Limited distribution IOC/IODE-XX/15\
14 January 2009\
Original: English

**INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION**

**(of UNESCO)**

**Twentieth Session of the IOC Committee on International Oceanographic
Data**

**and Information Exchange (IODE-XX)**

**Beijing, China, 4-8 May 2009**

**Project Report: Global Temperature and Salinity Profile Programme
(GTSPP)**\
Charles Sun, National Oceanographic Data Center, USA

**Summary of the document**

*The document summarizes the Global Temperature and Salinity Profile
Programme (GTSPP) progress made covering the past two year period 2007
-- 2008 and provides the GTSPP work plans in 2009 and 2010. A summary
meeting report for the most recent ad hoc session on the GTSPP is also
attached in the Appendix.*

**DRAFT TEXT FOR INCLUSION IN THE SUMMARY REPORT**

*The Global Temperature and Salinity Profile Programme (GTSPP) is a
joint program of the International Oceanographic Data and Information
Exchange committee (IODE) and the Joint Commission on Oceanography and
Marine Meteorology (JCOMM). IODE and JCOMM are technical committees of
the Intergovernmental Oceanographic Commission and the World
Meteorological Organization.*

*Over past two year period 2007--2008, GTSPP continued to deal in
greater volumes of data. The Integrated Science Data Management (ISDM)
of Canada managed Real-time data. The number of BATHYs reported steadily
increased from 24,855 in 2007 to 27,775 in 2008, while the number of
TESACs was 1,630,360 to the end of 2008, dramatically increased from
821,321 in 2007. A new data set of 6,869 CTD profiles derived from
marine mammals was made available the first time since July 2008. The
data are useful because they get high data return from areas far to
south between 60 S and 70S where data are very little.*

*The U.S. National Oceanographic Data Center (NODC) provided data
processing services for delayed mode data and maintenance of the
Continuously Managed Database (also known as the GTSPP archive). Delayed
mode data include the full resolution data from XBTs or CTDs from the
ships, or fully processed and quality controlled data from the
organizations that provided the real time low resolution data to the GTS
(Global Telecommunication System). The numbers of the delayed-mode
measurements added to the archive were 12,737 and 62,252 in 2007 and
2008, respectively.*

*GTSPP continued to improve its capabilities of serving the GTSPP data
for operations and climate research. The GTSPP data sets were available
at GTSPP's Web site at <http://www.nodc.noaa.gov/GTSPP/>. The usage
statistics of the GTSPP data transferred for 2008 increased to
1,557.33GB from 927.409GB in 2007; while the average number of distinct
hosts served was 20,238 per year in 2007and 2008.*

*GTSPP collaborated with a number of international programs. In
particular, it managed the XBT data collected by the operators of the
Ship-of-Opportunity Programme (SOOP), which is a subprogram of the Ship
Observations Team (SOT) of JCOMM. GTSPP developed a strategy for linking
XBT profiles to the SOOP XBT survey lines that were sampled and has been
working closely with SOOP to assist in proper documentation of the XBT
fall rate in the CMD. GTSPP produced monthly real-time maps including
data density maps. GTSPP published a catalog of the data collected,
statistics of data on the GTS from various sources and monitoring
reports for each ocean basin. In addition, GTSPP also publishes a
monthly ship report that contains errors found. This is then sent to the
operators for corrections*

*GTSPP also collaborated with the Argo program to fix GTS reports from
Argo floats that were reporting pressure instead of depth to the GTS.
GTS also worked with the World Ocean Database project and the
CLIVAR-Carbon Hydrographic Office (CCHDO) to pull CCHDO data from the
Internet quarterly for providing the fully quality controlled high
quality CTD data to the Argo CTD Reference Database used for
delayed-mode quality control of Argo salinity data.*

*In May 2007, Mr. Bob Keeley resigned from the GTSPP Chair position. Dr.
Charles Sun, NODC, assumed Mr. Keeley's responsibility of managing
GTSPP. The GTSPP Steering Group met twice in conjunction with the Argo
Data Management Team meetings over the last intersessional period. The
most recent meeting of GTSPP took place at the East-West Center,
Honolulu, Hawaii, USA on 27 October 2008. Topics discussed at the
meeting included, but were not limited to, the XBT fall rate issue,
GTSPP data formats, evaluation of a Cyclical Redundancy Check (CRC) in
identification of real-time and delayed mode duplicates,, identifying
GTSPP data product centres and delayed-mode data assembly centres,
cooperation with other programs, and the future of GTSPP. A summary
report of the meeting is attached in the Appendix of this document so
readers can become familiar with GTSPP.*

**DRAFT ITEMS FOR THE 2009-2011 WORK PLAN AND BUDGET**

*GTSPP will continue its operations in 2009 --* 2011. The following
table shows the highlights of the activities planed for the period from
2009 to 2011. The tasks listed for completion in 2009 may spill into
2010 or 2011 depending on competing work pressures. Tasks listed as
continuing are activities that are expected to continue into the future.

