Ambient parameters

Ambient parameters determine the physical properties of the ambient water masses. The properties may with time and depth.

It is required to supply either a complete set of explicit parameters (ambient.time, ambient.depth, ambient.coflow, ambient.crossflow and ambient.dens) or the name of an external file containing the parameters (ambient.csv.file, ambient.nc.file or ambient.roms.file).

ambient.time
Type:

array

Units:

date

Time and date associated with the pipe data.

ambient.depth
Type:

array

Units:

m

Depth below sea surface.

ambient.coflow
Type:

array of arrays

Units:

m / s

Horizontal velocity in co-flow direction, i.e., in the direction parallel to the pipe. There should be one array for each ambient.time value. Each array should have the same number of elements as ambient.depth.

ambient.crossflow
Type:

array of arrays

Units:

m / s

Horizontal velocity in crossflow direction. When facing in the same direction as the pipe outlet, the positive crossflow direction is to the right. There should be one array for each ambient.time value. Each array should have the same number of elements as ambient.depth.

ambient.dens
Type:

array of arrays

Units:

kg / m³

Mass density of ambient water masses. There should be one array for each ambient.time value. Each array should have the same number of elements as ambient.depth. Alternatively: Supply both ambient.temp and ambient.salt, in which case the density is computed using the UNESCO seawater equation of state (Jackett and Mcdougall, 1995).

ambient.salt
Type:

array of arrays

Units:

psu

Salinity of ambient water masses. There should be one array for each ambient.time value. Each array should have the same number of elements as ambient.depth. Either supply both ambient.temp and ambient.salt, or provide values for ambient.dens.

ambient.temp
Type:

array of arrays

Units:

degrees Celcius

Temperature of ambient water masses. There should be one array for each ambient.time value. Each array should have the same number of elements as ambient.depth. Either supply both ambient.temp and ambient.salt, or provide values for ambient.dens.

ambient.csv.file
Type:

string

Read ambient parameters from the specified text file. The file must have one column (with header) for each ambient parameter. Columns must be comma-separated. Lines starting with # are treated as comments, and whitespace is ignored.

ambient.nc.file
Type:

string

Read ambient parameters from the specified netCDF4 file. The file must have one variable for each pipe parameter. Each of the two-dimensional variables should have time as its first dimension and depth as its second dimension.

ambient.roms.file
Type:

string

Read ambient parameters from the ocean model ROMS. If wildcards are given, the matching files are assumed to be ordered sequentially in time. The software reads the fields salt and temp, and computes seawater density from them.

Reading ROMS files requires dask to be installed.

Time must be indexed by the ocean_time coordinate. Horizontal coordinates lat_rho and lon_rho must be present in the first file. Depth coordinates h, Cs_r and vertical parameters hc, Vtransform must also be present.

ambient.roms.latitude
Type:

number

Latitude of the relevant data points from ambient.roms.file.

ambient.roms.longitude
Type:

number

Longitude of the relevant data points from ambient.roms.file.

ambient.roms.azimuth
Type:

number

Units:

degrees

Azimuthal direction of the co-flow direction (i.e., the direction of the pipe outlet). North is 0 and east is 90.


Bibliography

Jackett, D. R., and Mcdougall, T. J. (1995). Minimal Adjustment of Hydrographic Profiles to Achieve Static Stability. Journal of Atmospheric and Oceanic Technology 12(2): 381–89. doi:10.1175/1520-0426(1995)012<0381:MAOHPT>2.0.CO;2.