The World Ocean Circulation
Experiment
The oceans are a
key element in the climate system because they transport heat and fresh
water and exchange these with the atmosphere. The World Ocean Circulation
Experiment (WOCE) was a part of the World Climate Research Programme (WCRP)
which used resources from nearly 30 countries to make unprecedented in-situ
and satellite observations of the global ocean between 1990 and 1998 and
to observe poorly-understood but important physical processes. The Scientific
Steering Group (SSG) of WOCE oversaw the scientific development and
the International Project Office (IPO) the implementation
of the Experiment. See the
Design
and Implementation of WOCE and the
WOCE
Data System for further details.
The resulting diverse
WOCE data sets contained on these disks will serve as a unique resource
for climate researchers and marine scientists for decades to come.
The
WOCE Global Data Resource - An Overview |
Standardization of
file format and structure using
netCDF
and a COARDS/WOCE
convention for the variables is a significant step in the integration
of the WOCE dataset as is the availability of an inventory
and a search tool which can
locate files according to chosen parameter ranges.
The table
summarises the data content of the DVDs.
Following the production
of the DVDs, Updates
and Amendments to
the contents will be posted on-line. You may order copies of the DVD WOCE Global Dataset Version 3.0 from the US National
Oceanographic Data Center (NODC). The content of the DVDs will also be
available on-line at http://www.nodc.noaa.gov/woce_v3/
.
The present widely
varying granularity (resolution) of the inventories of each DAC reflects
the traditional methods of presentation of each data set. An optimum inventory
for space, time, parameter searches across the whole WOCE resource will
possibly look rather different.
Each WOCE Data Assemby
Centre (DAC) adopted and has fully described the quality control procedures
appropriate to their specific observations.The satellite datasets were
assembled by JPL/USA and CNES/France. A brief summary of the quality control
procedures at the DACs follows:
Hydrography
The one time surveys
were examined intensively by PIs , DACs and by Data Quality Evaluators
(DQEs) cross-comparing to other WOCE and historical data. The repeat surveys
were largely checked by the WOCE Hydrographic Programme Office against
historical data and for internal consistency.
Current Meters
Current meter data
was examined by the DAC for spikiness and instrument performance. If necessary
interpolated and replacement data are suggested over small segments.
XBTs
(Upper Ocean Thermal Data)
XBT data was examined
firstly for position consistency and quality of record and then by science
groups for climatological consistency. Note: XBT high density lines were
treated essentially as repeat hydrography lines without the salinity.
Sea level
The in-situ tide gauge
data (part of the Global Sea Level Observing System (GLOSS) network with
an emphasis towards island stations) were originally processed through
two separate streams which have generally converged towards similar results.
The fast stream,
intended for rapid use in conjunction with altimetry, generated data
sets with typically a month's delay, but initially without all the ground
controls for a long term set, though these were incorporated later.
The delayed mode
set retained the original raw data and assembled the reference information
necessary to bring the data to a common stable baseline at a later date.
Floats
The relatively small
community of ‘floaters’ largely quality controlled their own
data and generated datasets which were assembled into common format by
the DAC.
Drifters
Surface drifters, the
majority drogued at 10m, made use of the operational ARGOS satellite system
for initial data collection, but thereafter were put through quality control
and interpolation to standard intervals as well as cross checking against
other nearby drifters.
Shipboard
ADCP
This technique came
of age during WOCE and quality control procedures developed in association
with the DAC were adopted and adapted widely. The DAC scrutinises the
datasets carefully but does not amend or flag the datasets, relying on
the submitting PIs to subscribe to guidelines issued by the DAC.
Surface Meteorology
The majority of WOCE
ships submitted surface observations. These were carefully quality controlled
and range in type from high resolution automatic systems (~1minute) to
standard bridge observations (once a watch).
Profiling
Floats
These data, from profiling
ALACE floats have been quality controlled only by the PIs. They yield
vertical TS profiles, at typically 10m resolution, over periods of years
at intervals of ~10 days. The floats were just coming into wide use at
the end of WOCE.
Sea Surface
Salinity
These data, which included
both underway temperature and salinity observations from thermosalinographs
on ~120 cruises were only checked by the originators. The data centre
checked positional and time consistency.
The
Electronic Atlas of WOCE Data (eWOCE) |
The data of most WOCE
data streams have been compiled in integrated, global or basin-wide datasets
for easy access and analysis with the Ocean Data View (ODV) visualization
software. This "Electronic Atlas of WOCE Data" (eWOCE) can be
found on DVD 2.
|