Changeset 12769
- Timestamp:
- 2020-04-17T17:06:11+02:00 (3 years ago)
- Location:
- NEMO/branches/2020/ticket_2444/doc
- Files:
-
- 1 added
- 1 deleted
- 4 edited
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NEMO/branches/2020/ticket_2444/doc/latex/NEMO/main/bibliography.bib
r12377 r12769 119 119 issn = "0148-0227", 120 120 doi = "10.1029/2001jc000922" 121 } 122 123 @Article{ Asaydavis2016, 124 author = {Asay-Davis, X. S. and Cornford, S. L. and Durand, G. and Galton-Fenzi, B. K. and Gladstone, R. M. and Gudmundsson, G. H. and Hattermann, T. and Holland, D. M. and Holland, D. and Holland, P. R. and Martin, D. F. and Mathiot, P. and Pattyn, F. and Seroussi, H.}, 125 title = {Experimental design for three interrelated marine ice sheet and ocean model intercomparison projects: MISMIP v. 3 (MISMIP$+$), ISOMIP v. 2 (ISOMIP$+$) and MISOMIP v. 1 (MISOMIP1)}, 126 journal = {Geoscientific Model Development}, 127 volume = {9}, 128 year = {2016}, 129 number = {7}, 130 pages = {2471--2497}, 131 url = {https://www.geosci-model-dev.net/9/2471/2016/}, 132 doi = {10.5194/gmd-9-2471-2016} 121 133 } 122 134 … … 899 911 } 900 912 913 @Article{ favier2019, 914 author = {Favier, L. and Jourdain, N. C. and Jenkins, A. and Merino, N. and Durand, G. and Gagliardini, O. and Gillet-Chaulet, F. and Mathiot, P.}, 915 title = {Assessment of sub-shelf melting parameterisations using the ocean--ice-sheet coupled model NEMO(v3.6)--Elmer/Ice(v8.3)}, 916 journal = {Geoscientific Model Development}, 917 volume = {12}, 918 year = {2019}, 919 number = {6}, 920 pages = {2255--2283}, 921 url = {https://www.geosci-model-dev.net/12/2255/2019/}, 922 doi = {10.5194/gmd-12-2255-2019} 923 } 924 901 925 @article{ flather_JPO94, 902 926 title = "A storm surge prediction model for the northern Bay of … … 1222 1246 } 1223 1247 1248 @article{ grosfeld1997, 1249 author = {Grosfeld, K. and Gerdes, R. and Determann, J.}, 1250 title = {Thermohaline circulation and interaction between ice shelf cavities and the adjacent open ocean}, 1251 journal = {Journal of Geophysical Research: Oceans}, 1252 1253 volume = {102}, 1254 number = {C7}, 1255 pages = {15595-15610}, 1256 doi = {10.1029/97JC00891}, 1257 url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/97JC00891}, 1258 year = {1997} 1259 } 1260 1224 1261 @article{ guilyardi.madec.ea_CD01, 1225 1262 title = "The role of lateral ocean physics in the upper ocean … … 1451 1488 doi = "10.1029/91jc01842" 1452 1489 } 1490 1491 @article{ jenkins2001, 1492 author = {Jenkins, Adrian and Hellmer, Hartmut H. and Holland, David M.}, 1493 title = {The Role of Meltwater Advection in the Formulation of Conservative Boundary Conditions at an Ice–Ocean Interface}, 1494 journal = {Journal of Physical Oceanography}, 1495 volume = {31}, 1496 number = {1}, 1497 pages = {285-296}, 1498 year = {2001}, 1499 doi = {10.1175/1520-0485(2001)031<0285:TROMAI>2.0.CO;2}, 1500 url = {https://doi.org/10.1175/1520-0485(2001)031<0285:TROMAI>2.0.CO;2} 1501 } 1502 1503 @article{ jourdain2017, 1504 author = {Jourdain, Nicolas C. and Mathiot, Pierre and Merino, Nacho and Durand, Gaël and Le Sommer, Julien and Spence, Paul and Dutrieux, Pierre and Madec, Gurvan}, 1505 title = {Ocean circulation and sea-ice thinning induced by melting ice shelves in the Amundsen Sea}, 1506 journal = {Journal of Geophysical Research: Oceans}, 1507 volume = {122}, 1508 number = {3}, 1509 pages = {2550-2573}, 1510 keywords = {Amundsen Sea, ice shelf, efficiency, circumpolar deep water, ocean circulation, sea ice}, 1511 doi = {10.1002/2016JC012509}, 1512 url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012509}, 1513 year = {2017} 1514 } 1515 1453 1516 1454 1517 @article{ kantha.carniel_JMR03, -
NEMO/branches/2020/ticket_2444/doc/latex/NEMO/subfiles/apdx_DOMAINcfg.tex
r11693 r12769 319 319 Defining the bathymetry also defines the coastline: where the bathymetry is zero, 320 320 no wet levels are defined (all levels are masked). 321 322 The \ifile{isfdraft\_meter} file (Netcdf format) provides the ice shelf draft (positive, in meters) at323 each grid point of the model grid.324 This file is only needed if \np[=.true.]{ln_isfcav}{ln\_isfcav}.325 Defining the ice shelf draft will also define the ice shelf edge and the grounding line position.326 321 \end{description} 327 322 … … 530 525 This option is described in the Report by Levier \textit{et al.} (2007), available on the \NEMO\ web site. 531 526 527 \section{Ice shelf cavity definition} 528 \label{subsec:zgrisf} 529 530 If the under ice shelf seas are opened (\np{ln_isfcav}{ln\_isfcav}), the depth of the ice shelf/ocean interface has to be include in 531 the \ifile{isfdraft\_meter} file (Netcdf format). This file need to include the \ifile{isf\_draft} variable. 532 A positive value will me an ice shelf/ocean or ice shelf bedrock interface below the reference 0m ssh. 533 The exact shape of the ice shelf cavity (grounding line position and minimum thickness of the water column under an ice shelf, ...) can be specify in \nam{lst:namzgr_isf}. 534 535 536 \begin{listing} 537 \nlst{namzgr_isf_domcfg} 538 \caption{\forcode{&namzgr_isf}} 539 \label{lst:namzgr_isf} 540 \end{listing} 541 542 The options available to define the shape of the under ice shelf cavities are listed in \nam{namzgr_isf}{namzgr\_isf} (\texttt{DOMAINcfg} only, \autoref{lst:namzgr_isf}). 543 544 \subsection{Model ice shelf draft definition} 545 \label{subsec:zgrisf_isfd} 546 547 First of all, the tool make sure, the ice shelf draft ($h_{isf}$) is sensible and compatible with the bathymetry. 548 There are 3 compulsory steps to achieve this: 549 550 \begin{description} 551 \item{\np{rn_isfdep_min}{rn\_isfdep\_min}:} this is the minimum ice shelf draft. This is to make sure there is no ridiculous thin ice shelf. If \np{rn_isfdep_min}{rn\_isfdep\_min} is smaller than the surface level, \np{rn_isfdep_min}{rn\_isfdep\_min} is set to $e3t\_1d(1)$. 552 Where $h_{isf} < MAX(e3t\_1d(1),\np{rn_isfdep_min}{rn\_isfdep\_min}$), $h_{isf}$ is set to \np{rn_isfdep_min}{rn\_isfdep\_min}. 553 554 \item{\np{rn_glhw_min}{rn\_glhw\_min}:} This parameter is used to define the grounding line position. 555 Where the difference between the bathymetry and the ice shelf draft is smaller than \np{rn_glhw_min}{rn\_glhw\_min}, the cell are grounded (ie masked). 556 This step is needed to take into account possible small mismatch between ice shelf draft value and bathymetry value (sources are coming from different grid, different data processes, rounding error, ...). 