pCO2 data base and synthesis efforts

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pCO2 data base and synthesis efforts
Pfeil, B., Kozyr, A., Olsen, A., Bakker, D. and
N. Dittert

• Benjamin Pfeil
• CARBOOCEAN data manager
• Bjerknes Centre for Climate Research
• University of Bergen, Norway

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Outline

• Data base of public underway data from
  CDIAC/CARINA
  
• Data base of CARBOOCEAN and other not yet public
  underway data
  
• Combining both data bases

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Historic underway data was not easy to compare,
because of

• different file formats (txt, xls, csv, tsv, etc)
• metadata was inconsistent (date, time, latitude,
  longitude, etc.)
  
• different naming for parameters and for missing
  values
  
• different parameters were reported
• derived parameters were reported based on
  different calculation
  
• missing parameters!

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Why doing the job?

• As
• How do you want to compare data if the data was
  not calculated the same way?
  
• Now data can be easily combined or queried since
  the metadata and parameter are the same
  
• On most important Makes your work easier if you
  want to use the data!

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What data are we talking about?

• All public underway data hosted at CDIAC
• Underway data from CARINA (Carbon dioxide in the
  Atlantic Ocean)
  
• Public historic data that was delivered to me
  from CARBOOCEAN Pis

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Total around 300 cruises

• Time frame starting from 1973 - 2005
• Approx. 1.3 million samples with various reported
  carbon parameters

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Overview
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What corrections have been made to the metadata?

• Interpolation of the position (if missing) and if
  it was possible otherwise deleted
  
• Time added e.g. recalcuted from julian day or
  0000 for missing time values
  
• Intake depth was added if not reported in the
  file either known depth from the vessel/mooring
  or 5 m if not reported
  

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What corrections have been made to the data?

• During quality controlling data outliers were
  found
  
• SST, SSS and atmospheric pressure interpolated
  if it was sensible from prior data otherwise
  missing value
  
• Carbon data missing value or interpolation

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Re-calculating the data (done by Are
Olsen)fCO2 in the water column was
re-calculated from

• xCO2 water
• fCO2 water
• pCO2 water

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How was the fCO2 from xCO2 re-calculated?

• fCO2 in water at SST, 100 humidity was
  re-calcuted from
  
• xCO2 in water at SST, dry air
• xCO2 in water at equilibration temperature, dry
  air

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How was fCO2 from fCO2 re-calculated if it was
not reported?

• fCO2 in water at SST, 100 humidity was
  re-calcuted from
  
• fCO2 in water at equilibrator temperature, 100
  humidity
  

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How was fCO2 from pCO2 re-calculated?

• fCO2 in water at SST, 100 humidity was
  re-calcuted from
  
• pCO2 in water, at equilibrator temperature, 100
  humidity
  
• pCO2 in water, at SST, 100 humidity

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Note more different pCO2, xCO2 and fCO2
parameter were reported, but ignored if one of
the mentioned ones were also reported
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How have missing parameters been treated?

• Missing SSS was extracted from World Ocean Atlas
  2005 (Antonov et al, 2005)
  
• Missing atmospheric pressure extracted from 6hrly
  NCEP/NCAR (Kalnay et al, 1996)

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How transparent is our work?

• It is very easy for everybody to follow up our
  work
  
• since the original data files and the matlab
  scripts will be online available
  
• Cruise data consists of the orginal and the
  re-calculated data (all in one file)
  
• Detailed metadata documentation for each cruise
  is available (total of a few hundred pages)
  
• a report will be published with detailed
  information
  
• All data will soon be available at CDIAC

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Now is

• All the data in the same output format
• All the metadata in the same format
• All derived parameters reported as agreed in
  Tsukuba 2004
  
• Data easily comparable

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But there are things to be done

• Introducing a systematic naming (expocode) for
  all historic cruises
  
• re-calculating athmospheric CO2 parameters
• Including non-European VOS line data (American,
  Japanese, Australian)
  
• Further quality controlling of data

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CARBOOCEAN underway database

• Contains CARBOOCEAN underway data (2005-2007)
• CAVASSOO data
• Data gathered by CARBOOCEAN scientists that is
  not yet publically available
  
• More than 1.7 million measurements all in the
  same format

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Overview
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What happens if you combine the data bases?

• Approx. 3 million measurements
• Atlantic Ocean is best covered (1.6 million
  measurements)
  
• Time frame 1972-2007
• Underway data from more than 550 cruises
• All parameters reported to the standards agreed
  in Tsukuba 2004
  
• Detailed metadata for all cruises

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Density of measurements in the North Atlantic
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Future plans

• Include all public underway data that is
  available please release your data to Alex
  Kozyr (CDIAC) or me
  

Just imagine what happens if you combine all the
data that is out there
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Thank you!