WHP CRUISE SUMMARY INFORMATION

WOCE section designation
A06 & A07

Expedition designation (EXPOCODE)
35A3CITHER1_1-2

Chief Scientist(s) and their affiliation
Alain MORLIERE( ORSTOM), 
Christian COLIN (ORSTOM)

Dates
1993.01.02 - 1993.03.19

Ship
L'ATALANTE

Ports of call
Pointe Noire (Congo) to Natal (Brazil), 
Cayenne (French Guyana) to Abidjan (Ivory Coast) 

Number of stations
224

Geographic boundaries of the stations
	820.42''N
5119.50''W	1050.39''E
	539.43''S

Floats and drifters deployed
none

Moorings deployed or recovered
none

Contributing Authors
(In order of appearance)
T. Mueller
A. Billant
P. Branellec 
M. Arhan

CITHER 1 CRUISE

HIGHLIGHTS

Expedition Designation:

The CITHER 1 cruise is a french contribution to WOCE Programme. This cruise 
describes WHP Lines A6 and A7

Scientist in charge of the cruise:

Claude OUDOT, Institut Franais de Recherche Scientifique pour le Developpement 
en Cooperation (ORSTOM)

Chief Scientists:

Leg 1:	Alain MORLIERE, Institut Franais de Recherche Scientifique pour le 
Developpement en Cooperation (ORSTOM)
Leg 2:	Christian COLIN, Institut Franais de Recherche Scientifique pour le 
Developpement en Cooperation (ORSTOM)

Ship:	R/V L'ATALANTE

Ports of call:

Leg 1:	Part 1: Pointe Noire (Congo) to Natal (Brazil): WHP Section A7
	Part 2: Natal (Brazil) to Cayenne (French Guyana)
Leg 2:	Part 1: Cayenne (French Guyana) to Abidjan (Ivory Coast): WHP 
	Section A6
	Part 2: Abidjan (Ivory Coast) to Pointe Noire (Congo)

Cruise Dates:

Leg 1:	Part 1: January 2 (Pointe Noire) to January 23 (Natal), 1993
	Part 2: January 26 (Natal) to February 10 (Cayenne), 1993
Leg 2:	Part 1: February 13 (Cayenne) to March 8 (Abidjan), 1993
	Part 2: March 10 (Abidjan) to March 19 (Pointe Noire), 1993

Cruise Summary

Cruise Track

The cruise track and station locations are shown above.

Sampling accomplished

Water sampling on the cruise included measurements of salinity both by CTD and 
water bottle samples, CTD and bottle sample oxygen determinations, CTD 
temperature, and nutrients (silicate, phosphate, nitrate, nitrite).  Tracer 
analyses were made for CFC-11 and CFC-12 as well as sampling for tritium/helium.

Besides water sampling was made for measurements of CO2 system parameters (TCO2, 
pH, fugacity of CO2), dissolved gases (nitrogen, argon, methane and nitrous 
oxide).

Type and number of stations

During the two legs of the cruise a total of 224 CTDO/Rosette stations were 
occupied using a 32-bottle IFREMER rosette equipped with 8 liters PVC water 
sampling bottles.

The usual spacing of stations was 30 nm, except over the continental slope (4 to 
5 nm) and the abyssal plains (40 nm).

List of Principal Investigators

The parameters with the principal investigators and their affiliation are listed 
in Table 1.

Table 1:	List of measured parameters and the Principal Investigators for 
		each.

Parameter		Sampling Group		Principal Investigator
CTDO2 / Rosette		LPO/IFREMER-Brest	M. Arhan / H. Mercier
S, O2			LPO/IFREMER-Brest	M. Arhan / H. Mercier
NO3, NO2, PO4, Si(OH)4	ORSTOM-Brest		C. Oudot
			LOC/UBO-Brest		P. Morin
CFC-11, CFC-12		ORSTOM/LODYC-Paris	C. Andrie
Tritium, Helium		LMCE-Saclay		P. Jean-Baptiste
CO2 system		ORSTOM-Brest		C. Oudot
Dissolved gases (N2, Ar)ORSTOM-Brest		C. Oudot
Trace gases (N2O, CH4)	LOC/UBO-Brest		M. Guevel
ADCP			ORSTOM/LODYC-Paris	A. Morliere
			LPO/IFREMER-Brest	H. Mercier
PEGASUS			IFM-Kiel		F. Schott
			ORSTOM-Cayenne		C. Colin

Preliminary results

The R/V L'ATALANTE departed Pointe Noire, Congo for the WHP Section A7 on 
January 2nd, 1993.  The first station near 504 N, 1040 E (bottom depth = 2100 
m) was to test one of the two CTD systems and its rosette water sampling 
equipment.  The CTDs are EG&G Neil Brown Mark III equipped with Beckman 
dissolved oxygen sensor.  The first CTD equipment was replaced by the second one 
at station 83 (January 29, 1993) owing to problems with the conductivity sensor.  
All the CTD temperature, pressure and conductivity sensors were calibrated at 
the IFREMER calibration facility both before and after the cruise.  The 
conductivity and oxygen sensors were also calibrated at sea using data from the 
analyses of the salinity and oxygen samples collected at each station.  Water 
samples were collected from 32 PVC sampler bottles (capacity 8 liters)) mounted 
on the two-storied IFREMER Rosette sampler.  The water sample conductivity 
measurements and oxygen titrations were made in a constant temperature (20C) 
portable laboratory.

Additional samples were also collected from each PVC bottle for the shipboard 
analysis of nutrients (silicate, phosphate, nitrate, nitrite) and 
chlorofluorocarbons CFC-11 and CFC-12 (every other station until station number 
66, every station beyond and until the last station).  Helium and tritium 
samples were also collected at many of the stations (a total of 58): the 
analysis of these samples will be later carried out in a shore-based laboratory.

Other samples were also collected from PVC bottles for the shipboard analysis of 
dissolved gases (nitrogen - argon - total CO2 - methane and nitrous oxide) and 
the determination of pH and fugacity of CO2 (in surface water and in 
atmosphere).  The phytoplankton biomass (chlorophyll) was also sampled for 
shore-based analysis.

Underway ADCP and thermosalinograph data were recorded along the track of the 
ship (10 154 nm).  Twelve PEGASUS profilings were done near the western coast in 
the boundary currents.

Problems

During the first leg (station number 83) we must have to replace the CTD system: 
shift and noises of the conductivity sensor.  The second CTD system will be used 
until the end of the cruise without problems.

Through the cruise we used successively three Guildline salinometers: one 
Autosal and two Portasal.  The problems were a shift of the calibration between 
the stations; or drift within a series of measurements.  The later acquired 
Portasal model has given the best results and was used to measure all the 
salinities during the leg 2.

With the analytical measurements of the tracers, the most serious problem was 
the CFC contaminations from the PVC sampling bottles, mainly due to the grease 
of the stopcocks.  A few special stations (5) were made to test the 
contaminations, by closing all the bottles at the same depth where the CFC 
concentrations were the lowest (generally around 2500 m depth).  The mean 
contamination is estimated to about 0.005  0.002 pmol/l for F-12 and to about 
0.008  0.002 pmol/l for F-11.

List of the cruise participants

The list of the cruise participants is given in Table 2.

