
NODC DOCUMENTATION FOR CTD DATASETS

#documentation_file_name:          w0008.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 W0008A
     29 July to 17 August, 2000
     Newport, Oregon to Newport, Oregon
     Seasoar sampling in 12 tows as follows:

Tow no. Start date,time    End date,time            Parameters measured
          (2000) (UT)        (2000) (UT)
  1       30 Jul 1501        31 Jul 1010      P, T1, C1, T2, C2, PAR, FL1, FL2
  2       31 Jul 1432        01 Aug 0625      P, T1, C1, T2, C2, PAR, ---, FL2
  3       01 Aug 1326        04 Aug 0622      P, T1, C1, T2, C2, PAR, ---, FL2
  4       04 Aug 1103        04 Aug 2317      P, T1, C1, T2, C2, PAR, ---, FL2
  5       05 Aug 1323        06 Aug 1716      P, T1, C1, T2, C2, PAR, ---, FL2
  6       06 Aug 1748        06 Aug 1959      P, T1, C1, T2, C2, PAR, ---, FL2
  7       06 Aug 2106        09 Aug 1606      P, T1, C1, T2, C2, PAR, ---, FL2
  8       09 Aug 1647        11 Aug 0203      P, T1, C1, T2, C2, PAR, ---, FL2
  9       11 Aug 1429        11 Aug 2038      P, T1, C1, T2, C2, PAR, ---, FL2
 10       11 Aug 2237        12 Aug 1925      P, T1, C1, T2, C2, PAR, ---, FL2
 11       14 Aug 1525        16 Aug 0148      P, T1, C1, T2, C2, PAR, ---, FL2
 12       16 Aug 0318        17 Aug 1157      P, T1, C1, T2, C2, PAR, ---, FL2

 Tows 1 - 4 composed an inshore mapping survey, and were bounded to the 
 north by 44.7 degrees N, to the south by 43.7 degrees N, to the west by  
 126.2 degrees W, and to the east by 124.1 degrees W.  

 Tows 5 - 7: covered a finer mapping survey to the north, bounded to the  
 north by 44.4 degrees N, to the south by 43.7 degrees N, to the west by 
 126.3 degrees W, and to the east by 124.1 degree W.

 Tow 7 also contained the filament survey, bounded to the north by 43.8 
 degrees N, to the south by 42.3 degrees N, to the west by 126.3 degrees W, 
 and to the east by 124.4 degree W.

 Tows 7 - 8: was a finer mapping survey to the south, bounded to the north
 by 43.3 degrees N, to the south by 42.1 degrees N, to the west by 125.4 
 degrees W, and to the east by 124.4 degrees W.

 Tows 9 - 10:  a finer repeat mapping of the north region (north2), bounded 
 to the north by 44.7 degrees N, to the south by 43.9 degrees N, to the west 
 by 125.3 degrees W, and to the east by 124.1 degrees W.

 Tows 11 - 12:  final mapping survey, offshore, bounded to the north by 44.7
 degrees N, to the south by 41.8 degrees N, to the west by 126.1 degrees
 W, and to the east by 124.6 degrees W.

 Maximum sampling depth generaly 120 m for tows 1-10; tow 11 and 12's maximum 
 sampling depth was generaly less than 330 m.

#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
     tow  2         preferred sensor pair: 1
     tow  3         preferred sensor pair: 2
     tow  4         preferred sensor pair: 1
     tow  5         preferred sensor pair: 2
     tow  6         preferred sensor pair: 1
     tow  7         preferred sensor pair: 1
     tow  8         preferred sensor pair: 1,2
     tow  9         preferred sensor pair: 1
     tow 10         preferred sensor pair: 1
     tow 11         preferred sensor pair: 2
     tow 12         preferred sensor pair: 1

 on tow 8 the preferred sensor pair clogged; the alternate pair was then 
 used in its place.

 for tow 1 - 12:

     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 November 1995 
         T1:(SN 2127) 11 July 2000
         T2:(SN 2128) 11 July 2000
         C1:(SN 1737) 11 July 2000
         C2:(SN 1738) 13 July 2000

 for tow 2-12:

    Dates of SBE CTD #256 calibrations as follows:

         P:(SN 50506) 10 February 1999 
         T1:(SN 2127) 11 July 2000
         T2:(SN 2128) 11 July 2000
         C1:(SN 1737) 11 July 2000
         C2:(SN 1738) 13 July 2000


 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.  


