
NODC DOCUMENTATION FOR CTD DATASETS

#documentation_file_name:          t0205.csr.txt     
#nodc_accession_number:            *
#nodc_reference_number:            * 
#nodc_documentation_date:          *
#nodc_documentor:                  *                    
#distribution_restriction:         none
#date_received:                    *
#submission_medium:                ftp tar file	
#submittor_name:                   Robert O'Malley
#submittor_institution:            College of Oceanic and Atmosperic Sciences
                                   Oregon State University
#submitter_street_address:         104 Ocean Admin Bldg
#submitter_city:                   Corvallis 
#submitter_state:                  Oregon
#submitter_country:                USA
#submitter_zip_code:               97331-5503
#sumitter_telephone_no:            541-737-2180
#submitter_internet:               *
#submitter_email:                  omalley@coas.oregonstate.edu
#collection_information:
 (i.e cruise dates, ports, cast numbers, time of cast, 
      longitude and latitude of casts)

     Wecoma cruise T0205
     31 May to 17 June, 2002
     Newport, Oregon to Newport, Oregon
     Seasoar sampling in 8 tows as follows:

Tow no. Start date,time    End date,time            Parameters measured
          (2002) (UT)        (2002) (UT)
  1       01 Jun 2254        02 Jun 1817      P, T1, C1, T2, C2, PAR, FL1, FL2, FL3
  2       03 Jun 0259        06 Jun 0344      P, T1, C1, T2, C2, PAR, FL1, FL2, FL3
  3       06 Jun 2134        07 Jun 1901      P, T1, C1, T2, C2, PAR, FL1, FL2, FL3
  4       08 Jun 1513        09 Jun 1930      P, T1, C1, T2, C2, PAR, FL1, FL2, FL3
  5       10 Jun 1510        11 Jun 0402      P, T1, C1, T2, C2, PAR, FL1, FL2, FL3
  6       12 Jun 1444        13 Jun 1654      P, T1, C1, T2, C2, PAR, FL1, FL2, FL3
  7       13 Jun 2010        15 Jun 0841      P, T1, C1, T2, C2, PAR, FL1, FL2, FL3
  8       16 Jun 0742        17 Jun 1539      P, T1, C1, T2, C2, PAR, FL1, FL2, FL3

 Tows 1 - 3 composed the mesoscale-1 mapping survey, and were bounded to the 
 north by 44.7 degrees N, to the south by 41.8 degrees N, to the west by  
 125.8 degrees W, and to the east by 124.1 degrees W.  

 Tows 4 - 5 covered a finescale mapping survey to the north, bounded to the  
 north by 44.7 degrees N, to the south by 43.7 degrees N, to the west by 
 125.2 degrees W, and to the east by 124.1 degree W.

 Tows 6 - 7 was a finescale survey to the south, bounded to the north
 by 43.3 degrees N, to the south by 41.8 degrees N, to the west by 125.5 
 degrees W, and to the east by 124.3 degrees W.

 Tow8  was the second mesoscale mapping (meso2), bounded to the north
 by 44.7 degrees N, to the south by 43.2 degrees N, to the west by
 125.3 degrees W, and to the east by 124.1 degrees W.

 Maximum sampling depth of 225 m for all tows.

#principal_investigator_name:      John A. Barth
#pi_institution:                   College of Oceanic and Atmosperic Sciences, 
    	       	                   Oregon State University 
#pi_street-address:                104 Ocean Admin Bldg
#pi_city:                          Corvallis
#pi_state:                         Oregon
#pi_country:                       USA
#pi_zip_code:                      97331-5503
#pi_telephone_no:                  541-737-1607
#pi_internet:                      *
#pi_email:                         barth@coas.oregonstate.edu
#project:                          The GLOBEC NEP Mesoscale Surveys
#funding agency:                   NSF
#grant/contract-no:                OCE-0001035
#platform_type:                    research vessel
#platform_name:                    Wecoma
#collection_methods:  
 (i.e. how were the data obtained) 

 SeaBird 9/11 plus CTD inside Seasoar vehicle; with dual ducted SBE-3 and SBE-4
 temperature and conductivity sensors inside seasoar vehicle; flow through 
 sensor duct pumped by SBE-5 pumps; intake and outlet for each sensor pair was 
 directed forward through center of lower nose with intake and outlet 
 separated by about 2 cm, the T1-C1 pair were starboard of the centerline,
 and the T2-C2 pair were port of the centerline; final data were from
 the T-C pair indicated below; final data were from the following pairs 
 of sensors:  

     tow  1         preferred sensor pair: 1,2
     tow  2         preferred sensor pair: 1
     tow  3         preferred sensor pair: 1
     tow  4         preferred sensor pair: 1
     tow  5         preferred sensor pair: 1
     tow  6         preferred sensor pair: 2
     tow  7         preferred sensor pair: 2,1
     tow  8         preferred sensor pair: 2,1

 for tow 1 - 8:

     preferred sensor pair 1:  SN 2127 and 1737 for T and C
     preferred sensor pair 2:  SN 2128 and 1738 for T and C