STATION SUMMARY

The station positions, time, etc are tabulated in a summary file.  This file 
(CITHER1.SUM) is reported on attached pages (numbered 1 to 12) and on attached 
floppy disk in MS-DOS format (ASCII characters).

The parameter numbers are defined in Table 3.

Table 2:	Cruise participants

PARTICIPANTS		ROLE			AFFILIATION		LEG
Chantal Andrie		CFCs			ORSTOM/LODYC-Paris	1 - 2
Michel Arhan		CTDO2			LPO/IFREMER-Brest	1
Sabine Arnault		Tritium, Helium		ORSTOM/LODYC-Paris	2
Franois Baurand	Nutrients		ORSTOM-Brest		1 - 2
Andre Billant		S, O2			LPO/IFREMER-Brest	2
Jean-Michel Bore	CTDO2			ORSTOM-Cayenne		1 - 2
Bernard Bourles		CTDO2			ORSTOM-Cayenne		1 - 2
Pierre Branellec	S, O2			LPO/IFREMER-Brest	1
Elisabete Braga		Oxygen			IOUSP-Sao Paulo		2
Remy Chuchla		Oxygen			ORSTOM-Cayenne		1
Souleymane Cissoko	CTDO2			CRO-Abidjan		2
Christian Colin		Chief Scientist,Pegasus	ORSTOM-Cayenne		2
Daniel Corre		CTDO2			ORSTOM-Brest		2
Franois Dangu		Salinity - CTDO2	ORSTOM-Cayenne		1 - 2
Nathalie Daniault	CTDO2			LPO/IFREMER-Brest	1
Andre Dapoigny		Tritium, Helium		LMCE/CEN-Saclay		1
Alain Dessier		CO2, N2, Ar		ORSTOM-Brest		2
Jean-Pierre Girardot	CTDO2			LPO/IFREMER-Brest	2
Jean-Pierre Gouillou	CTDO2			LPO/IFREMER-Brest	1
Yves Gouriou		CTDO2			ORSTOM-Brest		1 - 2
Stephanie Gueneley	Nutrients		ORSTOM-Brest		1
Mickael Guevel		Trace gases		LOC/UBO-Brest 		1 - 2
Catherine Hemon		CTDO2			LPO/IFREMER-Brest	2
Philippe Hisard 	Salinity		ORSTOM-Brest		2
Philippe Jean-Baptiste	Tritium, Helium		LMCE/CEN-Saclay		2
Milton Kampel		CTDO2			INPE-Brazil		1
Lamine Keita		CTDO2			CERESCOR-Conakry	2
Jean-Jacques Lechauve	CTDO2			ORSTOM-Brest		1
Jerome Lecomte		CO2, N2, Ar		ORSTOM-Cayenne		1 - 2
Nathalie Lefevre	CO2 Fugacity		LODYC-Paris		2
Jean-Franois Maguer	Nutrients		LOC/UBO-Brest		1
Jean-Franois Makaya	CTDO2			ORSTOM-Pte Noire	1
Laurent Memery		CFCs			LODYC-Paris		1
Herle Mercier		CTDO2, ADCP		LPO/IFREMER-Brest	2
Marie-Jose Messias	CFCs			LODYC-Paris		2
Pascal Morin		Nutrients		LOC/UBO-Brest		2
Alain Morliere		Chief scientist, ADCP	ORSTOM/LODYC-Paris	1
Claude Oudot		CO2, N2, Ar		ORSTOM-Brest		1 - 2
Christophe Peignon	CO2, N2, Ar		ORSTOM-Lome		1
Jean-Paul Rebert	Tritium, Helium		ORSTOM-Brest		1
Joerg Reppin		Pegasus			IFM-Kiel		1
Birane Samb		CTDO2			CRO-Dakar		2
Jean-Franois Ternon	CFCs			ORSTOM-Brest		1 - 2
Mohideen Wafar		Nutrients		LOC/UBO-Brest		1

Table 3:	Parameter numbers in the CITHER1.SUM file

Parameter	Parameter		Unit
Number
1		Salinity		PSS-78
2		Oxygen			mol/kg
3		Silicate		mol/kg
4		Nitrate			mol/kg
5		Nitrite			mol/kg
6		Phosphate		mol/kg
7		Freon 11 (CFC-11)	pmol/kg
8		Freon 12 (CFC-12)	pmol/kg
9		Tritium			TU
10		Helium			nmol/kg
11		Delta Helium-3		%
12		
13		
14		
14		
15		
16		
17		
18		
19		
20		
21		
22		
23		Total Carbon		mol/kg
24		Total Alkalinity	mol/kg
25		Fugacity fCO2		Pa - atm
26		pH			None
33		Nitrogen		mol/kg
15		Argon			nmol/kg
33		Nitrous oxide		nmol/kg
31		Methane			nmol/kg
34		Chlorophyll a		g/l
35		Phaeophytin		g/l

Thomas J. Mueller
Institut fuer Meereskunde
an der Universitaet Kiel
Duesternbrooker Weg 20
24105 KIEL, Germany
e-mail: tmueller@ifm.uni-kiel.de

Woods Hole, MA, U.S.A.
02 Oct, 1996

WOCE Hydrographic Programme
Data Quality Expert (DQE) Report on CTD data

One Time Sections A6, A7
N/O L'Atalante
Jan - Mar 1993
CTD-O2 data

Introduction

The French written cruise report consists of four volumes:

-	Volume 1 with general cruise information.  Also, procedures of calibration 
	and processing of 'En Route' data, ship borne ADCP, and some PEGASUS 
	stations are described. 
-	Volume 2 (Le Groupe CITHER-1, 1994) with a description of CTD-O2 data 
	calibration, processing and extensive hard copy displays. 
-	Volumes 3 and 4 with geochemical measurements.

Also, an English written cruise report is available at the WHPO (6 pages plus -
.SUM file).

The present DQE report deals with the CTD-O2 data from A6 and A7.  It consists 
of three parts:

(A)	A brief summary of the French written A6/A7 CTD-O2 data report (Le Groupe 
	CITHER-1, 1994; GC1 henceforth) which describes the procedures of 
	laboratory calibrations, data acquisition and processing, in-situ 
	calibrations and verifications. Along with this summary, I have included 
	(and flagged as such) some comments at the end of sections where 
	appropriate. No figures and tables are available in electronic form from 
	the above report, and therefore reference is made to figures and tables as 
	they appear in the report.
(B)	A report of evaluation of the A6 and A7 CTD-O2 data as they were available 
	at the WHP-O in September 1996. 
(C)	Recommendations

Part A.

Campagne CITHER-1 of R/V L'ATALANTE (2 janvier-19 mars 1993). Recueil de 
donnees, Volume 2: CTD-O2

(English summary by DQE with comments added at ends of sections; sections, 
figures and tables are numbered as in the French report)

I	The CITHER-1 Group

To obtain WOCE one time zonal sections A6 (along 07N30') and A7 (04S30') is one 
among other French contributions to WOCE.  The cruise in 1993 was divided into 
two legs.  In addition to stations along A6 and A7, two meridional sections were 
obtained between A6 and A7, along 035W and 004W. 

PI's for CTD-O2/rosette were Michel Arhan (leg 1) and Herle Mercier (leg 2); see 
Table 1 in the report for other PI's.

