Completed Project: ONR Coastal Mixing and Optics Moored Array Experiment (CMO)

COMBINED NON-DIRECTIONAL WAVE DATA

Release 1.0 February 25, 1998

This data was collected with support from the U.S. Office of Naval Research through Grant No. N00014-95-1-0339.

Please contact Dr. A. Plueddemann if you have any questions.

*WARNING*

This is a preliminary processed file and should be used with caution. Please forward an email message to A. Plueddemann or S. Anderson when you have picked up the data. We will place you on our mailing list and notify you when the file is updated.

Download files:

  • WHOI_cmowave.txt - Text version of this documentation file
  • WHOI_cmowave96.dat - (now offline) ASCII Aug 16 - Sept 18, 1996
  • WHOI_cmowave97.dat - (now offline) ASCII Apr 20 - May 15, 1997

Summary

Three data sources were used to form a continuous time series of significant wave height (SWH), peak wave period (PWP) and average wave period (AWP) during the Coastal Mixing and Optics Experiment. The primary data were a subset of non-directional wave parameters from the three deployments of the Seatex Waverider buoy. The Seatex buoy was deployed at the central site of the CMO moored array (40.49 N, 70.50 W). When Seatex data were not available, wave parameters from NDBC buoys 44008 and 44025 were used. Buoy 44008 is located at 40.50 N, 69.42 W, about 90 km east of the CMO site. Buoy 44025 is located at 40.25 N, 73.17 W, about 225 km west and 25 km south of the CMO site.

The combined wave data are in the files cmo_wave.mat and cmo_wave.asc. cmo_wave.mat is a Matlab binary data file containing the four variables below. cmo_wave.asc is in ASCII format, containing 7608 rows (time) of 4 columns (data) in the order below. The time base is UTC, the sample interval is hourly, and the yearday is continuous relative to Jan 1 1996 (= day 1). Recall that 1996 was a leap year.

Variables

  • cmo_jday = decimal yearday (UTC)
  • cmo_swh = significant wave height (m)
  • cmo_pwp = peak wave period (s)
  • cmo_awp = average wave period (s)

Processing Details

The second Seatex deployment was the longest continuous time period where both Seatex and NDBC data were available. This period was used to assess the relationship between Seatex and NDBC wave parameters. Wave parameters from NDBC buoy 44008 showed the best correlation with those from the Seatex, and could be used reliably (see rms errors below) to fill Seatex data gaps. Unfortunately, the record from buoy 44008 ended before the end of the CMO experiment and could not be used to completely fill the gap between Seatex deployments 2 and 3. Parameters from buoy 44025 showed the next best correlation with the Seatex, and were used during the short (7.5 day) period that neither Seatex nor buoy 44008 data were available.

Coefficients from a linear regression analysis between NDBC and Seatex records during deployment 2 were used to adjust the NDBC data prior to merging with the Seatex record. The correlation coefficients and rms error of the fits for each variable were: 



                    CORRELATION             RMS ERROR
                  ----------------    ----------------------
    SEATEX        SWH   PWP   AWP      SWH     PWP     AWP
                  ----------------    ----------------------
    NDBC 44008 |  0.93  0.74  0.91    0.37 m  1.68 s  0.47 s
    NDBC 44025 |  0.79  0.67  0.77    0.61 m  1.86 s  0.73 s
The gap between Seatex deployments 1 and 2 was filled completely with NDBC 44008 data. Six gaps in the Seatex deployment 2 record of greater than 3 h, but less than 1 day, were also filled with NDBC 44008 data. The gap between Seatex deployments 2 and 3 was only partially filled since the NDBC 44008 record ended prior to the start of deployment 3. The remaining gap of about 7.5 days was filled with NDBC 44025 data. The data sources for various time periods in the continuous record are noted below.


    TIME PERIOD            DATA SOURCE
    ------------------     ---------------------
    212.9167 - 248.8750    Seatex (deployment 1)
    248.9167 - 270.8750    NDBC 44008
    270.9167 - 403.7083    Seatex (deployment 2)
    403.7500 - 465.6667    NDBC 44008
    465.7083 - 473.1667    NDBC 44025
    473.2083 - 529.8750    Seatex (deployment 3)

Contacts

Dr. A. Plueddemann
Woods Hole Oceanographic Institution
Department of Physical Oceanography
Mail Stop 29
Woods Hole, MA 02543
(508) 289 - 2789
aplueddemann@whoi.edu

Reference

Galbraith, N., W. Ostrom, B. Way, S. Lentz, S. Anderson, M. Baumgartner, A. Plueddemann, and J. Edson, 1997. Coastal Mixing and Optics Experiment: Mooring deployment cruise report. Woods Hole Oceanographic Institution Technical Report WHOI-97-13, 92 pp.

Acknowledgments

The Seatex buoy was deployed in cooperation with E. Terray. Buoy preparation was done by N. McPhee. Mooring deployments and recoveries were handled by the Upper Ocean Processes Group. Two unscheduled recoveries after buoy failures were made possible by the generous assistance of other CMO investigators. This work was supported by ONR 322PO, Grant N00014-95-1-0339 awarded to Co-PIs S. Lentz, S. Anderson, A. Plueddemann and J. Edson of the Woods Hole Oceanographic Institution.



Last updated: April 23, 2008