557 558 \item{\np{rn_isfhw_min}{rn\_isfhw\_min}:} This parameter is minimum water column thickness in the cavity. 559 Where the water column thickness is lower than \np{rn_isfhw_min}{rn\_isfhw\_min}, the ice shelf draft is adjusted to match this criterion. 560 If for any reason, this adjustement break the minimum ice shelf draft allowed (\np{rn_isfdep_min}{rn\_isfdep\_min}), the cell is masked. 561 \end{description} 562 563 Once all these adjustements are made, if the water column thickness contains one cell wide channels, these channels can be closed using \np{ln_isfchannel}{ln\_isfchannel}. 564 565 \subsection{Model top level definition} 566 After the definition of the ice shelf draft, the tool defines the top level. 567 The compulsory criterion is that the water column needs at least 2 wet cells in the water column at U- and V-points. 568 To do so, if there one cell wide water column, the tools adjust the ice shelf draft to fillful the requierement.\\ 569 570 The process is the following: 571 \begin{description} 572 \item{step 1:} The top level is defined in the same way as the bottom level is defined. 573 \item{step 2:} The isolated grid point in the bathymetry are filled (as it is done in a domain without ice shelf) 574 \item{step 3:} The tools make sure, the top level is above or equal to the bottom level 575 \item{step 4:} If the water column at a U- or V- point is one wet cell wide, the ice shelf draft is adjusted. So the actual top cell become fully open and the new 576 top cell thickness is set to the minimum cell thickness allowed (following the same logic as for the bottom partial cell). This step is iterated 4 times to ensure the condition is fullfill along the 4 sides of the cell. 577 \end{description} 578 579 In case of steep slope and shallow water column, it likely that 2 cells are disconnected (bathymetry above its neigbourg ice shelf draft). 580 The option \np{ln_isfconnect}{ln\_isfconnect} allow the tool to force the connection between these 2 cells. 581 Some limiters in meter or levels on the digging allowed by the tool are available (respectively, \np{rn_zisfmax}{rn\_zisfmax} or \np{rn_kisfmax}{rn\_kisfmax}). 582 This will prevent the formation of subglacial lakes at the expense of long vertical pipe to connect cells at very different levels. 583 584 \subsection{Subglacial lakes} 585 Despite careful setting of your ice shelf draft and bathymetry input file as well as setting described in \autoref{subsec:zgrisf_isfd}, some situation are unavoidable. 586 For exemple if you setup your ice shelf draft and bathymetry to do ocean/ice sheet coupling, 587 you may decide to fill the whole antarctic with a bathymetry and an ice shelf draft value (ice/bedrock interface depth when grounded). 588 If you do so, the subglacial lakes will show up (Vostock for example). An other possibility is with coarse vertical resolution, some ice shelves could be cut in 2 parts: 589 one connected to the main ocean and an other one closed which can be considered as a subglacial sea be the model.\\ 590 591 The namelist option \np{ln_isfsubgl}{ln\_isfsubgl} allow you to remove theses subglacial lakes. 592 This may be useful for esthetical reason or for stability reasons: 593 594 \begin{description} 595 \item $\bullet$ In a subglacial lakes, in case of very weak circulation (often the case), the only heat flux is the conductive heat flux through the ice sheet. 596 This will lead to constant freezing until water reaches -20C. 597 This is one of the defitiency of the 3 equation melt formulation (for details on this formulation, see: \autoref{sec:isf}). 598 \item $\bullet$ In case of coupling with an ice sheet model, 599 the ssh in the subglacial lakes and the main ocean could be very different (ssh initial adjustement for example), 600 and so if for any reason both a connected at some point, the model is likely to fall over.\\ 601 \end{description} 602 603 \section{Closed sea definition} 604 \label{sec:clocfg} 605 606 \begin{listing} 607 \nlst{namclo_domcfg} 608 \caption{\forcode{&namclo}} 609 \label{lst:namclo} 610 \end{listing} 611 612 The options available to define the closed seas and how closed sea net fresh water input will be redistributed by NEMO are listed in \nam{clo} (\texttt{DOMAINcfg} only, \autoref{lst:namclo}). 613 The individual definition of each closed sea is managed by \np{sn_lake}{sn\_lake}. In this fields the user needs to defined:\\ 614 \begin{description} 615 \item $\bullet$ the name of the closed sea (print output purposes). 616 \item $\bullet$ the seed location to define the area of the closed sea (if seed on land because not present in this configuration, this closed sea will be ignored).\\ 617 \item $\bullet$ the seed location for the target area. 618 \item $\bullet$ the type of target area ('local','coast' or 'global'). See point 6 for definition of these cases. 619 \item $\bullet$ the type of redistribution scheme for the net fresh water flux over the closed sea (as a runoff in a target area, as emp in a target area, as emp globally). For the runoff case, if the net fwf is negative, it will be redistribut globally. 620 \item $\bullet$ the radius of the target area (not used for the 'global' case). So the target defined by a 'local' target area of a radius of 100km, for example, correspond to all the wet points within this radius. The coastal case will return only the coastal point within the specifid radius. 621 \item $\bullet$ the target id. This target id is used to group multiple lakes into the same river ouflow (Great Lakes for example). 622 \end{description} 623 624 The closed sea module defines a number of masks in the \ifile{domain\_cfg} output: 625 \begin{description} 626 \item[\textit{mask\_opensea}:] a mask of the main ocean without all the closed seas closed. This mask is defined by a flood filling algorithm with an initial seed (localisation defined by \np{rn_lon_opnsea}{rn\_lon\_opnsea} and \np{rn_lat_opnsea}{rn\_lat\_opnsea}). 627 \item[\textit{mask\_csglo}, \textit{mask\_csrnf}, \textit{mask\_csemp}:] a mask of all the closed seas defined in the namelist by \np{sn_lake}{sn\_lake} for each redistribution scheme. The total number of defined closed seas has to be defined in \np{nn_closea}{nn\_closea}. 628 \item[\textit{mask\_csgrpglo}, \textit{mask\_csgrprnf}, \textit{mask\_csgrpemp}:] a mask of all the closed seas and targets grouped by target id for each type of redistribution scheme. 629 \item[\textit{mask\_csundef}:] a mask of all the closed sea not defined in \np{sn_lake}{sn\_lake}. This will allows NEMO to mask them if needed or to inform the user of potential minor issues in its bathymetry. 630 \end{description} 631 532 632 \subinc{\input{../../global/epilogue}} 533 633 -