+----------------+--------------+------------+------------+----------+
| *Action item   | *To be       | *Deadline  | *Requested | *R       |
| description*   | implemented  | date*      | from       | equested |
|                | by \[name\]* |            | UNESCO RP* | from     |
|                |              |            |            | other    |
|                |              |            |            | sources* |
+----------------+--------------+------------+------------+----------+
| *2009*         |              |            |            |          |
+----------------+--------------+------------+------------+----------+
| *Continue to   | *ISDM and    | *c         | *None*     | *ISDM    |
| acquire        | NODC*        | ontinuing* |            | and      |
| profiles and   |              |            |            | NODC*    |
| make real-     |              |            |            |          |
| time & delayed |              |            |            |          |
| mode profile   |              |            |            |          |
| data           |              |            |            |          |
| available.*    |              |            |            |          |
+----------------+--------------+------------+------------+----------+
| *Continue      | *ISDM*       | *c         | *None*     | *ISDM*   |
| production of  |              | ontinuing* |            |          |
| metrics in     |              |            |            |          |
| support of     |              |            |            |          |
| JCOMM OPA and  |              |            |            |          |
| SOT*           |              |            |            |          |
+----------------+--------------+------------+------------+----------+
| *Evaluation of | *NODC*       | *c         | *None*     | *NODC*   |
| the use of a   |              | ontinuing* |            |          |
| CRC in         |              |            |            |          |
| real-time and  |              |            |            |          |
| delayed mode   |              |            |            |          |
| duplicates     |              |            |            |          |
| i              |              |            |            |          |
| dentification* |              |            |            |          |
+----------------+--------------+------------+------------+----------+
| *Continue      | *GTSPP       | *Continue* | *Assist in | *None*   |
| discussions to | Steering     |            | i          |          |
| find data      | Group*       |            | dentifying |          |
| product        |              |            | c          |          |
| centres &      |              |            | andidates* |          |
| delayed-mode   |              |            |            |          |
| data assembly  |              |            |            |          |
| centres*       |              |            |            |          |
+----------------+--------------+------------+------------+----------+
| *Complete      | *NODC and    | *April     | *None*     | *NODC    |
| bi-annual      | ISDM*        | 2009*      |            | and      |
| report for     |              |            |            | ISDM*    |
| 2007 - 2008*   |              |            |            |          |
+----------------+--------------+------------+------------+----------+
| *Prepare a     | *GTSPP       | *September | *None*     | *NODC*   |
| paper on the   | Steering     | 2009*      |            |          |
| CRC tag        | Group*       |            |            |          |
| i              |              |            |            |          |
| mplementation* |              |            |            |          |
+----------------+--------------+------------+------------+----------+
| *Update the    | *NODC and    | *March     | *None*     | *NODC    |
| GTSPP RT QC    | ISDM*        | 2009*      |            | and      |
| Manual*        |              |            |            | ISDM*    |
+----------------+--------------+------------+------------+----------+
| *Update the    | *NODC*       | *June      | *None*     | *NODC*   |
| GTSPP NetCDF   |              | 2009*      |            |          |
| format in      |              |            |            |          |
| compliance     |              |            |            |          |
| with the       |              |            |            |          |
| Climate        |              |            |            |          |
| Forecast       |              |            |            |          |
| NetCDF         |              |            |            |          |
| conventions*   |              |            |            |          |
+----------------+--------------+------------+------------+----------+
| *Collaborate   | *NODC*       | *November  | *None*     | *NODC*   |
| with Argo in   |              | 2009*      |            |          |
| making profile |              |            |            |          |
| data from      |              |            |            |          |
| other          |              |            |            |          |
| instruments    |              |            |            |          |
| available in   |              |            |            |          |
| Argo*          |              |            |            |          |
|                |              |            |            |          |
| *format*       |              |            |            |          |
+----------------+--------------+------------+------------+----------+

  ----------------- --------------- ------------- ---------------- ------------
  *Action item      *To be          *Deadline     *Requested from  *Requested
  description*      implemented by  date*         UNESCO RP*       from other
                    \[name\]*                                      sources*

  2010                                                             

  *Convene a        *ISDM, SISMER,  *May 2010*    *US\$10,000.00   *ISDM,
  two-day workshop  and NODC*                     for supporting   SISMER, and
  for design and                                  two-three people NODC*
  requirements of                                 to attend the    
  adapting                                        workshop\        
  objective                                       (or to be hosted 
  analysis                                        by IOC Project   
  (OA)-like tests                                 Office).*        
  and serving the                                                  
  GTSPP data via                                                   
  the WMO                                                          
  Integrated Global                                                
  Observing Systems                                                
  (WIGOS)*                                                         

  *Implement a BUFR *ISDM*          *November     *None*           *ISDM*
  read-write                        2010*                          
  capability for                                                   
  ocean profile                                                    
  data*                                                            

