MB-System Unix Manual Page: mblevitus

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    mblevitus
    Section:  MB-System 5.0  (1)
    Updated:  26 October 2009
    Index

    NAME

    mblevitus - Create a water velocity profile which is representative
    of the mean annual water column for a specified 1 degree by 1 degree
    region.

    VERSION

    Version 5.0

    SYNOPSIS

    mblevitus [-Rlon/lat -Ooutfile -V -H]

    DESCRIPTION

    mblevitus generates a mean water sound velocity profile for a
    specified location using temperature and salinity data
    from the 1982 Climatological Atlas of the World Ocean [Levitus, 1982].
    The water velocity profile is representative of the mean annual
    water column structure for a specified 1 degree by 1 degree region.
    The profile is output to a specified file which can be read and
    used by programs (e.g. mbbath or mbvelocitytool)
    which calculate swath sonar sonar
    bathymetry from travel times by raytracing through a water velocity
    model.

    The Levitus [1982] reference is:

         Levitus, S, Climatological Atlas of the World Ocean,

         NOAA Professional Paper 13, U.S. Government Printing Office,

         Washington D.C., 173pp, 1982.

    The water sound velocity values are calculated using
    the DelGrosso equations, following:

         Dusha, B. D., P. F. Worcester, B. D. Cornuelle,

           B. M. Howe, "On equations for the speed of

           sound in seawater", J. Acoust. Soc. Am., 93,

           255-275, 1993

    The implementation of these equations follows code written
    at the Ocean Data Facility of the Scripps Institution of
    Oceanography.
    The depth to which the Levitus database defines the water
    column reflects regional water depths which may be exceeded in
    places.  mblevitus extends the water sound velocity profiles
    to a depth of 12000 meters using the deepest salinity and
    temperature values available in the database.
    If the specified location is
    subaerial, then no water velocity profile is calculated.

    AUTHORSHIP

    David W. Caress (caress@mbari.org)

      Monterey Bay Aquarium Research Institute

    Dale N. Chayes (dale@ldeo.columbia.edu)

      Lamont-Doherty Earth Observatory

    OPTIONS

    -H

    This "help" flag cause the program to print out a description
    of its operation and then exit immediately.
    -O

    outfile

    Sets the output file for the water velocity profile.
    Default: outfile = "velocity".
    -R

    lon/lat

    Sets the longitude and latitude of the location of the water
    velocity profile.  Whole degrees should be used, as the database
    has a 1 degree by 1 degree resolution.
    Default: lon=0, lat=0.
    -V

    Normally, mblevitus outputs only a minor bit of information
    to the stdout stream.  If the
    -V flag is given, then mblevitus works in a "verbose" mode and
    also outputs the program version being used and the complete
    water column structure used to calculate the water velocity profile.

    EXAMPLES

    Suppose that one wishes to obtain a mean annual water velocity profile
    for processing Hydrosweep DS bathymetry data collected on the
    Cocos-Nazca spreading center at 95W longitude and 2N latitude.
    The following will suffice:

            mblevitus -R-95/2 -Ovelocity_profile -V

    The output will be:

     Program MBLEVITUS

     MB-system Version 4.5

     Location for mean annual water velocity profile:

       Requested:  -95.0000 longitude   2.0000 latitude

       Used:       265.5000 longitude   2.5000 latitude

     Values defined directly by Levitus database:      27

     Values assuming deepest salinity and temperature: 19

     Velocity points written:                          46

     Output file: velocity_profile

     Mean annual water column profile:

