PowerPointPrsentation

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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Cruise track of R/V Meteor cruise 36-1 from
Hamilton, Bermuda to Las Palmas, Gran Canaria,
Spain.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Temperature and salinity range encountered during
the course of the experiment.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Schematic diagram of the underway pumping system
for use in the moon pool of research vessels as
used during the intercomparison exercise. All
underway systems were connected to this system.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Laboratory setup of the intercomparison exercise
during Meteor cruise 36-1
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
WHOI
IFM
MRI
UEA
CSIRO
OU
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Test of CO2 calibration performance Shown are
the observed deviations from the concentrations
of all measured NOAA/CMDL CO2 standards. Pink
crosses indicate the concentrations of the
standards used in the exercise. The legend gives
details of the nominal concentrations used for
calibration. Also shown is the range of measured
xCO2 during the whole intercomparison.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Test of equilibrator temperature probes Shown
are the deviations of the measured temperatures
from the reference temperature. Equilibrator
probe and reference probe were kept together in
the same water bath until readings became stable.
Also shown are the linear correction lines which
were applied to temperature readings of that
particular system.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Comparison of measured CO2 mole fraction in dry
air (xCO2air) The black horizontal lines
represent the overall mean xCO2air value ( 1
s.d.) calculated from systems BE.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Mean values of the CO2 mole fraction in dry air
(xCO2air) as measured by laboratories AE and
G during the period of the intercomparison
exercise where data from all six systems are
available (June 7, 2230 UTC to June 13, 1230
UTC). Also shown is the standard deviation of all
xCO2air data sets from their mean. The horizontal
line represents the mean xCO2air value calculated
from the means of profiles BE for this
limited period of time.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Table 3. Daily mean ( standard deviation) of
deviations from the 11-min running mean of D
and E (reference). Deviations exceeding 2
µatm are marked in bold. Smaller deviations are
not significant under the technical circumstances
of this exercise. The results for D and E are
shown in italics to indicate that this data have
been used to calculate the reference.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Typical picture from second half of the cruise
where little variability in SST and SSS prevailed.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
Typical picture from second half of the cruise
where little variability in SST and SSS prevailed.
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan

• Summary
• Equilibrator design with regard to the
  achievable accuracy no best choice can be
  identified. Different design, however, has
  consequences for the equilibration time constant.
  Also, higher water flow rates generally lead to a
  smaller warming effect.
• Wet air NDIR measurements (using the LI-COR
  6252) may be characterized by some loss in
  accuracy although this does not seem to be a
  major problem.
• The factory-calibration of the LI-COR
  instruments (zero and span adjustment of the
  factory-polynomial) does not achieve the
  necessary accuracy.
• Thermostatting the sample air flow prior to the
  NDIR measurement is recommended.
• Temperature measurements are not always done
  with the necessary care and appear to introduce
  large errors (up to 7 µatm during this exercise).
• Seawater pCO2 measurements can be made to a high
  degree of agreement ( 1 µatm). However, even
  apparently well-functioning system can disagree
  by several µatm

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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan
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Workshop on Ocean Surface pCO2, Data Integration
and Database Development, Jan 14-17, 2004, NIES,
Tsukuba/Japan