Introduction
ADCIRC uses specific file names to represent different types of input and output (the number at the end of the file name represents the Fortran logical unit number that is used to perform i/o on the file). The fort.15 file is one of two input files that ADCIRC absolutely requires (the other is the fort.14 file which contains the mesh and boundaries). The fort.15 is used to specify run parameters, physics, additional files included in the run, output types and timing, and boundary conditions that apply to the boundaries identified in the fort.14. Although the fort.14 and fort.15 are separate files, they are really not independent of one another, as a result of the boundaries being in the fort.14 and the boundary conditions being in the fort.15.
The format of the ADCIRC input files (including the fort.15) tends to be rigid. That is, ADCIRC expects to find each specific parameter on a specific line in the input file, and if the file contains any extra or unexpected line, the run will stop. If the file is missing any lines, the run will stop.
The format of ADCIRC input files is also highly conditional, meaning that parameter values found on earlier lines in the file will dictate the expected number and/or format of later lines in the file. For example, if NWS (meteorlogical data type parameter, near the top of the file) is nonzero, ADCIRC will then expect, among other things, additional lines at a certain point near the end of the file that specify the type of meteorological data in the output (even if no meterological output is desired). Also, the actual value of the NWS parameter will dictate the number and types of parameters that are expected on the "WTIMINC" line later in the file.
This combination of rigidity and conditional formatting means that it may take several tries to successfully construct an ADCIRC fort.15 file manually. It is generally not an issue when input files are constructed by another program that is used as a preprocessor for ADCIRC (e.g., SMS or NumCat), as these other programs already have logic to ensure that the right input is placed at the right location in the file under all possible conditions.
The file structure of an ADCIRC fort.15 file is shown below. Each line of input data is represented by a section header containing the input variable name(s). Loops indicate multiple lines of input. The basis of conditional input is indicated by an if clause in the description. Commas are used to enhance readability; there should be no commas in the fort.15 input file. The actual parameter names are the same as the corresponding variable names used in the code itself; the sometimes cryptically abbreviated variable names were conceived when Fortran only allowed variable names to be six characters long. Overall, the format of this documentation is designed to mimic the way that ADCIRC actually reads the files (i.e., one line at a time, from beginning to end, with data read in earlier influencing the expectations of data to be read in later).
File Format at a Glance
for j=1 to NWP
AttrName(j)
end j loop
NCOR
NTIP
NWS
NRAMP
G
TAU0
Tau0FullDomainMin Tau0FullDomainMax  include this line only if TAU0 is between 5.0 and 5.99 (inclusive).
DTDP
STATIM
REFTIM
WTIMINC  include this line only if NWS =2, 4, 4, 5, 5, 7, 7, 10
YYYY MM DD HH24 StormNumber BLAdj  include this line only if NWS = 8, 9, 19
RSTIMINC  include this line only if NWS =100, 101, 111
WTIMINC RSTIMINC  include this line only if the hundreds place of NWS is nonzero, and the last two digits are 2, 3, 5, 7, 8, 10, or 12.
IREFYR IREFMO IREFDAY IREFHR IREFMIN REFSEC  include this line only if NWS =3, 103
NWLAT NWLON WLATMAX WLONMIN WLATINC WLONINC WTIMINC  include this line only if NWS =3, 6
NWLAT NWLON WLATMAX WLONMIN WLATINC WLONINC WTIMINC RSTIMINC  include this line only if NWS =103, 106
RNDAY
DRAMP  include this line if NRAMP = 0 or 1
DRAMP DRAMPExtFlux FluxSettlingTime  include this line if NRAMP = 2
DRAMP DRAMPExtFlux FluxSettlingTime DRAMPIntFlux  include this line if NRAMP = 3
DRAMP DRAMPExtFlux FluxSettlingTime DRAMPIntFlux DRAMPElev  include this line if NRAMP = 4
DRAMP DRAMPExtFlux FluxSettlingTime DRAMPIntFlux DRAMPElev DRAMPTip  include this line if NRAMP = 5
DRAMP DRAMPExtFlux FluxSettlingTime DRAMPIntFlux DRAMPElev DRAMPTip DRAMPMete  include this line if NRAMP = 6
DRAMP DRAMPExtFlux FluxSettlingTime DRAMPIntFlux DRAMPElev DRAMPTip DRAMPMete DRAMPWRad  include this line if NRAMP = 7
A00 B00 C00
H0  include this line if NOLIFA =0, 1
H0 NODEDRYMIN NODEWETMIN VELMIN  include this line if NOLIFA =2, 3
SLAM0 SFEA0
TAU ? include this line only if NOLIBF = 0
CF  include this line only if NOLIBF =1
CF HBREAK FTHETA FGAMMA  include this line only if NOLIBF =2
ESLM  include this line only if IM =0, 1, 2
ESLM ESLC  include this line only if IM =10
CORI
NTIF
for k=1 to NTIF
TIPOTAG(k)
TPK(k) AMIGT(k) ETRF(k) FFT(k) FACET(k)
end k loop
NBFR
for k=1 to NBFR
BOUNTAG(k)
AMIG(k) FF(k) FACE(k)
end k loop
for k=1 to NBFR
ALPHA(k)
for j=1 to NETA
EMO(k,j) EFA(k,j)
end j loop
end k loop
ANGINN
NFFR  include this line only if IBTYPE = 2, 12, 22, 32 in the Grid and Boundary Information File
for k=1 to FBOUNTAG(k)
FAMIGT(k) FFF(k) FFACE(k)
end k loop
for k=1 to NFFR
ALPHA(k)
for j=1 to NVEL
QNAM(k,j) QNPH(k,j)  use this line if IBTYPE = 2, 12, 22 in the Grid and Boundary Information File
QNAM(k,j) QNPH(k,j) ENAM(k,j) ENPH(k,j)  use this line if IBTYPE = 32 in the Grid and Boundary Information File
end j loop
end k loop
for k=1 to NSTAE
XEL(k) YEL(k)
end k loop
for k=1 to NSTAV
XEV(k) YEV(k)
end k loop
NOUTC TOUTSC TOUTFC NSPOOLC  include this line only if IM =10
NSTAC  include this line only if IM =10
for k=1 to NSTAC
XEC(k) YEC(k)
end k loop
NOUTM TOUTSM TOUTFM NSPOOLM  include this line only if NWS = 1, 2, 3, 4, 4, 5, 5, 6, 8, 9, 10, 101, 102, 103, 104, 104, 105, 105, 110, 111
NSTAM  include this line only if NWS = 1, 2, 3, 4, 4, 5, 5, 6, 8, 9, 10, 101, 102, 103, 104, 104, 105, 105, 110, 111
for k=1 to NSTAM
XEM(k) YEM(k)
end k loop
NOUTGE TOUTSGE TOUTFGE NSPOOLGE
NOUTGV TOUTSGV TOUTFGV NSPOOLGV
NOUTGC TOUTSGC TOUTFGC NSPOOLGC  include this line only if IM =10
NOUTGW TOUTSGW TOUTFGW NSPOOLGW  include this line only if NWS =1, 2, 3, 4, 4, 5, 5, 6, 8, 9, 10, 101, 102, 103, 104, 104, 105, 105, 110, 111
NFREQ
for k=1 to NFREQ
NAMEFR(k)
HAFREQ(k) HAFF(k) HAFACE(k)
end k loop
For a 2DDI ADCIRC run that does not use NetCDF, the file ends here. For any ADCIRC run that uses NetCDF, the lines NCPROJ through NCDATE (described at the end of this file format) are required metadata and must be added at the end of the fort.15 file.
The following information is only included for a 3D run:
for k=1 to NFEN (include this loop only if IGC = 0, k=1 at bottom, k= NFEN at surface)
SIGMA(k)
end k loop
for k=1 to NFEN (include this loop only if IEVC = 0, k=1 at bottom, k= NFEN at surface)
EVTOT(k)
end k loop
THETA1 THETA2 (include this line only if IEVC = 50 or 51)
I3DSD TO3DSDS TO3DSDF NSPO3DSD
NSTA3DD
for k=1 to NSTA3DD
X3DS(k) Y3DS(k)
end k loop
for k=1 to NSTA3DV
X3DS(k) Y3DS(k)
end k loop
for k=1 to NSTA3DT
X3DS(k) Y3DS(k)
end k loop
The following lines will be read in only if IDEN is > 0.
The following line will be read in only if IDEN = 3 or 4.
The following lines will be read in only if netCDF output format is chosen
Input Data
Each line of input is described in order, and the definitions of the parameters on each line are provided.
Comment Lines
RUNDES
RUNDES is a comment line that is copied to the headers of all output files. It should be unique enough that the output files from a run can be matched to the input files that generated them. Must be less than 32 characters long.
RUNID
RUNID is a second comment line that is also copied to the headers of output files. It is often used to record the version of ADCIRC that was used for the run.
Debugging and Logging
NFOVER
NFOVER is the nonfatal error override option (NFOVER stands for Non Fatal Override):
NFOVER=0

