepack_warnings_add(warnstr)
if (ktherm == 2) then
zqin(k) = enthalpy_of_melting(zSin(k)) - c1
zTin(k) = icepack_mushy_temperature_mush(zqin(k),zSin(k))
write(warnstr,*) subname, 'Corrected quantities'
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zqin=',zqin(k)
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zTin=',zTin(k)
call icepack_warnings_add(warnstr)
else
call icepack_warnings_setabort(.true.,__FILE__,__LINE__)
call icepack_warnings_add(subname//" init_vertical_profile: Starting thermo, zTin > Tmax, layer" )
return
endif
endif ! tice_high
if (tice_low) then
write(warnstr,*) ' '
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Starting thermo T < Tmin, layer', k
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'zTin =', zTin(k)
call icepack_warnings_add(warnstr)
write(warnstr,*) subname, 'Tmin =', Tmin
call icepack_warnings_add(warnstr)
call icepack_warnings_setabort(.true.,__FILE__,__LINE__)
call icepack_warnings_add(subname//" init_vertical_profile: Starting thermo, zTin < Tmin, layer" )
return
endif ! tice_low
!-----------------------------------------------------------------
! correct roundoff error
!-----------------------------------------------------------------
if (ktherm /= 2) then
if (zTin(k) > c0) then
zTin(k) = c0
zqin(k) = -rhoi*Lfresh
endif
endif
! echmod: is this necessary?
! if (ktherm == 1) then
! if (zTin(k)>= -zSin(k)*depressT) then
! zTin(k) = -zSin(k)*depressT - puny
! zqin(k) = -rhoi*cp_ocn*zSin(k)*depressT
! endif
! endif
!-----------------------------------------------------------------
! initial energy per unit area of ice/snow, relative to 0 C
!-----------------------------------------------------------------
einit = einit + hilyr*zqin(k)
enddo ! nilyr
end subroutine init_vertical_profile
!=======================================================================
!
! Compute growth and/or melting at the top and bottom surfaces.
! Convert snow to ice if necessary.
!
! authors William H. Lipscomb, LANL
! C. M. Bitz, UW