  *Document the     *ISDM, SISMER,  *November     *None*           *ISDM,
  procedure of      and NODC*       2010*                          SISMER, and
  processing the                                                   NODC*
  CTD data derived                                                 
  from marine                                                      
  mammals*                                                         

  *Continue the     *SISMER,        *November     *None*           *SISMER,
  feasibility study CORIOLIS, and   2010*                          CORIOLIS,
  of serving the    NODC*                                          and NODC*
  GTSPP data via                                                   
  the WIGOS*                                                       
  ----------------- --------------- ------------- ---------------- ------------

  ------------------- --------------- -------------- ----------------- ------------
  *Action item        *To be          *Deadline      *Requested from   *Requested
  description*        implemented by  date*          UNESCO RP*        from other
                      \[name\]*                                        sources*

  2011                                                                 

  *Complete bi-annual *NODC and ISDM* *April 2011*   *None*            *NODC and
  report for 2009 -                                                    ISDM*
  2010*                                                                

  *Design and Publish *GTSPP Steering *September     *US\$30,000.00*   *NODC*
  GTSPP data on DVD   Group*          2011*                            
  for using in the                                                     
  IODE                                                                 
  training/outreach                                                    
  programs*                                                            

  *Populate the GTSPP *SISMER,        *November      *None*            *NODC and
  data via the WIGOS* CORIOLIS, and   2011*                            ISDM*
                      NODC*                                            

  *complete the       *NODC and ISDM* *November      *None*            *NODC and
  feasibility study                   2011*                            ISDM*
  of adding OA-like                                                    
  methods to the                                                       
  existing QC tests*                                                   

  *Conduct a training *NODC*          *2011 (To be   *US\$7,000.00 for *NODC*
  course on ocean                     determined)*   travelling to     
  data management in                                 Oostende and      
  Oostende*                                          return*           
  ------------------- --------------- -------------- ----------------- ------------

**APPENDIX**

**Ad Hoc Session of the Joint IOC-WMO Steering Group on**

**Global Temperature-Salinity Profile Program**

**Honolulu, Hawaii, USA, 27 October 2008**

**Meeting Report**

**By Charles Sun**

1.  **Opening of the session**

The session opened at 0900 on 27 October 2008 at the John A. Burns Hall
of the East-West Center. Charles Sun of the US National Oceanographic
Data Center (NODC) chaired the meeting and welcomed participants. The
local host, Dr. Steven Piotrowicz, US Argo Program Manager, explained
the local arrangements. On behalf of the NODC director, Charles
presented a certificate of appreciation to Steve for providing meeting
arrangements and logistics for the GTSPP meeting.

2.  **Session arrangements**

Charles said that the meeting would have two sessions with a lunch break
around 12:00 pm and adjourn before 5:00 pm. Charles also said that he
along with a few meeting participants would attend the Argo Executive
Board meeting in the afternoon and would be absent from the meeting. Ann
Gronell Thresher would chair afternoon session. He then introduced the
provisional agenda to the group, noting no changes. The meeting
participants adopted the final agenda (Annex 3). Ann was designated
rapporteur.

3.  **Status of GTSPP -- Chair's report**

Charles Sun gave the Chair's report. He reported that Bob Keeley has
retired from his role in the GTSPP and the SOOPIP (Ship-of-Opportunity
Programme Implementation Panel) of the Joint WMO-IOC Technical
Commission for Oceanography and Marine Meteorology (JCOMM) endorsed
Charles as Chairperson of the GTSPP at the 7^th^ session of the SOOPIP
at Geneva, Switzerland on 21 April 2007. Charles emphasized that GTSPP
is an on-going program, not project and the primary objective of GTSPP
is to provide improved access to the highest resolution, highest quality
data as quickly as possible. He then continued to review the history of
the GTSPP, including the four contributing countries (USA, Australia,
France and Canada), and the collaborating programs.

Charles reported that NODC is the biggest player in the GTSPP, but
funding is limited. He encouraged everyone to become involved in the
evolution of the GTSPP, including resource sharing. Charles reported
that he recruited two new partners -- the National Marine Data and
Information Service (NMDIS) of China and the Federal Maritime and
Hydrographic Agency (BSH) of Germany as GTPP delayed-mode (DM) data
assembly centers in 2007 and really wants all SOOP operators to be DM
operators. He plans to add Korea/KODC, Italy, JMA, JODC, BODC, NIO of
India and wants more coordination in data deliveries, management, etc.
and plans also to implement data product centres (DPCs). The core
functions of the DPCs will be: 1) Provide data product service on the
Internet, 2) Report GTSPP-related activities at the GTSPP annual
meeting, if any, and 3) Provide feedback to the GTSPP steering group on
data quality issues. Other functions, including but not limited to, are
to perform GTSPP data quality control and return the QCed GTSPP data to
the NODC. He also would like Mr. Yoshiaki Kanno to act as liaison with
JODC to become the delayed mode data centre for Japan. He reported that
it is still difficult to monitor who is using data and for what.
Currently NODC only knows if someone asks for help with the data or
reports independently to NODC. We need feedback from data users and we
need a product server. This will replace science centres, which no
longer exist.