NEMO/branches/2020/ticket_2444/doc/latex/NEMO/subfiles/chap_SBC.tex
r12377 r12769 18 18 Release & Author(s) & Modifications \\ 19 19 \hline 20 {\em X.X} & {\em Pierre Mathiot} & {\em update of the ice shelf section (2019 development)} \\ 20 21 {\em 4.0} & {\em ...} & {\em ...} \\ 21 22 {\em 3.6} & {\em ...} & {\em ...} \\ … … 75 76 (\np[=0..3]{nn_ice}{nn\_ice}), 76 77 \item the addition of river runoffs as surface freshwater fluxes or lateral inflow (\np[=.true.]{ln_rnf}{ln\_rnf}), 77 \item the addition of ice-shelf melting as lateral inflow (parameterisation) or78 as fluxes applied at the land-ice ocean interface (\np[=.true.]{ln_isf}{ln\_isf}),79 78 \item the addition of a freshwater flux adjustment in order to avoid a mean sea-level drift 80 79 (\np[=0..2]{nn_fwb}{nn\_fwb}), … … 100 99 One of these is modification by icebergs (see \autoref{sec:SBC_ICB_icebergs}), 101 100 which act as drifting sources of fresh water. 102 Another example of modification is that due to the ice shelf melting/freezing (see \autoref{sec:SBC_isf}),103 which provides additional sources of fresh water.104 101 105 102 %% ================================================================================================= … … 1201 1198 1202 1199 %% ================================================================================================= 1203 \section[Ice shelf melting (\textit{sbcisf.F90})]{Ice shelf melting (\protect\mdl{sbcisf})}1204 \label{sec: SBC_isf}1200 \section[Ice Shelf (ISF)]{Interaction with ice shelves (ISF)} 1201 \label{sec:isf} 1205 1202 1206 1203 \begin{listing} 1207 \nlst{nam sbc_isf}1208 \caption{\forcode{&nam sbc_isf}}1209 \label{lst:nam sbc_isf}1204 \nlst{namisf} 1205 \caption{\forcode{&namisf}} 1206 \label{lst:namisf} 1210 1207 \end{listing} 1211 1208 1212 The namelist variable in \nam{sbc}{sbc}, \np{nn_isf}{nn\_isf}, controls the ice shelf representation. 1213 Description and result of sensitivity test to \np{nn_isf}{nn\_isf} are presented in \citet{mathiot.jenkins.ea_GMD17}. 1214 The different options are illustrated in \autoref{fig:SBC_isf}. 1215 1209 The namelist variable in \ngn{namisf}, \np{ln_isf}{ln\_isf}, controls the ice shelf interactions: 1216 1210 \begin{description} 1217 \item [{\np[=1]{nn_isf}{nn\_isf}}]: The ice shelf cavity is represented (\np[=.true.]{ln_isfcav}{ln\_isfcav} needed). 1218 The fwf and heat flux are depending of the local water properties. 1219 1220 Two different bulk formulae are available: 1211 \item $\bullet$ representation of the ice shelf/ocean melting/freezing for opened cavity (cav, \np{ln_isfcav_mlt}{ln\_isfcav\_mlt}). 1212 \item $\bullet$ parametrisation of the ice shelf/ocean melting/freezing for closed cavities (par, \np{ln_isfpar_mlt}{ln\_isfpar\_mlt}). 1213 \item $\bullet$ coupling with an ice sheet model (\np{ln_isfcpl}{ln\_isfcpl}). 1214 \end{description} 1215 1216 \subsection{Ocean/Ice shelf fluxes in opened cavities} 1217 1218 \np{ln_isfcav_mlt}{ln\_isfcav\_mlt}\forcode{ = .true.} activates the ocean/ice shelf thermodynamics interactions at the ice shelf/ocean interface. 1219 If \np{ln_isfcav_mlt}\forcode{ = .false.}, thermodynamics interactions are desctivated but the ocean dynamics inside the cavity is still active. 1220 The logical flag \np{ln_isfcav}{ln\_isfcav} control wether or not the ice shelf cavities are closed. \np{ln_isfcav}{ln\_isfcav} is not defined in the namelist but in the domcfg.nc input file.\\ 1221 1222 3 options are available to represent to ice-shelf/ocean fluxes at the interface: 1223 \begin{description} 1224 \item[\np{cn_isfcav_mlt}\forcode{ = 'spe'}]: 1225 The fresh water flux is specified by a forcing fields \np{sn_isfcav_fwf}{sn\_isfcav\_fwf}. Convention of the input file is: positive toward the ocean (i.e. positive for melting and negative for freezing). 1226 The latent heat fluxes is derived from the fresh water flux. 1227 The heat content flux is derived from the fwf flux assuming a temperature set to the freezing point in the top boundary layer (\np{rn_htbl}{rn\_htbl}) 1228 1229 \item[\np{cn_isfcav_mlt}\forcode{ = 'oasis'}]: 1230 The \forcode{'oasis'} is a prototype of what could be a method to spread precipitation on Antarctic ice sheet as ice shelf melt inside the cavity when a coupled model Atmosphere/Ocean is used. 1231 It has not been tested and therefore the model will stop if you try to use it. 1232 Actions will be undertake in 2020 to build a comprehensive interface to do so for Greenland, Antarctic and ice shelf (cav), ice shelf (par), icebergs, subglacial runoff and runoff. 1233 1234 \item[\np{cn_isfcav_mlt}\forcode{ = '2eq'}]: 1235 The heat flux and the fresh water flux (negative for melting) resulting from ice shelf melting/freezing are parameterized following \citet{Grosfeld1997}. 1236 This formulation is based on a balance between the vertical diffusive heat flux across the ocean top boundary layer (\autoref{eq:ISOMIP1}) 1237 and the latent heat due to melting/freezing (\autoref{eq:ISOMIP2}): 1238 1239 \begin{equation} 1240 \label{eq:ISOMIP1} 1241 \mathcal{Q}_h = \rho c_p \gamma (T_w - T_f) 1242 \end{equation} 1243 \begin{equation} 1244 \label{eq:ISOMIP2} 1245 q = \frac{-\mathcal{Q}_h}{L_f} 1246 \end{equation} 1247 1248 where $\mathcal{Q}_h$($W.m^{-2}$) is the heat flux,q($kg.s^{-1}m^{-2}$) the fresh-water flux, 1249 $L_f$ the specific latent heat, $T_w$ the temperature averaged over a boundary layer below the ice shelf (explained below), 1250 $T_f$ the freezing point using the pressure at the ice shelf base and the salinity of the water in the boundary layer, 1251 and $\gamma$ the thermal exchange coefficient. 