     (values shown are for the indicated sensor pair):

          tow 1 (pair 1) (from tow 3):

               alpha = 0.008214(lag) + 0.00667
               tau   = 1.342(lag**0.5) + 7.153
			  
          tow 2 (pair 1) (from tow 3):

               alpha = 0.008214(lag) + 0.00667
               tau   = 1.342(lag**0.5) + 7.153
			  
          tow 3 (pair 2):

               alpha = 0.005520(lag) + 0.00933
               tau   = 1.341(lag**0.5) + 7.150
			  
          tow 4 (pair 1) (from tow 3):

               alpha = 0.008214(lag) + 0.00667
               tau   = 1.342(lag**0.5) + 7.153
			  
          tow 5 (pair 2):

               alpha = 0.003497(lag) + 0.00768
               tau   = 1.338(lag**0.5) + 7.149
		
          tow 6  (pair 1) (from tow 7):

               alpha = 0.004464(lag) + 0.00915
               tau   = 1.331(lag**0.5) + 7.150

          tow 7 (pair 1):

               alpha = 0.004464(lag) + 0.00915
               tau   = 1.331(lag**0.5) + 7.150
			  
          tow 8 (pair 1):

               alpha = 0.000000(lag) + 0.01344
               tau   = 1.338(lag**0.5) + 7.148
			  
          tow 8 (pair 2):

               alpha = 0.008219(lag) + 0.00606
               tau   = 1.341(lag**0.5) + 7.150
			  
          tow 9 (pair 1):

               alpha = 0.000000(lag) + 0.01343
               tau   = 1.338(lag**0.5) + 7.148
			  
          tow 10 (pair 1):

               alpha = 0.000000(lag) + 0.01361
               tau   = 1.348(lag**0.5) + 7.163
			  
          tow 11 (pair 2):

               alpha = 0.014474(lag) + 0.00000
               tau   = 1.334(lag**0.5) + 7.151
			  
          tow 12 (pair 1):

               alpha = 0.000000(lag) + 0.01342
               tau   = 1.341(lag**0.5) + 7.150
		
	  
     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.

     The two FlashPak fluorometers were run with different optical
     filters; the first with a violet filter (lamda = 440 +/- 30 nm), 
     the second with a green filter (lamda = 490 +/- 30 nm).  The
     FPAK data sample water that is pumped in series between them, and
     as such are offset in time from the rest of the SeaSoar data.  This
     offset has been corrected for in the final data set.  Conversion
     from the 0-5 volt output to chlorophyll-a can be done with the 
     following calibration equations:

          (Violet) Chla (ug/L) =  N/A
          (Green)  Chla (ug/L) =  8.8862*Fl(V) - 4.4040

     The (green filter) fluorescence was selected to represent the 
     chlorophyll-a values, as the other sensor was damaged at the
     end of tow 1.

     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:                     *
#associated_datasets:              CTD data from W0008A
#associated_versions:              *
#data_set_information:             *
#data_set_name:                    * 
#data_set_volume:                  142,025 kbytes  (1,193,746 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:    W0008A
#data_dates:                       30 July - 17 August 2000 
#left_geographic_upper_bound:      127W  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:  (violet filter) (volts)
     col 14:  (green filter)  (volts)
     col 15:  (green filter)  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 (violet filter) (volts), accurate to 0.001
          fluorescence (green  filter) (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,i4.4,3f6.3, f7.2)


     "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;

     flourescence 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 (inshore,north,south,process,middle,offshore) 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:  inshore.line2_1.dat2c 
 goes from the end of line2 to the start of line1 for the inshore map).
 Repeat coverage of the same line on the same map is given a decimal
 number (eg: process.line7.1.dat2c and process.line7.2.dat2c).

#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.



 * leave blank

