Shipboard ADCP Archive Center Advances

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     Shipboard Acoustic Doppler Current Profilers (ADCP) have been an increasingly
common configuration on most research vessels over the past decade.  In 1994, the National
Oceanographic Data Center established the Shipboard ADCP Archive Center (SAC) at the
University of Hawaii (UH) (ESM, Vol. 5, No. 3, March 1995).  Through collaboration with
scientists and computer specialists at the UH, the SAC continues to fine tune its management
system and provide high quality data to the scientific community.

       The SAC has a node on the World Wide Web (WWW)
(http://www.soest.hawaii.edu/caldwell/index.html) which provides inventories, plots of cruise
tracks, cruise summaries, and data products.  The primary data product is the ASCII standard
subset of current velocity components averaged hourly in time and to 10 m intervals in the
vertical.   The subset also includes near-surface temperature and ship velocity.  Within the
Web page, explicit instructions on obtaining and contributing data are provided.  The high-
resolution data, which are stored in the Common Oceanographic Data Analysis System
(CODAS) at the time and space intervals as collected at sea and processed on shore, are
presently not available through the WWW although they can be easily transferred upon
request using other media.

     An important technical management advance is the addition of machine signatures
within the CODAS data storage system. This allows CODAS block files written on one type
of computer to be read automatically by another with a different binary design; for example,
CODAS software on an IBM-compatible PC can read CODAS block files created on a SUN. 
This will greatly facilitate distribution of CODAS data and software on CDROMs, the media 
most suitable for these voluminous sets.   The NODC has plans for preparing CDROMs of
shipboard ADCP in the near future.

     The SAC archive now consists of over 120 cruises.  Although the archive continues to
grow at a steady pace, the contribution of data from outside the sphere of influence of the UH
scientists has been disappointing.  The NODC strongly encourages shipboard ADCP data
collectors to provide copies of their high-resolution data sets to the SAC.  As the data
accumulates, more and more applications will be possible, such as regional climatological
charts (Figure 1) in which data from all cruises in the Hawaiian region at the 30 m depth
level were synthesized with other current data sources (current meters and sub-surface
drifters).in preparation of an atlas (R.Lumpkin and P.Flament, SOEST, University of Hawaii,
from the Ocean Atlas of Hawaii, http://satftp/atlas/).


Figure 1. Average surface flow, based on 40,000 observations of ship drift, 
and 85,000 satellite-tracked drifting buoys and 8,000 modern current
measurements. Sources and periods: historical ship drift, 1895-1993, 
National Ocean Data Center (NODC), NOAA; drifting buoys, 1986-1995: Atlantic
Oceanographic and Meteorological Laboratory, NOAA, and Pelagic Fisheries 
Research Project, University of Hawaii; direct current measurements, 
1987 to 1995: Shipboard ADCP Archive Center, University of Hawaii/NODC/NOAA. 
Units: centimeters/seconds. Source of figure: Hawaiian Ocean Atlas, 
http://satftp/atlas/.  The shading denotes Root-mean-square variability of 
modern current observations; higher variability is lighter.

                           
             oOOOOOO                Mr. Patrick Caldwell
          /oOO    OO|               NODC Hawaii Liaison Officer
        oOO/                        Dept. of Oceanography
      /OOO                          University of Hawaii
    /oOOO.O|       _O___            1000 Pope Road, MSB 317
    oOOOOO.Oo     /                 Honolulu, Hawaii 96822 USA
  /oOOOOOOOO..o     |            Internet: caldwell@kapau.soest.hawaii.edu
 ooOOOOOOOOOOO.. ___|_\___       fax: 808-956-2352 or 808-956-4104
 oOOOOOOOOOOOOOOO / OOOooooooo.. office phone: 808-956-4105
 OOOOOOOOOOOOOOOOOOOOOOOOOOOooooooo.....
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