1252 1253 \item[\np{cn_isfcav_mlt}\forcode{ = '3eq'}]: 1254 For realistic studies, the heat and freshwater fluxes are parameterized following \citep{Jenkins2001}. This formulation is based on three equations: 1255 a balance between the vertical diffusive heat flux across the boundary layer 1256 , the latent heat due to melting/freezing of ice and the vertical diffusive heat flux into the ice shelf (\autoref{eq:3eq1}); 1257 a balance between the vertical diffusive salt flux across the boundary layer and the salt source or sink represented by the melting/freezing (\autoref{eq:3eq2}); 1258 and a linear equation for the freezing temperature of sea water (\autoref{eq:3eq3}, detailed of the linearisation coefficient in \citet{AsayDavis2016}): 1259 1260 \begin{equation} 1261 \label{eq:3eq1} 1262 c_p \rho \gamma_T (T_w-T_b) = -L_f q - \rho_i c_{p,i} \kappa \frac{T_s - T_b}{h_{isf}} 1263 \end{equation} 1264 \begin{equation} 1265 \label{eq:3eq2} 1266 \rho \gamma_S (S_w - S_b) = (S_i - S_b)q 1267 \end{equation} 1268 \begin{equation} 1269 \label{eq:3eq3} 1270 T_b = \lambda_1 S_b + \lambda_2 +\lamda_3 zisf 1271 \end{equation} 1272 1273 where $T_b$ is the temperature at the interface, $S_b$ the salinity at the interface, $\gamma_T$ and $\gamma_S$ the exchange coefficients for temperature and salt, respectively, 1274 $S_i$ the salinity of the ice (assumedto be 0), $h_{isf}$ the ice shelf thickness, $\rho_i$ the density of the iceshelf, 1275 $c_{p,i}$ the specific heat capacity of the ice, $\kappa$ the thermal diffusivity of the ice 1276 and $T_s$ the atmospheric surface temperature (at the ice/air interface, assumed to be -20C). 1277 The Liquidus slope ($\lambda_1$), the liquidus intercept ($\lambda_2$) and the Liquidus pressure coefficient ($\lambda_3$) 1278 for TEOS80 and TEOS10 are described in \citep{AsayDavis2016} and in \citep{Jourdain2017}. 1279 The linear system formed by \autoref{eq:3eq1}, \autoref{eq:3eq2} and the linearised equation for the freezing temperature of sea water (\autoref{eq:3eq3}) can be solved for $S_b$ or $T_b$. 1280 Afterward, the freshwater flux ($q$) and the heat flux ($\mathcal{Q}_h$) can be computed. 1281 1282 \end{description} 1283 1284 \begin{table}[h] 1285 \centering 1286 \caption{Description of the parameters hard coded into the ISF module} 1287 \label{tab:isf} 1288 \begin{tabular}{|l|l|l|l|} 1289 \hline 1290 Symbol & Description & Value & Unit \\ 1291 \hline 1292 $C_p$ & Ocean specific heat & 3992 & $J.kg^{-1}.K^{-1}$ \\ 1293 $L_f$ & Ice latent heat of fusion & $3.34 \times 10^5$ & $J.kg^{-1}$ \\ 1294 $C_{p,i}$ & Ice specific heat & 2000 & $J.kg^{-1}.K^{-1}$ \\ 1295 $\kappa$ & Heat diffusivity & $1.54 \times 10^{-6}$& $m^2.s^{-1}$ \\ 1296 $\rho_i$ & Ice density & 920 & $kg.m^3$ \\ 1297 \hline 1298 \end{tabular} 1299 \end{table} 1300 1301 Temperature and salinity used to compute the fluxes in \autoref{eq:ISOMIP1}, \autoref{eq:3eq1} and \autoref{eq:3eq2} are the average temperature in the top boundary layer \citep{losch_JGR08}. 1302 Its thickness is defined by \np{rn_htbl}{rn\_htbl}. 1303 The fluxes and friction velocity are computed using the mean temperature, salinity and velocity in the first \np{rn_htbl}{rn\_htbl} m. 1304 Then, the fluxes are spread over the same thickness (ie over one or several cells). 1305 If \np{rn_htbl}{rn\_htbl} larger than top $e_{3}t$, there is no more direct feedback between the freezing point at the interface and the top cell temperature. 1306 This can lead to super-cool temperature in the top cell under melting condition. 1307 If \np{rn_htbl}{rn\_htbl} smaller than top $e_{3}t$, the top boundary layer thickness is set to the top cell thickness.\\ 1308 1309 Each melt formula (\np{cn_isfcav_mlt}\forcode{ = '3eq'} or \np{cn_isfcav_mlt}\forcode{ = '2eq'}) depends on an exchange coeficient ($\Gamma^{T,S}$) between the ocean and the ice. 1310 Below, the exchange coeficient $\Gamma^{T}$ and $\Gamma^{S}$ are respectively defined by \np{rn_gammat0}{rn\_gammat0} and \np{rn_gammas0}{rn\_gammas0}. 1311 There are 3 different ways to compute the exchange velocity: 1312 1313 \begin{description} 1314 \item[\np{cn_gammablk}\forcode{='spe'}]: 1315 The salt and heat exchange coefficients are constant and defined by: 1316 \[ 1317 \gamma^{T} = \Gamma^{T} 1318 \] 1319 \[ 1320 \gamma^{S} = \Gamma^{S} 1321 \] 1322 This is the recommended formulation for ISOMIP. 1323 1324 \item[\np{cn_gammablk}\forcode{='vel'}]: 1325 The salt and heat exchange coefficients are velocity dependent and defined as 1326 \[ 1327 \gamma^{T} = \Gamma^{T} \times u_{*} 1328 \] 1329 \[ 1330 \gamma^{S} = \Gamma^{S} \times u_{*} 1331 \] 1332 where $u_{*}$ is the friction velocity in the top boundary layer (ie first \np{rn_htbl}{rn\_htbl} meters). 1333 See \citet{jenkins.nicholls.ea_JPO10} for all the details on this formulation. It is the recommended formulation for realistic application and ISOMIP+/MISOMIP configuration. 1334 1335 \item[\np{cn_gammablk}\forcode{'vel\_stab'}]: 1336 The salt and heat exchange coefficients are velocity and stability dependent and defined as: 1337 \[ 1338 \gamma^{T,S} = \frac{u_{*}}{\Gamma_{Turb} + \Gamma^{T,S}_{Mole}} 1339 \] 1340 where $u_{*}$ is the friction velocity in the top boundary layer (ie first \np{rn_tbl}{rn\_htbl} meters), 1341 $\Gamma_{Turb}$ the contribution of the ocean stability and 1342 $\Gamma^{T,S}_{Mole}$ the contribution of the molecular diffusion. 1343 See \citet{holland.jenkins_JPO99} for all the details on this formulation. 1344 This formulation has not been extensively tested in NEMO (not recommended). 1345 \end{description} 1346 1347 \subsection{Ocean/Ice shelf fluxes in parametrised cavities} 1221 1348 1222 1349 \begin{description} 1223 \item [{\np[=1]{nn_isfblk}{nn\_isfblk}}]: The melt rate is based on a balance between the upward ocean heat flux and 1224 the latent heat flux at the ice shelf base. A complete description is available in \citet{hunter_rpt06}. 1225 \item [{\np[=2]{nn_isfblk}{nn\_isfblk}}]: The melt rate and the heat flux are based on a 3 equations formulation 1226 (a heat flux budget at the ice base, a salt flux budget at the ice base and a linearised freezing point temperature equation). 1227 A complete description is available in \citet{jenkins_JGR91}. 1350 1351 \item[\np{cn_isfpar_mlt}\forcode{ = 'bg03'}]: 1352 The ice shelf cavities are not represented. 1353 The fwf and heat flux are computed using the \citet{beckmann.goosse_OM03} parameterisation of isf melting. 1354 The fluxes are distributed along the ice shelf edge between the depth of the average grounding line (GL) 1355 (\np{sn_isfpar_zmax}{sn\_isfpar\_zmax}) and the base of the ice shelf along the calving front 1356 (\np{sn_isfpar_zmin}{sn\_isfpar\_zmin}) as in (\np{cn_isfpar_mlt}\forcode{ = 'spe'}). 1357 The effective melting length (\np{sn_isfpar_Leff}{sn\_isfpar\_Leff}) is read from a file. 1358 This parametrisation has not been tested since a while and based on \citet{Favier2019}, 1359 this parametrisation should probably not be used. 1360 1361 \item[\np{cn_isfpar_mlt}\forcode{ = 'spe'}]: 1362 The ice shelf cavity is not represented. 1363 The fwf (\np{sn_isfpar_fwf}{sn\_isfpar\_fwf}) is prescribed and distributed along the ice shelf edge between 1364 the depth of the average grounding line (GL) (\np{sn_isfpar_zmax}{sn\_isfpar\_zmax}) and 1365 the base of the ice shelf along the calving front (\np{sn_isfpar_zmin}{sn\_isfpar\_min}). Convention of the input file is positive toward the ocean (i.e. positive for melting and negative for freezing). 