#analysis_methods:
 (i.e. how were the data processed, calibrated etc)

 Calibrations from SeaBird Electronic, Inc. (SBE) were used for the 
 temperature, conductivity and pressure sensors.
 
 for tow 1:

    Dates of SBE CTD #428 calibrations as follows:

         P:(SN 64256) 28 March 2001 
         T1:(SN 2127) 26 March 2002
         T2:(SN 2128) 26 March 2002
         C1:(SN 1737) 26 March 2002
         C2:(SN 1738) 26 March 2002

 for tow 2-12:

    Dates of SBE CTD #258 calibrations as follows:

         P:(SN 50506) 10 February 1999 
         T1:(SN 2127) 26 March 2002
         T2:(SN 2128) 26 March 2002
         C1:(SN 1737) 26 March 2002
         C2:(SN 1738) 26 March 2002


 Data Processing:

     We compute lagged correlations between the temperature and
     conductivity time series for each sensor pair.  In order to 
     calculate the correlation between T and C, we work with the 
     first-differences of those time series.  We then find the 
     maximum cross correlation, along with the values on each side 
     of it, and fit a parabola to those three points.  The maximum
     of the parabola gives the fractional scan offset to be used 
     in shifting the conductivity time series to match up with the 
     temperature time series.  This is done for every up- and down-
     trace profile of seasoar data.  The time series of up-trace
     lags and the time series of down-trace lags were then individualy 
     cleaned by statistical methods.  Each lag value is examined with
     its time series to see if it falls within three standard deviations 
     of the mean of a centered, 101-point window.  Those outside three 
     sigma of the mean are then replaced with the window's average 
     value, in an iterative process.

     To correct the 24-Hz conductivity data for the thermal mass of the
     conductivity cell, we allowed both the amplitude (alpha) and time 
     constant (tau) of the thermal mass correction to be functions of the 
     lag between T and C.  These variable alpha and tau values can be
     obtained by minimizing the area in T-S space of selected test hours 
     for each tow.  These values then represent the optimal thermal 
     mass correction for each tow.  If the data were too noisy, or the
     tow too short, then the thermal mass values optimizations from
     the closest useful tow were used.  


     Using the above method, the thermal mass variable alpha and tau
     can be calculated as functions of lag as:


        alpha = alpha.slope * lag  +  alpha.offset
        tau = tau.slope * lag**0.5 + tau.offset


      the slopes and offsets can be summarized for each tow as follows:

            sensor  [--- alpha ---]    [--- tau ---]
       tow   pair   slope    offset    slope   offset
        
        1     1   0.000000   0.01516   1.340   7.149  
        1     2   0.012552   0.00285   1.316   7.132  
        2     1   0.000000   0.01354   1.339   7.150 
        3     1   0.000009   0.01529   1.337   7.144
        4     1   0.000000   0.01572   1.340   7.150
        5     1   0.000000   0.01476   1.344   7.150
        6     2   0.007712   0.00822   1.344   7.155
        7     2   0.004097   0.00968   1.339   7.158
        7     1   0.001292   0.00535   1.337   7.163
        8     2   0.003343   0.01323   1.343   7.153
        8     1   0.000345   0.00864   1.347   7.152
		
	  
     The corrected and realigned 24-Hz temperature and conductivity data are
     used to calculate 24-Hz salinity, and these are averaged to yield one-
     second averages stored in hourly files.

     Three fluorometers were used on this survey; two from WetStar
     and one from SeaPoint.  The SeaPoint fluorometer was tuned to 
     detect fluoroscein tracers, and the two WetStar fluorometers
     were set from Chl and CDOM detection.  Converting the 0-5 volt 
     output of the chl fluorometer to chlorophyll-a was be done with  
     the following calibration equations:

          Chla (ug/L) =  18.9316*Fl(V) - 4.3217

     Successive hourly files of the reprocessed one-second average data
     were joined to yield a single data file for each tow of the survey.
     The single file for each tow was then broken into the different
     component lines.
	
