
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: omalley@oce.orst.edu
#submitter_email:
#collection_information (i.e cruise dates, ports, cast numbers, 
 time of cast, longitude and latitude of casts):
 Endeavor cruise EN-287 (referred to here as E9608)
 14 August to 01 September, 1996
 Narragansett to Narragansett, Rhode Island
 Seasoar sampling in 15 tows during E9608 as follows:

Tow no. Start date,time       End date,time          Parameters measured
            (1996) (UT)         (1996) (UT)
  1         15 Aug 2320         16 Aug 0836          P, T1, C1, T2, C2, FL
  2         16 Aug 0939         16 Aug 1527          P, T1, C1, T2, C2, FL
  3         17 Aug 0200         19 Aug 0308          P, T1, C1, T2, C2, FL
  4         20 Aug 0139         20 Aug 1440          P, T1, C1, T2, C2, FL
  5         20 Aug 1703         21 Aug 1122          P, T1, C1, T2, C2, FL
  6         21 Aug 1301         21 Aug 2158          P, T1, C1, T2, C2, FL
  7         22 Aug 2100         22 Aug 2157          P, T1, C1, T2, C2, FL
  8         24 Aug 1247         24 Aug 1420          P, T1, C1, T2, C2, FL
  9         24 Aug 2001         26 Aug 1653          P, T1, C1, T2, C2, FL
 10         26 Aug 2359         27 Aug 0059          P, T1, C1, T2, C2, FL
 11         27 Aug 0405         27 Aug 2128          P, T1, C1, T2, C2, FL
 12         27 Aug 2352         29 Aug 0023          P, T1, C1, T2, C2, FL
 13         29 Aug 0400         30 Aug 1210          P, T1, C1, T2, C2, FL
 14         30 Aug 1452         31 Aug 0802          P, T1, C1, T2, C2, FL
 15         31 Aug 0900         01 Sep 1108          P, T1, C1, T2, C2, FL

 All observations were in the area between 39.6 degrees N. and 40.7
 degree N., and between 70.0 degrees W. and 70.8 degrees W.
 Maximum sampling depth approximately 120 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@oce.orst.edu
#project: Coastal Mixing and Optics Experiment
#funding agency: ONR
#grant/contract-no: ONR Grant N00014-95-1-0382
#platform_type: research vessel
#platform_name: Endeavor
#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 tows 1-4, and tows 12-15; the T2-C2 pair were used for
 tows 5-11; final data were from the following pairs of sensors:  

	Tows   1-4 and 12-15:  SN 2127 and 1737 for T and C

	Tows  5-11:  SN 2128 and 1738 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 calibrations as follows:

		P:(SN 64256) 28 November 1995 
                T1:(SN 2127) 26 March 1996
		T2:(SN 2128) 26 March 1996
                C1:(SN 1737) 22 March 1996
		C2:(SN 1738) 22 March 1996

 Data Processing:
	We compute lagged correlations between temperature and 
	conductivity for each sensor pair, separately for ascending and
	descending profiles, and separately for two depth ranges: 10 to
	90 dbar, and deeper than 90 dbar, provided the segment contains  
	at least 180 scans. The fractional value of the lag at maximum 
	correlation was determined by fitting a parabola to the cross-
	correlation values. Outlying lag values (obtained occasionally 
	for data segments lasting <10 seconds or having relatively low 
	correlations between T and C) were not used in processing the data. 
	The edited values of the alignment offset were applied sequentially 
	in reprocessing the 24-Hz T/C data. To reprocess data from depths 
	shallower than 10 m, we used the value determined from the associated 
	(ascending or descending) shallowest layer. Outlying lag values 
	that were not used were replaced with local estimates of the lag 
	based on nearby values.

	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:

	tows 1-4 (for T1-C1):
		alpha = 0.0082 + 0.0036(lag)
		tau   = 7.153  + 1.340 (lag**0.5)
			  
	tows 5-11 (for T2-C2):
		alpha = 0.0009 + 0.0136(lag)
		tau   = 7.145  + 1.312 (lag**0.5)
			  
	tow 12 (for T1-C1):
		alpha = 0.0073 + 0.0003(lag)
		tau   = 7.150  + 1.340 (lag**0.5)

	tows 13-15 (for T1-C1):
		values change during each tow; see the data report for details. 

	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 each set of tows.
			  
	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.
	The single file for each tow was then broken into the different
	component lines.
	
#instruments: 
	tow 1-15:  SBE 9/11 plus CTD SN 0428 with
	           temperature  sensors SN 2127 and SN 2128 and
	           conductivity sensors SN 1737 and SN 1738
	           WetLABS prototype FlashPak Fluorometer

#publications: "SeaSoar CTD Observation During the Coastal Mixing and Optics
	Experiment:  R/V Endeavor Cruises from 14-Aug to 1-Sep 1996 and
	25 Apr to 15-May 1997" by R. O'Malley et al., Data Report 168, 
	Reference 98-1, October 1998
#associated_datasets: CTD data from E9608 
#associated_versions:		     *
#data_set_information:               *
#data_set_name:			     * 
#data_set_volume: 75,768 kbytes  (879,494 records)
#source_computer:  Sun Sparc 20
#source_computer_operating_system: Sun OS 4.1.3
#source_language: Fortran, C
#computer_code: ASCII
#originator_dataset_identifier: E9608
#data_dates: 14 August - 01 September 1996 
#left_geographic_upper_bound:        71W  41N
#right_geographic_lower_bound:	     70W  39N
#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 1996), date and time (integral year, month, day, 
 hour, minute, second), flag, fluorometer (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 1996),
  integral year, month, day, hour, minute, second 
  flag word (see format comments below for interpretation)
  fluorometer (volts), accurate to 0.02 volts 
      (note that the flourometer failed during tow 4, and only
       tows 1-3 give reliable data).

 The FORTRAN format for each record is:
 format(f10.5,f11.5,f6.1,3f8.4,f10.5,1x,6i2.2,1x,a4,1x,f5.3)
#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".  The data for each tow
 were divided into "small box" (sb) and "big box" (bb) surveys.  We
 repeated the small box survey nine times (sb1-sb9) and the big box
 surveys were repeated three times (bb1-bb3).  The small box is composed
 of N-S lines 1 through 6, so file sb4line5.dat indicates it contains
 the data for line 5 of the small box survey pattern on its fourth
 repetition.  The big box is made up of N-S lines A through F and has 
 similar file naming (eg:  bb2lineD.dat).  Connecting lines are noted 
 with an underscore:  sb7line4_5.dat is the section that connects line 4 
 with line 5 for small box 7.  We also used a repeat "butterfly" pattern, 
 with approximate N-S-E-W apexes.  File bf2sw.dat is the second butterfly
 repetition along the south to west line.  Lastly, we attempted several 
 individual profiles while observing solitons; these sections are named 
 "sol" and go from "a" through "l":  solh.dat is section "h" of a profile 
 used to observe solitons.

#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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