Inconsistent input parameters will cause program termination. 
NFOVER=1

Inconsistent input parameters will, (when possible), be automatically corrected to a default or consistent value and execution continued. Be sure to read the nonfatal warning messages to see whether any parameters have been modified. 
Note

Not all inconsistent parameters can be corrected automatically and therefore fatal error messages and program termination may still result. 
NABOUT
NABOUT controls the logging level for output from ADCIRC to the screen or console as well as the ADCIRC log file (fort.16). ADCIRC writes log messages at 5 levels of severity: DEBUG, ECHO, INFO, WARNING, and ERROR (from lowest or least important to highest or most important). Selection of a logging level indicates that messages of that level and higher should be logged. Setting the logging level to WARNING or ERROR will reduce the log file size, but information of interest to the user could be missed. ERROR messages generally result from problems that also cause the run to stop.
NABOUT=1

DEBUGlevel log messages and higher. This may consume a lot of disk space and slow ADCIRC down, perhaps dramatically. Generally only useful for ADCIRC developers. 
NABOUT=0

ECHOlevel log messages and higher. ECHOlevel log messages include echo printing of most input files including the fort.13, fort.14 and fort.22 files. 
NABOUT=1

INFOlevel log messages and higher. These messages inform the user about something that ADCIRC has done that is important but is not the result of a problem or issue. 
NABOUT=2

WARNINGlevel log messages and higher. These messages indicate a potential problem that is generally not fatal to the run. 
NABOUT=3

ERRORlevel log messages only. These messages indicate a severe problem that usually causes the run to stop. 
Prior to ADCIRC version 49, 0 (ECHO) and 1 (INFO) were the only available options. NABOUT originally stood for "Abbreviated Output" (to log files).
NSCREEN
NSCREEN controls log message output to the screen (i.e., to standard output). Timestep logging will be written every abs(NSCREEN) timesteps. Output to the screen consists mainly of timestep logging, as well as warning and error messages.
NSCREEN<0

Log messages that would normally be written to the screen are written to a file called adcirc.log instead. 
NSCREEN=0

Log messages will not be written to the screen. 
NSCREEN>0

Log messages are written to the screen (a.k.a. standard out). 
Physics
IHOT
IHOT determines whether the model is to be hot started. The hotstart facility is available for 2D and 3D runs. The hotstart file will also contain harmonic analysis data if harmonic analysis was underway, so that the harmonic analysis can be hotstarted as well.
IHOT=0

cold start the model 
IHOT=17

hot start from ascii file fort.17 
IHOT=67

hot start from binary file fort.67 
IHOT=68

hot start from binary file fort.68 
IHOT=367

hot start from netCDF file fort.67.nc 
IHOT=368

hot start from netCDF file fort.68.nc 
IHOT=567

hot start from netCDF4 file fort.67.nc 
IHOT=568

hot start from netCDF4 file fort.68.nc 
ICS
ICS Specifies whether the model is run in spherical or Cartesian coordinates (ICS is an abbreviation representing "coordinate system").
ICS=1

ADCIRC interprets the nodal coordinates in the mesh (fort.14) file as Cartesian. ADCIRC governing equations are in standard Cartesian coordinates. In the unlikely case that tidal potential forcing (NTIP=1 or 2) and/or a spatially variable Coriolis coefficient (NCOR=1) are desired for this type of run, an inverse map projection (Carte Parallelogrammatique) is used to obtain longitude and latitude values for the grid. However, we strongly recommend that if the model domain is large enough for either spatially variable Coriolis or tidal potential forcing to be considered important, the model should be run with spherical governing equations (ICS=2) using a longitude, latitude grid. 
ICS=2

ADCIRC interprets the nodal coordinates in the mesh (fort.14) file as longitude,latitude pairs. ADCIRC governing equations are in spherical coordinates transformed into Cartesian coordinates prior to discretization using a map projection (Carte Parallelogrammatique  CPP). Coordinates in the grid file (fort.14) are in decimal degrees longitude and latitude. 
IM
IM specifies the model run type. Main options include 2D depth integrated (2DDI); 3D barotropic, or 3D baroclinic. There are also several researchoriented options available for this parameter.
IM=0

Barotropic 2DDI run using the standard GWCE and Momentum equation. 
IM=111112

Barotropic 2DDI run using the lumped GWCE formulation and standard Momentum equation formulation. 
IM=1

Barotropic 3D run using the standard GWCE and velocity based Momentum equations. 
IM=611112

Barotropic 3D run using the lumped GWCE (instead of the default fully consistent GWCE). This option is needed to run ADCIRC in lumped explicit mode, thereby bypassing the iterative solver. Explicit mode also requires specifying coefficients A00, B00, C00 (= 0.0, 1.0, 0.0) in this file. (see below) 
IM=2

3D run using New GWCE and stress based Momentum equations (not fully implemented). 
IM=10

Barotropic 2DDI run using New GWCE and Momentum equation formulations plus passive scalar transport (not fully implemented) 
IM=11

Barotropic 3D run using New GWCE and velocity based Momentum equations plus passive scalar transport (not fully implemented). 
IM=20

Baroclinic 2DDI run using New GWCE and Momentum equation formulations (not fully implemented). 
IM=21

Baroclinic 3D run using New GWCE and velocity based Momentum equations (not fully implemented). 
IM=30

Baroclinic 2DDI run using New GWCE and Momentum equation formulations plus passive scalar transport (not fully implemented). 
IM=31

Baroclinic 3D run using New GWCE and velocity based Momentum equations plus passive scalar transport (not fully implemented). 
IDEN
The IDEN line should be included only if IM = 20 or 30. IDEN is used to specify the form of density forcing for a 2DDI or 3D run.
IDEN=0