Discussions/Questions -- We need a formal citation for GTSPP data --
currently users can only cite the web page. Charles reported that it is
hard for NODC to determine who and how many are using data. Dr. Yu of
the International Pacific Research Center (IPRC) suggested that GTSPP
needs words on the web page to specify citation form if users use the
GTSPP data.

Dr. Moon-Sik Suk of Korea Ocean Research and Development Institute
(KORDI) clarified that depth and temperature are as important as
temperature, salinity, and pressure, and asked where data should be sent
in real-time or delayed-mode. There is some confusion about the US NODC
and the Word Data Center system. Charles replied that there is a
division between NODC, GTSPP and WOD, so we currently need to coordinate
all three to access the complete data set.

4.  **GTSPP Data Centers Overview\
    **

    1.  Real-Time Data Center Overview (Anh Tran, ISDM)

Anh Tran of the [I]{.underline}ntegrated [S]{.underline}cientific
[D]{.underline}ata [M]{.underline}anagement of Canada (ISDM) previously
known as MEDS reported that ISDM has been involved in GTSPP since 1989.
Mr. Bob Keeley was the chair for GTSPP until 2007. Some of the ISDM's
activities also support Ship Observation Opportunity Program (SOOP).

ISDM collected data reported on the GTS from JMA, BSH, NMC data centers
and from the ship and buoys to ensure that we got the most complete data
sets possible. ISDM performs manual decoding for messages that are
incorrectly encoded in an attempt to rescue the data. They then perform
automatic and visual QC of track, speed and profile as well as removing
duplicate data. Once data have been properly quality control, ISDM
updates the archive and sends a copy of the data to NODC, IFREMER, and
other users. ISDM processes GTSPP data 3 times per week. And each time,
it takes at least 6 hours to complete.

Each month, ISDM processes and archives in near real-time approximately
100,000 profiles in TESAC format compared to only 2000 profiles in 1999.
The total number of profiles reported in BATHY format decreased from
more than 60,000 profiles in 1999 to about 20,000 profiles in 2008. On
average 50% of the profiles reported in BATHY format are on the GTS
within 30 days of the observation date.

One of the common errors we discovered at ISDM are format errors such as
unexpected characters, confusion between variable identification codes
in BATHY format, depth not increasing, and strange call signs (such as
JJVV?).

On the product side, ISDM provides a website for GTSPP which updates on
a monthly basis. We produce monthly real-time maps, catalogs, statistics
of GTS data from various sources, monitoring reports for each ocean
basin, and we also generate maps of data density for SOOP. We also
publish monthly ship reports that list any errors found and this is sent
to the operators for corrections.

Since most of the ISDM's system to process GTSPP was developed in the
1990s with old technologies (VMS, FORTRAN and ISAM), ISDM is planning to
upgrade its system to the newer technology. ISDM plans to migrate data
base management software to Oracle, improve QC tests, duplicate checks
and automate more checks because of increasing in volume of data, setup
the system to handle BUFR messages (operational by 2012), as well as
provide online data access, additional products and remove products that
are no longer useful.

2.  Long-Term Archive Overview (Charles Sun, NODC)

Charles reported the activities of the GTSPP Long-Term Archive (LTA)
Center since the last GTSPP meeting in Hobart 2007. The LTA center
completed the scheme to assign profiles to TWI Lines, which improved the
delivery of the GTSPP data via the Internet, collaborated with WOD and
CCHDO in support of the Argo reference data set, and developed a
strategy to fix the confusion of some Argo profiling floats reporting
pressure as depth on GTS. Currently, NODC is collaborating with the
Naval Postgraduate School to adapt the Optimal Spectral Decomposition
method which is a possible test that can be added to the existing QC
procedures.

Charles suggested a new test for detecting bad or suspect data.
Climatology doesn't work well for anomalous conditions. Objective
Analysis (OA) is an obvious candidate but has limitations. It can be
enhanced by the Optimal Spectrum Decomposition (OSD) developed by Dr.
Peter Chu of the Naval Postgraduate School. OSD will assess and see if
it's useable, particularly near shore or across fronts.

The LTA Web service interface was improved. We now have monthly archives
and data sorted by ocean basin. Web service use is increasing (as is ftp
server -- total usage has increased massively since 2005)

China offered to produce GTSPP data on DVD but they are not here so the
status of this is uncertain. The current size of the GTSPP data is about
17GB total. So we need new and better compression methods (tar/gzip) to
reduce this volume of data to one DVD.