II	Cruise participants with respect to CTD-O2 work

see Table 2

III	Calibration of CTD-O2 measurements
(A. Billant and P. Branellec, LPO)

1. Acqusition of CTD-O2 data
A total of 223 stations with two Mark III CTD-O2 systems were obtained along 
with a 36x8 l bottle rosette PASH 6000 developed by LPO.  For locations of stations 
see Figure 1.

Major events
 
(i)	Section A7 was interrupted westbound after Stat. 77 before the vessel 
	entered the 200 nm EEZ of Brazil.  Prior to continuate A7, L'ATALANTE had 
	to call port of Natal, Brazil, to pick up a Brazilian observer.  Five days 
	later, A7 was continued with Stat. 78 as repeat station on the position of 
	Sta. 77.
(ii)	The first CTD-O2, S/N 2521, was replaced due to problems with the 
	conductivity sensor after Stat. 82 by the second CTD-O2, S/N 2782.
(iii)	Stations 27, 75, 118 and 190 were taken in between WHP stations, with 
	bottle being closed at special depths for calibration and test purposes.

Data acquisition and processing

The CTD's data cycles were transferred to the computer at a 32 Hz rate and on-
line processed.  Processed data then were stored on magnetic tape.  Two steps of 
processing were applied.  First, each data value was compared with the one in 
the preceding cycle.  If the absolute difference of a value to the preceding one 
exceeded a certain amount (see table below), the complete cycle was omitted.  
The parameters for this comparison were:

Pressure	0.5 dbar
Temperature	0.032 K for pressure < 1500 dbar
		0.005 K for pressure > 1500 dbar
Conductivity	0.032 mS/cm for pressure < 1500 dbar
		0.005 mS/cm for pressure > 1500 dbar
Oxygen curr.	0.010 UA 
Oxygen temp.	0.3 K

Next, cycles were averaged in pressure intervals.  The intervals were chosen 
such that of all data cycles at least 25% were kept as 'good' and contribute to 
the average.  For a lowering speed of 1 m/s, this means that at least 8 cycles 
contribute to an average over 1 dbar.

Only, lowering profiles are considered.

DQE's comments on section 1:

From the French report, I understand that the original data set is not stored 
but only the (single value) de-spiked and averaged cycles with no other 
processing steps being applied before or afterwards.  If this is true, I see 
some principal problems with this procedure.  Although such a procedure may not 
affect very much CTDs that behave well, and although the non-averaged data may 
not be available any longer (as I understand the report), let me describe some 
steps necessary in processing open sensor CTD data.

(i)	the de-spiking method as described above can only recognize single spikes. 
	It also is problematic in that it compares only with preceding values.  If 
	two or more spikes occur in turn (which to my experience may happen) these 
	are smeared into the average during the averaging process; they can never 
	be re-identified, and it is hard to detect and remove such 'bad' averages.
(ii)	Before averaging or low pass filtering, other important processing steps 
	are performed for 'open sensor' CTD's by other institutes like WHOI (see 
	Yang and Millard, 199xx) and IFM Kiel.  They are not described for A6 and 
	A7.  The steps are:

	-	create (if not already available) a cycle number or time and keep it 
		throughout the processing.
	-	check the (single value) despiked series for further spikes.
	-	apply a low pass filter to the pressure series; this matches the 
		pressure sensor resolution (0.1 dbar) to the lowering speed which at 
		1 m/s requires a resolution of 0.03 dbar.
	-	monotonize the profile with respect to pressure; conductivity and 
		oxygen sensor respond quite differently under different lowering 
		speeds.  Even better would be to first apply a 'minimum lowering 
		speed' criterion to the profile and then monotonizing.
	-	match the time constants of the (combined) temperature signal and 
		the conductivity sensor.  This can be done either 'by eye' looking 
		at salinity spikes in sharp gradient regions, or more objectively by 
		looking at the coherence and phase spectra.
	-	apply a low pass filter to 0.5 dbar response and average on 0.5 dbar 
		intervals.
	-	apply the (static) calibrations for pressure, temperature and 
		conductivity.
	-	apply a low pass filter to 2 dbar response.
	-	apply the correction for the dynamic response of the pressure sensor 
		to temperature changes
	-	average on 2 dbar intervals
	-	calculate follow up quantities (salinty, pot. temperatur, pot. 
		density)
	-	apply the calibration of the oxygen sensor.

2. Sampling

Sampling was done with a 36 x 8 l bottle rosette PASH 6000 developed by LPO.  
Bottles were closed on the way up (see Fig. 2, 3).  A total of 6269 samples for 
salinity and 6460 samples of analysis of dissolved oxygen were taken.  12 
bottles carried reversing temperature and pressure sensors made by SIS.  Samples 
from bottles were drawn according to the instructions in the WOCE operation 
manual.

DQE's comment on section 2
	ok

3. Sample analysis for salinity and dissolved oxygen

3.1 Salinity

Samples for salinity were drawn to 125 ml flasks, stored in a constant 
temperature (20C  1 K) laboratory and analyzed within 20 h to 30 h. 

Standard seawater, batch P120 (K15=0.99985) from Wormley by 06 April 1992, was 
used to standardize the salinometers.  Standardizations were performed before 
analysis started each day.  After 36 bottles, standardization was verified and 
the result noted in a log.  Each sample was rinsed three times before measuring 
and read three times.

Due to stability problems of order 0.003 psu within a series of 36 bottles, 
salinometers were changed:

Stat		ID		Stability 36 samples
001 to 010	PORTASAL	A	0.001 psu
011 to 018	AUTOSAL 8400	B	<0.003 psu
019 to 119	PORTASAL	A	0.001 psu
120 to 223	PORTASAL	B	<0.001 psu

Whenever unstable conditions were observed, standard seawater was used and 
salinity linearly corrected for drift.

At four (non-WHP) stations, bottles were closed at same depths to get multiple 
samples for comparison.  The maximum deviations from the means were less 0.003 
psu.  From the following statistics it follows that the precision is better 
0.002 psu.

Test stations: Salinity

Stat	depth	Bottles close	Stand. dev
27	2000	32		0.0009
75	4400	26		0.0018
118	2500	27		0.0011
190	1000	24		0.0016

Figures 4 and 5 show the results from 275 double samples from pairs of bottles 
taken throughout the cruise from the whole water column.  Of these, 51% differ 
by less than 0.001 psu, and 85% by less than 0.003 psu.  This result is not 
significantly improved when only samples from deeper than 980 dbar are 
considered.

DQE's comment on section 3.1

All salinity measurements were done and reported thoroughly.  As the comparisons 
of oxygen measurements (see 3.2 below) from the same test stations with 
significantly improved results from deeper levels show, the relative high value 
in salinity precision seems not to be due to mistakes in sampling but to the 
trouble with drifts in all 3 salinometers, rather.  Nevertheless, from the high 
number of samples one may expect a good calibration the CTD's salinities.

3.2 Dissolved Oxygen

Samples for oxygen were drawn after those for CFC's and helium into flasks of 
120 ml.  Temperature of the sample was measured before rinsing the flask three 
times.  Samples were measured along the guidelines of the WOCE Operations Manual 
in constant temperature (20C  1 K) laboratory.  The method included to 
automatically detect the inflection.

Multiple samples from same depths at three test stations show that a precision 
of 0.01 ml/l is expected.