Barotropic model run 
IDEN=1

Prognostic Baroclinic ADCIRC run with Sigma T forcing 
IDEN=2

Prognostic Baroclinic ADCIRC run with Salinity forcing 
IDEN=3

Prognostic Baroclinic ADCIRC run with Temperature forcing 
IDEN=4

Prognostic Baroclinic ADCIRC run with Salinity and Temperature forcing 
IDEN=1

Diagnostic Baroclinic ADCIRC run with Sigma T forcing 
IDEN=2

Diagnostic Baroclinic ADCIRC run with Salinity forcing 
IDEN=3

Diagnostic Baroclinic ADCIRC run with Temperature forcing 
IDEN=4

Diagnostic Baroclinic ADCIRC run with Salinity and Temperature forcing 
For all Baroclinic model runs, the initial conditions for the density, temperature and/or salinity field(s) are read in from UNIT 11.
NOLIBF
NOLIBF is an abbreviation of Nonlinear Bottom Friction and this parameter controls the type of bottom stress parameterization used in a 2DDI ADCIRC run. This parameter must be specified but is ignored in a 3D run.
NOLIBF=0

Linear bottom friction law will be used. The friction coefficient (FFACTOR) is specified later in this file. 
NOLIBF=1

Quadratic bottom friction law will be used. The friction coefficient (FFACTOR) is specified later in this file. 
NOLIBF=2

Hybrid nonlinear bottom friction law will be used. In deep water, the friction coefficient is constant and a quadratic bottom friction law results. In shallow water the friction coefficient increases as the depth decreases (e.g. as in a Manningtype friction law). The friction coefficient is determined as: FFACTOR=FFACTORMIN*(1+(HBREAK/H)**FTHETA)**(FGAMMA/FTHETA). The required parameters (FFACTORMIN, HBREAK, FTHETA, FGAMMA) are specified below. 
Note

In the NWP (nodal attributes) section, if the user selects quadratic_friction_coefficient_at_sea_floor, mannings_n_at_sea_floor, or chezy_friction_coefficient_at_sea_floor, then NOLIBF must be 1 (nonlinear friction formulation) since all those formulations are nonlinear. If the NOLIBF were anything other than 1, it is an error that will cause ADCIRC to stop. 
NOLIFA
NOLIFA is an abbreviation of Nonlinear Finite Amplitude and this parameter controls the finite amplitude terms in ADCIRC. When the finite amplitude terms are turned on, the time derivative portion of the advective terms should also be turned on for proper mass conservation and consistency (i.e. when NOLIFA>0, then NOLICAT=1).
NOLIFA=0

Finite amplitude terms ARE NOT included in the model run (i.e., the depth is linearized by using the bathymetric depth, rather than the total depth, in all terms except the transient term in the continuity equation) and wetting and drying of elements is disabled. Initial water depths are assumed equal to the bathymetric water depth specified in the mesh file (fort.14). 
NOLIFA=1

Finite amplitude terms ARE included in the model run and wetting and drying of elements is disabled. Initial water depths are assumed equal to the bathymetric water depth specified in the mesh file (fort.14). 
NOLIFA=2

Finite amplitude terms ARE included in the model run and wetting and drying of elements is enabled. Initial water depths are assumed equal to the bathymetric water depth specified in the mesh file (fort.14). 
The value of NOLIFA also affects the meaning of the minimum water depth parameter (H0) and requires the specification of additional parameters together with H0 (see below).
NOLICA
NOLICA is an abbreviation of Nonlinear Convective Acceleration although Convective really is the wrong term. It would be better to describe NOLICA as standing for Nonlinear Advection terms (e.g., U dU/dx + V dU/dy in the 2DDI x momentum equation; U dV/dx + V dV/dy in the 2D y momentum equation)
This parameter controls the advective terms in ADCIRC (with the exception of a time derivative portion that occurs in the GWCE form of the continuity equation and is controlled by NOLICAT). When these (spatial derivative) portions of the advective terms are included, the time derivative portion of the advective terms in the GWCE should also be included (i.e. when NOLICA=1, NOLICAT=1).
NOLICA=0

Advective terms ARE NOT included in the computations. 
NOLICA=1

Advective terms ARE included in the computations. 
NOLICAT
NOLICAT is an abbreviation of Nonlinear Convective Acceleration  Time Derivative and this parameter controls the time derivative portion of the advective terms that occurs in the GWCE form of the continuity equation in ADCIRC. The remainder of the advective terms in the GWCE and the entire advective terms in the momentum equation are controlled by NOLICA. These terms should be included if either the finite amplitude or the remainder of the advective terms are included to maintain mass conservation and solution consistency.
NOLICAT=0

The time derivative portion of the advective terms that occur in the GWCE continuity equation ARE NOT included in the computations. 
NOLICAT=1

The time derivative portion of the advective terms that occur in the GWCE continuity equation ARE included in the computations. 
NWP
NWP is the number of different nodal attributes to be used in the run. If NWP is not zero, then the names of the nodal attributes appear on the following lines, one per line:
FOR j=1 to NWP AttrName(j) end j loop
Nodal attributes are properties of each node in the grid and are spatially varying but constant in time. See AttrName for examples. The nodal attribute data itself must be provided by the user in the Nodal Attributes File (fort.13).
NCOR
NCOR controls whether the Coriolis parameter is constant in space and read in below or spatially varying as computed from the ycoordinates of the nodes in the grid (assumed to be in degrees Latitude). The grid coordinate system is specified by the ICS parameter (see above).
NCOR=0

Coriolis force is treated as a constant and the Coriolis parameter will be read in later in this file. 
NCOR=1

Coriolis force is spatially varying and will be computed by ADCIRC at each node based on its Latitude. 
NTIP
NTIP controls whether tidal potential and self attraction/load tide forcings will be used to force ADCIRC.
NTIP=0

Tidal potential and self attraction/load tide forcings are not used. 
NTIP=1

Tidal potential forcing is used and will be calculated by ADCIRC at each node and time step based on the tidal parameters provided later in this file. 
NTIP=2

Tidal potential and self attraction/load tide forcings are used. In this case the self attraction/load tide information is read in for each constituent at each node in the grid from the Self Attraction/Earth Load Tide Forcing File (fort.24). 
NWS
NWS controls whether wind velocity or stress, wave radiation stress and atmospheric pressure are used to force ADCIRC. ADCIRC is able to read and apply meteorological data in a wide variety of formats, indicated by different values of NWS. The meaning of different NWS values is described in the documentation for the fort.22 (meteorological data file).
NRAMP
NRAMP indicates the number of different ramp functions to apply to different types of ADCIRC forcing. See description of DRAMP for further information on setting the ramp values.
G
G represents gravitational acceleration. The units of this constant determine the distance units that ADCIRC operates with (ADCIRC always operates in seconds and therefore the time units for G must be seconds). When ICS = 2, it is required that G = 9.81 m/sec2. Regardless of ICS, when either NTIP = 1 or NCOR = 1, it is required that G = 9.81 m/sec2.
TAU0
TAU0 relates to the generalized WaveContinuity Equation (GWCE) weighting factor that weights therelative contribution of the primitive and wave portions of the GWCE. If "primitive_weighting_in_continuity_equation" is specified as a nodal attribute in the fort.15 file above, this line will be read in but ignored. If a nodal attribute file is not used or "primitive_weighting_in_continuity_equation" is in the nodal attribute (fort.13) file, but not specified in the fort.15 file this TAU0 parameter will be used.
Tau0=0

