MOCNESS_CTD

Dataset description

Acquisition description

MOCNESS CTD

 Methodology: none provided with data
 
 Change history: YYMMDD
    070626: downloaded original merged data from EDDIES data web site;
    071206: prepared for OCB database by Nancy Copley (OCB DMO)
    090828: added to database by Cyndy Chandler (OCB DMO)
 

 The following notes apply to both OC415-1 and OC415-3:

 CTD sensor metadata for MOCNESS tows: m_415_17 through m_415_28 
 Temperature Probe #  1678  Conductivity Probe #  199
 Pressure Probe #  105      Oxygen Probe #  130349
 Transmissometer #  243     Fluorometer #  1


 To view the final data acquisition screen for each MOCNESS tow:

  
Cruise ID = OC415-1 
  
  

    
MOC-1


    
MOC-2

    
MOC-3

    
MOC-4

  
  

    
MOC-5


    
MOC-6

    
MOC-7

    
MOC-8

  
  


    
MOC-9

    
MOC-10

    
MOC-11

    
MOC-12

  

  

    
MOC-13

    
MOC-14
    
MOC-15

    
MOC-16


  
  
Cruise ID = OC415-3 
  
  

    
MOC-17

    
MOC-18


    
MOC-19

    
MOC-20

  
  

    
MOC-21

    
MOC-22


    
MOC-23

    
MOC-24

  
  

    
MOC-25


    
MOC-26

    
MOC-27

    
MOC-28

  


 Unless otherwise indicated, these data have not been post-processed, and include some bad lat/lon points.

Original raw MOCNESS tow CTD data
MOCNESS tow CTD files (123 MB)
MOCNESS tow CTD files (90 MB)

 For additional information, contact the chief scientist for the cruise
 or the OCB Data Management Office (DMO).

 Parameter     Description                                      Units


 Cruise_ID     Cruise identification,                           dimensionless
                 e.g. OC415-1, for Oceanus cr. 415, leg 1       
 tow           MOCNESS tow number                               dimensionless
 date_local    8 digit year month day, local time               YYYYMMDD
 yrday_local   year day, Julian Calendar local time             decimal day
 time_local    time of day; local time using 24 hour clock.     HHmm.m
 lat           latitude, negative = South                       decimal degrees
 lon           longitude, negative = West                       decimal degrees
 press         depth of sample                                  meters
 echo          unknown                                          unknown
 temp          temperature                                      degrees C.
 potemp        potential temperature (1)                        degress C.
 sal           salinity calculated from conductivity;           dimensionless
                  if salinity exceeds 50 or is less than
                  0 o/oo, salinity is set to 50.
 sigma_0       potential density(1) at the surface                kg/m3-1000
 angle         angle of net frame relative to                   degrees
                  vertical (0-89 dgrees)      
 flow          consecutive flow counts                          counts
 hzvel         horizontal net velocity m/min                    meters/minute
 vtvel         vertical net velocity m/min                      meters/minute
 vol           volume filtered                                  meters^3
 net           sequential MOCNESS net number                    integer
 fluor         fluorescence (0-5 volts)                         volts
 trans_V       light transmission (0-5 volts)                   volts
 oxycurrent    oxygen sensor current                            
 oxytemp       oxygen sensor temperature                        
 oxygen        oxygen; dissolved                                milliliters/liter

 nd indicates missing or no data


  Background information provided by DMO:
 The MOCNESS is based on the Tucker Trawl principle (Tucker, 1951). 
 The particular MOCNESS system from which these CTD data came is the 
 MOCNESS-1 which has nine rectangular nets (1m x 1.4 m) that are opened
 and closed sequentially by commands through conducting cable from the
 surface (Wiebe et al., 1976).  "The underwater unit sends a data frame,
 comprised of temperature, depth, conductivity, net-frame angle, flow
 count, time, number of open net, and net opening/closing, to the deck
 unit in a compressed hexadecimal format every 2 seconds and from the deck
 unit to a microcomputer every 4 seconds... Temperature (to approximately
 0.01 deg C) and conductivity are measured with SEABIRD sensors. Normally,
 a modified T.S.K.-flowmeter is used... Both the temperature and
 conductivity sensors and the flowmeter are mounted on top of the frame so
 that they face horizontally when the frame is at a towing angle of 45deg...
 Calculations of salinity (to approximately 0.01 o/oo S), potential
 temperature (theta), potential density (sigma), the oblique and vertical
 velocities of the net, and the approximate volume filtered by each net
 are made after each string of data has been received by the computer."
 (Wiebe et al., 1985) In addition, data may be collected from four other
 sensors attached to the frame: the Transmissometer, the Fluorometer, the
 Downwelling light sensor, and the Oxygen sensor. A SeaBird underwater
 pump was also included in the sensor suite.
 
 References
 (1) Fofonoff and Millard, 1983, UNESCO technical papers in Marine Sciences, #44
 
 Tucker, G.H., 1951. Relation of fishes and other organisms to the
 scattering of underwater sound. Journal of Marine Research, 10: 215-238.
 
 Wiebe, P.H., K.H. Burt, S. H. Boyd, A.W. Morton, 1976. The multiple
 opening/closing net and environmental sensing system for sampling zooplankton.
 Journal of Marine Research, 34(3): 313-326
 
 Wiebe, P.H., A.W. Morton, A.M. Bradley, R.H. Backus, J.E. Craddock, V. Barber,
 T.J. Cowles and G.R. Flierl, 1985. New developments in the MOCNESS, an 
 apparatus for sampling zooplankton and micronekton. Marine Biology, 87: 313-323.

Processing description

1. MOCNESS:

This document is created from the content of the BCO-DMO metadata database.    2009-11-22  09:24:14