Charles reported that there has been cohesive cooperation between the
GTSPP and WOD (World Ocean Database). WOD uses the GTSPP data to update
its database every three months. With input provided by Tim Boyer,
Charles reported the main support to Argo from the NODC World Ocean
Database (WOD) is in relation to the Argo CTD Reference Database used
for delayed-mode quality control of Argo salinity data. The quality
control of Argo salinity data requires high quality CTD measurements
delivered in a timely manner. The WOD provides fully quality controlled
data sets approximately every 4 years. To increase the timely
dissemination of more recent data to the Argo community, the WOD[^1] is
now updated on a quarterly schedule. The quality control is not as
complete as for the full updates every 4 years and is considered
preliminary. The WOD has now been updated 3 times in 2008, most recently
in late September. To date, 284,244 CTD or bottle casts containing
salinity data have been added in the 3 updates since WOD05. Of these,
26,767 came from the Global Temperature-Salinity Profile Program[^2]
(GTSPP). 33,204 of these additional casts are from cruises completed
between January, 2006 and August, 2008, with 19,806 coming from GTSPP.

There has been CCHDO and GTSPP cooperation as well. NODC are developing
a 'webcrawler' to pull CCHDO data from the Internet quarterly, while
CCDHO's non-public CTD profiles will be pushed to CORIOLIS. This data
will be used for DMQC of Argo data.

GTSPP monitors floats reporting on the GTS. There have been issues with
floats reporting pressure as depth and Charles went through the
procedure used to identify these floats. The Argo data centre
responsible is then notified that they need to fix their reporting
methods.

Cyclical Redundancy Check (CRC) was discussed -- XBT data arrives at
NODC in a split path from bathy to full resolution data. So NODC gets
CRCs direct from AOML and from the GTS and can directly compare the two
to see if there are any transmission errors, etc. Tests show this seems
to be working, catching up to 90% of duplicates, simplifying matching.
Australia already supplies delayed mode data with the CRC attached, so
does France.

We will suggest JCOMM/IODE implement this test so we need to publish
paper on the method as a GTSPP group publication. We will need to
compare results and get statistics together for the paper. All of us
should be involved but Charles will take the lead.

Charles raised a few issues for the group to consider. The issues are:
Should we have an outside review of GTSPP? Do we need feedback? He also
mentioned that Scientific QC has ceased -- we need other partners or
other methods to push this forward.

Future plans:

-   Complete report to JCOMM/IODE by mid-March 2009.

-   Continue collaborations with Argo, WOD and CCHDO,

-   Work on CRC tag,

-   Work on or assess spectral decomposition method, and

-   Implement Google earth layers to make data more visible and useable.

5.  **GTSPP Data Issue -- I\
    **

    1.  BUFR format (Anh Tran, ISDM)

Anh reported that ISDM reminded the members of GTSPP that BUFR message
will be operational by 2012. At the moment, a SOOP template has been
populated but needs approval. GTSPP will plan to send and receive data
in BUFR format. GTSPP will have a task team to assess all templates to
see if there are commonalities and will put Anh, Ann, and Birgit on a
template working group. Is it unclear if Devil transmits BUFR now? Ann
replied that Devil does not currently produce BUFR format files. CSIRO
will work on this with Alex Papij.

2.  NetCDF format (Charles Sun, NODC)

Charles reviewed the GTSPP format history and informed the meeting that
the GTSPP NetCDF format is due to change because: 1.) Some
characters/variables are not readable in Matlab, 2) We need to extend
the conventions for climate and forecast metadata and 3) we need to
extend the format to meet Argo requirements. He proposed: 1) all
variables need dimensions even if scalar, 2) global attributes need to
be standardized, 3) "no_hist" (number of histories) should be changed to
the unlimited dimension, and 4) we need a creation date and time for
each file.

6.  **New data sets -- CTDs from animals/seals\
    **

Lesley Rickards, Deputy Director of the British Oceanographic Data
Centre (BODC), was invited by the GTSPP chair to give a presentation on
developing procedures to attach CTDs to diving marine animals. She began
with the "SEaOS (Southern Elephant Seals as Oceanographic Samplers)"
project which is aimed at increasing our understanding of how southern
elephant seals interact with their physical environment. BODC works
closely with the research scientists at the Sea Mammal Research Unit
(SMRU) of the University of St. Andrews, UK to acquire, archive and
deliver real-time temperature and salinity profile data from seal tags
to the Global Telecommunication System (GTS) for incorporation into Met
Office models.

Scientists at SMRU have designed and built special tags that can be
harmlessly attached to the seals, which take continuous measurements of
the water temperature, conductivity and depth while the seals are
swimming. The seal tags are moulded resin blocks containing small
computers with memory, a transmitter, a clock, batteries and a sensor.
These small computers last for several months (10 or more) and can be
retrieved and recalibrated if still attached. The tag collects
temperature and salinity data to reasonable resolution so the data are
useful for oceanographers. Data are stored until can transmit via ARGOS.

