5 ctd Tables

The following are listings of the tables in the ctd database, including attribute names, data types (and any range restrictions), and comments.

5.1 Table 1: t_trip

Comment:

Gives a brief description of each trip where and/or salinity profiles were obtained. The description includes species being targeted (if any) and area. The table also contains comments on data and an indication of whether data have been loaded onto the database.

Attributes

Data Type

Null?

Comment

trip_code

character(7,1)

No

Trip code - 3-character vessel name, 2-digit year and 2-digit trip number.


smatch "[a-z0-9][a-z0-9][a-z0-9][0-9][0-9][0-9][0-9]"

description

text(20,20,20,1)


Brief description of purpose of trip and area or areas surveyed.

trip_comments

text(20,20,20,1)


Notes on processing of trip data and/or reliability of data, including missing data and methods of calibration.

status

character(1,1)


Indicates whether loading of physical oceanography data (i.e., CTD or other data related to temperature and salinity casts) for this trip has been completed:

y = all data for this voyage that can be recovered at time of processing have been loaded onto the database

n = loading of data has not been completed for this voyage.


smatch "[ny]"



Creator:

dba



Indices:

PRIMARY KEY BTREE voyex ON (trip_code)



5.2 Table 2: t_station

Comment:

Identifying and descriptive features of each station.



Attributes

Data Type

Null?

Comment

trip_code

character(7,1)

No

Trip code - 3-character vessel name, 2-digit year and 2-digit trip number.

station

integer

No

Sequential number for each station in the voyage.

cast

smallint


Number of the cast at the station. There is usually only one cast per station, but occasionally there are more due to trials of gear, comparisons or gear malfunctions.

cast_date

date(5)

No

Date of cast.

cast_time

integer

No

Time of cast (24 hour format). This is usually the start time of the cast.


range 0 to 2359



timezone

character(1,1)


1-character code for the time zone used for the cast time:

D = NZDT

S = NZST


smatch "[DS]"



fix_meth

character(2,1)


Method of fixing position. For method codes refer to rdb:t_fix_meth_codes

since_fix

smallint


Time between the last position fix made and the time the cast was performed, in minutes. This attribute is often null as the time since fix was often not noted, or the advent of GPS with continuous navigation fixes has made it redundant.

latitude

longinteger

No

Latitude (DDMMmm) of the cast with the last 4 digits are minutes and hundredths of minutes; e.g., 453480 is 45 degrees 34.80 minutes.


match "[2-5][0-9][0-5][0-9][0-9][0-9]"



nors

character(1,1)

No

Hemisphere of latitude: N = north, S = south.


smatch "[NS]"



longitude

longinteger

No

Longitude (DDDMMmm) of the cast with the last 4 digits are decimal minutes. E.g., 1743480 is 174 degrees 34.80 minutes.


match "1[5-8][0-9][0-5][0-9][0-9][0-9]"



eorw

character(1,1)

No

Hemisphere of longitude: E = east, W = west.


smatch "[EW]"



gear_meth

character(8,1)


Type of measurements made. This attribute can contain up to 3 method codes separated by commas. The codes are defined below:

80 = Nansen bottle hydrocast

82 = CTD only

83 = rosette only

84 = CTD and rosette

85 = MBT

86 = XBT

88 = MOCNESS CTD

probe_no

longinteger


Digits of serial number of CTD probe.

press_cal_no

longinteger


Identification number of pressure sensor calibration used for the CTD probe in the cast.

temp_cal_no

longinteger


Identification number of temperature sensor calibration used for the CTD probe in the cast.

bottom_depth

character(7,1)


Bottom depth in metres.

bttm_meas_meth

character(1,1)


1-character code for the method used to determine the bottom depth:

C = read off a chart (often a rough estimate)

S = echo sounder (often accurate to 1 metre).


smatch "[CS]"



max_probe_depth

decimal(5,1)


Deepest depth reached in cast rounded down to the nearest metre. This is usually recorded only for CTD probes.

depth_mix_layer

decimal(5,1)


Depth of mixed layer, defined as the depth which the rate at which temperature decreases with depth equals or exceeds 0.5 degrees Celsius in 10 m. Generally, if this depth is less than 10 m then it is considered that no mixed layer exists and the attribute is null. However, there are exceptions to this, e.g. Bays, sounds, etc.

cond_cal_no

longinteger


Identification number of conductivity correction used for cast.

area

character(4,1)


Area in which cast took place. This must be a valid 4 character area code as listed in the rdb:area_codes table. Areas are not well defined and for many stations this attribute is null.

notes

text(20,20,20,1)


Notes on data, methods or conditions at the station.