1366 The heat flux ($Q_h$) is computed as $Q_h = fwf \times L_f$. 1367 1368 \item[\np{cn_isfpar_mlt}\forcode{ = 'oasis'}]: 1369 The \forcode{'oasis'} is a prototype of what could be a method to spread precipitation on Antarctic ice sheet as ice shelf melt inside the cavity when a coupled model Atmosphere/Ocean is used. 1370 It has not been tested and therefore the model will stop if you try to use it. 1371 Action will be undertake in 2020 to build a comprehensive interface to do so for Greenland, Antarctic and ice shelf (cav), ice shelf (par), icebergs, subglacial runoff and runoff. 1372 1228 1373 \end{description} 1229 1374 1230 Temperature and salinity used to compute the melt are the average temperature in the top boundary layer \citet{losch_JGR08}. 1231 Its thickness is defined by \np{rn_hisf_tbl}{rn\_hisf\_tbl}. 1232 The fluxes and friction velocity are computed using the mean temperature, salinity and velocity in the the first \np{rn_hisf_tbl}{rn\_hisf\_tbl} m. 1233 Then, the fluxes are spread over the same thickness (ie over one or several cells). 1234 If \np{rn_hisf_tbl}{rn\_hisf\_tbl} larger than top $e_{3}t$, there is no more feedback between the freezing point at the interface and the the top cell temperature. 1235 This can lead to super-cool temperature in the top cell under melting condition. 1236 If \np{rn_hisf_tbl}{rn\_hisf\_tbl} smaller than top $e_{3}t$, the top boundary layer thickness is set to the top cell thickness.\\ 1237 1238 Each melt bulk formula depends on a exchange coeficient ($\Gamma^{T,S}$) between the ocean and the ice. 1239 There are 3 different ways to compute the exchange coeficient: 1240 \begin{description} 1241 \item [{\np[=0]{nn_gammablk}{nn\_gammablk}}]: The salt and heat exchange coefficients are constant and defined by \np{rn_gammas0}{rn\_gammas0} and \np{rn_gammat0}{rn\_gammat0}. 1242 \begin{gather*} 1243 % \label{eq:SBC_isf_gamma_iso} 1244 \gamma^{T} = rn\_gammat0 \\ 1245 \gamma^{S} = rn\_gammas0 1246 \end{gather*} 1247 This is the recommended formulation for ISOMIP. 1248 \item [{\np[=1]{nn_gammablk}{nn\_gammablk}}]: The salt and heat exchange coefficients are velocity dependent and defined as 1249 \begin{gather*} 1250 \gamma^{T} = rn\_gammat0 \times u_{*} \\ 1251 \gamma^{S} = rn\_gammas0 \times u_{*} 1252 \end{gather*} 1253 where $u_{*}$ is the friction velocity in the top boundary layer (ie first \np{rn_hisf_tbl}{rn\_hisf\_tbl} meters). 1254 See \citet{jenkins.nicholls.ea_JPO10} for all the details on this formulation. It is the recommended formulation for realistic application. 1255 \item [{\np[=2]{nn_gammablk}{nn\_gammablk}}]: The salt and heat exchange coefficients are velocity and stability dependent and defined as: 1256 \[ 1257 \gamma^{T,S} = \frac{u_{*}}{\Gamma_{Turb} + \Gamma^{T,S}_{Mole}} 1258 \] 1259 where $u_{*}$ is the friction velocity in the top boundary layer (ie first \np{rn_hisf_tbl}{rn\_hisf\_tbl} meters), 1260 $\Gamma_{Turb}$ the contribution of the ocean stability and 1261 $\Gamma^{T,S}_{Mole}$ the contribution of the molecular diffusion. 1262 See \citet{holland.jenkins_JPO99} for all the details on this formulation. 1263 This formulation has not been extensively tested in \NEMO\ (not recommended). 1264 \end{description} 1265 \item [{\np[=2]{nn_isf}{nn\_isf}}]: The ice shelf cavity is not represented. 1266 The fwf and heat flux are computed using the \citet{beckmann.goosse_OM03} parameterisation of isf melting. 1267 The fluxes are distributed along the ice shelf edge between the depth of the average grounding line (GL) 1268 (\np{sn_depmax_isf}{sn\_depmax\_isf}) and the base of the ice shelf along the calving front 1269 (\np{sn_depmin_isf}{sn\_depmin\_isf}) as in (\np[=3]{nn_isf}{nn\_isf}). 1270 The effective melting length (\np{sn_Leff_isf}{sn\_Leff\_isf}) is read from a file. 1271 \item [{\np[=3]{nn_isf}{nn\_isf}}]: The ice shelf cavity is not represented. 1272 The fwf (\np{sn_rnfisf}{sn\_rnfisf}) is prescribed and distributed along the ice shelf edge between 1273 the depth of the average grounding line (GL) (\np{sn_depmax_isf}{sn\_depmax\_isf}) and 1274 the base of the ice shelf along the calving front (\np{sn_depmin_isf}{sn\_depmin\_isf}). 1275 The heat flux ($Q_h$) is computed as $Q_h = fwf \times L_f$. 1276 \item [{\np[=4]{nn_isf}{nn\_isf}}]: The ice shelf cavity is opened (\np[=.true.]{ln_isfcav}{ln\_isfcav} needed). 1277 However, the fwf is not computed but specified from file \np{sn_fwfisf}{sn\_fwfisf}). 1278 The heat flux ($Q_h$) is computed as $Q_h = fwf \times L_f$. 1279 As in \np[=1]{nn_isf}{nn\_isf}, the fluxes are spread over the top boundary layer thickness (\np{rn_hisf_tbl}{rn\_hisf\_tbl}) 1280 \end{description} 1281 1282 $\bullet$ \np[=1]{nn_isf}{nn\_isf} and \np[=2]{nn_isf}{nn\_isf} compute a melt rate based on 1375 \np{cn_isfcav_mlt}\forcode{ = '2eq'}, \np{cn_isfcav_mlt}\forcode{ = '3eq'} and \np{cn_isfpar_mlt}\forcode{ = 'bg03'} compute a melt rate based on 1283 1376 the water mass properties, ocean velocities and depth. 1284 Th is flux is thus highly dependent of the model resolution (horizontal and vertical),1285 realism of the water masses onto the shelf ...\\1286 1287 $\bullet$ \np[=3]{nn_isf}{nn\_isf} and \np[=4]{nn_isf}{nn\_isf} read the melt rate from a file.1377 The resulting fluxes are thus highly dependent of the model resolution (horizontal and vertical) and 1378 realism of the water masses onto the shelf.\\ 1379 1380 \np{cn_isfcav_mlt}\forcode{ = 'spe'} and \np{cn_isfpar_mlt}\forcode{ = 'spe'} read the melt rate from a file. 1288 1381 You have total control of the fwf forcing. 1289 1382 This can be useful if the water masses on the shelf are not realistic or 1290 1383 the resolution (horizontal/vertical) are too coarse to have realistic melting or 1291 for studies where you need to control your heat and fw input.\\ 1292 1293 The ice shelf melt is implemented as a volume flux as for the runoff. 1294 The fw addition due to the ice shelf melting is, at each relevant depth level, added to 1295 the horizontal divergence (\textit{hdivn}) in the subroutine \rou{sbc\_isf\_div}, called from \mdl{divhor}. 1384 for studies where you need to control your heat and fw input. 1385 However, if your forcing is not consistent with the dynamics below you can reach unrealistic low water temperature.\\ 1386 1387 The ice shelf fwf is implemented as a volume flux as for the runoff. 