#instruments: 

     tow 1:  
          SBE 9/11 plus CTD SN 0428 with:
          SBE pressure sensor SN 64256
          SBE temperature  sensors SN 2127 and SN 2128 and
          SBE conductivity sensors SN 1737 and SN 1738

     tow 2-12:  
          SBE 9/11 plus CTD SN 0258 with:
          SBE pressure sensor SN 50506
          SBE temperature  sensors SN 2327 and SN 2329 and
          SBE conductivity sensors SN 1896 and SN 1898

#publications:                     *

     "SeaSoar Observation During the GLOBEC NEP California
      Current Survey III (T0205) 31 May - 17 June 2002" 
      by R. O'Malley et al., Data Report 196, Reference 2004-4, 
      December 2004

#associated_datasets:              CTD data from T0205
#associated_versions:              *
#data_set_information:             *
#data_set_name:                    * 
#data_set_volume:                  111,083 kbytes  (894,547 records)
#source_computer:                  Sun Sparc Ultra 10
#source_computer_operating_system: Sun OS 5.6
#source_language:                  Fortran, C
#computer_code:                    ASCII
#originator_dataset_identifier:    T0205
#data_dates:                       01 June - 17 June 2002 
#left_geographic_upper_bound:      126W  45N
#right_geographic_lower_bound:     124W  41N
#geographic_region:                Northeast Pacific
#data_type:                        SEASOAR  data 
#sphere:                           * 
#parameters:

     col  1:  latitude (decimal degrees) 
     col  2:  longitude (decimal degrees)
     col  3:  pressure (dbars)
     col  4:  temperature (C) 
     col  5:  salinity (psu) 
     col  6:  Sigma-t (kg/cubic meter)
     col  7:  potential temperature (C)
     col  8:  sigma-theta (kg/cubic meter) 
     col  9:  time (decimal year-day of 2000)
     col 10:  date and time (integral year, month, day, hour, minute, second)
     col 11:  flag
     col 12:  PAR (0-5 volts)
     col 13:  FL1 (Chl) (volts)
     col 14:  FL2 (CDOM)  (volts)
     col 15:  FL3 (flscn)  (volts)
     col 16:  chlorophyl-a (micro g/liter)

#format_description:
 (e.g. description of the header, data, record layouts. Include
 units, scales, resolution, accuracy)

     no header; each line contains:

          unfiltered GPS latitude
          unfiltered GPS longitude
          pressure (dbars), accurate to better than plus/minus 2 db
          temperature (C), accurate to plus/minus 0.01 C
          salinity (psu), accurate to plus/minus 0.01 psu
          sigma-t (kg/cubic meter),
          potential temperature (C),
          sigmat-theta (kg/cubic meter),
          decimal year-day (of 2000),
          integral year, month, day, hour, minute, second 
          flag word (see format comments below for interpretation)
          PAR (volts), accurate to 0.001 volts
          fluorescence (Chl) (volts), accurate to 0.001
          fluorescence (CDOM) (volts), accurate to 0.001
          fluorescence (flscn) (volts), accurate to 0.001
          (green filter)  chlorophyll-a (micro g/liter), accurate to 0.01 

 The FORTRAN format for each record is:
 format (f10.5,f11.5,f6.1,5f8.4,f10.5,1x,6i2.2,1x,i4.4,4f6.3,f6.2)


     "no data" values are indicated by 9-filling:
 
     temperature, salinity, sigma-t, potential temerature, or
     sigma-theta all use 99.9999 to indicate "no data"
     present for that record;

     voltages uses 9.999 to indicate "no data"

     chlorophyll uses 999.99 to indicat "no data"

#format_publication:               *
(a reference for any document which defines/describes the data format(s))

#format_comments: 
 (any information about the format that will be useful, but is not
 elsewhere on this form)
 
 The variable at the end of each line (the flag word) indicates
 different items:

	the ones place:  

		0 indicates use of sensor pair 1 (T1, C1)
		1 indicates use of sensor pair 2 (T2, C2)

	the tens place:
  
		0 indicates gps fix for location
		1 indicates linear interpolation between gps fixes

	the hundreds place:  

		2 indicates top or bottom of seasoar cycle
		0 indicates otherwise

	the thousands place:  

		1 indicates collection of water sample from the 
		  5-m intake
		0 indicates otherwise
 
 The files all have the extension of ".dat2c".  All data are identified 
 by their maps (meso1,north,south,meso2) and are separated into their
 E-W lines (line1 through line12 overall, with
 intermediate lines indicate by line1a (between line1 and line2, etc) 
 or are identified as connecting lines (eg:  north.line2a_3.dat2c 
 goes from the end of line2a to the start of line3 for the north map).
 Partial coverage of a line is incremented alphabeticly (eg:
 south.line9.a.dat2c and south.line9.b.dat2c). Repeat coverage of 
 the same line on the same map is given a decimal number (eg:
 line9.1  and line9.2) (none on this survey).

#misc_documentation:               *
#submittor_documentation:          *
 any textual information about the data, provided by the submitter,
 or investigator, (not NODC folks)  For example, in most cases this
 has been an ASCII text file accompanying the data on a DAT , diskette,
 or CDROM.  It may contain information which is redundant with other
 parts of this form.



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