Test stations: Oxygen

Stat	depth	Bottles close	Stand. dev
27	2000	32		0.003
75	4400	26		0.007
190	1000	24		0.009

In figures 6 and 7 the results from 297 double samples from pair of bottles 
throughout the cruise and the water column are displayed.  Of all double 
samples, 39% agree to within 0.005 ml/l, and 70% to within 0.015 ml/l.  This 
result is much improved if one restricts to the 213 samples from depths larger 
than 980 m: then, even 45% agree to within 0.005 ml/l.  For depths larger 2480 
m, the standard deviation is 0.013 ml/l.

DQE's comment on section 3.2

As the multiple and the double samples show, oxygen measurements meet the 
requirements of the WHP.

4. CTD pressure sensor calibration

Both CTD's carried a Paine strain gauge sensor.  These sensors routinely are 
calibrated at IFREMER's calibration center which is certified by the 'Bureau 
National de Metrologie' (BNM).  A dead weight tester made by 'Desgranges et 
Huot' with an accuracy of  0.75 dbar at 6000 dbar is used.

4.1 Calibration under laboratory conditions (20C)

Pre- and post cruise calibrations were made for both CTD's with repeated loading 
(upper panels in fig. 8, 9) and unloading (lower panels) cycles.  Third order 
polynomials have residuals less 2 dbar.

4.2 Static temperature effects

Pressure sensor temperature was measured during the profiles.  Laboratory 
calibrations at 7 different temperatures that cover the range are available.  
The effect is less 5 dbar.  The additional corrections are necessary after 
having applied the 20C basic calibration less than 3 dbar.  The inner sensor 
temperature is modeled for a typical decent and hatched in figure 10.

4.3 Dynamic effects of temperature changes

The dynamic responses to about 20 K temperature shocks were measured in the 
laboratory for both CTD's (fig. 11).  The corrections applied for CTD profiles 
assume a single shock of this order within the thermocline, a lowering speed of 
1m/s, 13 minutes at maximum pressure before the up-profile starts, and a 1 
minute stop to close a bottle.

4.4 Corrections of pressure measurements

Taking the 20 C basic 3rd order regressions at the 400 dbar interval calibration 
points, the corrections for the effects of both, static and dynamic temperature 
corrections are added.  For the combined effects, a 5th order polynomial 
regression is applied to all pressure measurements (fig. 12, 13: loading mode in 
upper panels, unloading mode in lower panels).

4.5 Verifications after corrections

For both CTDs, the differences at the surface before and after the profile 
corresponded well to the overall laboratory calibrations displayed in figures 12 
and 13.

Reversing electronic pressure sensors of SIS were used on the up profile.  Pre- 
and post cruise calibrations were performed at 2.5C at 7 points between 0 dbar 
and 6000 dbar.  The corrected values of CTD and SIS sensors compare well within 
2 dbar which may be assumed to be the overall accuracy of pressure measurements 
for WHP cruises A6 and A7.

DQE's comment on section 4

Both sensors show a major change in their response characteristics at pressures 
larger than 4500 dbar in the post cruise calibration (fig. 8, 9) which appears 
strange to me.  While the pre cruise calibration has the 3rd order polynomial 
response as it is typical for the Paine sensor, the post cruise calibrations for 
both sensors are more or less parabolic.  The effect results in an order 3.5 
dbar change for CTD2521 at 5400 dbar, which is the maximum pressure during the 
cruise; the effect is less for CTD2782.  I wonder if such a change in the 
response characteristics found in other sensor calibrations from this period of 
time in which case they might indicate a shift in reference rather than CTD 
sensors.

Hysteresis may depend on the maximum pressure to which the sensor was exposed 
before unloading, with maximum hysteresis being expected at the high end of the 
range at 6000 dbar.  During these calibrations, the maximum pressure was kept to 
6000 dbar.  This excludes check of hysteresis effects at lower maximum 
pressures.  However, since hysteresis was less than about 1.5 dbar at all 
pressures this will have a minor effect on the final calibration.

The corrections for static temperature responses could better have been applied 
directly by linear interpolation since the inner temperature was measured, as I 
understand.  However, the effect will be small, anyway.  The same holds for the 
dynamic response. 

All corrections are modeled empirically into one 5th order polynomial for each, 
loading and unloading mode.  As the comparison of corrected CTD pressures with 
corrected SIS pressures shows this method was able to meet the WHP requirements 
for CTD pressure measurements.

5. CTD temperature sensor calibration

The measurements of a high precision Rosemount and that of a fast response NTC 
resistance are combined to standard MKIIIB temperature output at a resolution of 
5 mK.

5.1 Operational mode

CTD temperature sensors are routinely calibrated at IFREMER before and after a 
cruise.  During calibration, the CTD is completely immersed into the temperature 
stabilized calibration bath.  Temperature readings are compared to a reference 
Rosemount sensor which ITS90 calibration is traced back on a regular basis to 
the BNM.

Both CTDs were in use since 1982 with changes in calibration not exceeding 10 
mK.  While CTD2521 stayed stable during the cruise (fig. 16a), CTD2782 showed a 
clear offset of 2 mK at 0C and 8 mK at 25C (fig. 16b).  The uncertainty of 
CTD2782 is 2 mK up to 5C, and 4 mK for larger temperatures.

5.2 Verification after correction

Seven reversing electronic thermometers made by SIS and calibrated, both before 
and after the cruise, were used throughout the cruise.  After the change of CTDs 
between stations 82 and 83, a 'jump' in the difference to all SIS sensors is 
observed (15 mK  1 mK) that corresponds well to the difference in the CTD 
laboratory calibration at 2C (16 mK; see fig. 17 for temperature range 2.5 to 
5C and fig 18 for the 1C to 2.5C range).  Final offsets between SIS and CTD 
are probably due to a pressure effect on the SIS sensors.

For stations 1 to 82, accuracy as derived from figures 17 and 18 is of order 1 
mK, over the whole cruise 2 mK.

DQE's comment on section 5

From the calibration curve of CTD2521, its uncertainty seems to be of the order 
of 1 mK.  As for CTD2782, it might be interesting to search for similiar 'jumps' 
in earlier calibrations. 

Accuracy of CTD temperatures as estimated from pre- and post cruise 
calibrations, and from comparisons with the seven SIS thermometers seems better 
than 2 mK, thus meeting WHP requirements.

6. CTD conductivity sensor in-situ calibration

6.1 Operational mode

The conductivity sensor output is averaged while bottles are closed.  This 
average is subject to the cell's pressure and temperature correction.  The 
result is compared to in-situ conductivity values as derived from bottle 
salinities.  A first order linear polynomial regression is calculated for 
stations or groups of stations:

	COR=C0 + C1*COS

Outliers are removed until all differences are within 2.8*STDEV, STDEV being the 
standard deviation.

6.2 Station grouping

CTD2782 stayed rather stable for large groups of stations.  CTD2521, however, 
needed a station by station calibration from station 57 on until its exchange 
after station 82.  Since the linear coefficient C1 did not change when 
calculated for stations 1 to 56 or station 1 to 77, the change in calibration 
was totally due to the offset C0.  Thus, taking C1 as fixed, C0 was adjusted for 
station 57 to 77.  For stations 78 (after the call of port) to 82, both 
coefficients were calculated station by station.  See table III-1 for a complete 
listing of coefficients.

