SECTION 3 NEW WAYS OF OBSERVING THE OCEAN
182
3.5.1.1 Primary functions of the data system
WOCE data activities fall in three areas: assembly and distribution of data, production of data
products, and participation in analysis/interpretation of the data sets in order to understand ocean
processes. The initial framework for a WOCE Data
System was developed to assist in these functions.
At least one Data Assembly Centre (DAC) exists
for each type of data. Their primary functions
are to assemble data sets, subject them to quality
control, and ensure distribution. The collection
and quality review processes are different for each
data stream; however, each DAC maintains an
updated and public inventory of data received and
also documents its quality control procedures. The
DACs take an active role in tracking data quality,
including contacting data providers to confirm suspected reasons for problematic data. This feedback
leads to improved observation systems, procedures
and review criteria. Providing for easy access to
the data sets for WOCE and other investigators is
also a necessary function of the DACs. Online
access has been emphasized wherever possible.
A second function of the DACs and a Data
Information Unit (DIU) is to provide information
about how the data were obtained. This metadata
must include origination and quality review results
and should be as easily accessible in a reasonable
way as the data sets. Metadata is particularly valuable for future climate studies when biases from
the observation system must be considered. Useful
information in metadata also includes primary references such as journal publications and technical
reports where available.
A third function of the centres is to create, compile, and/or track data products that are deemed
useful for WOCE.
For two types of data – hydrographic and surface fluxes – there are also Special Analysis Centres (SAC) that perform additional functions to
address science-driven objectives such as developing gridded products for analysis of water mass
properties or evaluating various surface flux products for forcing ocean models.
The WOCE archive has been established to
ensure a permanent home for the original and
quality-reviewed WOCE data. The complete list of
data streams with listings of the DACs, SACs and
archive site is presented in Table 3.5.1.
The WOCE Data System is fundamentally
different from anything formerly organized in
oceanography. It was unprecedented in scope of
data types and sources to be assembled and relatively uncompromising in the high priority it put
on data quality and documentation. It attempted
to place responsibility for assembly of data and
Fig. 3.5.1 Number of hydrographic stations and data-years of measurements taken by WOCE Hydrographic
Programme (WHP) and previous oceanographic expeditions. Figure reproduced courtesy of WOCE International
Project Office.
14 000
12 000
10 000
8000
6000
2000
0
4000
IGY
Stations
1957–58
GEOSECS
Stations
1972–76
WHP
One-Time
Survey
Stations
WHP
Repeat
Hydrography
Stations
WOCE
Current
Meter
Years
WOCE
Subsurface
Float
Years
WOCE
Surface
Drifter
Years
182
3.5.1.1 Primary functions of the data system
WOCE data activities fall in three areas: assembly and distribution of data, production of data
products, and participation in analysis/interpretation of the data sets in order to understand ocean
processes. The initial framework for a WOCE Data
System was developed to assist in these functions.
At least one Data Assembly Centre (DAC) exists
for each type of data. Their primary functions
are to assemble data sets, subject them to quality
control, and ensure distribution. The collection
and quality review processes are different for each
data stream; however, each DAC maintains an
updated and public inventory of data received and
also documents its quality control procedures. The
DACs take an active role in tracking data quality,
including contacting data providers to confirm suspected reasons for problematic data. This feedback
leads to improved observation systems, procedures
and review criteria. Providing for easy access to
the data sets for WOCE and other investigators is
also a necessary function of the DACs. Online
access has been emphasized wherever possible.
A second function of the DACs and a Data
Information Unit (DIU) is to provide information
about how the data were obtained. This metadata
must include origination and quality review results
and should be as easily accessible in a reasonable
way as the data sets. Metadata is particularly valuable for future climate studies when biases from
the observation system must be considered. Useful
information in metadata also includes primary references such as journal publications and technical
reports where available.
A third function of the centres is to create, compile, and/or track data products that are deemed
useful for WOCE.
For two types of data – hydrographic and surface fluxes – there are also Special Analysis Centres (SAC) that perform additional functions to
address science-driven objectives such as developing gridded products for analysis of water mass
properties or evaluating various surface flux products for forcing ocean models.
The WOCE archive has been established to
ensure a permanent home for the original and
quality-reviewed WOCE data. The complete list of
data streams with listings of the DACs, SACs and
archive site is presented in Table 3.5.1.
The WOCE Data System is fundamentally
different from anything formerly organized in
oceanography. It was unprecedented in scope of
data types and sources to be assembled and relatively uncompromising in the high priority it put
on data quality and documentation. It attempted
to place responsibility for assembly of data and
Fig. 3.5.1 Number of hydrographic stations and data-years of measurements taken by WOCE Hydrographic
Programme (WHP) and previous oceanographic expeditions. Figure reproduced courtesy of WOCE International
Project Office.
14 000
12 000
10 000
8000
6000
2000
0
4000
IGY
Stations
1957–58
GEOSECS
Stations
1972–76
WHP
One-Time
Survey
Stations
WHP
Repeat
Hydrography
Stations
WOCE
Current
Meter
Years
WOCE
Subsurface
Float
Years
WOCE
Surface
Drifter
Years