Creator:

dba



Referential:

No such area (area) INSERT rdb:area_codes (code) Pressure calibration (press_cal_no) INSERT t_press_cals (press_cal_no)


Temperature calibration (temp_cal_no) INSERT t_temp_cals (temp_cal_no)


Conductivity calibration (cond_cal_no) INSERT t_cond_cals (cond_cal_no)


No such fix meth (fix_meth) INSERT rdb:t_fix_meth_codes (fix_meth_code)

Indices:

FOREIGN KEY BTREE ON (trip_code)

PRIMARY KEY BTREE ON (trip_code, station_no, cast)



5.3 Table 3: t_metres

Comment:

Table of temperature, conductivity, salinity and sigmaT data in whole metre slices. Data is from downcast only.

Attributes

Data Type

Null?

Comment

trip_code

character(7,1)

No

Trip code - 3-character vessel name, 2-digit year and 2-digit trip number.


smatch "[a-z0-9][a-z0-9][a-z0-9][0-9][0-9][0-9][0-9]"

station_no

integer


No Sequential number for each station in the trip.

cast

smallint


Number of the cast at the station. There is usually only one cast per station, but occasionally there are more due to trials of gear, comparisons or gear malfunctions.

depth

decimal(5,1)

No

Depth in metres.

temp

decimal(5,3)


Temperature in degrees Celsius.


range 1.000 to 30.000



cond

decimal(6,5)


Conductivity ratio = conductivity of water in metre slice as measured by conductivity sensor : conductivity of standard seawater at 0m at 15 degrees Celsius.


range 0.60000 to 1.20000



uncorr_sal

decimal(5,3)


Salinity according to International Practical Salinity Scale 78 (IPSS-78) without correction from calibration being applied.


range 25.000 to 37.700



corr_status

character(1,1)

No

Status of correction of salinity data for cast.

C = salinity corrected.

N = salinity not corrected; i.e., calibration not possible or calibration not performed.

Y = calibration possible but correction not applied as yet.


= "c"




= "n"




= "y"



corr_sal

decimal(5,3)


Salinity according to International Practical Salinity Scale, after correction found by calibration has been applied. Except where otherwise stated, calibration is performed by back-calculating conductivities of water samples collected in bottles to conductivities at the pressures and temperatures when the samples were collected, and comparing these conductivities with in situ conductivities as measured by the CTD.


range 25.000 to 37.700



sigma_t

decimal(5,3)


Specific gravity anomaly. If both corrected and uncorrected salinities are available sigmaT is calculated using corrected salinity


range 20.000 to 30.000



sound_vel

decimal(6,2)


Speed of sound through water (m/s) range 1450.00 to 2000.00

Creator:

wjt



Referential:

wstatcheck (trip_code, station, cast) INSERT t_station (trip_code, station, cast)

Indices:

NORMAL (2, 15) i_wcruise ON (trip_code)

NORMAL (2, 15) i_wstation ON (station)

NORMAL (2, 15) i_wcast ON (cast)

NORMAL (2, 15) i_wdepth ON (depth)

UNIQUE i_unidepth ON (trip_code, station, cast, depth)



The following listings are views of the table t_metres. These views are instances of t_metres where for selected depths. Each record has the temperature, conductivity, salinity and density anomaly information for each standard depth in a cast (downcast only). See above listing for a most complete description of the attributes.

