.. include:: ../defs.hrst .. _sub_phys_pkgs_darwin_sediments: Sediments ^^^^^^^^^ The iron sediment source is discussed in :numref:`ssub_phys_pkgs_darwin_iron_sedimentation`. Two versions of the RADI metamodel for sediments are supported: Defining :varlink:`DARWIN_ALLOW_RADIv1` in DARWIN_OPTIONS.h activates version 1 :cite:`sulpis:22`; Version 2 :cite:`van_der_zant:2026` is activated by :varlink:`DARWIN_ALLOW_RADIv2`. Both require :varlink:`DARWIN_BOTTOM_SINK` to be defined. RADI v1 ''''''' Sediment fluxes are based on modeled sinking fluxes of POC and PIC into the bottom, see :eq:`eq_darwin_sink`. DIC, alkalinity and oxygen fluxes can be out of the sediment (positive) or burial into the sediment (negative): .. math:: F^{\mathrm{sed}}_{\mathrm{DIC}} = \left( a_1 \Omega_{\mathrm{C}} c + b_1 F^{\mathrm{sink}}_{\mathrm{POC}} + c_1 F^{\mathrm{sink}}_{\mathrm{PIC}} + d_1 c \right) f^{\mathrm{Tcorr}}_{\mathrm{DIC}} .. math:: F^{\mathrm{sed}}_{\mathrm{ALK}} = \left( a_2 \Omega_{\mathrm{C}} c + b_2 F^{\mathrm{sink}}_{\mathrm{POC}} + c_2 F^{\mathrm{sink}}_{\mathrm{PIC}} + d_2 c \right) f^{\mathrm{Tcorr}}_{\mathrm{ALK}} .. math:: F^{\mathrm{sed}}_{\mathrm{O2}} = \left( a_3 \Omega_{\mathrm{C}} c + b_3 F^{\mathrm{sink}}_{\mathrm{POC}} + c_3 F^{\mathrm{sink}}_{\mathrm{PIC}} + d_3 c \right) f^{\mathrm{Tcorr}}_{\mathrm{O2}} POC and Calcite fluxes are burial-only (always negative): .. math:: F^{\mathrm{sed}}_{\mathrm{POC}} = \min\left(0, - \left( a_4 \Omega_{\mathrm{C}} c + b_4 F^{\mathrm{sink}}_{\mathrm{POC}} + c_4 F^{\mathrm{sink}}_{\mathrm{PIC}} + d_4 c \right) \right) .. math:: F^{\mathrm{sed}}_{\mathrm{Clc}} = \min\left(0, - \left( a_5 \Omega_{\mathrm{C}} c + b_5 F^{\mathrm{sink}}_{\mathrm{POC}} + c_5 F^{\mathrm{sink}}_{\mathrm{PIC}} + d_5 c \right) \right) DIC, ALK and O2 fluxes are enhanced at higher temperatures: .. math:: f^{\mathrm{Tcorr}}_{\mathrm{O2}} &= \frac{0.031558 + 0.001428\cdot|T|}{0.0335572} f^{\mathrm{Tcorr}}_{\mathrm{DIC}} &= \frac{0.015179 + 0.000795\cdot|T|}{0.016292} f^{\mathrm{Tcorr}}_{\mathrm{ALK}} &= \frac{0.015179 + 0.000795\cdot|T|}{0.016292} These are normalized to 1 at :math:`|T|=1.4`. .. rst-class:: right-align-secondright-col .. csv-table:: RADI sediment metamodel version 1 parameters :delim: & :widths: auto :header: Name, Symbol, Default, Units :name: phys_pkg_darwin_radiv1_parameters :varlink:`sed_a1` & :math:`a_1` & --0.101 & :varlink:`sed_b1` & :math:`b_1` & 1.040 & :varlink:`sed_c1` & :math:`c_1` & 0.128 & :varlink:`sed_d1` & :math:`d_1` & 0.125 & :varlink:`sed_a2` & :math:`a_2` & --0.225 & :varlink:`sed_b2` & :math:`b_2` & 0.581 & :varlink:`sed_c2` & :math:`c_2` & 0.273 & :varlink:`sed_d2` & :math:`d_2` & 0.211 & :varlink:`sed_a3` & :math:`a_3` & --0.018 & :varlink:`sed_b3` & :math:`b_3` & --0.800 & :varlink:`sed_c3` & :math:`c_3` & 0.011 & :varlink:`sed_d3` & :math:`d_3` & --0.033 & :varlink:`sed_a4` & :math:`a_4` & 0.000 & :varlink:`sed_b4` & :math:`b_4` & 0.027 & :varlink:`sed_c4` & :math:`c_4` & 0.012 & :varlink:`sed_d4` & :math:`d_4` & --0.001 & :varlink:`sed_a5` & :math:`a_5` & 0.117 & :varlink:`sed_b5` & :math:`b_5` & --0.251 & :varlink:`sed_c5` & :math:`c_5` & 0.852 & :varlink:`sed_d5` & :math:`d_5` & --0.127 & :varlink:`sed_c` & :math:`c` & 3.17E-5 & mmol m\ :sup:`-2` s\ :sup:`-1` RADI v2 ''''''' Sediment fluxes into the water column (if