Argo Status

1
Argo Status

• M. Belbeoch, Argo TC(inputs from AST)

2
Argo Infrastructure

• Argo is internationally managed by the Argo
  Steering Team.2 co-chairs, National Argo
  programmes representatives, TC
• Argo Data Management team coordinates data issues
• Argo Data Management is a distributed system
• National Data Centres (DACs) feed GTS of WMO and
  Internet GDACs
• REAL TIME ( GTS, GDACs) with standard/automatic
  QC
• DELAYED-MODE files replace RT files (GDACs,
  after 6-12 months)
• 2 Global Data Centres (USA, FR) - mirrored
• Regional Centres being developed
• Long term archival centre at US NODC
• Argo Information Centre/JCOMMOPS/Argo Project
  Office

3
Argo Status what has been achieved ?

• Argo has achieved the 3000 floats milestone
  with global distribution and a comprehensive data
  management system
• Argo Core Mission (3200 floats between 60N and
  60S, no marginal seas) is NOT YET ACHIEVED
• All floats are nor performing well ...
• All floats are not operating where they should ...

4
Argo Status network density
Float density (1004 floats) good floats
onlyChallenge in South Indian, and South Atlantic
5
Argo Status network density
436,000 Argo profiles were collected during
2004-2008. Left profiles per 1o box, 2004-mid
2008.(Roemmich, Gilson, Scripps/USA)
More floats (600) are needed in the southern
hemisphere, especially the South Indian and South
Atlantic. Of the 3300 active floats, gt600 are
either in marginal seas, high latitudes,
over-sampled regions, or greylisted.
Argo floats per degree of latitude (black).
Argos design requirement (red) Equal area
sampling (blue). (Freeland, IOS/Canada)
6
Argo Status network density
How effective is Argo in estimating large-scale
(10o x 10o x 3 months) variability? Estimates of
large-scale signal variance (black, green) and
noise (red) are made using (a,b) altimetric
height subsampling experiments, (c) subsets of
Argo data, and (d) related datasets such as SST.
(Roemmich)
More floats (600) are needed in the southern
hemisphere signal-to-noise ratio is good in
tropics.
7
Argo Status deployment plans
Argo groups are making substantial efforts to
plan their deployments and optimize the array
coverage taking into account network density
/age. Implementing an empty ocean ? maintaining
a global array. All deployments are registered
on line from a draft state to the final
confirmation/notification. GODAE gt Maps of
dispersion to help planning
8
Argo logistical challenge
2000 2001 2002 2003 2004 2005 2006 2007 2008
Total 116 295 452 672 869 1008 933 747 848
6344 units deployed !
Ship time is an issue Sustained funding and
cooperation critical
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Argo logistical challenge

• Most floats are deployed by opportunistic use of
  commercial ships and RVs.
• In some remote regions this is not sufficient.
• U.S./New Zealand collaboration has resulted in
  deployment of over 600 floats (plus drifters)
  using a cost effective vessel, RV Kaharoa (28 m
  length, 5 crew).
• Future uncertain (lack of funding)

New Zealands Minister of Research, Science and
Technology studies float deployment. Photo by A.
Blacklock, NIWA.
Deployment positions of Argo floats from
dedicated RV cruises. Kaharoas Argo-10 voyage to
the South Indian Ocean (previous slide) is
planned for late 2009.
10
Argo is the most internationally collaborative
program in the history of oceanography
A dozen countries are sustaining the global
network, another dozen takes care of regional
gaps, and many other are supporting Argo. Euro
Argo contribution growth needs to balance the
potential USA contribution decrease.
Argo makes a lot of efforts to foster
participation by new countries
11
Argo 100 000 profiles / year

• All Profiles 562230
• DM Profiles 289774
• 90 optimal quality (but not for all
  applications)
• 90 reach the GTS/GDACs within 24h

12
Argo QC issues

• Salinity Drift bio-fooling and others reasons
• DMQC (dedicated working group)
• Comparison with CTD data, and nearby float data
• Accuracy of temperature versus pressure
• Applications of Argo data for climate change
  issues requires highest quality possible (heat
  content, steric sea level change).
• Years required to detect small biases (comparison
  with CTD)
• Free data gt educate users
• Recent problem on SBE CTD pressure most of new
  deployments will be postponed

13
Argo QC issues

• Salinity drift is estimated and adjusted (Owens
  and Wong, 2008).
• An issue is small systematic errors in pressure.

The effect of 1-dbar time-varying pressure bias
on temperature .009oC on steric height
(0/2000) 5 dyn mm.
Systematic errors of this magnitude are difficult
to detect and correct. Example SBE 41 changeover
from Amatek and Paine p-sensors to Druck in
2003. Global change research requires long
time-series and careful standardization.
Shipboard CTD data are critical for Argo. The
dataset requires several years to achieve best
quality. Users need to understand the limitations!
14
Argo QC issues, pressure sensor severe pb.

