NODC DOCUMENTATION FOR CTD DATASETS #documentation_file_name: r0208.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) Roger Revelle cruise R0208 31 July to 19 August, 2002 Newport, Oregon to Newport, Oregon Seasoar sampling in 10 tows as follows: Tow no. Start date,time End date,time Parameters measured (2002) (UT) (2002) (UT) 1 01 Aug 0304 02 Aug 0044 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 2 02 Aug 0313 07 Aug 1616 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 3 09 Aug 0704 09 Aug 1521 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 4 09 Aug 1707 10 Aug 2226 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 5 10 Aug 2322 11 Aug 0554 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 6 11 Aug 2206 12 Aug 1559 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 7 13 Aug 2348 15 Aug 1425 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 8 15 Aug 1627 17 Aug 0220 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 9 17 Aug 0424 17 Aug 1526 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 10 17 Aug 1543 18 Aug 1036 P, T1, C1, T2, C2, PAR, FL1, FL2, FL3 Tows 1 - 2: composed the first mesoscale mapping survey (meso1), and were bounded to the north by 44.7 degrees N, to the south by 41.8 degrees N, to the west by 126.2 degrees W, and to the east by 124.1 degrees W. Tows 3 - 5: covered a finer mapping survey to the north, bounded to the north by 44.7 degrees N, to the south by 43.8 degrees N, to the west by 125.3 degrees W, and to the east by 124.1 degree W. Tow 6: a coarser middle survey, bounded to the north by 44.1 degrees N, to the south by 43.1 degrees N, to the west by 125.1 degrees W, and to the east by 124.4 degree W. Tows 7: a finer mapping survey to the south, bounded to the north by 43.0 degrees N, to the south by 42.1 degrees N, to the west by 125.6 degrees W, and to the east by 124.3 degrees W. Tows 8 - 10: a rough repeat mapping of the mesoscale region (meso2), bounded to the north by 44.7 degrees N, to the south by 41.8 degrees N, to the west by 127.1 degrees W, and to the east by 124.1 degrees W. Maximum sampling depth generaly 115 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: Roger Revelle #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: 2 tow 2 preferred sensor pair: 1 tow 3 preferred sensor pair: 1 tow 4 preferred sensor pair: 2 tow 5 preferred sensor pair: 1 tow 6 preferred sensor pair: 1,2,1 tow 7 preferred sensor pair: 2,1,2 tow 8 preferred sensor pair: 2 tow 9 preferred sensor pair: 1,2,1 tow 10 preferred sensor pair: 2 on tow 6 and tow 9 the preferred sensor pair clogged; the alternate pair was then used in its place until the clog ceared in tow 7 the preferred sensor was used for all exept one hour when the reponse time of the temperature probe was impacted by biology for tow 1 - 10: 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. 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 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 2): alpha = 0.007898(lag) + 0.00588 tau = 1.323(lag**0.5) + 7.194 tow 2 (pair 1) (part 1): alpha = 0.010450(lag) + 0.00056 tau = 1.340(lag**0.5) + 7.129 tow 2 (pair 1) (part 2): alpha = 0.000263(lag) - 0.00034 tau = 1.343(lag**0.5) + 7.154 tow 3 (pair 1): alpha = 0.000000(lag) + 0.01460 tau = 1.336(lag**0.5) + 7.150 tow 4 (pair 2): alpha = 0.015147(lag) + 0.00000 tau = 1.342(lag**0.5) + 7.150 tow 5 (pair 1): alpha = 0.011468(lag) + 0.00000 tau = 1.376(lag**0.5) + 7.180 tow 6 (pair 1): alpha = 0.005296(lag) + 0.00938 tau = 1.340(lag**0.5) + 7.152 tow 6 (pair 2): alpha = 0.018088(lag) + 0.00125 tau = 1.335(lag**0.5) + 7.142 tow 7 (pair 2): alpha = 0.012676(lag) + 0.00000 tau = 1.340(lag**0.5) + 7.150 tow 7 (pair 1): alpha = 0.012191(lag) + 0.00000 tau = 1.343(lag**0.5) + 7.154 tow 8 (pair 2): alpha = 0.003070(lag) + 0.01584 tau = 1.326(lag**0.5) + 7.141 tow 9 (pair 1): alpha = 0.006495(lag) + 0.01884 tau = 1.339(lag**0.5) + 7.150 tow 9 (pair 2): alpha = 0.000000(lag) + 0.02152 tau = 1.323(lag**0.5) + 7.146 tow 10 (pair 2): alpha = 0.011912(lag) - 0.00034 tau = 1.345(lag**0.5) + 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 for 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) = 16.3147*Fl(V) - 4.3043 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: 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 WetStar fluorometer (chl) SN 741 WetStar fluorometer (cdom) SN 811 #publications: * "SeaSoar Observation During the GLOBEC NEP California Current Survey IV (R0208) 31 July - 19 August 2002" by R. O'Malley and J.A. Barth, Data Report 195, Reference 2004-3, November 2004 #associated_datasets: CTD data from R0208 #associated_versions: * #data_set_information: * #data_set_name: * #data_set_volume: 152,336 kbytes (1,229,878 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: R0208 #data_dates: 01 August - 18 August 2002 #left_geographic_upper_bound: 128W 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 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,middle,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: meso1.line4.a.dat2c and meso1.line4.b.dat2c). Repeat coverage of the same line on the same map is given a decimal number (eg: meso2.line1.1 and meso2.line1.2). #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