The computer manages internal specs as well -- battery power, etc and
also needs to manage what is transmitted on the limited band width. New
instruments will include fluorometers. SMRU deployed 70 transmitters in
between 2003 and 2004 -- fascinating data. The data are useful because
they get high data return from data sparse areas. Areas far to south are
now being sampled between 60 S and 70S where there is very little other
data. Depths are normally to 800m+ and can reach 2000m. The profiles are
effectively transects. Kerguelen tagged seals: allow you to look at
monthly variability in the data, movement of the polar front. Now we
need a similar island in the south Pacific.

Lesley continued to brief us on another project, known as "Marine
Mammals Exploring the Oceans -- Pole to Pole (MEOP)". MEOP is a proposed
project for International Polar Year (2007-2008) which builds upon
existing Polar research, including strands from SEaOS. MEOP uses beluga
whales and 4 species of seals. It involves tagging deep-diving seal
species to provide data on their location and behaviour, and information
relating to the waters they inhabit. MEOP is similar to the SEaOS
project in aims and results and can get data within sea ice. MEOP is now
extended to the poles, getting data from 100 seals, 3 species, and more,
providing 24,000 profiles since February. These are nice transects. But
there is still a gap in the Pacific.

Data will shortly be freely available on GTS in real-time, submitted by
BODC. BODC has taken on this role in part because it already sends data
to GTS and other data users. SMRU and MEOP data fits well with their
mandate. BODC will probably be involved in data QC as the program
evolves. Currently BODC does not do any QC since it's up to the
scientists to work the data. WMO have allocated 300 WMO numbers
(Q9900000-Q9900299) for biological tags so they are identifiable in
databases. Delayed-mode data is still a problem but real-time data will
be available freely

Anh commented that she has problems with this data e.g., some partial
profiles, different data points which look like two profiles but are not
identified properly, multiple profiles from same animal. She is in
contact with BODC to resolve these issues.

7.  **GTSPP Data Issue -- II\
    **

    1.  XBT fall rate issue (Ann Thresher, CSIRO)

Ann updated the GTSPP group on the XBT bias issue. She reported that
XBTs remain important and useful elements of the Global Ocean
Observation Systems. XBT profiles comprise 60-70% of past ocean in-situ
temperature data and is crucial for determining past ocean structure,
variability and change. The XBT network complements Argo in many ways:
it resolves Ocean geostrophic transport and associated heat transports
of major current systems and eddies along repeat transects. XBTs have a
long and valuable history. Many lines have been occupied for 10-20+
years. Currently no mature technology exists to replace XBT sampling
along these lines. XBTs also sample in marginal seas which Argo
currently does not cover such as the Banda Sea. The science community is
not the major user of XBTs but navies are.

She continued to report that technology changes and bias issues are now
being recognised, for examples: Gouretski and Koltermann (2007) reported
a warm bias in XBT's and Lyman et al, 2007 reported 'spurious recent
ocean cooling'. Currently, the oceanographic community does not have
consensus on what causes the error and how to correct it. Several
scientists, such as Ishii and Kimoto, Wijffels et al , Levitus et al,
and Gouretski, have different approaches to correct the XBT data bias .
Gouretski , for instance, thinks that XBT bias is a temperature offset
plus a depth bias, where Wijffels and Ishii et al believe it is a fall
rate error. Ann recommended that 1) until we have a definitive
understanding of the problem, the recommended fall-rate for reporting
data should NOT CHANGE -- all data should be reported with the Hanawa et
al, (1995) coefficients, 2) Meta data should label fall-rates correctly,
and 3) we must avoid any further confusion or ambiguity regarding
fall-rates used in data reported to the NODCs. She also proposed draft
recommendations:

[Quantifying Past Biases]{.underline}

The time history of past XBT biases requires further investigation --
there is no consensus recommendation -- the work is very new. We have 4
statistical approaches (Gouretski, Ishii & Kimoto, Levitus et al and
Wijffels et al) with differing results, and 2 altimetric approaches
(Willis, de Nezio). Currently there is no agreement on the true bias and
its associated error bars. Thus we recommend:

A -- that comparisons of the indirect statistical approaches be made -
NODC has volunteered to host the corrections for users to compare and
apply.

<http://www.nodc.noaa.gov/OC5/XBT_BIAS/xbt_bias.html>

B -- that the community work to assemble all known side-by-side XBT and
CTD data sets, and that these be re-analysed in a consistent way to
determine, if possible, the time-history of the fall-rates. They should
then be used to test the results of the indirect methods. This is
happening now (Boyer, Tchen, Wijffels, etc)

<http://www.nodc.noaa.gov/OC5/XBT_BIAS/xbt_bibliography.html>

C -- that past test data from the manufacturers (Sippican/LMCO and TSK)
should also be sought and examined, and possibly compared with other
(BATS) data. Who will do this?