5.3.1 v_std_depths

View:

select * from "t_metres" where (((((((((((((((((((((((((attr "depth" = 10 or attr "depth" = 20) or attr "depth" = 30) or attr "depth" = 50) or attr "depth" = 75) or attr "depth" = 100) or attr "depth" = 125) or attr "depth" = 150) or attr "depth" = 200) or attr "depth" = 250) or attr "depth" = 300) or attr "depth" = 400) or attr "depth" = 500) or attr "depth" = 600) or attr "depth" = 700) or attr "depth" = 800) or attr "depth" = 900) or attr "depth" = 1000) or attr "depth" = 1100) or attr "depth" = 1200) or attr "depth" = 1300) or attr "depth" = 1400) or attr "depth" = 1500) or attr "depth" = 1750) or attr "depth" = 2000))

Attributes

Data Type

trip_code

character(7,1)

station_no

integer

cast

smallint

depth

decimal(5,1)

temp

decimal(5,3)

cond

decimal(6,5)

uncorr_sal

decimal(5,3)

corr_status

character(1,1) corr_sal decimal(5,3)

sigma_T

decimal(5,3)

sound_vel

decimal(6,2)

Creator:

wjt





5.4 Table 4: t_bottle_casts

Comment:

Table listing rosette or Nansen bottle casts. The table gives methods used for measuring depth, temperature and salinity as well as notes on accuracy of data or variations in measuring depth.

Attributes

Data Type

Null?

Comment

trip_code

character(7,1)

No

Voyage code - 3-character vessel name, 2-digit year and 2-digit trip number.


smatch "[a-z0-9][a-z0-9][a-z0-9][0-9][0-9][0-9][0-9]"

station_no

integer

No

Sequential number for each station in the voyage.

cast

smallint


Number of the cast at the station. There is usually only one cast per station, but occasionally there are more due to trials of gear, comparisons or gear malfunctions.

temp_meas_meth

character(3,1)


Method used to measure water temperatures during the cast. This attribute gives the more accurate method used if both CTD and reversing thermometers were used.

Codes are:

CTD = CTD

TEM = reversing thermometers.


= "CTD"

= "TEM"



cond_meas_meth

character(3,1)


Salinometer used to determine salinity of seawater samples.

Codes are:

FRC = Autolab salinometer

NOI = NZOI/MRC Guildline Autosal 8400 salinometer.


= "FRC"

= "NOI"



cast_notes

text(75,0,75,1)


Remarks on cast. These often include an indication of variation in methods used to measure depth during the cast, such as the use of protected and unprotected thermometers at given depths.

Creator:

wjt



Referential:

botvalcheck (trip_code, station_no, cast) DELETE t_bot_values (trip_code, station_no, cast)

checkstat (trip_code, station_no, cast) INSERT t_station (trip_code, station_no, cast)

Indices:

NORMAL (2, 15) i_botvoy ON (trip_code)

NORMAL (2, 15) i_botstat ON (station_no)

NORMAL (2, 15) i_botcast ON (cast)

UNIQUE i_unicast ON (trip_code, station_no, cast)



5.5 Table 5: t_bot_values

Comment:

Table containing depth, temperature and conductivity data from Nansen bottle and rosette casts. Corresponding data from the CTD probe are also included where the CTD probe was used at the same position and time. These data can be used to calibrate CTD conductivity against conductivity of samples collected in sample bottles.

Attributes

Data Type

Null?

Comment t

rip_code

character(7,1)

No

Voyage code - 3-character vessel name, 2-digit year and 2-digit trip number.


smatch "[a-z0-9][a-z0-9][a-z0-9][0-9][0-9][0-9][0-9]"



station_no

integer

No

Sequential number for each station in the voyage.

cast

smallint


Number of the cast at the station. There is usually only one cast per station, but occasionally there are more due to trials of gear, comparisons or gear malfunctions.

sample

smallint


Number of sample at the give depth for a cast. There is usually only one sample for each depth in a cast, but occasionally more than one bottle may be tripped to collect samples.

depth_meas_meth

character(3,1)


Method of determining depth at which sample was taken and/or thermometers were reversed. Codes are: CTD = CTD probe (accurate to about 0.5 m over 1000 m, but greater accuracy at shallower depths).CWA = cosine of wire angle (accuracy in the order of metres).MBC = metre block counter reading (not as accurate as cosine of wire angle).PUT = determined from difference between readings of protected and unprotected thermometers (accuracy in the order of metres if thermometer readings are accurate).