positive) or burial into the sediment (if negative) are parametrized in terms of modeled sinking fluxes into the bottom, see :eq:`eq_darwin_sink`, .. math:: F^{\mathrm{sed}}_{\mathrm{DIC}} &= a_1 + b_1 |T| + c_1 \Omega_{\mathrm{C}} + d_1 \left( F^{\mathrm{sink}}_{\mathrm{POC}} + F^{\mathrm{sink}}_{\mathrm{plank,C}} \right) + e_1 F^{\mathrm{sink}}_{\mathrm{PIC}} F^{\mathrm{sed}}_{\mathrm{ALK}} &= a_2 + b_2 |T| + c_2 \Omega_{\mathrm{C}} + d_2 \left( F^{\mathrm{sink}}_{\mathrm{POC}} + F^{\mathrm{sink}}_{\mathrm{plank,C}} \right) + e_2 F^{\mathrm{sink}}_{\mathrm{PIC}} F^{\mathrm{sed}}_{\mathrm{O2}} &= a_3 + b_3 |T| + c_3 \Omega_{\mathrm{C}} + d_3 \left( F^{\mathrm{sink}}_{\mathrm{POC}} + F^{\mathrm{sink}}_{\mathrm{plank,C}} \right) + e_3 F^{\mathrm{sink}}_{\mathrm{PIC}} F^{\mathrm{sed}}_{\mathrm{NO3}} &= a_4 + b_4 \left( F^{\mathrm{sink}}_{\mathrm{PON}} + F^{\mathrm{sink}}_{\mathrm{plank,N}} \right) + c_4 F_{\mathrm{DIC}} + d_4 F_{\mathrm{O2}} &\quad + e_4 |T| F_{\mathrm{DIC}} + f_4 |T| F_{\mathrm{O2}} + g_4 F_{\mathrm{DIC}} F_{\mathrm{O2}} F^{\mathrm{sed}}_{\mathrm{PO4}} &= a_5 + b_5 |T| + c_5 \Omega_{\mathrm{C}} + d_5 \left( F^{\mathrm{sink}}_{\mathrm{POP}} + F^{\mathrm{sink}}_{\mathrm{plank,P}} \right) + e_5 F^{\mathrm{sink}}_{\mathrm{PIC}} F^{\mathrm{sed}}_{\mathrm{NH4}} &= a_6 + b_6 |T| + c_6 \Omega_{\mathrm{C}} + d_6 \left( F^{\mathrm{sink}}_{\mathrm{PON}} + F^{\mathrm{sink}}_{\mathrm{plank,N}} \right) + e_6 F^{\mathrm{sink}}_{\mathrm{PIC}} .. rst-class:: right-align-right-col .. csv-table:: RADI sediment metamodel version 2 parameters :delim: & :widths: auto :header: Name, Symbol, Default :name: phys_pkg_darwin_radiv2_parameters :varlink:`sed_globala1` & :math:`a_1` & 2.07E-5 :varlink:`sed_globalb1` & :math:`b_1` & --5.64E-7 :varlink:`sed_globalc1` & :math:`c_1` & --5.42E-6 :varlink:`sed_globald1` & :math:`d_1` & 1.45 :varlink:`sed_globale1` & :math:`e_1` & 4.19E-1 :varlink:`sed_globala2` & :math:`a_2` & 1.55E-5 :varlink:`sed_globalb2` & :math:`b_2` & --2.94E-7 :varlink:`sed_globalc2` & :math:`c_2` & --6.55E-6 :varlink:`sed_globald2` & :math:`d_2` & 5.83E-1 :varlink:`sed_globale2` & :math:`e_2` & 1.38E-1 :varlink:`sed_globala3` & :math:`a_3` & --1.35E-5 :varlink:`sed_globalb3` & :math:`b_3` & 5.08E-8 :varlink:`sed_globalc3` & :math:`c_3` & 1.79E-6 :varlink:`sed_globald3` & :math:`d_3` & --1.07 :varlink:`sed_globale3` & :math:`e_3` & --4.47E-1 :varlink:`sed_globala4` & :math:`a_4` & 3.0E-6 :varlink:`sed_globalb4` & :math:`b_4` & --7.14E-1 :varlink:`sed_globalc4` & :math:`c_4` & 1.94E-1 :varlink:`sed_globald4` & :math:`d_4` & 2.81E-1 :varlink:`sed_globale4` & :math:`e_4` & --2.21E-2 :varlink:`sed_globalf4` & :math:`f_4` & --2.97E-2 :varlink:`sed_globalg4` & :math:`g_4` & --3.20E2 :varlink:`sed_globala5` & :math:`a_5` & --2.42E-7 :varlink:`sed_globalb5` & :math:`b_5` & 1.54E-8 :varlink:`sed_globalc5` & :math:`c_5` & --4.77E-8 :varlink:`sed_globald5` & :math:`d_5` & 1.64 :varlink:`sed_globale5` & :math:`e_5` & 1.20E-2 :varlink:`sed_globala6` & :math:`a_6` & --3.87E-6 :varlink:`sed_globalb6` & :math:`b_6` & 9.15E-8 :varlink:`sed_globalc6` & :math:`c_6` & --7.26E-7 :varlink:`sed_globald6` & :math:`d_6` & 1.73 :varlink:`sed_globale6` & :math:`e_6` & 1.51E-1 Diagnostics ''''''''''' Diagnostics available with :varlink:`DARWIN_ALLOW_RADIv1`: .. tabularcolumns:: |\Y{.16}|\Y{.16}|\Y{.18}|\Y{.5}| .. csv-table:: RADI