• micro leaks in the Druck sensor used in SBE
  CTD, on all floats
• Recent study (by UW Scripps / USA)
• Increase in the occurrence rate of floats showing
  negative surface pressure
• Before 2007 3
• 2007 12
• 2008 10-30
• most of new deployments will be postponed
• Manufacturer doing tests but still in phase of
  understanding
• Equip some CTD with new pressure sensor (Paine)
• Return floats and repair CTDs
• It takes more than a year for a float to exhibit
  such negative pressure offset
• In general to have feedback on a float generation
  and impact of new features we need to wait years

15
Argo QC issues

• DM QC time consuming activity (resources
  required) 67 achieved

16
Argo is revolutionizing global oceanography ...
2000 -2008 August XBT profiles(gt 300m, source
WOD)
1951-2000 August hydrographic T/S stations (gt
1000m, source WOD)
2004-2008 August Argo T,S profiles
... and its impact will be greatest in the
southern hemisphere where there are large climate
signals and there is little historical data.
17
Argo benefits

• Operational use requirements for long term
• 14 Operational Centres using Argo data
• Research applications growing
• Training WorkshopsCapacity building initiatives
  on data use
• Argo has enormous potential valuein education
  applications.
• Google Ocean Argo partnership network status
  (gateway) products (T, S, anomalies)
  stories by oceanographers climate
  change focus
• To be extended to other networks monitored by
  JCOMMOPS.
• GODAE, myOcean prepare KML

18
Capacity Building cooperation with GODAE ?

• Raising capacity in Argo national programs (3
  DMQC, 1 float technology workshop, one-on-one
  visits and training)
• Increasing Argos international user community
  (e.g. PI-GOOS Marine Data Workshop). All nations
  should benefit from global ocean observations.
• Secondary and tertiary education (teacher
  training workshops).

South Atlantic Argo training workshop on US Navy
vessel HSV-2 Swift.
PI-GOOS Marine Data Workshop in Fiji to acquaint
meteorological service and fisheries scientists
with Argo and other ocean datasets.
SEREAD (Argo-sponsored) teacher training workshop
in Samoa.
19
Argo Float Technology float reliability improving
45 of floats deployed in 2004 are still active
at age 4 years. Deployment failure rate 2.5

• Still room for improvement all floats do not
  reach yet the 4 years lifetime
• This target will likely be reached and
  exceeded
• This will help to fill gaps without
  deploying more floats

20
Argo Float Technology Telecom. slowly improving
8 of deployments with Iridium (2007, 2008)
Argos 3 pilot projects started More are
anticipated in 2009 (Australia)
21
Argo Float Technology Cycles rather homogeneous
80 of the fleet is set up to drift at 1000 dbar
as decided by the AST 70 to profile at a depth
gt 1500 dbar 80 to cycle on a 9-11 days basis
22
Argo Float Technology new designs, new sensors

• New generation floats are longer-lived, smaller,
  and more capable.
• Extended domains are being explored or
  considered under ice, marginal seas, boundary
  currents, abyssal ocean.
• New sensors are being developed and tested
  (oxygen, bio-optical, surface layer, )
• At present 150 Argo floats carry dissolved
  oxygen sensors.
• First floats are providing SST (at no cost). This
  is likely to be extended to all floats.

Left to right SOLO/SOLO-II w/Iridium, ARVOR,
PROVOR w/optical sensor, APEX w/SBE oxygen sensor.
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Argo GODAE / OSE

• Feedback from data users on requirements
  (networks design, data issues, ...)
• Argo Science Workshops , OceanObs 09, (next ADMT
  in Toulouse ...)
• 3x 3 everywhere ?
• How many T/S levels are assimilated by models ?
  (50 or 1000 needed?)
• Metadata required?
• Routine feedback from operational centres on data
  quality tools to be developed and maintained
• DBCP/SOT operational system
• Argo being developed (e. g. Altimetry QC by
  CLS/Coriolis)
• JCOMMOPS acts as a centralized relay tool data
  users data producers
• UKMO maintain blacklists
• Integrated QC from data centres (GODAE Server)
• JCOMMOPS can help to design, finalize and promote
  products
• Continuous demonstration of the value of the Argo
  array
• Specific impact studies
• E.g. What would give the models with half Argo
  array ?

24
Argo Objectives

• Objectives for the Argo Program in the coming
  years related to array performance are
• Achieve mean float lifetimes of 4 years or
  longer, needed to sustain the core Argo array
  with 800 floats deployed per year.
• Deploy more floats in the southern hemisphere to
  achieve the arrays design requirements.
• Extend instrument capabilities for profiling to
  2000 m everywhere in the oceans.
• Sustain funding (Argo is 20 underfunded)
• GODAE/Argo
• What should be Argos sampling plan for high
  latitudes or marginal seas ?
• Should Argo sample the deep ocean ?
• Should Argo be denser in all WBC regions ?