= "CTD"




= "CWA"




= "MBC"




= "PUT"



depth

decimal(5,1)

No

Depth at which water samples were taken and/or thermometers tripped. Accuracy of depth is dependent on the measurement method used.

bottle_temp

decimal(5,3)


Temperature as measured by protected reversing thermometer after thermometer corrections (for index and expansion of mercury and glass) have been applied. Accuracy is at best + or -0.01 degrees Celsius, but is often less.


range "1.000 to 30.000



ctd_temp

decimal(5,3)


Temperature as measured by CTD at depth given. This is usually done by interpolating data that are averages of temperature over depths of about 1 metre. Accuracy of the CTD temperature is about + or - 0.03 degrees Celsius.


range 1.000 to 30.000



raw_cond

decimal(6,5)


Conductivity of hydrocast or rosette bottle sample water as measured by the salinometer (generally at 15 degrees Celsius near or at sea level).


range 0.80000 to 1.20000



equiv_cond

decimal(6,5)


Conductivity of bottle sample backcalculated to the in situ pressure and temperature where the sample was collected. Some error may be introduced during back-calculation.


range 0.60000 to 1.30000



ctd_cond

decimal(6,5)


Conductivity ratio as measured by CTD probe.


range 0.60000 to 1.20000



remarks

text(75,0,75,1)


Notes on any errors that may occur (e.g. Loose tops on salinity sample bottles), or on any change in method of determining values (e.g., finding raw conductivity by back-calculating salinity).

Creator:

wjt



Referential:

checkcast (trip_code, station_no, cast) INSERT t_bottle_casts (trip_code, station_no, cast)

Indices:

NORMAL (2, 15) i_valvoy ON (trip_code)

NORMAL (2, 15) i_valstat ON (station_no)

NORMAL (2, 15) i_valcast ON (cast)

NORMAL (2, 15) i_valdepth ON (depth)

UNIQUE i_unival ON (trip_code, station_no, cast, depth, sample)



5.6 Table 6: t_press_cals

Comment:

Information about each pressure sensor calibration.

Attributes

Data Type

Null?

Comment

press_cal_no

longinteger

No

Identification number of pressure sensor calibration.

pcal_date

date(5)

No

Date of pressure calibration.

probe_no

longinteger

No

Serial number of probe to which the calibration relates.

sensor_no

longinteger

No

Serial number of pressure sensor that was calibrated.

cal_meth

character(3,1)

No

Site or organisation where pressure calibration was performed.




MAN = manufacturer.




PEL = former Physics and Engineering Laboratory. (now Industrial Research Ltd, Gracefield).




NOI = NZ Oceanographic Institute.

press_notes

text(75,0,75,1)


Remarks about pressure calibration method, data or results.

Creator:

wjt



Referential:

statpress (press_cal_no) DELETE t_station (press_cal_no)

press_coeff (press_cal_no) DELETE t_pre_coeffs (press_cal_no)

Indices:

UNIQUE i_presscal ON (press_cal_no)\end{tabbing}



5.7 Table 7: t_pre_coeffs

Comment:

Pressure corrections used in summarising raw CTD data are found by using a polynomial whose coefficients are listed in this table. The polynomial is of the form Pc = p0 + p1Pr + p2Pr**2 + ... + pnPr ** n where:

Pc is corrected pressure

Pr is raw pressure and

p0, p1, etc, are the correction coefficients.

NB. Depth data in the database that were obtained by CTD observations were calculated using corrected pressure.

Attributes

Data Type

Null?

Comment

press_cal_no

longinteger

No

Identification number of pressure sensor calibration.

p_coeff_no

smallint

No

Which coefficient in correction formula; e.g., 0 denotes that the coefficient is the constant term.

press_coeff

decimal(4,3)

No

Value of coefficient.

Creator:

wjt



Referential:

check_pcal (press_cal_no) INSERT t_press_cals (press_cal_no)

Indices:

UNIQUE i_pcoeff ON (press_cal_no, p_coeff_no)



5.8 Table 8: t_temp_cals

Comment:

Information on each temperature sensor calibration. Calibrations of probe 45656 up to calibration number 1006 and those of probe 49088 up to calibration number 5 were performed according to International Practical Temperature Scale 68 (IPTS-68). Later calibrations were performed according to International Temperature Scale 90 (ITS-90).

To calculate salinity according to the International Salinity Scale (ITSS-78) using temperature measured according to ITS-90, it is necessary to convert these temperatures to IPTS-68 temperatures using the formula:

T68 = 1.00024*T90

Attributes

Data Type

Null?