          Depth Temperature Salinity   Velocity

         0.0000   25.6560   33.8830   1534.6998

        10.0000   25.4080   33.8230   1534.2112

        20.0000   24.5410   34.0190   1532.5010

        30.0000   23.3290   34.2400   1529.9032

        50.0000   19.7940   34.7450   1521.4298

        75.0000   15.9700   34.9210   1510.8373

       100.0000   14.5630   34.9400   1506.8495

       125.0000   13.9500   34.9320   1505.2728

       150.0000   13.5920   34.9270   1504.5077

       200.0000   13.0430   34.9100   1503.4935

       250.0000   12.4510   34.8780   1502.2893

       300.0000   11.4720   34.8190   1499.6840

       400.0000    9.4060   34.6990   1493.8119

       500.0000    8.0400   34.6390   1490.2903

       600.0000    7.0330   34.5950   1488.0126

       700.0000    6.2200   34.5740   1486.4380

       800.0000    5.5640   34.5620   1485.4464

       900.0000    5.0280   34.5620   1484.9211

      1000.0000    4.5840   34.5650   1484.7546

      1100.0000    4.1950   34.5730   1484.8076

      1200.0000    3.8570   34.5820   1485.0649

      1300.0000    3.5860   34.5970   1485.6061

      1400.0000    3.3320   34.6090   1486.2123

      1500.0000    3.1020   34.6140   1486.9097

      1750.0000    2.6290   34.6280   1489.0920

      2000.0000    2.3010   34.6440   1491.9139

      2500.0000    1.8770   34.6670   1498.6154

      3000.0000    0.0000    0.0000   1507.2345

      3500.0000    0.0000    0.0000   1515.9406

      4000.0000    0.0000    0.0000   1524.7273

      4500.0000    0.0000    0.0000   1533.5883

      5000.0000    0.0000    0.0000   1542.5173

      5500.0000    0.0000    0.0000   1551.5078

      6000.0000    0.0000    0.0000   1560.5533

      6500.0000    0.0000    0.0000   1569.6471

      7000.0000    0.0000    0.0000   1578.7823

      7500.0000    0.0000    0.0000   1587.9523

      8000.0000    0.0000    0.0000   1597.1499

      8500.0000    0.0000    0.0000   1606.3682

      9000.0000    0.0000    0.0000   1615.6001

      9500.0000    0.0000    0.0000   1624.8383

     10000.0000    0.0000    0.0000   1634.0754

     10500.0000    0.0000    0.0000   1643.3042

     11000.0000    0.0000    0.0000   1652.5171

     11500.0000    0.0000    0.0000   1661.7062

     12000.0000    0.0000    0.0000   1670.8641

    The contents of the output file velocity_profile are:

     # Water velocity profile created by program MBLEVITUS

     # MB-system Version 4.5

     # Run by user <caress> on cpu <menard> at <Wed Mar 26 15:43:53 1997>

     # Water velocity profile derived from Levitus

     # temperature and salinity database.  This profile

     # represents the annual average water velocity

     # structure for a 1 degree X 1 degree area centered

     # at 265.5000 longitude and 2.5000 latitude.

     # This water velocity profile is in the form

     # of discrete (depth, velocity) points where

     # the depth is in meters and the velocity in

     # meters/second.

     # The first 27 velocity values are defined using the

     # salinity and temperature values available in the

     # Levitus database; the remaining 19 velocity values are

     # calculated using the deepest temperature

     # and salinity value available.

     0.000000 1534.699829

     10.000000 1534.211182

     20.000000 1532.500977

     30.000000 1529.903198

     50.000000 1521.429810

     75.000000 1510.837280

     100.000000 1506.849487

     125.000000 1505.272827

     150.000000 1504.507690

     200.000000 1503.493530

     250.000000 1502.289307

     300.000000 1499.683960

     400.000000 1493.811890

     500.000000 1490.290283

     600.000000 1488.012573

     700.000000 1486.437988

     800.000000 1485.446411

     900.000000 1484.921143

     1000.000000 1484.754639

     1100.000000 1484.807617

     1200.000000 1485.064941

     1300.000000 1485.606079

     1400.000000 1486.212280

     1500.000000 1486.909668

     1750.000000 1489.092041

     2000.000000 1491.913940

     2500.000000 1498.615356

     3000.000000 1507.234497

     3500.000000 1515.940552

     4000.000000 1524.727295

     4500.000000 1533.588257

     5000.000000 1542.517334

     5500.000000 1551.507812

     6000.000000 1560.553345

     6500.000000 1569.647095

     7000.000000 1578.782349

     7500.000000 1587.952271

     8000.000000 1597.149902

     8500.000000 1606.368164

     9000.000000 1615.600098

     9500.000000 1624.838257

     10000.000000 1634.075439

     10500.000000 1643.304199

     11000.000000 1652.517090

     11500.000000 1661.706177

     12000.000000 1670.864136

    SEE ALSO

    mbsystem(l), mbvelocitytool(l), mbprocess(l), mbset(l),
    mbm_xbt(l)

    BUGS

    None known.

     Index

    NAME
    VERSION
    SYNOPSIS
    DESCRIPTION
    AUTHORSHIP
    OPTIONS
    EXAMPLES
    SEE ALSO
    BUGS

Last Updated: 26 October 2009

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