D -- that we work to reduce metadata problems (which fall rate?). Where
possible originating institutions should check their XBT data held at
NODC and its associated meta-data to ensure the data and meta-data
match. Tim Boyer will assist -- many institutions might just want to
replace all XBT data at NODC.

[Tracking Future Biases]{.underline}

Until the source of the time-variable bias is understood and removed, we
recommend that future biases be tracked through ongoing and regular
XBT/CTD intercomparisons.

A - Co-ordinate and collaborate with the manufacturers for regular and
ongoing comparison data to be collected and analysed in a timely and
consistent way. Any fall-rate detectable changes should be discussed by
an XBT WG. Several ongoing activities present opportunities for this --
the CLIVAR/Carbon repeat hydrographic sections, ocean-time series sites
(BATS, HOTS, PAPA), Argo, altimetry.

B -- A system needs to be created to associate biases with XBT data
arriving at the NODCs -- this will require much better tracking of meta
data such as SN, batch date etc.

C -- Further field comparisons are required to tease out possible
sources of biases (besides manufacture changes) such as drop height,
wind speed, ship speed, acquisition system, water temperature or
viscosity.

D --the form of the fall-rate equation itself be revisited -- we need to
understand near-surface acceleration, startup transients and other
non-uniformity of the fall-rate. This may well require field or
laboratory experiments.

[Future -- more questions than answers]{.underline}

-   Challenging!

-   The source of the error needs to be confirmed -- rework past CTD/XBT
    data sets

-   We will revisit the form of the fall rate equation -- early
    acceleration, acquisition delay,

-   We need to continue to exploit altimetry - is the basin divergence
    in deep XBTs after 2000 real or a meta-data problem?

```{=html}
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```
-   Can we do better using ocean reanalyses -- remove possible biasing
    of decadal signals into bias estimates (especially for regionally
    dominated data sets such as TSK probes

```{=html}
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```
-   What to do about future fall-rate changes? Can we piggy back on the
    CLIVAR lines to 'batch' calibrate? But what is a batch?

    1.  Logic of identifying the XBT probe information in the GTSPP
        long-term archive (Charles Sun, NODC)

Charles reported that an XBT fall rate workshop was held 10-12 March
2008 at the Atlantic Oceanographic and Meteorological Laboratory (AOML),
Miami, Florida, USA. Charles gave a presentation about how NODC manages
XBT data in the GTSPP database. He reported that NODC has preserved XBT
data in the GTSPP Continuously Managed Database (CMD). The probe type
and fall rate equation information is stored in the GTSPP CMD if it was
provided. The NODC also worked with Canada's Integrated Science Data
Management and Australia's Commonwealth Scientific and Industrial
Research Organisation (CSIRO) to develop logic for the depth correction
process of archived XBT data. It was agreed that corrections to the
depth will be applied only to the data that will be placed on the WOCE
(World Ocean Circulation Experiment) DVDs. The NODC will not make depth
corrections on the archived XBT data. Two new codes will be created to
retain depth correction information in the surface codes structure. The
\"DPC\$\" indicates the status of depth correction and the \"FRA\$\"
will retain the conversion factor of 1.0336. The \"DPC\$\" code will
have the following states:

01 = Known Probe Type, Needs Correction,\
02 = Known Probe Type, No need to Correct\
03 = Unknown Probe Type, Not enough information to know what to do,
leave alone,\
04 = Known XBT Probe Type, Correction was done, and\
05 = Unknown Probe Type, but a correction was done.

Having determined which profiles are from XBTs by querying the data
type, then determining the XBT probe type and the fall rate equation as
they are stored in the XBT archives, the strategy for the fall rate
correction (if required) is to simply multiply the existing depths by a
factor of 1.0336. This was the technique employed with the
multiplication factor stored in the file structure, when GTSPP played a
key role in the WOCE (World Ocean Circulation Experiment) and
contributed to the final WOCE Data Resource DVD.

It is suggested that the correction to global archives be carried out in
cooperation with other data centers around the world to ensure
international standards.

8.  **QuOTA Project (Ann Thresher, CSIRO)\
    **

Ann Thresher briefed the GTSPP group on an on-going project, known as\
"Quality-controlled Ocean Temperature Archive" or "QuOTA" for short. The
aim of QuOTA is to build a high quality upper ocean temperature dataset
for the Indian Ocean and the South-West Pacific. QuOTA uses a process of
automated screening, followed by 'hand-QC' of data that fails the
automated tests. A critical step is to ensure that all depths are
calculated using consistent coefficients -- this relies on accurate
metadata. All XBT data have been (where possible) checked to make sure
depths conform to Hanawa (95). Older data are still a challenge as well
as some modern profiles which lack adequate metadata to identify the
fall rate coefficients used. The procedures[^3] was published in 2008.