Comment

temp_cal_no

longinteger

No

Identification number of temperature sensor calibration.

tcal_date

date(5)

No

Date of temperature sensor calibration.

probe_no

longinteger

No

Serial number of probe to which the calibration relates.

tsensor_no

longinteger

No

Serial number of temperature sensor that was calibrated.

cal_meth

character(3,1)

No

Site or organisation where temperature sensor was calibrated. Codes are: MAN = manufacturer.




PEL = former Physics and Engineering Laboratory. (now Industrial Research Ltd, Gracefield).




NOI = NZ Oceanographic Institute.

temp_notes

text(75,0,75,1)


Remarks on temperature calibration method, data, or result.

Creator:

wjt



Referential:

statemp (temp_cal_no) DELETE t_station (temp_cal_no) temp_coeff (temp_cal_no) DELETE t_tem_coeffs (temp_cal_no)

Indices:

UNIQUE i_tcal ON (temp_cal_no)\end{tabbing}



5.9 Table 9: t_tem_coeffs

Comment:

Temperature corrections used in summarising raw CTD data are found by using a polynomial whose coefficients are listed in this table.

The polynomial is of the form:

Tc = t0 + t1Tr + t2Tr**2 + ... tn*Tr**n

Where:

Tc is corrected temperature

Tr is raw temperature and

t0, t1, t2, etc, are correction coefficients.

NB. Temperature data in the database that were obtained by CTD probes has already had the corrections applied to them.

Attributes

Data Type

Null?

Comment

temp_cal_no

longinteger

No

Identification number of temperature sensor calibration.

temp_coeff_no

smallint

No

Which coefficient in correction equation;e.g., 0 denotes that the coefficient is a constant.

temp_coeff

decimal(6,5)

No

Value of temperature correction coefficient.

Creator:

wjt



Referential:

check_tcal (temp_cal_no) INSERT t_temp_cals (temp_cal_no)

Indices:

UNIQUE i_tcoeff ON (temp_cal_no, t_coeff_no)



5.10 Table 10: t_cond_cals

Comment:

Information on each calibration of CTD conductivity against conductivity of rosette or hydrocast samples. These calibrations are made so that the conductivity measured by the CTD conductivity sensor can be corrected. Corrected conductivity is then used to calculate corrected salinity.

Attributes

Data Type

Null?

Comment

cond_cal_no

longinteger

No

Identification number of conductivity calibration.

ccal_date

date(5)

No

Date on which conductivity correction coefficients were determined. NB. This is neither the date of the voyage nor the date that the conductivity of water samples was measured.

probe_no

longinteger

No

Serial number of probe to which the calibration relates.

csensor_no

longinteger

No

Serial number of conductivity sensor to which calibration relates.

cal_meth

character(3,1)


Which salinometer -




NOI = NZOI/FRC Guildline Autosal 8400.




FRC = FRC Guildline Mark IV


= "NOI"




= "FRC"



cond_notes t

ext(75,0,75,1)


Remarks about conductivity calibration method, data or results.

Creator:

wjt



Referential:

statcond (cond_cal_no) DELETE t_station (cond_cal_no) check_ccal (cond_cal_no) DELETE t_con_coeffs cond_cal_no)

Indices:

UNIQUE i_condex ON (cond_cal_no)\end{tabbing}



5.11 Table 11: t_con_coeffs

Comment:

Coefficients used to correct the conductivity as measured by the conductivity sensor are listed in this table. Corrected conductivity is found by using a polynomial of the form:

Cc = co + c1Cr + c2Cr ** 2 + ... + cnCr ** n

Where:

Cc is corrected conductivity

Cr is raw conductivity and

c0, c1, c2, etc, are the correction coefficients listed in the table.

Attributes

Data Type

Null?

Comment

cond_cal_no

longinteger

No

Identification number of conductivity calibration.

c_coeff_no

smallint

No

Which coefficient in correction equation;e.g., 0 denotes that the coefficient is the constant term.

cond_coeff

decimal(6,5)

No

Value of conductivity correction coefficient.

Creator:

wjt



Referential:

cond_calcheck (cond_cal_no) INSERT t_cond_cals (cond_cal_no)

Indices:

UNIQUE i_ccoeff ON (cond_cal_no, c_coeff_no)



Updated : 16 November 2007