The GWCE is a pure wave equation. 
Tau0>0

Tau0 will be set at every node to this input value (i.e., spatially and temporally constant). The GWCE will behave as a combination of the wave continuity equation and the primitive continuity equation, with the contribution of the primitive continuity equation being directly proportional to tau0. A good rule of thumb for setting TAU0 is to set it equal to the largest value of an equivalent linear friction factor; e.g, for linear friction TAU0 = TAU and for quadratic friction TAU0 = maximum (speed*CF/depth). Typical values for TAU0 are in the range of 0.001  0.01. 
Tau0>1

The GWCE behaves like a pure primitive continuity equation. 
Tau0<0

Tau0 will be spatially variable; there is one general scheme and several specific schemes for specifying a spatially variable Tau0. A specific scheme can be selected by choosing one of the negative values listed below. Any other negative value will cause tau0 to be set as follows: spatially varying but constant in time; if the depth at a node is >=10 TAU0 is set to 0.005 at that node, if the depth at a node is < 10, TAU0 is set to 0.020 at that node. 
Tau0=2

The TAU0 is spatially varying but constant in time; it is calculated according to depth as follows: if the depth is >=200 TAU0 is set to 0.005, if the depth is < 200 but > 1, then TAU0 is set to 1/depth, and if depth < 1, TAU0 is set to 1.0. 
Tau0=3

The TAU0 varies spatially and in time; TAU0 is computed from TAU0Base read in from the Nodal Attribute file as follows: if TAU0Base is less then 0.025, then TAU0 at that node is set equal to TAU0Base (constant in time). If TAU0Base at a node is >= 0.025, then TAU0 is set equal to TAU0Base + 1.5TK(i) where TK(i)=Cd*abs(U)/H (i.e., the quadratic friction). 
Tau0=3.1

This is the same as TAU0=3, except that the tau0 will be written out to a file called fort.tau0 at the same time that the fort.63 (full domain water surface elevation) is written out. 
Tau0=5

TAU0 varies varies spatially and in time, and is dependent on the local friction; it is limited to a range specified by Tau0FullDomainMin and Tau0FullDomainMax. Tau0=Tau0Min+1.5*TK(i). 
If Tau0 is set to 3 or 3.1, the recommended scheme for setting TAU0Base is to use mesh density and bathymetric depth as follows: if the average distance between a node and its neighbors is less than 1750m, set TAU0Base=0.03; if it is less than 1750m and depth is greater than 10m, set TAU0Base=0.02; if it is less than 1750m and depth is less than 10m, set TAU0Base to 0.005.
Note

TAU0Base values can be generated using the ADCIRC utility program tau0_gen.f from adcirc.org. The program generates TAU0Base values according to the logic described above. 
Tau0FullDomainMin, Tau0FullDomainMax
Include this line only if TAU0 is between 5.0 and 5.99 (inclusive).
These are specified values that the spatially and time varying TAU0 scheme must stay between. Suggested values are Tau0FullDomainMin = 0.005 and Tau0FullDomainMax = 0.2.
DTDP
DTDP (abbreviation of Delta Time Double Precision because ADCIRC stores it as a real number with double precision) represents the ADCIRC time step (in seconds).
DTDP>0

The ADCIRC time step will be set to the DTDP value. The predictorcorrector algorithm is not used. 
DTDP<0

The ADCIRC time step will be set to the value of abs(DTDP) and the predictorcorrector solution algorithm will be activated. 
Note

Time in the model is computed as: TIME = STATIM*86400.+DTDP*IT. 
STATIM
STATIM is the starting simulation time (in days). The first time step computes results at: TIME = STATIM*86400+DTDP. A nonzero value may be useful, for example, to align model output times with a specific time reference.
REFTIM
REFTIM is reference time (in days). This is used only to compute time for the harmonic forcing and analysis terms. A nonzero value allows equilibrium arguments to be used that have been calculated for a time other than TIME0 = STATIM*86400. The time used for harmonic terms is compute as: TIMEH = (STATIMREFTIM)*86400.+DTDP*IT.
WTIMINC Line(s)
WTIMINC lines can take many forms and is used to provide additional information about meteorological input data, and its presence and format depend on the NWS value that was earlier. It is also used to provide information about wave radiation stress forcing and/or wave model coupling (if the NWS value was three digits) and/or time varying ice coverage information (if the NWS value has four or more digits).
 WTIMINC

Time increment of input meteorological data in seconds (e.g., WTIMINC is 3600 for hourly meteorological input). If NWS = 1, 101, ADCIRC assumes WTIMINC = DTDP (model time step). If NWS = 11, 111, ADCIRC assumes WTIMINC = 10800 (3 hrs) is the time interval between the Multiple File Meteorological Forcing Input Files.
 RSTIMINC

RSTIMINC is the time increment of the input wave radiation stress data from the Wave Radiation Stress Forcing File (fort.23) in seconds. This value must be specified in the if the 100s place in NWS is nonzero.
 YYYY MM DD HH24

Year, month, day, and hour corresponding to ADCIRC cold start time; used by NWS=8 (Symmetric Holland Vortex Model) to determine the model time relative to the date/times in the fort.22 (ATCF file).
 StormNumber

Experimental parameter for NWS=8 (Symmetric Holland Vortex Model); should always be set to 1.
 BLAdj

BLAdj is the adjustment factor between wind speed at 10m and the wind speed at the top of the atmospheric boundary layer (winds at top of atm. b.l.)=(winds at 10m)/BLAdj. Reasonable range is 0.7 to 0.9.
 IREFYR, IREFMO, IREFDAY, IREFHR, IREFMIN, REFSEC

These arethe starting time parameters (year, month, day, hour, minute, second at the start of the simulation) for a Single File Meteorological Forcing Input File in US Navy Fleet Numeric format (1s place in NWS is 3). These values are used in ADCIRC to compute WREFTIM which is the start time of the simulation in seconds since the beginning of the calendar year. ADCIRC is configured to accept only 1 calendar year’s data, i.e., it is not possible to combine Fleet Numeric met data from two different years into a single file and then run.
 NWLAT, NWLON, WLATMAX, WLONMIN, WLATINC, WLONINC

These parameters describe the spatial structure of a Single File Meteorological Forcing Input File where met data is set up on a simple rectangular grid (1s place of NWS is 3 or 6).
 NWLAT

number of latitude values in the met file.
 NWLON

number of longitude values in met file.
 WLATMAX

maximum latitude (decimal deg) of data in met file (lt 0 south of the equator).
 WLONMIN

minimum longitude (decimal deg) of data in the met file (lt 0 west of Greenwich meridian).
 WLATINC

latitude increment (decimal deg) of data in the met file (must be > 0).
 WLONINC

longitude increment (decimal deg) of data in the met file (must be > 0).
RNDAY
RNDAY is the length of the ADCIRC run (in decimal days).
DRAMP
The DRAMP line is conditionally formatted, with higher values of NRAMP corresponding to greater control over ramping of forcing physics.
DRAMP=0

No ramp function is used with forcing functions. 
DRAMP=1

A hyperbolic tangent ramp function is specified and applied to forcing from surface elevation specified boundary conditions, nonzero flux boundary conditions, tidal potential, wind and atmospheric pressure and wave radiation stress. 
DRAMP=2

A hyperbolic tangent ramp function is specified and applied to forcing from surface elevation specified boundary conditions, tidal potential, wind and atmospheric pressure and wave radiation stress. A separate hyperbolic tangent ramp function is specified and applied to the nonzero external flux boundary conditions. See description of DRAMP for further information on the ramp function. 
DRAMP=3