6.3 Overview profile calibration

With the 5580 samples (89%) used for the calibration (see fig. 19, 20 for 
conductivity; fig. 21 for salinity), the overall standard deviation of the 
residuals is 0.0023 mS/cm.  Only station group 204 to 219 is slightly worse 
(0.0029 mS/cm).  Overall the cells' in-situ calibrations are close to WHP 
standards.

6.4 Verification

Stations 31 and 119 were repeated with a different CTD at stations 223 and 156, 
respectively. Also, positions of stations 211 and 145 are close to SAVE station 
45 and TTO station 63, respectively.  All 4 theta-S diagrams coincide well in 
the deep sea with salinity deviations of just 0.001 psu. 

DQE's comment on section 6

The method applied to determine the calibration coefficients is well 
established.  Comparison in theta-S space of two 'cross stations' of this cruise 
and two 'cross stations' with stations from SAVE and TTO establish an accuracy 
in salinity close to 0.001 psu meeting WHP standards.

7. CTD dissolved oxygen sensor in-situ calibration

7.1 Operational modes

The calibration of the oxygen sensor followed the method described first by 
Millard (1982, see GC1 for the complete reference).  The formula models the 
effects of temperature, inner and outer temperature difference and pressure, and 
salinity through the saturation formula by Krause (1984, see CG1 for the 
complete reference) on the electrical current (OC) that is measured in the cell.  
Compared are averages of OC over a 15 dbar interval from those depths of the 
lowering profile where sample oxygen were measured.  The calibration 
coefficients are determined for groups of stations.

7.2 Units of dissolved oxygen

The calibration is performed and reported in units of ml/l.  All units are 
converted then to Umol/Kg keeping those values in ml/l.

7.3 Station grouping

Three sensors were used:

Stat.	CTD	Oxygen sensor
001-069	2521	A
070-082	2521	B
083-223	2782	C

Sensor A, in addition to Millard's regression needed a 5th order polynomial 
regression in pressure.  Sensor B needed a calibration by stations.  Only sensor 
C was stable over large parts.  See Tables III-2 and III-3 for coefficients and 
details.

7.4 Overview of profile calibration

The results are presented in figures 24 and 25.  A total of 6052 samples (93.7%) 
were used in the calibration procedure.  Of these 42.4% have residuals less 
0.025 ml/l, and 83.9% less 0.075 ml/l with a standard deviation of 0.066 ml/l.  
Disregarding samples from depths less 980 dbar, this result improves to 49.8% 
and 92.2%, respectively and a standard deviation of 0.041.  The subset of 
stations 70 to 223 has an overall (all depths) standard deviation of 0.046 ml/l.

7.5 Verification

One station pair (Stat. 119, 156) from this cruise with different sensors, and 
two SAVE stations can be compared (fig. 26, 27).  The obvious differences 
between stations 119 and 156 also show up in other chemical parameters, and thus 
probably are due to a change in deep water masses at that position during the 
cruise.

Stations 218 and 130 compare well with SAVE station 158 and TTO station 25.

DQE's comment on section 7

The formula used to model the oxygen sensor response did not account for the 
sensor's speed through the water as requested in a later version in the WHP 
Operations and Methods Handbook.  Nevertheless, the standard deviations reported 
for the residuals of the sensor calibration meet well the WHP requirements.

Part B.
CTD data evaluation

8. Basics

A6 and A7 data available at the WHP-O were:

-.SUM file
-.WCT CTD data
-.HY2 bottle data

and additional two meridional sections linking A6 and A7.

CTD data were on 1 dbar intervals. WHP requirements are 2 dbar intervals; the 
higher vertical resolution has led to problems with computer (PC) storage and 
computing time using the programs kindly provided by R. Millard, WHOI.

CTDTMP and CTDSAL in the CTD files are reported with 4 decimal places, however 
with tailoring zeros.  This is not WHP standard.  Also, the quality byte for 
oxygen was set to zero throughout the CTD-files.

Although the overall quality of the data set is expected to meet WHP standards, 
the remarks above and the quick evaluation below will show that some revision of 
the data needs to be made.  I therefore restrict to the (more problematic 
section A7 plus some meridional stations (Stat. 1 - 99); nevertheless, all 
recommendations made below also hold for A6.

The set of DQE programs allows to compare the CTD files with the CTD values in 
the bottle file. Only data flagged as 'good' were used.  The following checks 
including some blow-up figures (not always shown) were made:
-	theta-CTDSAL, overall in the east and in the west
-	theta-CTDOXY, overall in the east and in the west
-	deviations CTDSAL and SALNTY on pressure levels by station
-	deviations CTDOXY(downcast) and OXYGEN on pressure levels by stations
-	same by pressure in station groups (waterfall plots)
-	noise level in the deep ocean
-	static stability in profiles

9. Theta-CTDSAL, Theta-SALNTY 

These plots are grouped for Stat. 1-50, and 41 -91.  For stations 1 - 50 in the 
eastern basin, the overall plot (*Fig. 28a) shows extremely low salinities at 
the surface as a result of the Congo River plume.  At least two non-flagged 
CTDSAL outliers from the upcast at the high end are detectable (and marked in 
*fig. 28a).  Others are identified at lower temperatures (*Fig.28b).  In the 
deep ocean (*Fig. 28c), some SALNTY values are aside the bunch.  An example 
(*Fig 28c) shows that large deviations between samples and the CTD are observed 
at Stat. 9.  This station needs to be compared directly with neighboring 
stations for the salinity calibration.  A more careful check will later identify 
other stations with calibration offsets.

In *Fig. 29a to 29.c the same is repeated for Stat. 41 to 91. Again, some few 
outliers of SALNTY are identified in the deep ocean.

Overall, flags need to be checked.

10. Theta-Oxygen

Station groups 1 to 51 (*Fig. 30a-c) and 41 to 91 (*Fig. 31 a-c), both show 
some extreme non-flagged spikes (Stat. 7, Stat. 38) in CTDOXY and some bad non-
flagged values in the samples.  Also, some CTDOXY profiles look rather noisy.  
Overall, flags need to be set/checked.

11. Residuals in calibration

11.1 CTDSAL

In *figure 32a these differences are plotted as single dots by STNNBR for all 
depths (upper panel), for depths larger 1000 dbar (middle) and by pressure 
(lower panel).  Also included are the mean differences for each station (bold 
line).  *Fig. 32b gives a blow-up of the upper and lower panels of *Fig. 32a.  
Some non-flagged outliers are marked. 

The marked minima and the maxima of the bold line in the *Fig. 32a (middle 
panel) identify those stations, where the differences between CTDSAL and SALNTY 
need a check of the CTDSAL calibration by comparing neighbouring deep CTD 
stations: This is recommended for the following stations: 009, 010, 023, 033, 
035, 048, 076, 077, 078.

A more severe problem is obvious from *Fig. 32b: It shows a bias in CTDSAL 
calibration at pressures higher than 4000 dbar.  Perhaps, the pressure 
compensation that has been applied is not sufficient.  To my experience, these 
sensors may need additional corrections to the linear one applied to the 
compensated raw data.

While *Fig. 32 allows one to identify stations with suspicious overall 
calibration, the waterfall plots in *Fig. 33a to 33i give insight to the 
residuals' distribution over single profiles.  Although the resolution is 
sparse, some stations can be identified to have a systematic bias against the 
samples on that station.  This holds for almost all stations which have samples 
from depths larger than 4000 dbar (as seen already in *Fig. 32).  In *Fig. 33a 
and 33b, the subset shallow stations may have calibration problems: stations 
005, 006, 010 and 097.

