Cruise ANT9/2: Expocode 06AQNTIX/2
The cruise covers  the sections Sr04. 

CFCs:
CFCs have not been measuremed from our lab during this cruise


Tritium:
Tritium is sampled in 1 l glas bottles which are analysed after the cruise
in the laboratory at Bremen. Tritium is measured through the ingrowth of
helium3 from the radioactive decay. For the precedure the water samples are
degased and transferred to special glas containers which are sealed off and
placed into freezers. After a storage time of 6 month to about a year to
allow the ingrowth of sufficient amounts of helium3 the samples are measured
with the noble gas spectrometer described below.

Tritium concentrations are scaled to 1 December 1990 and individual errors
have been assigned. The quality flag follows woce standards

2 good measurement
3 questionable measurement
4 bad measurement
9 no sample drawn



Helium and Neon:
Two different sets of samples were taken:

1.
40 ml water samples are filled into cupper tubes at sea which are pinched
off. In the laboratory the gas amount is vacuum extracted from the sample
and transferred to a specialized helium/ neon isotope mass spectrometer.

2. 
Water was sampled into glas-pipettes and extracted at sea. The glas
ampoulles with the extracted gas were then transported back to the labe
for measurements and measurement in the same way with the helium/neon
isotope mass spectrometer.

The noble gas mass spectrometer is no commercial unit but has been
speciallly designed at the University of Bremen. It contains two
commercial units: a quadropole mass spectrometer (Balzer QMG 112) and a
sector field (Mass Analyzer Products, type 215).

Two helium isotopes 3He, 4He and two Neon iostopes 20Ne, 22Ne are measured.
Air aliquots provide the instrument calibration and monitor sensitivity
changes. An internal standard filled with regular air has been used for the
helium isotope and neon measurements at the lab in Bremen to make all
measurements internally self-consistent. An external standard does not exist.

Helium data have not been corrected for tritium decay during storage
because the correction is very small due to the low tritium concentrations
in the southern ocean. Given maximum tritium concentrations of 200 mTu the
correction would amount only to 0.1%. 

Helium and neon measurements have been assigned individual errors based on 
replicate samples measured from this cruise and 'calibration' samples 
manufactured at the lab from sea water during the measurement period.
The quality flags for helium and neon follow the woce standard. 

1= sample taken but could not be measured
2= good measurement (lab extraction+sea extraction)
3= questionable measurement 
9= sample not drawn


The laboratory extracted samples and the samples extracted at sea showed
slight differences in values. In order to make the data set internally 
consistent the following correction factors have been applied:

Helium (sea extraction) had to be multiplied by a factor of 0.984 to be
compatible with the lab extraction.
Neon (sea extraction) had to multiplied by a factor of 1.009 to be
compatible with the lab extraction.
delta-He3 (sea extraction) had to be offset by 0.07% to be compatible with
the lab extraction.