A hyperbolic tangent ramp function is specified and applied to forcing from tidal potential, wind and atmospheric pressure and wave radiation stress. Two additional hyperbolic tangent ramp functions are specified and applied to the nonzero external flux boundary conditions and the nonzero internal flux boundary conditions. See description of DRAMP for further information on the ramp function. 
DRAMP=4

A hyperbolic tangent ramp function is specified and applied to forcing from tidal potential, wind and atmospheric pressure and wave radiation stress. Two additional hyperbolic tangent ramp functions are specified and applied to the nonzero external flux boundary conditions, the nonzero internal flux boundary conditions and the surface elevation specified boundary conditions. See description of DRAMP for further information on the ramp function. 
DRAMP=5

A hyperbolic tangent ramp function is specified and applied to forcing from wind and atmospheric pressure and wave radiation stress. Four additional hyperbolic tangent ramp functions are specified and applied to the nonzero external flux boundary conditions and the nonzero internal flux boundary conditions, the surface elevation specified boundary conditions and to the tidal potential. See description of DRAMP for further information on the ramp function. 
DRAMP=6

A hyperbolic tangent ramp function is specified and applied to forcing from wave radiation stress. Five additional hyperbolic tangent ramp functions are specified and applied to the nonzero external flux boundary conditions, the nonzero internal flux boundary conditions, the surface elevation specified boundary conditions, to the tidal potential and the wind and atmospheric pressure. See description of DRAMP for further information on the ramp function. 
DRAMP=7

A general hyperbolic tangent ramp function is specified, and six additional hyperbolic tangent ramp functions are specified and applied to the nonzero external flux boundary conditions, the nonzero internal flux boundary conditions, the surface elevation specified boundary conditions, to the tidal potential, the wind and atmospheric pressure, and the wave radiation stress. See description of DRAMP for further information on the ramp function. 
 DRAMP

Value (in decimal days) used to compute the ramp function that ramps up ADCIRC forcings from zero (if NRAMP=1). The ramp function is computed as RAMP=tanh(2.0*IT*DTDP/(86400.*DRAMP)) where IT = the time step number since the beginning of the model run. DRAMP is equal to the number of days when RAMP=0.96.
 DRAMPExtFlux

Value (in decimal days) used to compute the ramp function that ramps up the nonzero external flux boundary condition.
 FluxSettlingTime

Time in days that it takes for the river flux boundary condition and the river bottom friction to equilibrate so the water surface elevation can find its steady state. From the start of the simulation until FluxSettlingTime has passed, the only forcing that is active is the external boundary flux forcing. All other forcings are set to zero. Once the FluxSettlingTime has passed, the other forcing functions begin their ramp up.The new IBTYPE=52 only works with periodic flux boundary conditions. Nonperiodic flux boundary conditions cannot be specified for IBTYPE=52 boundaries.
 DRAMPIntFlux

Value (in decimal days) used to compute the ramp function that ramps up the nonzero internal flux boundary condition.
 DRAMPElev

Value (in decimal days) used to compute the ramp function that ramps up the elevationspecified boundary condition.
 DRAMPTip

Value (in decimal days) used to compute the ramp function that ramps up the tidal potential.
 DRAMPMete

Value (in decimal days) used to compute the ramp function that ramps up the wind and atmospheric pressure.
 DRAMPWRad

Value (in decimal days) used to compute the ramp function that ramps up the wave radiation stress.
A00 B00 C00
A00 B00 C00 represent time weighting factors (at time levels k+1, k, k1, respectively) in the GWCE.
H0
 H0

Minimum water depth. If NOLIFA = 0, 1, H0 = minimum bathymetric depth: all bathymetric depths in the Grid and Boundary Information File less than H0 are changed to be equal to H0. If NOLIFA = 2, H0 = nominal water depth for a node (and the accompanying elements) to be considered dry (typical value 0.01  0.1 m).
 INTEGER

In the past, the wetting and drying algorithm required two additional integers as input. These extra parameters are no longer needed by the code, but they are still present to maintain backward compatibility. Their values will be ignored.
 VELMIN

Minimum velocity for wetting. A dry node wets if a water surface slope exists that would drive water from a currently wet node to the dry node and the steadystate current velocity that resulted would have a velocity > VELMIN. This parameter helps to keep nodes/elements from repeatedly turning on and off during the wetting process. A typical value might be 0.05 m/s.
SLAM0, SFEA0
SLAM0 and SFEA0 are the longitude and latitude on which the CPP coordinate projection is centered (in degrees) if ICS = 2.
Bottom Friction (TAU, CF, HBREAK, FTHETA, FGAMMA)
The bottom friction parameters line is conditionally formatted based on the value of NOLIBF, provided earlier in the file.
 TAU

Bottom friction is a linear function of depthaveraged velocity and TAU is the corresponding linear friction coefficient (units of 1/sec). In this case it is strongly recommended that TAU0 = TAU (Used with NOLIBF = 0). If some type of spatially varying bottom friction is specified in the NWP section, this input is ignored, and the friction coefficients will be read in from the nodal attributes file.
 CF

CF is the 2DDI bottom friction coefficient used in ADCIRC unless spatially varying bottom friction is specified using nodal attributes. If Manning’s n is the spatially variable friction coefficient, then CF will be used as the floor on the equivalent quadratic friction coefficient (see the documentation on the Manning’s n nodal attribute for the formula used to convert Manning’s n to an equivalent quadratic friction coefficient). If some other type of spatially varying bottom friction is specified in the NWP section, then CF is ignored entirely. If NOLIBF = 1, bottom friction is a quadratic function of depthaveraged velocity and FFACTOR is the corresponding quadratic friction coefficient (dimensionless). If NOLIBF = 2, minimum friction coefficient (dimensionless) in the hybrid bottom friction relationship. This friction coefficient is approached in deep water (H > HBREAK) where the hybrid friction relationship reverts to a quadratic function of depthaveraged velocity.
 HBREAK

The break depth (units of length) utilized for NOLIBF = 2 in the hybrid bottom friction relationship FFACTOR = FFACTORMIN*[1+(HBREAK/H)FTHETA](FGAMMA/FTHETA). If the water depth (H) is greater than HBREAK, bottom friction approaches a quadratic function of depthaveraged velocity with FFACTOR = FFACTORMIN. If the water depth is less than HBREAK, the friction factor increases as the depth decreases (e.g. like a manning type friction law). (HBREAK = 1 m is recommended). If some type of spatially varying bottom friction is specified in the NWP section, this input is ignored, and the friction coefficients will be read in from the nodal attributes file.
 FTHETA

A parameter (dimensionless) that determines (for NOLIBF = 2) how rapidly the hybrid bottom friction relationship approaches its deep water and shallow water limits when the water depth is greater than or less than HBREAK. (FTHETA = 10 is recommended). If some type of spatially varying bottom friction is specified in the NWP section, this input is ignored, and the friction coefficients will be read in from the nodal attributes file.
 FGAMMA

A parameter (dimensionless) that determines (for NOLIBF = 2) how the friction factor increases as the water depth decreases. Setting this to 1/3 gives a manning friction law type of behavior (FGAMMA = 1/3 is recommended). If some type of spatially varying bottom friction is specified in the NWP section, this input is ignored, and the friction coefficients will be read in from the nodal attributes file.
ESLM
 ESLM

Spatially constant horizontal eddy viscosity for the momentum equations (units of length2/time).
 ESLC

