Download The ocean observing system

BACKGROUND DOCUMENT
JOINT WMO/IOC TECHNICAL COMMISSION FOR
OCEANOGRAPHY AND MARINE METEOROLOGY
(JCOMM)
SECOND SESSION
HALIFAX, CANADA, 19 TO 27 SEPTEMBER 2005
JCOMM-II/BG. 4.1 (1)
__________
ITEM 4.1
English only
REQUIREMENTS FOR OCEAN DATA FOR CLIMATE
(RESEARCH, ASSESSMENT AND PREDICTION)
(Submitted by the Chairman of the OOPC)
JCOMM-II/Information Document
Agenda Item 4.1
Requirements for ocean data for climate (research, assessment and prediction)
Report of the Chairman of the OOPC (D. E. Harrison)
Background
The GCOS-GOOS-WCRP Ocean Observations Panel for Climate (OOPC) has been tasked
by its sponsors to recommend requirements for sustained observations of the ocean for
climate and related services. OOPC is a scientific advisor to JCOMM in the development and
implementation of the global ocean observing system.
The foundation for the work of the OOPC was provided by the Ocean Observing System
Development Panel (OOSDP) Report of 1995. OOPC was charged with developing and
implementing the recommendations of that Report, in concert with relevant implementation
bodies, taking due account of new developments in science and technology. An international
conference1 was held in October 1999 to reach ocean research and operational community
consensus on the Next Steps forward for the global ocean observing system. The
recommended Next Steps were endorsed by the sponsors of OOPC. JCOMM-I in 2001
agreed that these Next Steps "would provide a blueprint for much of its own work over the
coming decade."2
OOPC has contributed to two recent documents updating the requirements and
implementation plans for the global observing systems for climate, with broad input from
ocean community scientists. In response to a request in 2001 from the UN Framework
Convention on Climate Change (UNFCCC), GCOS undertook an evaluation of the status of
the existing global observing efforts for ocean, land and atmosphere. The April 2003 Second
Report on the Adequacy of the Global Observing Systems for Climate in Support of the
UNFCCC3 was accepted by the Conference of the Parties (COP) of the UNFCCC, and an
implementation plan was requested. OOPC and other ocean community scientists
contributed the ocean domain section of this implementation plan4, which was reviewed and
in December 2004, recommended for implementation by COP-10 in Buenos Aires.
This briefing paper outlines the objectives of the global component of the ocean observing
system, the strategy that is being used to meet those objectives including JCOMM's role as
an implementer, and key actions necessary to fully implement the recommended initial ocean
observing system.
Objectives
The ocean observing system is being developed with a broad set of objectives, including:
 Monitoring and detection of climate change, including projection to regional scales
and characterization of extreme events
 Seasonal-to-interannual climate prediction
 Marine and weather forecasts
 Short-range ocean forecasts
 Understanding decadal variations
1
International Conference on the Ocean Observing System for Climate (OceanObs), St Raphaël, France, 18-22
October 1999.
2
Abridged Final Report of JCOMM-I, WMO publication No. 931, agenda item 5.1.3.
3
Global Climate Observing System report GCOS-82 (WMO/TD No. 1143), available from
http://www.wmo.ch/web/gcos/gcoshome.html
4
Implementation Plan for the Global Observing System for Climate in Support of the United Nations
Framework Convention on Climate Change, GCOS report GCOS-92, available from
http://www.wmo.ch/web/gcos/gcoshome.html
3


Support of scientific research
Routine ocean state estimation
The design and implementation strategy have been developed and refined with these multipurpose goals in mind, since a broad user base will strengthen the resource base and
increase the likelihood of the observing system being sustained.
The ocean observing system
New technology, developed and proven by the ocean climate research programmes of the
1990s, has allowed the ocean community to design and begin implementation of an initial
ocean observing system, significant parts of which are implemented under JCOMM. The
OOPC is advocating, and its sponsors have endorsed, the implementation of a composite
system of satellite and in situ observations collected by operational and research groups, to
be synthesized into information products. The recommended observations are feasible for
global implementation with current technologies, and are of high impact, contributing to the
multiple objectives of the ocean observing system. The composite strategy makes the best
use of existing observing efforts and organizational structures.
Surface ocean composite observing network
The surface ocean composite observing network will provide information about patterns of
ocean surface temperature, pressure, winds, salinity, sea level, waves, and sea ice that are
important both to the global climate and ocean and weather forecasting. The surface
observing network depends critically on the continuity of some satellite observations, most of
which are in research rather than operational status, and on the full implementation of a
number of in situ activities.
The essential ocean satellite systems are: vector-wind (scatterometer), sea-ice, sea-surface
temperature (microwave and infrared), ocean-colour, and high-precision and high-resolution
sea-level measurements, which require one high-precision and two low-precision altimeters.
The essential in situ surface ocean observations are:
 high-accuracy geocentrically-located tide gauge measurements, the GCOS subset of
the total JCOMM Global Sea Level Observing System (GLOSS) Core Network
 global coverage for the drifting buoy array, organized under JCOMM's Data Buoy
Cooperation Panel (DBCP)
 an enhanced Tropical Moored Buoy network including observations in all three
tropical oceans, organized under DBCP's Tropical Moored Buoy Implementation
Panel (TIP)
 an enhanced Voluntary Observing Ships (VOS) network including sea surface salinity
(SSS) and an enhanced VOS Climate (VOSClim) network, organized under
JCOMM's Ship Observations Team (SOT)
 a globally-distributed reference mooring network, with a wave measurement
component coordinated through the JCOMM Expert Team on Waves and Surges
Subsurface ocean composite observing network
The subsurface ocean network will provide critical information on ocean climate variability
and change. The network will provide a capacity for monitoring the regional oceanic uptake
of heat, freshwater and carbon, and identification of abrupt climate change arising from
changes in the planetary hydrological cycle processes. Combined with the surface
observations, they also provide the basis for seasonal-to-interannual predictions and longerterm weather forecasting.
The essential subsurface ocean observations are:





the enhanced network of Ship-of-Opportunity Expendable Bathythermograph (XBT)
trans-oceanic sections, organized under JCOMM's SOT
the Argo profiling float array
systematic repeat hydrographic sampling of the global ocean full-depth water column
key ocean current and transport measurements
the Tropical Moored Buoy and reference mooring networks referred to above
The surface and subsurface observing networks outlined above were about 45 % globally
implemented at the end of 2004. Continuity and sustained funding for many components
remains a challenge, as does achieving and maintaining the recommended global coverage.
In recognition of the importance of potential changes to the ocean carbon cycle and marine
ecosystems, the OOPC is also advocating a number of important research and
implementation actions dealing with the establishment of an observing network for the partial
pressure of carbon dioxide and the measurement of the state and change of carbon sources
and sinks in the oceans.
The OOPC has promoted various paths towards implementation. JCOMM is a primary
pathway for implementation of the in situ elements of the ocean observing system,
predominantly in cases where the methods are well-known and proven. Informal
mechanisms include partnerships with research programmes such as the Climate Variability
and Predictability (CLIVAR) and the Climate and Cryosphere (CliC) programmes of the
WCRP and the Partnership for Observations of the Global Ocean (POGO), a consortium of
oceanographic institutions with an interest in supporting the ocean observing system. The
OOPC has also promoted focused pilot projects such as Argo and the Global Ocean Data
Assimilation Experiment (GODAE), which are making important contributions to the
observing network and ocean analysis. Wherever possible, OOPC has taken advantage of
synergies with other components of GCOS, with GCOS's engagement with the UNFCCC,
and with the GEOSS process, to encourage participation and investment in the observing
system.
Finally, continuing support for climate and ocean research and technology programmes are
needed to enhance the efficiency and effectiveness of observing efforts, and to develop
capabilities for important ocean variables that cannot currently be observed globally. This
need for enhanced capability is particularly acute for remote and extreme environmental
locations, for improved understanding of the ocean ecosystems, for improving the estimates
of uncertainty of climate and ocean products, and for research in understanding the
mechanisms of climate change.
Key Actions
The OOPC has identified a number of key actions necessary in the next five to ten years to
build the ocean observing networks and associated systems. Here those with relevance to
JCOMM are summarized.
The first is the full implementation (with global coverage at the recommended density) of the
recommended ocean surface and subsurface observing networks. Many of these are
organized under JCOMM, and others, such as Argo, will benefit from links with the JCOMM
Observations Coordination Group (OCG) and will help OCG in maintaining global coverage.
Sea ice, which plays a key role in climate feedbacks, is a complex variable needing
continued research into improved in situ and satellite measurements and analyses, and
better linkages between the research community and operational groups such as JCOMM's
Expert Team on Sea Ice. For climate monitoring and research, the observing activities
should adhere to the GCOS Climate Monitoring Principles5, which provide basic guidance for
5
available at http://gosic.org/GCOS/GCOS_climate_monitoring_principles.htm
5
the planning, operation, and management of observing networks to ensure high quality
climate data.
In order to succeed in the full implementation of the ocean observing system, JCOMM and
other sponsors of the observing system need to designate and support national Agents for
Implementation for the ocean observation system, and establish effective partnerships
between ocean research and operational communities for implementation. Coordination of
planning of national efforts to accomplish full implementation could be improved.
To realize all of the objectives of the ocean observing network, the players involved will also
need to engage in timely, free, and unrestricted data exchange, and adopt comprehensive
data management procedures. The real-time exchange and archiving of high-frequency
JCOMM GLOSS data, as well as the recovery and exchange of historical sea-level records,
are specific short-term goals. In the longer term, the IODE and JCOMM, in cooperation with
the WMO Future Information Systems Initiative, should develop an ocean data transport
system for the free and open exchange of data between data centres and data users.
As climate records are of most value when they can be rationally reprocessed and
reanalyzed, international standards for metadata for the essential ocean climate variables
need to be established and adopted in the creation and archiving of climate data records.
Improved metadata collection and measurements systems are of particular importance to the
JCOMM VOSClim program, but apply to all JCOMM networks, and JCOMM should
cooperate with IODE in the establishment and implementation of these standards.
The ability to effectively communicate data from remote observing platforms is critical to
many of the objectives of the ocean observing system, and JCOMM should encourage and
assist in the coordination of the development and implementation of enhanced and more
cost-effective communication technologies, including two-way communications.
Finally, to meet the climate monitoring and research objectives of the ocean observing
system, an internationally-coordinated approach to the development of integrated global
climate products needs to be adopted. As far as possible these products should incorporate
past data covering at least the last 30 years in order to serve as a reference for climate
variability and change studies. A number of ocean analysis and reanalysis efforts participate
in GODAE, and JCOMM, in collaboration with CLIVAR and other research activities, should
develop plans for and coordinate the construction of climate-quality historical datasets for
use in these efforts. JCOMM will also be an important partner in the assembly of an ocean
surface current analysis.
OOPC and JCOMM
The OOPC attaches great importance to JCOMM, and is dedicated to providing advice and
assistance as appropriate to ensure its successful operation. In many areas JCOMM
provides an appropriate and effective mechanism for implementation of ocean observations.
The OOPC looks forward to continuing productive partnerships with JCOMM, in particular
with the OCG and its implementation panels, but also with the Data, Services, and CapacityBuilding areas.