
NODC DOCUMENTATION FOR CTD DATASETS

#documentation_file_name:            *     
#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):
	R/V Oceanus cruise OC343 (referred to here as O9906)
	14 June to 01 July, 1999
	Woods Hole to Woods Hole, Massachusetts
	Seasoar sampling in 10 tows during O9903 as follows:

Tow no. Start date,time       End date,time          Parameters measured
          (1999) (UT)           (1999) (UT)
  1       15 Jun 1547           16 Jun 1921     P, T1, C1, T2, C2, FL, TRANS
  2       16 Jun 2320           19 Jun 0100     P, T1, C1, T2, C2, FL, TRANS, FPAK
  3       19 Jun 0803           21 Jun 1012     P, T1, C1, T2, C2, FL, TRANS, FPAK
  4       21 Jun 1624           21 Jun 2331     P, T1, C1, T2, C2, FL, TRANS, FPAK
  5       22 Jun 0140           24 Jun 0108     P, T1, C1, T2, C2, FL, TRANS, FPAK
  6       24 Jun 0814           25 Jun 1348     P, T1, C1, T2, C2, FL, TRANS, FPAK
  7       25 Jun 1826           25 Jun 2151     P, T1, C1, T2, C2, FL, TRANS, FPAK
  8       25 Jun 2322           26 Jun 1233     P, T1, C1, T2, C2, FL, TRANS, FPAK
  9       26 Jun 1304           28 Jun 0302     P, T1, C1, T2, C2, FL, TRANS, FPAK
 10       28 Jun 0852           30 Jun 1413     P, T1, C1, T2, C2, FL, TRANS, FPAK

 All observations were between 41.3 and 40.5 degrees N. latitude, and 
 between 67.8 degrees and 66.8 degrees W. longitude. Maximum sampling 
 depth approximately 120 m for all tows.

#principal_investigator_name: John A. Barth (also D. Hebert from URI)
#pi_institution:College of Oceanic and Atmospheric 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: GLOBEC Georges Bank
#funding agency: NSF
#grant/contract-no: OCE-9813641
#platform_type: research vessel
#platform_name: Oceanus
#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 T1-C1 pair for all or part of tows 1-10; the T2-C2 pair were used 
 in part of tows 4,6,8,9; final data were from the following pairs of 
 sensors: 

	Tows      1-10:  SN 2128 and 1738 for T and C

	Tows   4,6,8,9:  SN 2127 and 1737 for T and C


#analysis_methods:
 (i.e. how were the data processed, calibrated etc)
  - used SBE (SeaBird Electronic, Inc.) calibrations for temperature,
    conductivity and pressure sensors;
 
    dates of SBE CTD #428 calibrations as follows:

		P:(SN 64256) 28 November 1995 
                T1:(SN 2128) 20 February 1999
		T2:(SN 2127) 20 February 1999
                C1:(SN 1738) 23 February 1999
		C2:(SN 1737) 23 February 1999

 Data Processing:

	We compute lagged correlations between temperature and 
	conductivity for each sensor pair, and separately for each  
	ascending and descending profile, provided the segment contains  
	at least 180 scans, and were obtained between depths of 1 and 
	150 m. The fractional value of the lag at maximum correlation 
	was determined by fitting a parabola to the cross-correlation 
	values.  The lags were then repeatedly cleaned using a three-
	sigma test on a centered, moving, 100-pt window until all values 
	were within three sigma of the mean, the nulled outliers were 
	then replaced with the mean value at that point.  This time series 
	of lags was then examined to be certain the automated cleaning 
	was appropriate, and corrections were made when necessary.  The 
	final values of the alignment offset were then applied sequentially 
	in reprocessing the 24-Hz T/C data.  To reprocess data from depths 
	shallower than 1 m, we used the value determined from the associated 
	(ascending or descending) shallowest layer.

	To correct the 24-Hz conductivity data for the thermal mass of the
	conductivity cell, we used variable values for both the thermal
	amplitude and the thermal anomaly time constant depending on the 
	alignment offset (values shown are for all tows):

	T1-C1:
		alpha = 1.06833E-02 + 0.00000(lag)
		tau   = 7.15258     + 1.34014 (lag**0.5)
			  
	T2-C2:
		alpha = 5.26523E-03 + 0.00000(lag)
		tau   = 7.20144     + 1.35586 (lag**0.5)
			  
			  
	These variable alpha and tau values represent the optimal
	thermal mass correction based on minimizing the area in
	T-S space of selected test hours for the survey.
			  
	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.

	Successive hourly files of the reprocessed one-second average data
	were joined to yield a single data file for each tow of the survey.

	
#instruments: 
	tow 1-10:  SBE 9/11 plus CTD SN 0428 with
	           SBE pressure sensor SN 64256
	           SBE temperature  sensors SN 2127 and SN 2128
	           SBE conductivity sensors SN 1737 and SN 1738
	           WetLABS WETStar Fluorometer 
	           Seatech Transmissometer 
	           WetLABS FlashPAK Fluorometer SN 016

#publications: 
#associated_datasets:  
#associated_versions:		     *
#data_set_information:               *
#data_set_name:			     * 
#data_set_volume: 107,073 kbytes  (1,116,760 records)
#source_computer:  Sun Sparc 20
#source_computer_operating_system: Sun OS 5.6
#source_language: Fortran, C
#computer_code: ASCII
#originator_dataset_identifier: O9906
#data_dates: 15 June - 30 June 1999 
#left_geographic_upper_bound:       68W  41N
#right_geographic_lower_bound:	    66W  40N
#geographic_region:  Northwest Atlantic
#data_type: SEASOAR  data 
#sphere:                             * 
#parameters: latitude (decimal degrees), longitude (decimal degrees), pressure
 (dbars), temperature (C), salinity (psu), Sigma-t (kg/cubic meter), time 
 (decimal year-day of 1999), date and time (integral year, month, day, hour, 
 minute, second), flag, fluorescence (0-5 volts), light transmission (0-5
 volts), FPAK fluorescence (460-nm excitation) (0-5 volts).
.
#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),
  decimal year-day (of 1999),
  integral year, month, day, hour, minute, second 
  flag word (see format comments below for interpretation)
  fluorescence (volts), accurate to 0.001 volts
  light transmission (volts), accurate to 0.001 volts
  FPAK fluorescence (volts), accurate to 0.001 volts

 The FORTRAN format for each record is:
 format (f10.5,f11.5,f6.1,3f8.4,f10.5,1x,6i2.2,1x,a4, 3f6.3)
#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 ".dat" and are divided into
 the ten tows (tow1.dat, etc).
#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