Spatially constant horizontal eddy diffusivity for the transport equation (units of length2/time). This is only specified if IM = 10.
CORI
CORI is the constant Coriolis coefficient. This value is always read in, however it is only used in the computations when NCOR = 0.
NTIF
NTIF and associated parameters control tidal potential forcing.
 NTIF

number of tidal potential constituents
 TIPOTAG(I)

Constituent name (M2, S2, etc).
 TPK(I),AMIGT(I),ETRF(I),FFT(I),FACET(I), I=1,NTIF

Tidal potential amplitude, frequency, earth tide potential reduction factor (generally taken to be 0.690 for all constituents (Hendershott) but for more precise calculations can take on slightly different values (e.g. see Wahr, 1981)), nodal factor and equilibrium argument in degrees.
Boundary Conditions
NBFR
 NBFR

number of periodic forcing frequencies on elevation specified boundaries. If NBFR=0 and a nonzero number of elevation specified boundary segments are included in the Grid and Boundary Information File, the elevation boundary condition is assumed to be nonperiodic and will be read in from the Nonperiodic Elevation Boundary Condition File. For reasons of backward compatability, NBFR is included in the Model Parameter and Periodic Boundary Condition File regardless of whether any elevation specified boundaries (IBTYPE=0) are defined in the fort.14 input.
 BOUNTAG(k)
 AMIG(k),FF(k),FACE(k) k=1,NBFR

Forcing frequency, nodal factor, equilibrium argument in degrees for tidal forcing on elevation specified boundaries.
ANGINN
ANGINN are the flow boundary nodes which are set up to have a normal flow essential boundary condition and have an inner angle less than ANGINN (specified in degrees) will have the tangential velocity zeroed. In either case, the normal velocity will be determined from the essential boundary condition.
NFFR
The NFFR parameter controls the flux at flux boundaries, such as rivers.
 NFFR

Number of frequencies in the specified normal flow external boundary condition. If NFFR=0, the normal flow boundary condition is assumed to be nonperiodic and will be read in from the Nonperiodic, Normal Flux Boundary Condition File. NFFR is only included in the Model Parameter and Periodic Boundary Condition File if one or more specified (nonzero) normal flow external boundaries were defined in the Grid and Boundary Information File (IBTYPE=2,12 OR 22).
Periodic Flux Boundary Parameters
 FBOUNTAG(k)

A short name or tag for constituent k of the periodic flux forcing.
 FAMIGT(k),FFF(k),FFACE(k) k=1,NFFR

Forcing frequency, nodal factor, equilibrium argument in degrees for periodic normal flow forcing on flow boundaries. These values are preceded by FBOUNTAG(k), an alphanumeric descriptor (i.e. the constituent name)
 ALPHA

see description of EMO(k,j), EFA(k,j) (⇐ 10 characters)
The EMO(k,j) and EFA(k,j) parameters control the amplitude and phase at periodic elevation specified boundaries.
 EMO(k,j) EFA(k,j) k=1,NBFR , j=1,NETA

Amplitude and phase (in degrees) of the harmonic forcing function at the elevation specified boundaries for frequency k and elevation specified boundary forcing node j. NOTE that the parameter NETA is defined and read in from Grid and Boundary Information File: the forcing values are preceded by an alphanumeric descriptor EALPHA to facilitate verifying that the correct data matches a given frequency
Alpha, QNAM(k,j) and QNPH(k,j) control the naming, amplitude, and phase of the harmonic constituents that drive periodic flux boundaries.
 ALPHA

Name or tag for a particular harmonic constituent of a periodic periodic flux boundary (must be less than or equal to 10 characters in length).
 QNAM(k,j) ,QNPH(k,j) k=1,NFFR, j=1,NFLBN

Amplitude and phase (in degrees) of the periodic normal flow/unit width (e.g. m2/s) for frequency I and "specified normal flow" boundary node j. A positive flow/unit width is into the domain and a negative flow/unit width is out of the domain. The forcing values are preceded by an alphanumeric descriptor ALPHA to facilitate verifying that the correct data matches a given frequency.
 ENAM(k,j) ,ENPH(k,j) k=1,NFFR, j=1,NFLBN

Amplitude and phase of outgoing wave in IBTYPE=32 boundary condition (in degrees).
Output Control
The ADCIRC output control parameters all follow the same pattern: there is a parameter to control the output format and appending behavior (NOUTx); there is a parameter to control when the output starts (TOUTSx, in days after cold start); there is a parameter to control when the output should finish (TOUTFx, in days after cold start); and there is a time step increment for output (NSPOOLx).
If the NOUTx parameter is negative, then the corresponding file will be started anew upon hotstarting ADCIRC. If the NOUTx parameter is positive, then the corresponding output file will be appended (in the proper position within the file) upon hotstart.
The absolute value of the NOUTx parameter is used to specify the output format as shown in the following table.
abs(NOUTx)=1

Output is an ascii file format. 
abs(NOUTx)=2

Output is a platformspecific (nonportable) binary file. 
abs(NOUTx)=3

Output is in NetCDF format. 
abs(NOUTx)=4

Output is in ascii "sparse" format, where only the values at wetted nodes are in the file. 
The TOUTSx and TOUTFx parameters are interpreted as relative to STATIM.
In the case of recording stations and their locations, if ICS = 1, coordinates are interpreted as standard cartesian. If ICS = 2, coordinates are interpreted as degrees longitude and latitude. In other words, the station coordinates should be consistent with the nodal coordinates in the mesh (fort.14) file.
If a recording station has coordinates that do not lie within the computational domain, a nonfatal error message will appear. If NFOVER has been set equal to 1, the code will estimate the nearest element and use that as the basis of interpolation. A proximity index is also printed out, which indicates how close or far the station coordinates are from the nearest element. This index may be interpreted as the number of elements that the station lies from the nearest element.
NOUTE, TOUTSE, TOUTFE, NSPOOLE
Output parameters for the water surface elevations at station locations (fort.61 file).
NSTAE
NSTAE is the number of elevation recording stations. This NSTAE line must be included, even if NSTAE is zero and NOUTE is zero.
 XEL(k), YEL(k)

The coordinates of the elevation recording station k, for all NSTAE stations.
NOUTV, TOUTSV, TOUTFV, NSPOOLV
These output parameters for the 2DDI water current velocities at station locations (fort.62 file).
NSTAV
NSTAV is the number of 2DDI water current velocity recording stations. This NSTAV line must be included, even if NSTAV is zero and NOUTV is zero.
 XEV(k), YEV(k)

The coordinates of the water current velocity recording station k, for all NSTAV stations.
NOUTC, TOUTSC, TOUTFC, NSPOOLC
Include this line only if IM =10
Output parameters for the 2DDI passive tracer at station locations (fort.81 file).
NSTAC
Include this line only if IM =10
 XEC(k), YEC(k)

The coordinates of the 2DDI passive tracer recording station k, for all NSTAC stations.
NOUTM, TOUTSM, TOUTFM, NSPOOLM
Include this line only if NWS = 1, 2, 3, 4, 4, 5, 5, 6, 8, 9, 10, 101, 102, 103, 104, 104, 105, 105, 110, 111.
Output parameters for barometric pressure at station locations (fort.71 file), and the wind at station locations (fort.72 file). The data in the fort.72 file could be wind stress or wind velocity; units here will match that of the meteorological input data).
NSTAM
Include this line only if NWS = 1, 2, 3, 4, 4, 5, 5, 6, 8, 9, 10, 101, 102, 103, 104, 104, 105, 105, 110, 111.
 XEM(k), YEM(k)