1388 The fwf addition due to the ice shelf melting is, at each relevant depth level, added to 1389 the horizontal divergence (\textit{hdivn}) in the subroutine \rou{isf\_hdiv}, called from \mdl{divhor}. 1296 1390 See the runoff section \autoref{sec:SBC_rnf} for all the details about the divergence correction.\\ 1391 1392 Description and result of sensitivity tests to \np{ln_isfcav_mlt}{ln\_isfcav\_mlt} and \np{ln_isfpar_mlt}{ln\_isfpar\_mlt} are presented in \citet{mathiot.jenkins.ea_GMD17}. 1393 The different options are illustrated in \autoref{fig:ISF}. 1297 1394 1298 1395 \begin{figure}[!t] 1299 1396 \centering 1300 \includegraphics[width=0.66\textwidth]{SBC_isf }1397 \includegraphics[width=0.66\textwidth]{SBC_isf_v4.2} 1301 1398 \caption[Ice shelf location and fresh water flux definition]{ 1302 1399 Illustration of the location where the fwf is injected and 1303 whether or not the fwf is interactif or not depending of \protect\np{nn_isf}{nn\_isf}.}1304 \label{fig: SBC_isf}1400 whether or not the fwf is interactif or not.} 1401 \label{fig:ISF} 1305 1402 \end{figure} 1306 1403 1307 %% ================================================================================================= 1308 \section{Ice sheet coupling} 1309 \label{sec:SBC_iscpl} 1310 1311 \begin{listing} 1312 \nlst{namsbc_iscpl} 1313 \caption{\forcode{&namsbc_iscpl}} 1314 \label{lst:namsbc_iscpl} 1315 \end{listing} 1404 \subsection{Available outputs} 1405 The following outputs are availables via XIOS: 1406 \begin{description} 1407 \item[for parametrised cavities]: 1408 \begin{xmllines} 1409 <field id="isftfrz_par" long_name="freezing point temperature in the parametrization boundary layer" unit="degC" /> 1410 <field id="fwfisf_par" long_name="Ice shelf melt rate" unit="kg/m2/s" /> 1411 <field id="qoceisf_par" long_name="Ice shelf ocean heat flux" unit="W/m2" /> 1412 <field id="qlatisf_par" long_name="Ice shelf latent heat flux" unit="W/m2" /> 1413 <field id="qhcisf_par" long_name="Ice shelf heat content flux of injected water" unit="W/m2" /> 1414 <field id="fwfisf3d_par" long_name="Ice shelf melt rate" unit="kg/m2/s" grid_ref="grid_T_3D" /> 1415 <field id="qoceisf3d_par" long_name="Ice shelf ocean heat flux" unit="W/m2" grid_ref="grid_T_3D" /> 1416 <field id="qlatisf3d_par" long_name="Ice shelf latent heat flux" unit="W/m2" grid_ref="grid_T_3D" /> 1417 <field id="qhcisf3d_par" long_name="Ice shelf heat content flux of injected water" unit="W/m2" grid_ref="grid_T_3D" /> 1418 <field id="ttbl_par" long_name="temperature in the parametrisation boundary layer" unit="degC" /> 1419 <field id="isfthermald_par" long_name="thermal driving of ice shelf melting" unit="degC" /> 1420 \end{xmllines} 1421 \item[for open cavities]: 1422 \begin{xmllines} 1423 <field id="isftfrz_cav" long_name="freezing point temperature at ocean/isf interface" unit="degC" /> 1424 <field id="fwfisf_cav" long_name="Ice shelf melt rate" unit="kg/m2/s" /> 1425 <field id="qoceisf_cav" long_name="Ice shelf ocean heat flux" unit="W/m2" /> 1426 <field id="qlatisf_cav" long_name="Ice shelf latent heat flux" unit="W/m2" /> 1427 <field id="qhcisf_cav" long_name="Ice shelf heat content flux of injected water" unit="W/m2" /> 1428 <field id="fwfisf3d_cav" long_name="Ice shelf melt rate" unit="kg/m2/s" grid_ref="grid_T_3D" /> 1429 <field id="qoceisf3d_cav" long_name="Ice shelf ocean heat flux" unit="W/m2" grid_ref="grid_T_3D" /> 1430 <field id="qlatisf3d_cav" long_name="Ice shelf latent heat flux" unit="W/m2" grid_ref="grid_T_3D" /> 1431 <field id="qhcisf3d_cav" long_name="Ice shelf heat content flux of injected water" unit="W/m2" grid_ref="grid_T_3D" /> 1432 <field id="ttbl_cav" long_name="temperature in Losch tbl" unit="degC" /> 1433 <field id="isfthermald_cav" long_name="thermal driving of ice shelf melting" unit="degC" /> 1434 <field id="isfgammat" long_name="Ice shelf heat-transfert velocity" unit="m/s" /> 1435 <field id="isfgammas" long_name="Ice shelf salt-transfert velocity" unit="m/s" /> 1436 <field id="stbl" long_name="salinity in the Losh tbl" unit="1e-3" /> 1437 <field id="utbl" long_name="zonal current in the Losh tbl at T point" unit="m/s" /> 1438 <field id="vtbl" long_name="merid current in the Losh tbl at T point" unit="m/s" /> 1439 <field id="isfustar" long_name="ustar at T point used in ice shelf melting" unit="m/s" /> 1440 <field id="qconisf" long_name="Conductive heat flux through the ice shelf" unit="W/m2" /> 1441 \end{xmllines} 1442 \end{description} 1443 1444 %% ================================================================================================= 1445 \subsection{Ice sheet coupling} 1446 \label{subsec:ISF_iscpl} 1316 1447 1317 1448 Ice sheet/ocean coupling is done through file exchange at the restart step. 1318 At each restart step :1319 1320 \begin{ enumerate}1321 \item the ice sheet model send a new bathymetry and ice shelf draft netcdf file.1322 \item a new domcfg.nc file is built using the DOMAINcfg tools.1323 \item \NEMO\run for a specific period and output the average melt rate over the period.1324 \item the ice sheet model run using the melt rate outputed in step 4.1325 \item go back to 1.1326 \end{ enumerate}1327 1328 If \np [=.true.]{ln_iscpl}{ln\_iscpl}, the isf draft is assume to be different at each restart step with1449 At each restart step, the procedure is this one: 1450 1451 \begin{description} 1452 \item[Step 1]: the ice sheet model send a new bathymetry and ice shelf draft netcdf file. 1453 \item[Step 2]: a new domcfg.nc file is built using the DOMAINcfg tools. 1454 \item[Step 3]: NEMO run for a specific period and output the average melt rate over the period. 1455 \item[Step 4]: the ice sheet model run using the melt rate outputed in step 4. 1456 \item[Step 5]: go back to 1. 1457 \end{description} 1458 1459 If \np{ln_iscpl}\forcode{ = .true.}, the isf draft is assume to be different at each restart step with 1329 1460 potentially some new wet/dry cells due to the ice sheet dynamics/thermodynamics. 1330 The wetting and drying scheme applied on the restart is very simple and described below for the 6 different possible cases:1461 The wetting and drying scheme, applied on the restart, is very simple. The 6 different possible cases for the tracer and ssh are: 1331 1462 1332 1463 \begin{description} 1333 \item [Thin a cell down]: T/S/ssh are unchanged and U/V in the top cell are corrected to keep the barotropic transport (bt) constant 1334 ($bt_b=bt_n$). 1335 \item [Enlarge a cell]: See case "Thin a cell down" 1336 \item [Dry a cell]: mask, T/S, U/V and ssh are set to 0. 