11.2 CTDOXY

In *Figure 34, the residuals between the CTD downcast and the sample oxygen are 
shown.  Some non-flagged outliers are marked (*Fig. 34a).  With better 
resolution, *Fig. 34b (middle) shows the station mean residuals well within  5 
Umol/Kg for pressures > 1000 dbar.  Problems may occur at the beginning (Sta.6), 
and only a few other stations.  I recommend comparison of neighboring stations 
in the deep ocean: 57, 58, 88, 95 and maybe 86.  Station 6 is shallow and may 
checked against station 008.

In the waterfall plots of *Fig. 35 those stations are marked that over wider 
parts of a profile show a bias in the residuals.  At these stations, the CTDOXY 
should be compared to neighboring stations to verify the calibration.

12. Noise level in CTD profiles

Since the data are provided on a 1-dbar interval rather than on 2-dbar 
intervals, the noise level maybe expected higher than usual for 2-dbar WOCE 
data.  The method calculates means and rms over 2 - 12 dbar high pass filtered 
data. 

For the deep ocean (*Fig. 36a), the rms of CTDSAL is well below 0.001 psu (upper 
panel), that of CTDOXY generally below 0.5 Umol/Kg (middle panel).  The mean rms 
for salinity is 0.0004 psu is slightly higher than for other WOCE cruises with 
low values in the deep eastern basin (stations 10 to 50) and high values between 
station 55 and 86 reflecting more variability in the deep western basin. 

The station averaged rms for oxygen (0.24 Umol/Kg is twice as high as the so far 
best WOCE cruises show probably reflecting the fact that the sensor's speed 
through the water column was not taken into account during the calibration.  
Some stations (around 20, 43, 51, and 75) peak in scatter and may be re-
examined.

Part C.
Recommendations

Resubmit the data set subject to:
 
**	check for the calibration procedure of CTDSAL for high pressures
**	incorporate the oxygen sensor's speed through the water column into the 
	calibration to improve the noise level.
**	deliver downcasts at:
	2dbar intervals
	4digit places for CTDTMP, CTDSAL, SALNTY (no zeros tailoring)
**	set flags for CTDOXY
**	carefully check all flags for SALNTY, CTDSAL, CTDOXY; setting flags may 
	make use of the known standard deviations for the calibration.

I'm prepared to inspect the complete data set when resubmitted.

Acknowledgements

The WHP-O at WHOI again has been a friendly and effective host. Software used 
for part B of this evaluation, was kindly made available by Bob Millard; special 
thanks to him for his helpful guidance. This work was supported by the 
Bundesminister fuer Bildung und Wissenschaft, Bonn, Germany, under grant WOCE 
IV.

References

Le Groupe CITHER-1: Campagne CITHER-1 N/O L'ATALANTE (2 janvier-19 mars 1993). 
	Recueil de donnees, Vol 2: CTD-O2. Rap. Interne LPO 94-04, Laboratoire de 
	Physique des Oceans, IFREMER, Brest, France, 1994.

Millard, R.R. and K.E. Yang. CTD calibration and processing methods used at 
	WHOI. WHOI Techn. Rep. 93-44, 1993

For further references see Le Groupe CITHER-1 (1994), there especially Billant 
(1985) for CTD calibration methods as applied at IFREMER; Billant (1990) for SIS 
pressure meter characteristics; Millard (1982) for the calibration of the oxygen 
sensor.

FIGURES

Fig.	1:	Position gographique des 223 stations de la campagne CITHER 1
		Les principaux 'vnements' intervenus en cours de campagne sont 
		rpertoris.

Fig.	2:	Coupes synoptiques indiquant le niveau des prlvements  chaque 
		station sur les radiales 430S et 35W.

Fig.	3:	Coupes synoptiques indiquant le niveau des prlvements  chaque 
		station sur les radiales 730S et 4W.

Fig.	4:	Ecarts de salinit entre deux bouteilles fermes au mme niveau:
		a) en fonction du numro de station  laquelle a t ralis le 
		doublet,
		b) en fonction de la pression  laquelle a t ralis le doublet.

Fig.	5:	Histogramme des carts de salinit: 
		a) pour les 275 doublets de la campagne, 
		b) pour les 209 doublets raliss  pression suprieure  980 dbars.

Fig.	6:	Ecarts en oxygne entre deux bouteilles fermes au mme niveau:
		a) en fonction du numro de station  laquelle a t ralis le 
		doublet,
		b) en fonction de la pression  laquelle a t ralis le doublet.

Fig.	7:	Histogramme des carts en oxygne: 
		a) pour les 275 doublets de la campagne, 
		b) pour les 209 doublets raliss  pression suprieure  980 dbars.

Fig.	8:	Rpartition des carts, tous les 400 dbars, entre la pression de 
		rfrence et la pression indique par le capteur Neil-Brown (sonde 
		2521) lors de l'talonnage pr- et post- campagne  la temprature 
		de 20C: 
		a) cycles monte en pression (profil descente), 
		b) cycles descente en pression (profil monte). 
		Le courbe de degr 3 qui rduit ces carts est reprsente.

Fig.	9:	Rpartition des carts, tous les 400 dbars, entre la pression de 
		rfrence et la pression indique par le capteur Neil-Brown (sonde 
		2782) lors de l'talonnage pr- et post- campagne  la temprature 
		de 20C: 
		a) cycles monte en pression (profil descente), 
		b) cycles descente en pression (profil monte). 
		Le courbe de degr 3 qui rduit ces carts est reprsente.

Fig.	10:	Ecarts, tous les 1000 dbars, entre la pression rfrence et la 
		pression indique par le capteur Neil-Brown  diffrentes 
		tempratures exprimentales.  Les limites de la surface pointille 
		sont, d'une part, la courbe obtenue  la temprature  20C et, 
		d'autre part, celle d'une temprature  la temprature quivalente 
		interne du capteur Neil-Brown mesure sur les profils "bathysonde": 
		cette surface correspond  la correction de temprature statique. 

Fig.	11:	Etude de l'effet dynamique de temprature sur les capteurs de 
		pression Neil-Brown (2521 et 2782) en laboratoire.  Aprs immersion 
		de la sonde dans un bain plus froid, les paramtres pression, 
		temprature et temprature interne du capteur de pression sont 
		reprsents en fonction du temps.  Le choc thermique provoque un 
		dcalage de l'indication de pression qui atteint environ 5 dbars 
		aprs 30 minutes.

Fig.	12:	Ecarts, tous les 400 dbars, entre la pression de rfrence et la 
		pression indique par le capteur Neil-Brown (sonde 2521) aprs 
		correction de la linarit du capteur  20 (figure 8), de 
		l'influence de temprature statique (figure 10) et de l'effet 
		dynamique de temprature (figure 11).
		a) monte en pression (profil descente),
		b) descente en pression (profil monte).
		La courbe de degr 5 qui corrige la pression sur les profils est 
		reprsente.

Fig.	13:	Ecarts, tous les 400 dbars, entre la pression de rfrence et la 
		pression indique par le capteur Neil-Brown (sonde 2782) aprs 
		correction de la linarit du capteur  20 (figure 9), de 
		l'influence de temprature statique (figure 10) et de l'effet 
		dynamique de temprature (figure 11).
		a) monte en pression (profil descente),
		b) descente en pression (profil monte).
		La courbe de degr 5 qui corrige la pression sur les profils est 
		reprsente.