sediment model version 1 diagnostic fields :delim: & :widths: auto :class: longtable :header: Name, Code, Units, Description DICFsed & ``SM______U1`` & mmol C/m\ :sup:`2`/s & DIC sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{DIC}}` ALKFsed & ``SM______U1`` & meq/m\ :sup:`2`/s & ALK sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{ALK}}` O2Fsed & ``SM______U1`` & mmol O\ :sub:`2` /m\ :sup:`2`/s & O\ :sub:`2` sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{O2}}` POCFbur & ``SM______U1`` & mmol C/m\ :sup:`2`/s & POC buried flux, :math:`F^{\mathrm{sed}}_{\mathrm{POC}}` (negative!) CALFbur & ``SM______U1`` & mmol C/m\ :sup:`2`/s & Calcite buried flux, :math:`F^{\mathrm{sed}}_{\mathrm{CAL}}` (negative!) sedFlPOC & ``SM_P____U1`` & mmol C/m\ :sup:`2`/s & POC flux from water column to sediment, :math:`F^{\mathrm{sink}}_{\mathrm{POC}}` sedFlPIC & ``SM_P____U1`` & mmol C/m\ :sup:`2`/s & PIC flux from water column to sediment, :math:`F^{\mathrm{sink}}_{\mathrm{PIC}}` TcorrO2 & ``SM_P____M1`` & 1 & Temperature correction factor for diffusive O\ :sub:`2` flux TcorrALK & ``SM_P____M1`` & 1 & Temperature correction factor for diffusive ALK flux TcorrDIC & ``SM_P____M1`` & 1 & Temperature correction factor for diffusive DIC flux OmegCbot & ``SM_P____M1`` & 1 & Calcite saturation ratio above the seabed Diagnostics available with :varlink:`DARWIN_ALLOW_RADIv2`: .. tabularcolumns:: |\Y{.16}|\Y{.16}|\Y{.18}|\Y{.5}| .. csv-table:: RADI sediment model version 2 diagnostic fields :delim: & :widths: auto :class: longtable :header: Name, Code, Units, Description DICFsed & ``SM______U1`` & mmol C/m\ :sup:`2`/s & DIC sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{DIC}}` ALKFsed & ``SM______U1`` & meq/m\ :sup:`2`/s & ALK sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{ALK}}` O2Fsed & ``SM______U1`` & mmol O\ :sub:`2` /m\ :sup:`2`/s & O\ :sub:`2` sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{O2}}` NO3Fsed & ``SM______U1`` & mmol N/m\ :sup:`2`/s & NO3 sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{NO3}}` PO4Fsed & ``SM______U1`` & mmol P/m\ :sup:`2`/s & PO4 sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{PO3}}` NH4Fsed & ``SM______U1`` & mmol N/m\ :sup:`2`/s & NH4 sediment flux, :math:`F^{\mathrm{sed}}_{\mathrm{NH4}}` sedFlPOC & ``SM_P____U1`` & mmol C/m\ :sup:`2`/s & POC flux from water column to sediment, :math:`F^{\mathrm{sink}}_{\mathrm{POC}}` sedFlPIC & ``SM_P____U1`` & mmol C/m\ :sup:`2`/s & PIC flux from water column to sediment, :math:`F^{\mathrm{sink}}_{\mathrm{PIC}}` sedFlPOP & ``SM_P____U1`` & mmol P/m\ :sup:`2`/s & POP flux from water column to sediment, :math:`F^{\mathrm{sink}}_{\mathrm{POP}}` sedFlPON & ``SM_P____U1`` & mmol N/m\ :sup:`2`/s & PON flux from water column to sediment, :math:`F^{\mathrm{sink}}_{\mathrm{PON}}` sedFplkC & ``SM_P____U1`` & mmol C/m\ :sup:`2`/s & C flux from bottom sink plankton to sed, :math:`F^{\mathrm{sink}}_{\mathrm{plank,C}}` sedFplkN & ``SM_P____U1`` & mmol N/m\ :sup:`2`/s & N flux from bottom sink plankton to sed, :math:`F^{\mathrm{sink}}_{\mathrm{plank,N}}` sedFplkP & ``SM_P____U1`` & mmol P/m\ :sup:`2`/s & P flux from bottom sink plankton to sed, :math:`F^{\mathrm{sink}}_{\mathrm{plank,P}}` OmegCbot & ``SM_P____M1`` & 1 & Calcite saturation ratio above the seabed