The coordinates of the meteorological recording stations, for all NSTAM stations.
NOUTGE, TOUTSGE, TOUTFGE, NSPOOLGE
Parameters to control output of full domain water surface elevation (fort.63 file).
NOUTGV, TOUTSGV, TOUTFGV, NSPOOLGV
Parameters to control output of full domain 2DDI water current velocity (fort.64 file).
NOUTGC, TOUTSGC, TOUTFGC, NSPOOLGC
Include this line only if IM =10
Parameters to control output of full domain 2DDI passive tracer concentration (fort.83).
NOUTGW, TOUTSGW, TOUTFGW, NSPOOLGW
Include this line only if NWS =1, 2, 3, 4, 4, 5, 5, 6, 8, 9, 10, 101, 102, 103, 104, 104, 105, 105, 110, 111.
Parameters to control output of full domain barometric pressure (fort.73) and winds (fort.74).
Harmonic Analysis
NFREQ
NFREQ is the number of frequencies included in harmonic analysis of model results. Harmonic output is only available for water surface elevation and 2DDI water current velocity.
 NAMEFR(k)

An alphanumeric descriptor (the constituent name, e.g. M2, N2, S2, etc) whose length must be 10 characters or less; this constituent is to be included in the harmonic analysis.
 HAFREQ(k), HAFF(k), HAFACE(k) k=1,NFREQ

Parameters describing the constituents to be included in the harmonic analysis of model results.
 HAFREQ(k)

Ffrequency (rad/s).
 HAFF(k)

Nodal factor.
 HAFACE(k)

Equilibrium argument (degrees).
Note

If a steady component will be included in the harmonic analysis, this must be the first constituent listed (i.e., the constituent corresponding to k=1). 
THAS, THAF, NHAINC, FMV
Parameters that control the calculation of harmonic constituents both at stations and globally.
 THAS

The number of days after which time series data starts to be harmonically analysed.
 THAF

The number of days after which time series data ceases to be harmonically analysed.
Note

THAS and THAF are relative to STATIM. If STATIM is zero, then THAS and THAF are relative to the coldstart time. 
 NHAINC

The number of time steps at which information is harmonically analysed (information every NHAINC time steps after THAS is used in harmonic analysis).
 FMV

Fraction of the harmonic analysis period (extending back from the end of the harmonic analysis period) to use for comparing the water elevation and velocity means and variances from the raw model time series with corresponding means and variances of a time series resynthesized from the harmonic constituents. This comparison is helpful for identifying numerical instabilities and for determining how complete the harmonic analysis was. Examples:
FMV=0

Do not compute any means and vars. 
FMV=0.1

Compute means and vars. over final 10% of period used in harmonic analysis. 
FMV=1.0

Compute means and vars. over entire period used in harmonic analysis. 
Note

The means and variance calculations are only done if global harmonic calculations are performed. Results are written out to fort.55. A summary of the poorest comparisons throughout the domain and the node numbers where these occurred is given at the end of the fort.16 output file. 
Warning

the time series resysthesis from the harmonic constituents can use up a lot of CPU time since this is done for every time step during the specified part of the harmonic analysis period. If the harmonic analysis period extends for only a few days, it is practical to set FMV=1. Otherwise, it becomes unreasonably time consuming to compute means and variances for more than 1020 days. Ultimately, the practical limit to these calculations depends on the number of nodes, the number of constituents in the harmonic analysis, and the size of the time step. 
NHASE, NHASV, NHAGE, NHAGV
Parameters that control the spatial locations where harmonic analysis is performed. When set to zero, harmonic analysis will be skipped. When set to 1, harmonic analysis will be performed.
 NHASE

Activation of harmonic analysis water surface elevation at elevation recording stations. Output will be written to the fort.51 file.
 NHASV

Acitvation of harmonic anaylsis at 2DDI water current velocity recording stations. Output will be written to the fort.52 file.
 NHAGE

Activation of harmonic analysis of water surface elevation at all nodes. Output will be written to the fort.53 file.
 NHAGV

Activation of harmonic analysis of 2DDI water current velocity at all nodes. Output will be written to the fort.54 file.
Hotstarting: NHSTAR, NHSINC
Parameters that control the generation of hot start output and the format of the hotstart file that ADCIRC writes.
 NHSTAR

Activation and format of hot start file output.
 NHSINC

The number of time steps between hotstart file writes (hot start file is generated every NHSINC time steps).
NHSTAR=0

Hot start files will not be generated. 
NHSTAR=1

Hot start output files generated in nonportable binary format. 
NHSTAR=3

Hot start output files generated in netCDF format. 
Solver: ITITER, ISLDIA, CONVCR, ITMAX
Parameters that provide information about the solver that will be used for the GWCE.
 ITITER

Solution algorithm that ADCIRC should use to solve the GWCE.
 ISLDIA

Logging verbosity level from ADCIRC’s iterative solver (based on itpack).
 CONVCR

Absolute convergence criteria if iterative solver is selectedi (should be no smaller than 500 times the machine precision).
 ITMAX

Maximum number of iterations per time step for iterative solver, if the iterative solver was selected.
ITITER=1

Use for lumped, explicit GWCE, matrix is diagonal and no external solver is needed. 
ITITER=1

use iterative JCG solver (from ITPACKV 2D). 
ISLDIA=0

fatal error messgs only from ITPACKV 2D(fort.33) 
ISLDIA=1

warning messgs and minimum output from ITPACKV 2D (fort.33) 
ISLDIA=2

reasonable summary of algorithm progress from ITPACKV 2D (fort.33) 
ISLDIA=3

parameter values and informative comments from ITPACKV 2D (fort.33) 
ISLDIA=4

approximate solution after each iteration from ITPACKV 2D (fort.33) 
ISLDIA=5

original system from ITPACKV 2D (fort.33) 
Note

All of the parameters must be input regardless of whether a diagonal or iterative solver is selected. However, ISLDIA, CONVCR and ITMAX are only used with the iterative solvers 
Note

We typically use CONVCR=1E6 on the CRAY and CONVCR=1E5 on a 32 bit machine. After the first few time steps, the solutions usually converge within 510 iterations. 
For a 2DDI ADCIRC run that does not use NetCDF, the file ends here. For any ADCIRC run that uses NetCDF, the lines NCPROJ through NCDATE (described at the end of this file format) are required metadata and must be added at the end of the fort.15 file.
3D Physics
The definition of IDEN was provided previously.
ISLIP, KP
ISLIP and KP are used to control the parameterization of bottom friction in ADCIRC.
 ISLIP

3D bottom friction code.
 KP

3D bottom friction coefficient used in ADCIRC.
ISLIP=0

No slip bottom b.c.; KP value is ignored. 
ISLIP=1

Linear slip bottom b.c.; KP is interpreted as the corresponding linear friction coefficient (units of velocity). 
ISLIP=2

Bottom friction is computed using the log layer formula and KP is the minimum quadratic bottom friction coefficient (dimensionless). 
ISLIP=3