1337 Furthermore, U/V into the water column are modified to satisfy ($bt_b=bt_n$). 1338 \item [Wet a cell]: mask is set to 1, T/S is extrapolated from neighbours, $ssh_n = ssh_b$ and U/V set to 0. 1339 If no neighbours, T/S is extrapolated from old top cell value. 1340 If no neighbours along i,j and k (both previous test failed), T/S/U/V/ssh and mask are set to 0. 1341 \item [Dry a column]: mask, T/S, U/V are set to 0 everywhere in the column and ssh set to 0. 1342 \item [Wet a column]: set mask to 1, T/S is extrapolated from neighbours, ssh is extrapolated from neighbours and U/V set to 0. 1343 If no neighbour, T/S/U/V and mask set to 0. 1464 \item[Thin a cell]: 1465 T/S/ssh are unchanged. 1466 1467 \item[Enlarge a cell]: 1468 See case "Thin a cell down" 1469 1470 \item[Dry a cell]: 1471 Mask, T/S, U/V and ssh are set to 0. 1472 1473 \item[Wet a cell]: 1474 Mask is set to 1, T/S is extrapolated from neighbours, $ssh_n = ssh_b$. 1475 If no neighbours, T/S is extrapolated from old top cell value. 1476 If no neighbours along i,j and k (both previous tests failed), T/S/ssh and mask are set to 0. 1477 1478 \item[Dry a column]: 1479 mask, T/S and ssh are set to 0. 1480 1481 \item[Wet a column]: 1482 set mask to 1, T/S/ssh are extrapolated from neighbours. 1483 If no neighbour, T/S/ssh and mask set to 0. 1344 1484 \end{description} 1485 1486 The method described above will strongly affect the barotropic transport under an ice shelf when the geometry change. 1487 In order to keep the model stable, an adjustment of the dynamics at the initialisation after the coupling step is needed. 1488 The idea behind this is to keep $\pd[\eta]{t}$ as it should be without change in geometry at the initialisation. 1489 This will prevent any strong velocity due to large pressure gradient. 1490 To do so, we correct the horizontal divergence before $\pd[\eta]{t}$ is computed in the first time step.\\ 1345 1491 1346 1492 Furthermore, as the before and now fields are not compatible (modification of the geometry), … … 1349 1495 The horizontal extrapolation to fill new cell with realistic value is called \np{nn_drown}{nn\_drown} times. 1350 1496 It means that if the grounding line retreat by more than \np{nn_drown}{nn\_drown} cells between 2 coupling steps, 1351 the code will be unable to fill all the new wet cells properly .1497 the code will be unable to fill all the new wet cells properly and the model is likely to blow up at the initialisation. 1352 1498 The default number is set up for the MISOMIP idealised experiments. 1353 1499 This coupling procedure is able to take into account grounding line and calving front migration. 1354 However, it is a non-conservative proc esse.1500 However, it is a non-conservative proccess. 1355 1501 This could lead to a trend in heat/salt content and volume.\\ 1356 1502 1357 1503 In order to remove the trend and keep the conservation level as close to 0 as possible, 1358 a simple conservation scheme is available with \np[=.true.]{ln_hsb}{ln\_hsb}. 1359 The heat/salt/vol. gain/loss is diagnosed, as well as the location. 1360 A correction increment is computed and apply each time step during the next \np{rn_fiscpl}{rn\_fiscpl} time steps. 1361 For safety, it is advised to set \np{rn_fiscpl}{rn\_fiscpl} equal to the coupling period (smallest increment possible). 1362 The corrective increment is apply into the cell itself (if it is a wet cell), the neigbouring cells or the closest wet cell (if the cell is now dry). 1504 a simple conservation scheme is available with \np{ln_isfcpl_cons}\forcode{ = .true.}. 1505 The heat/salt/vol. gain/loss are diagnosed, as well as the location. 1506 A correction increment is computed and applied each time step during the model run. 1507 The corrective increment are applied into the cells itself (if it is a wet cell), the neigbouring cells or the closest wet cell (if the cell is now dry). 1363 1508 1364 1509 %% ================================================================================================= … … 1811 1956 \end{description} 1812 1957 1958 \subsection[Closed sea freshwater budget control (\textit{sbcclo.F90})]{Closed sea freswater budget control (\protect\mdl{sbcclo})} 1959 \label{subsec:SBC_clo} 1960 1961 Some configurations include inland seas and lakes as ocean 1962 points. This is particularly the case for configurations that are 1963 coupled to an atmosphere model where one might want to include inland 1964 seas and lakes as ocean model points in order to provide a better 1965 bottom boundary condition for the atmosphere. However there is no 1966 route for freshwater to run off from the lakes to the ocean and this 1967 can lead to large drifts in the sea surface height over the lakes. The 1968 closea module provides options to either fill in closed seas and lakes 1969 at run time, or to set the net surface freshwater flux for each lake 1970 to zero and put the residual flux into the ocean. 1971 Full details on the usage on the closed sea module are available in \autoref{sec:MISC_closea} 1972 1973 The following outputs are availables via XIOS: 1974 \begin{xmllines} 1975 <field id="wclosea" long_name="closed sea empmr correction" standard_name="closea_empmr" unit="kg/m2/s" /> 1976 <field id="qclosea" long_name="closed sea heat content flux" standard_name="closea_heat_content_downward_flux" unit="W/m2" /> 1977 \end{xmllines} 1978 1979 1813 1980 % Griffies doc: 1814 1981 % When running ocean-ice simulations, we are not explicitly representing land processes, -
NEMO/branches/2020/ticket_2444/doc/latex/NEMO/subfiles/chap_misc.tex