Fig.	14:	Ecarts obtenus,  chaque station, entre la lecture de 3 
		pressiomtres SIS et la pression indique par le capteur Neil-Brown 
		en fonction de la pression d'observation.  Les carts, concernant 
		les deux sondes utilises pendant la campagne sont diffrencis.  
		Les courbes (en trait plein pour la sonde 2521 et en pointill pour 
		la sonde 2782) reprsentent la correction d'talonnage  apporter  
		la lecture des deux instruments compars (SIS et Neil-Brown).  
		Lorsque les talonnages pr- et post- campagne du pressiomtre sont 
		diffrents, deux courbes sont prsentes.
		Les points compars  ces courbes montrent que, aprs correction, la 
		pression SIS est gale  la pression CTD  2 dbars prs (le 
		pressiomtre 6199 est devenu dfectueux en cours de campagne).

Fig.	15:	mme lgende que la figure 14 pour une autre srie de 3 
		pressiomtres.
		- A noter le mauvais fonctionnement intermittent du pressiomtre 
		6196.
		- Dans le cas du pressiomtre 6137, les carts observs aprs 
		correction sont de l'ordre de 4 dbars : cette diffrence est 
		attribue  un talonnage incorrect du pressiomtre.

Fig.	16:	Ecarts entre la temprature de rfrence et la temprature indique 
		par le capteur Neil-Brown lors de l'talonnage pr- et post- 
		campagne:
		a) sonde 2521,
		b) sonde 2782.
		La courbe de degr 2 qui corrige la temprature sur les profils est 
		reprsente.

Fig.	17:	Ecarts obtenus,  chaque station, entre la lecture de 3 thermomtres 
		SIS, et la temprature indique par le sonde Neil-Brown: la 
		temprature exprimentale est comprise entre 2.5 et 5.0C.
		Les segments de droites reprsentent la correction d'talonnage  
		apporter  l'indication du capteur Neil-Brown additionne  celle du 
		thermomtre SIS.  La drive des thermomtres a t compense  
		raison de 0.001 entre les stations 1 et 82 et de 0.002C entre les 
		stations 83 et 223.
		Le dcalage des points par rapport  ces segments de droites est 
		attribu  un effet de pression sur le thermomtre SIS.

Fig.	18:	mme lgende que figure 17 pour 4 autres thermomtres. (entre 1C et 
		2.5C)

Fig.	19:	Ecarts entre la conductivit des 5580 chantillons valids et la 
		conductivit 'bathysonde', au niveau du prlvement, aprs recalage:
		a) en fonction du numro de la station concerne,
		b) en fonction de la pression au niveau du prlvement.

Fig.	20:	Histogramme des carts entre la conductivit des chantillons et la 
		conductivit 'bathysonde', au niveau du prlvement, aprs recalage:
		a) pour la totalit des 5580 chantillons valids sur la campagne,
		b) pour les 3852 chantillons valids et prlevs  pression 
		suprieure  980 dbars.

Fig.	21:	mme lgende que figure 20 pour les carts en salinit.

Fig.	22:	Comparaison de diagrammes theta-S tracs d'aprs les donnes de la
		campagne CITHER 1.
		Dans les deux cas, les stations ont t ralises  la mme position 
		gographique avec unesonde diffrente.

Fig.	23:	Comparaison de diagrammes theta-S de la campagne CITHER 1 avec les 
		donnes d'autres campagnes obtenues  une position gographique 
		proche:
		a) station 211 de CITHER 1 et station 45 de SAVE (leg 2) (donnes 
		 'bathysonde'),
		b) station 145 de CITHER 1 et station 63 de TTO-TAS (donnes 
		 'rosette').

Fig.	24:	Ecarts entre la valeur d'oxygne mesure sur les 6052 chantillons 
		valids et celle du profil descente 'bathysonde'  la pression du 
		prlvement, aprs recalage:
		a) en fonction du numro de la station concerne,
		b) en fonction de la pression au niveau du prlvement.

Fig.	25:	Histogramme des carts en oxygne entre la valeur mesure sur les 
		chantillons valids et celle du profil descente 'bathysonde'  la 
		pression du prlvement, aprs recalage:
		a) pour la totalit des 6052 chantillons valids sur la campagne,
		b) pour les 4387 chantillons valids et prlevs  pression 
		suprieure  980 dbars.

Fig.	26:	Profils d'oxygne dissous obtenus  la campagne CITHER 1.  Les 
		stations 119 et 156 ont t ralis  la mme position gographique 
		avec deux sondes diffrentes.  L'oxygne mesur sur les prlvements 
		de chaque station est report sur les profils avec un signe 
		distinctif.

Fig.	27:	Profils d'oxygne dissous obtenus aux stations 218 et 130 de CITHER 
		1.  Les valeurs d'oxygne mesures sur les prlvements de ces 2 
		stations sont indiques.
		Pour comparaison, les mesures d'oxygne extraites de stations, 
		ralises  une position gographique proche, au cours d'autres 
		campagnes sont portes sur ces figures.
		a) les valeurs de la station SAVE 158 (leg 3) sont les donnes 
		 'bathysonde',
		b) les valeurs de la station TTO-TAS 25 sont les donnes 'rosette'.

*Figures 28 - 32 are excluded in this report.

TABLE III-1

Bilan de la calibration des profils de conductivit de la campagne CITHER 1

Sonde 	Station Nombre 		Nombre 		Dviation 	Coefficients
utilise ou	d'chantillons 	d'chantillons 	Standard 		
	groupe	considrs	retenus par	(0-6000)	C1	  C0
				le calcu			
------------------------------------------------------------------------------
2521	1=>56	1367		1187		0.0024		0.999357  0.0320
	57	32		28				"	  0.0290
	58	32		29				"	  0.0227
	59	32		28				"	  0.0233
	60	32		27				"	  0.0239
	61	32		29				"	  0.0245
	62	32		31				"	  0.0252
	63	32		28				"	  0.0258
	64	32		29				"	  0.0264
	65	32		27				"	  0.0270
	66	32		29				"	  0.0277
	67	32		30				"	  0.0283
	68	32		30				"	  0.0271
	69	32		26				"	  0.0277
	70	32		28				"	  0.0284
	71	32		31				"	  0.0290
	72	32		28				"	  0.0296
	73	32		30				"	  0.0302
	74	32		30				"	  0.0309
2782	75	32		32		0.0017		0.999022  0.0423
2521	76	32		30				0.999357  0.0303
	77	32		27				"	  0.0310
	78	32		19				0.999492  0.0415
	79	32		29		0.0024		0.999716  0.0258
	80	32		30		0.0021		0.999520  0.0332
	81	32		29		0.0021		0.999382  0.0323
	82	32		29		0.0019		0.999096  0.0405
2782	83=>91	237		211		0.0022		0.999781  0.0063
	92=>118	769		686		0.0021		0.999695  0.0072
2521	119	32		29		0.0013		0.999862  0.0379
2782	120=>203 2425		2164		0.0021		0.999589  0.0112
	204=>219 479		442		0.0029		0.999545  0.0106
	220=>223 128		117		0.0020		0.999687  0.0106