Both Indian Ocean and SW Pacific data sets are now fully QC'd and
available for use. Web page links to documents and data can be found at
<http://www.marine.csiro.au/~cow074/quota/quota.htm>. CSIRO plans to
provide a data selection tool for full resolution profile data. The link
will appear on the Quota web page when available. Future plans include
continuing updates of the Indian Ocean and SW Pacific datasets.
Depending on pending funding (or partners), the dataset will be extended
to the east to complete the S Pacific dataset and eventually to extend
it globally (well down the track and dependent on major funding or
partners).

9.  **Scientific Presentations\
    **

    1.  GTSPP-related activities in JMA (Yoshiaki Kanno, JMA)

Charles Sun invited Mr. Yoshiaki Kanno of the Japan Meteorological
Agency (JMA) to brief the GTSPP group on the GTSPP-related activities in
JMA. Mr. Kanno showed a very nice coverage of temperature and salinity
data around Japan and through north Indian and central N Pacific.
Approximately 20% of the total are TESACs with salinity from CTDs on
research vessels. JMA collects data from multiple sources including
Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Japan
Coast Guard, Fisheries Research Institutes, universities, and local
governments and puts on GTS daily.

JMA participates in the NEAR-GOOS (North-East Asia Regional Global Ocean
Observing System) pilot project. Other participating countries are
China, Korea, and Russia. JMA operates the NEAR-GOOS
[R]{.underline}egional [R]{.underline}eal-[T]{.underline}ime
[D]{.underline}ata [B]{.underline}ase (RRTDB), makes GTS ocean data
available on RRTDB and sends real time data to ISDM on a daily basis.
ISDM provides JMA with the real-time GTSPP data for inserting into
RRTDB.

JMA uses the GTSPP data along with sea surface height and temperature
data for incorporation into the JMA operational model -- Meteorological
Research Institute Multivariate Ocean Variational Estimation system
(MOVE/MRI.COM). The MOVE/MRI.COM system produces maps of sea surface
height, currents, water temperature, and salinity with the resolution of
0.1 degree around Japan and 0.5 degree for N. Pacific.

2.  Optimal spectral decomposition (OSD) for ocean data analysis (Peter
    Chu, NPS)

Dr. Peter Chu of the Naval Postgraduate School was invited by Charles to
give a presentation about his recently published work on the new data
analysis scheme to help with QC. Peter raised an issue - how can we
ingest the many different data sources into a model?

Data density has changed massively in last 10 years. How can we analyze
these data best? Currently use the method of optimal interpolation (OI)
for interpolating observations from irregular grids to model grids for
predictions. The traditional OI has three requirements: it needs 1) need
the first guess field, 2) autocorrelation coefficients (scales) and 3)
high signal-to-noise ratio. However, if any of these are missing, we
can't do OI but can possibly use spectral representation.

The benefits of OSD are that you don't need first guess fields, don't
need autocorrelation functions, don't need high signal to noise ratio
and basis functions are predetermined before analysis. Advantages of
optimal spectral decomposition (OSD) in ocean data analysis are
demonstrated in this talk. This method is based on a classical
mathematical theory that any ocean variable (velocity, temperature, or
salinity,) can be represented by a generalized Fourier series with
pre-determined basis functions, which are the eigenfunctions of the
Laplacian operator with given boundary conditions. A cost function used
for poor data statistics is introduced to determine the optimal mode
truncation. An optimization scheme with iteration and regularization is
proposed to obtain unique and stable solutions. The capability of the
method is demonstrated through reconstructing a 2D circulation on the
Texas-Louisiana continental shelf from drifter data, deep circulation in
the North Atlantic from the Argo data, and global surface circulations
from the satellite altimetry data.

10. **Other business including additional partners should be pursued.\
    **

BODC has accepted Charles' invitation to resume its level of
participation in the GTSPP as a delayed-mode data assembly center and
will coordinate with the UK Hydrographic office for data submission to
the GTSPP long term archive.

11. **Next meeting date/place\
    **

The next meeting was discussed. Charles proposed to have a one-day GTSPP
workshop in conjunction with the annual Argo data management team
meeting 2009. Birgit said that BSH would host the 10^th^ Argo data
management team meeting in Hamburg and would like to host the next GTSPP
meeting at the same time. Charles accepted her offer.

12. **Closing\
    **

The Meeting closed at 5:00 pm on 27 October 2008 with the chair thanking
Steven Piotrowicz for providing meeting arrangements and logistics.

[^1]: <http://www.nodc.noaa.gov/OC5/WOD05/updates05.html>

[^2]: <http://www.nodc.noaa.gov/GTSPP/>

[^3]:
    > Gronell, A., and S.E. Wijffels. 2008. A Semiautomated Approach for
    > Quality Controlling Large Historical Ocean Temperature Archives.
    > Journal Atmospheric and Oceanic Technology. v25, pp990-1003.
    > Available at:
    > <http://www.marine.csiro.au/~cow074/quota/Quota_Paper.pdf>