Bottom friction is a quadratic function of bottom velocity and KP is the corresponding quadratic friction coefficient (dimensionless). 
Z0S,Z0B
Z0S and Z0B represent the free surface and bottom roughnesses (constant over horizontal). If the turbulent length scale is determined by q2l eqn and a slip coefficient is used, this should be the thickness of the constant stress layer (e.g., 1 m) above the surface boundary node and below the bottom boundary node.
For IEVC=50, Z0S is the spatially constant surface roughness length. For IEVC=51, the surface roughness length is computed dynamically (see IEVC=51), and Z0S is the minimum surface roughness length. For nodal attributes bottom_roughness_length and mannings_n_at_the_sea_floor, the bottom roughness length is read in from the nodal attribute file either directly or as a Manning’s n roughness. Currently Z0B is not used for either of these two cases. If a Manning’s n roughness is read in, the roughness length is expressed in terms of the water depth H and the Manning’s n, where κ = 0.4 is the von Karman constant, and g is the gravitational acceleration (Bretschneider et al., 1986). New roughness lengths are computed at each time step, based on the computed water depth and Manning’s n value at each mesh vertex.
ALP1,ALP2,ALP3
ALP1 are the time weighting coefficients for the 3D velocity solution.
 ALP1

weights the Coriolis term
 ALP2

weights the bottom friction terms
 ALP3

weights the vertical diffusion terms
0.0

fully explicit 
0.5

time centered 
1.0

fully implicit 
IGC,NFEN
 IGC

vertical grid code
 NFEN

number of nodes in the vertical grid
 SIGMA(k)

dimensionless level of the vertical grid node K from 1 (bottom) to +1 (surface)
IGC=0

vertical grid read in 
IGC=1

uniform vertical grid generated 
IGC=2

log vertical grid generated 
IGC=3

log linear vertical grid generated 
IGC=4

double log vertical grid generated 
IGC=5

Pgrid generated 
IGC=6

sine grid generated 
IEVC, EVMIN, EVCON
IEVC, EVMIN and EVCON are used to parameterize turbulence in the vertical in the 3D model.
 IEVC

vertical eddy viscosity code
 EVMIN

vertical eddy viscosity minimum value
 EVCON

vertical eddy viscosity constant
 EVTOT(K)

eddy viscosity associated with vertical grid node K
Note

EVCON is only used for some of the vertical eddy viscosity formulations as discussed below. 
Note

In cases where vertical eddy viscosity is specified to vary linearly over the lower 20% of the water column, it actually varies linearly with a constant slope up to the vertical FE grid node that is less than or equal to the 20% location. The value is constant as specified at all FE grid nodes above the 20% location. The vertical eddy viscosity above and below the 20% level is joined by one additional linearly varying segment. 
Note

The vertical eddy viscosity is constrained to always be greater than or equal to EVMIN. 
The values of IEVC are defined below.
IEVC=0or1

EV constant in time and horizontal space 
IEVC = 0

vertical eddy viscosities with respect to depth (i.e., EVTOT(k)) are read in on the following lines and EVCON is not used 
IEVC = 1

vertical eddy viscosity will be set to EVCON everywhere 
IEVC = 10 or 11

vertical eddy viscosity is proportional to omega*h*h (Lynch and Officer (1986) Lynch and Werner (1987, 1991)) 
IEVC = 10

EV = omega*h*h/10 over the entire water column 
IEVC = 11

EV = omega*h*h/1000 at bottom varies linear over lower 20% of water column and EV = omega*h*h/10 in upper 80% of water column. For this vertical eddy viscosity formulation, EVCON is not used and omega is hardwired for a 12.42 hour tide. 
IEVC = 20 or 21

EV proportional to kappa U* z 
IEVC = 20

EV = 0.41U*Zo at bottom and EV = 0.41U*Z over entire water column 
IEVC = 21

EV = 0.41U*Zo at bottom, EV = 0.41U*Z in lower 20% of water column, and EV = 0.082U*h in upper 80% of water column where U* is the friction velocity. For this EV formulation, EVCON is not used. 
IEVC = 30, 31, 32, or 33

EV proportional to Uh (Davies 1990). For this vertical eddy viscosity formulation, EVCON is used only for IEVC =31,33. 
IEVC = 30

EV = 0.025Uh/9.001 over entire water column 
IEVC = 31

EV = EVCON Uh over entire water column 
IEVC = 32

EV = 0.025Uh/9.001 in upper 80% of water column, EV = 0.000025hU/9.001 at bottom varies linear over lower 20% of water column 
IEVC = 33

EV = EVCON Uh in upper 80% of water column, EV = EVCON Uh/1000. at bottom varies linear over lower 20% of water column where U is depth averaged velocity. 
IEVC = 40, 41, 41, 43

EV proportional to U*U (Davies 1990). For this EV formulation, EVCON is used only for IEVC=41,43. 
IEVC = 40

EV = 2UU/9.001 over entire water column. 
IEVC = 41

EV = EVCON UU over entire water column 
IEVC = 42

EV = 2UU/9.001 in upper 80% of water column, EV = 0.002UU/9.001 at bottom varies linear over lower 20% of water column 
IEVC = 43

EV = EVCON UU in upper 80% of water column, EV = EVCON UU/1000. at bottom varies linear over lower 20% of water column where U is depth averaged velocity. 
IEVC = 50

EV computed from MellorYamada L2.5 closure. For this EV formulation, EVCON is not used. 
IEVC = 51

EV computed from MellorYamada L2.5 closure with parameterizations to include enhanced mixing in the surface layer. For this EV formulation, EVCON should be set to alpha in the surface roughness equation (order 10e4 to 10e5). In the surface TKE flux equation, alpha=150. 
THETA1, THETA2
Include this line only if IEVC = 50 or 51. THETA1 and THETA2 are time weighting coefficients for the MY2.5 turbulence solution.
 THETA1

Weights the dissipation term.
 THETA2

Weights the vertical diffusion term.
0.0

fully explicit 
0.5

time centered 
1.0

fully implicit 
3D Output Control
The 3D ADCIRC output control parameters follow a pattern similar to the other ADCIRC output parameters: there is a parameter to control the output format and appending behavior (I3Dxx); there is a parameter to control when the output starts (T3DOSxx, in days after cold start); there is a parameter to control when the output should finish (T3DOFxx, in days after cold start); and there is a time step increment for output (NSPO3Dxx).
If the I3Dxx parameter is negative, then the corresponding file will be started anew upon hotstarting ADCIRC. If the I3Dxx parameter is positive, then the corresponding output file will be appended (in the proper position within the file) upon hotstart.
The absolute value of the I3Dxx parameter is used to specify the output format in the same way as that described for output parameters previously, with the exception being the ascii "sparse" format, which is not available in 3D.
I3DSD,TO3DSDS,TO3DSDF,NSPO3DSD
Parameters controlling 3D output to the temperature, salinity, and/or density recording station output file (fort.41). The content of this file will depend on the value of IDEN; if temperature was specified, then the file will contain temperature profiles at the station location; if salinity was selected via IDEN, then the file will contain salinity data, etc.
NSTA3DD
I3DSV,TO3DSVS,TO3DSVF,NSPO3DSV
NSTA3DV
I3DST,TO3DSTS,TO3DSTF,NSPO3DST
NSTA3DT
I3DGD,TO3DGDS,TO3DGDF,NSPO3DGD
Parameters controlling 3D output to the full domain temperature, salinity, and/or density output file (fort.44). The content of this file will depend on the value of IDEN; if temperature was specified, then the file will contain temperature profiles at the station location; if salinity was selected via IDEN, then the file will contain salinity data, etc.
I3DGV,TO3DGVS,TO3DGVF,NSPO3DGV
3D Baroclinic Physics
The following lines will be read in only if IDEN is > 0.
NLSD, NVSD
NLTD, NVTD
Metadata
The following data will be stored in NetCDF output and hotstart files. These data will be read in only if netCDF was selected as an output file format or hotstart file format.