TABLE III-2

Bilan de la calibration des profils d'oxygne dissous de la campagne CITHER 1

Capteur	Station	Nombre		Nombre		Dviation Standard		Coefficients
utilis	ou	d'chantillons	d'chantillons	0-6000	0-1000	1000-	SOC	OXPC	 OXTC	  OXC2	
	groupe	considrs	retenus par			6000					
				le calcul								
-------------------------------------------------------------------------------------------------------------------
Capteur 1=>11	189		184		0.179	0.244	0.053	0.0356	0.000193 -0.0169  3.552	Correction
A	12	30		30		0.103	0.165	0.044	0.0394	0.000165 -0.0334  0.769	suppl-
	13	30		30		0.093	0.185	0.045	0.0404	0.000153 -0.0246  1.511	mentaire
	14	31		31		0.095	0.156	0.038	0.0398	0.000163 -0.0227  1.497	par 
	15	31		31		0.098	0.209	0.035	0.0409	0.000149 -0.0252  1677	polynome 
	16	32		32		0.131	0.240	0.029	0.0403	0.000155 -0.0260  1.553	de degr
	17=>21	160		143		0.061	0.120	0.045	0.0468	0.000122 -0.0348  2.678	5
	22	32		32		0.076	0.135	0.027	0.0408	0.000154 -0.0239  1.791	
	23	29		29		0.059	0.103	0.032	0.0425	0.000147 -0.0261  1.311	
	24	32		31		0.054	0.088	0.023	0.0404	0.000162 -0.0237  1.420	
	25	31		31		0.037	0.070	0.025	0.0444	0.000141 -0.0285  1.341	
	26et27	35		34		0.063	0.111	0.030	0.0422	0.000155 -0.0256  1.347	
	28=>67	1251		1216		0.082	0.127	0.046	0.0430	0.000149 -0.0267  1.402	
	68*	32		27		0.102	0.148	0.118	0.0430	0.000128 -0.0270  1.210	
	69*	32		31		0.049	0.064	0.046	0.0440	0.000137 -0.0272  0.972	
Capteur 70	32		32		0.062	0.111	0.043	0.0658	0.000138 -0.0348  0.596	
B	71	32		31		0.051	0.087	0.041	0.0712	0.000131 -0.0335  0.933	
	72	32		30		0.065	0.113	0.053	0.0750	0.000125 -0.0349  1.111	
	73	32		31		0.047	0.047	0.047	0.0732	0.000131 -0.0343  0.820	
	74	32		32		0.036	0.042	0.035	0.0712	0.000139 -0.0328  1.102	
	75**	32		29								

	* Les profils 68 et 69 sont partiellement inexploitables.
	** Le profil 75 est totalement inexploitable

TABLE III - 3

Bilan de la calibration des profils d'oxyne dissous de la campagne CITHER I

Capteur	Station	Nombre		Nombre		Dviation Standard		Coefficients
utilis	ou	d'chantillons	d'chantillons	0-6000	0-1000	1000-	SOC	OXPC	 OXTC	  OXC2
	groupe	considrs	retenus par			6000				
				le calcul							
---------------------------------------------------------------------------------------------------------
Capteur 76	32		31		0.037	0.043	0.037	0.0683	0.000143 -0.0326  0.799
B	77	32		31		0.031	0.033	0.031	0.0698	0.000142 -0.0341  0.657
	78	32		32		0.066	0.077	0.063	0.0698	0.000140 -0.0331  0.938
	79	32		32		0.044	0.080	0.029	0.0689	0.000144 -0.0328  0.687
	80	32		29		0.016	0.008	0.018	0.0694	0.000144 -0.0331  0.521
	81	32		29		0.048	0.043	0.050	0.0703	0.000142 -0.0333  0.817
	82	32		32		0.052	0.082	0.042	0.0707	0.000143 -0.0345  0.753
Capteur 83=>91	236		221		0.059	0.086	0.043	0.0566	0.000148 -0.0307  0.563
C	92=>118	769		717		0.054	0.074	0.044	0.0559	0.000149 -0.0295  0.658
Capteur 119	32		31		0.046	0.083	0.027	0.0679	0.000157 -0.0316  0.698
B 
Capteur 120=>203 2423		2213		0.045	0.058	0.040	0.0562	0.000147 -0.0304  0.609
C	204=>223 607		557		0.037	0.048	0.033	0.0551	0.000149 -0.0294  0.642

-------------------------------------------------------------------------------
Comments on the DQE recommendations for the CTD-O2 data of WHP lines A6 and A7
(M. Arhan, A. Billant)

The DQE considered the data as meeting the WHP standard, yet made several 
recommendations (Part C of the report).

**	Check for the calibration procedure of CTDSAL for high pressures. We have 
	checked the calibration procedure: It is the one recommended in the WHP 
	operations manual, and described in the Unesco Technical Paper in Marine 
	Science nb 54 (1988).  When using this procedure, some depth-dependency of 
	the residuals at high pressures (> 5000 dbar) cannot be avoided (as an 
	example, see figure 3.8 of the UNESCO report) at least in certain oceanic 
	area.

**	Oxygen sensor speed: No accurate measurement of the time was available on 
	that cruise, for which the in situ reference parameter was pressure.  We 
	usually remove the heave effect from the oxygen profiles by a ~10dbar 
	running mean.

**	Four digit places for CTDTMP, CTDSAL, SALNTY: As said in the cover letter, 
	we can create new exchange files at this format if you judge it necessary.

**	Set flags for CTDOXY: These are oxygen values from the down-profiles, 
	averaged over a 15 dbar pressure range centered at the pressures of bottle 
	triggering.  These values are compared with the water sample data and, in 
	case of a discrepancy exceeding 2.8 standard deviation, we choose to flag 
	the bottle value, not the CTD one.  This is a matter of convention, and 
	the DQE is right in pointing out that, in some cases, the high difference 
	is caused by inaccurate CTD values.  As these CTDOXY values are only used 
	for the calibration, we did not judge it necessary to examine the 
	problematic cases to decide which parameter should be flagged.  Had we 	done it, the choice could only have been subjective in most cases.

**	Carefully check all flags for SALNTY, CTDSAL, CTDOXY.  (See the set of 
	figures with the problematic points marked).  In several property-property 
	plots (e.g. 28b, c, d), some points are found slightly aside of the main 
	<< cloud of points >>, although the difference << CTD minus water sample 
	>> was less than 2.8 standard deviations, and the values were therefore 
	not flagged.  Again, this is a matter of convention.

In several other plots (e.g. 30a, 31a, 32a, 33, 34a), differences CTD-water 
sample were reported, although the water sample data were flagged to either 5 or 
3.  This leads to apparent problems (only apparent, because the data were 
flagged).  For instance, the value -9 was set when there was no data, with a flag 
of 5 (absence of data) in the WS files.  Taking into account the value -9 leads 
to several differences at ~44 (~35 -(-9)) in figure 32a, or ~209 (= 200 -(-9)) on 
figure 34a.  The same cause leads to horizontal lines on the <<waterfall plots>>, 
and to points aside of the <<main cloud>> in the property-property plots.  In 
particular, although CTDOXY was not measured at station 75 (all flags at 5) and 
was only partially present at stations 68, 69 (sensor problems), erroneous points 
for these stations are reported on figure 34a.