r12377 r12769 16 16 Release & Author(s) & Modifications \\ 17 17 \hline 18 {\em X.X} & {\em Pierre Mathiot} & {update of the closed sea section} 18 19 {\em 4.0} & {\em ...} & {\em ...} \\ 19 20 {\em 3.6} & {\em ...} & {\em ...} \\ … … 109 110 \end{figure} 110 111 111 \begin{figure}[!tbp]112 \centering113 \includegraphics[width=0.66\textwidth]{MISC_closea_mask_example}114 \caption[Mask fields for the \protect\mdl{closea} module]{115 Example of mask fields for the \protect\mdl{closea} module.116 \textit{Left}: a closea\_mask field;117 \textit{Right}: a closea\_mask\_rnf field.118 In this example, if \protect\np{ln_closea}{ln\_closea} is set to \forcode{.true.},119 the mean freshwater flux over each of the American Great Lakes will be set to zero,120 and the total residual for all the lakes, if negative, will be put into121 the St Laurence Seaway in the area shown.}122 \label{fig:MISC_closea_mask_example}123 \end{figure}124 125 112 %% ================================================================================================= 126 113 \section[Closed seas (\textit{closea.F90})]{Closed seas (\protect\mdl{closea})} 127 114 \label{sec:MISC_closea} 115 116 \begin{listing} 117 \nlst{namclo} 118 \caption{\forcode{&namclo}} 119 \label{lst:namclo} 120 \end{listing} 128 121 129 122 Some configurations include inland seas and lakes as ocean … … 138 131 to zero and put the residual flux into the ocean. 139 132 140 Prior to \NEMO\ 4 the locations of inland seas and lakes was set via 141 hardcoded indices for various ORCA configurations. From \NEMO\ 4 onwards 142 the inland seas and lakes are defined using mask fields in the 143 domain configuration file. The options are as follows. 144 145 \begin{enumerate} 146 \item {{\bfseries No ``closea\_mask'' field is included in domain configuration 147 file.} In this case the closea module does nothing.} 148 149 \item {{\bfseries A field called closea\_mask is included in the domain 150 configuration file and ln\_closea=.false. in namelist namcfg.} In this 151 case the inland seas defined by the closea\_mask field are filled in 152 (turned to land points) at run time. That is every point in 153 closea\_mask that is nonzero is set to be a land point.} 154 155 \item {{\bfseries A field called closea\_mask is included in the domain 156 configuration file and ln\_closea=.true. in namelist namcfg.} Each 157 inland sea or group of inland seas is set to a positive integer value 158 in the closea\_mask field (see \autoref{fig:MISC_closea_mask_example} 159 for an example). The net surface flux over each inland sea or group of 133 The inland seas and lakes are defined using mask fields in the 134 domain configuration file. Special treatment of the closed sea (redistribution of net freshwater or mask those), are defined in \autoref{lst:namclo} and 135 can be trigger by \np{ln_closea}{ln\_closea}\forcode{=.true.} in namelist namcfg. 136 137 The options available are the following: 138 \begin{description} 139 \item[\np{ln_maskcs}{ln\_maskcs}\forcode{ = .true.}] All the closed seas are masked using \textit{mask\_opensea} variable. 140 \item[\np{ln_maskcs}{ln\_maskcs}\forcode{ = .false.}] The net surface flux over each inland sea or group of 160 141 inland seas is set to zero each timestep and the residual flux is 161 distributed over the global ocean (ie. all ocean points where 162 closea\_mask is zero).} 163 164 \item {{\bfseries Fields called closea\_mask and closea\_mask\_rnf are 165 included in the domain configuration file and ln\_closea=.true. in 166 namelist namcfg.} This option works as for option 3, except that if 167 the net surface flux over an inland sea is negative (net 168 precipitation) it is put into the ocean at specified runoff points. A 169 net positive surface flux (net evaporation) is still spread over the 170 global ocean. The mapping from inland seas to runoff points is defined 171 by the closea\_mask\_rnf field. Each mapping is defined by a positive 172 integer value for the inland sea(s) and the corresponding runoff 173 points. An example is given in 174 \autoref{fig:MISC_closea_mask_example}. If no mapping is provided for a 175 particular inland sea then the residual is spread over the global 176 ocean.} 177 178 \item {{\bfseries Fields called closea\_mask and closea\_mask\_emp are 179 included in the domain configuration file and ln\_closea=.true. in 180 namelist namcfg.} This option works the same as option 4 except that 181 the nonzero net surface flux is sent to the ocean at the specified 182 runoff points regardless of whether it is positive or negative. The 183 mapping from inland seas to runoff points in this case is defined by 184 the closea\_mask\_emp field.} 185 \end{enumerate} 186 187 There is a python routine to create the closea\_mask fields and append 188 them to the domain configuration file in the utils/tools/DOMAINcfg directory. 142 distributed over a target area. 143 \end{description} 144 145 When \np{ln_maskcs}{ln\_maskcs}\forcode{ = .false.}, 146 3 options are available for the redistribution (set up of these options is done in the tool DOMAINcfg): 147 \begin{description}[font=$\bullet$ ] 148 \item[ glo]: The residual flux is redistributed globally. 149 \item[ emp]: The residual flux is redistributed as emp in a river outflow. 150 \item[ rnf]: The residual flux is redistributed as rnf in a river outflow if negative. If there is a net evaporation, the residual flux is redistributed globally. 151 \end{description} 152 153 For each case, 2 masks are needed (\autoref{fig:MISC_closea_mask_example}): 154 \begin{description} 155 \item $\bullet$ one describing the 'sources' (ie the closed seas concerned by each options) called \textit{mask\_csglo}, \textit{mask\_csrnf}, \textit{mask\_csemp}. 156 \item $\bullet$ one describing each group of inland seas (the Great Lakes for example) and the target area (river outflow or world ocean) for each group of inland seas (St Laurence for the Great Lakes for example) called 157 \textit{mask\_csgrpglo}, \textit{mask\_csgrprnf}, \textit{mask\_csgrpemp}. 158 \end{description} 159 160 \begin{figure}[!tbp] 161 \centering 162 \includegraphics[width=0.66\textwidth]{MISC_closea_mask_example} 163 \caption[Mask fields for the \protect\mdl{closea} module]{ 164 Example of mask fields for the \protect\mdl{closea} module. 165 \textit{Left}: a \textit{mask\_csrnf} field; 166 \textit{Right}: a \textit{mask\_csgrprnf} field. 167 In this example, if \protect\np{ln_closea}{ln\_closea} is set to \forcode{.true.}, 168 the mean freshwater flux over each of the American Great Lakes will be set to zero, 169 and the total residual for all the lakes, if negative, will be put into 170 the St Laurence Seaway in the area shown.} 171 \label{fig:MISC_closea_mask_example} 172 \end{figure} 173 174 Closed sea not defined (because too small, issue in the bathymetry definition ...) are defined in \textit{mask\_csundef}. 175 These points can be masked using the namelist option \np{ln_mask_csundef}{ln\_mask\_csundef}\forcode{= .true.} or used to correct the bathymetry input file.\\ 176 177 The masks needed for the closed sea can be created using the DOMAINcfg tool in the utils/tools/DOMAINcfg directory. 178 See \autoref{sec:clocfg} for details on the usage of definition of the closed sea masks. 189 179 190 180 %% =================================================================================================
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