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David M. LeglerU.S. CLIVAR Office

www.usclivar.orglegler@usclivar.org

CLIVARA presentation for

the NVODS Workshop

September 11, 2003

and member of US-DMAC committee as well as former chair of the WOCE Data Products Committee…

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• What is CLIVAR? (hint: it’s involves more than the ocean!)

• Scope of activities• CLIVAR needs/requirements• CLIVAR and data management

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CLIVARClimate Variability and Predictability

• What causes the variability of the earth's climate on time scales from seasons to centuries and can we predict it?

• Can we distinguish natural from anthropogenic induced variability?

•Science Plan - 1995•U.S. CLIVAR SSC formed - Summer 1998 •International CLIVAR Conference - December 1998•CLIVAR will extend for at least another 10 years

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Illustrative questions for CLIVAR

• How can we better predict El Niño and its impact on climate?

• What are its links to higher frequency (e.g., MJO) and to decadal variability?

• Decadal variability has been shown to impact climate in many regions…can we ever predict this variability?

• What are the some of the mechanisms than can lead to abrupt climate change?

• How does El Niño change under a changing climate?

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U.S. CLIVAR Objectives

• Identify and understand the major patterns of climate variability on seasonal and longer time scales and evaluate their predictability;

• Expand our capacity to predict short-term (seasonal to interannual) climate variability and search for ways to predict decadal variability;

• Better document the record of rapid climate changes in the past,as well as the mechanisms for these events, and evaluate the potential for abrupt climate changes in the future;

• Evaluate and enhance the reliability of models used to project climate change resulting from human activity, including anthropogenic changes in atmospheric composition; and

• Detect and describe any global climate changes that may occur.

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The CLIVAR Vision...An important legacy of CLIVAR will be an improved climate

observing system,as well as a more

comprehensive and useful climate record

CLIVAR will contribute the fundamental underpinnings of critical physical

processes that lead to reducing uncertainties

in coupled climate models used for

prediction

CLIVAR will help contribute to the development of

robust dynamical frameworks for understanding

climate changes

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Approach• Improvements in the instrumental record and observing system

– document past, ongoing, and future climate fluctuations– better elucidate their structures and mechanisms– provide initial conditions for model data assimilation and forecasting

• Model application, experimentation, and improvement– develop long-term model data sets (e.g. retrospective analyses) to study

climate variability– assess inadequacies and improve the capabilities of models to simulate and

predict climate variability– explore mechanisms of climate variability– develop dynamical hypotheses to help focus observational requirements

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Approach• Empirical studies of the climate record from instruments, satellites and

proxy records, and climate model simulations– define patterns of climate variability– develop and test hypotheses

• Regional and process field studies– quantify specific processes that must be included in successful climate

models– Identify processes for which present treatment is inadequate.

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CLIVAR Regional Implementation

Working groups address global synthesis, modeling, and prediction

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Atlantic Basin Issues• NAO/AO/AM

– Mechanisms that govern its variability?

– Low-frequency trends?

– Ocean, land, sea-ice feedbacks?

– Numerous applications

• TAV– Influence of

ENSO, NAO?– Role of coupling

in TNA? Of subtropical cells?

– Extent of land influences?

– Climate predictability beyond tropics?

• MOC– Variability of

ocean heat transport?

– Sensitivity to sfc forcing?

– Role of thermohaline circulation in abrupt climate change?

QuickTime™ and aGIF decompressor

are needed to see this picture.

11http://www.clivar.org/organization/atlantic/IMPL/

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East Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System (EPIC)

IOP: Sep/Oct 2001• 2 ships, 2 aircraft

Enhanced Monitoring 1999-2003• Enhancements to the TAO array• IMET mooring at 20S• Radionsonde, flux msmts, etc. from twice-

yearly TAO tender cruises 95W, 110W

Enhanced Regional Obs• Terrestrial and lower-atm obs

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Other Observations & Products of Interest

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Modeling ActivitiesSome Objectives: • Improve predictions on seasonal-to-interannual time scales• Assess predictability of decadal variability• Evaluate and enhance the reliability of models used to project

climate changeU.S. teams of modelers, observationalists, and diagnosticians will address

two major areas of uncertainties in climate change models– Ocean mixing and low-latitude cloud feedbacks

• Development of robust dynamical synthesis frameworks (e.g. data assimilation) for understanding climate variability and predictability and to guide observation system design

• Recent workshops on– Ocean data assimilation– Atmospheric data assimilation/reanalyses– Coupled data assimilation

CLIVAR will generate and utilize many TB of model data/products…data management challenge

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CLIVAR Needs…• The requirements for developing climate data are stringent

as the signals we are trying to detect are often very small• CLIVAR needs access to a variety of obs, models,

analyses, paleo-proxy data, archives, etc from multiple disciplines (e.g. ocean, atm, land) to address the coupled climate system

• Access to browse products • Time-critical data/products are needed for climate

forecasting (e.g. ENSO predictions) • Data/products of a known quality

– Attributes that describe errors, uncertainties, and data quality must be an integral part of the data system

– Versioning/tracking/tagging is critical (experiments must be repeatable)…observational data can be corrected many times.

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CLIVAR and Data Management• WOCE heritage: CLIVAR has picked up some parts of the

WOCE (ocean) data system…BUT CLIVAR is more than the oceans!

• CLIVAR is the home for – Some observation system elements and their data systems– Field experiment observation data (UCAR-JOSS)– Numerous model and value-added products– Various regional/system-wide data/product activities

• Many (not all) of these consider data managementAll of them need to be fully entrained in the development of a

comprehensive climate data/product/info management system

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Legacy of WOCEWOCE V3 DVD’s

2 DVDs, 12GB data

10+ yrs of in-situ & satellite ocean data and

products

netCDF-COARDS compliant files

Consistent and documented QC

Common metadata stds, conventions, etc.

Search tool/file pointers

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WOCE Data System

CLIVAR Data Assembly Data Centers (DACs) play a central role in assembling, QC’ing, and distributing ocean data

All DACs have OpenDAP servers, some with LAS, etc

Knowledgeable and cooperative team

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CLIVAR’s Role in Data Management

• Helps to develop and assess requirements of the systems that will deliver climate data, products, and information;

• Implements some (e.g. ocean) elements of the observing system and their respective data management systems, the frontline for new obs technology and data systems

• Develops synthesis frameworks (e.g. data assimilation/reanalyses) that utilize (and assess) the climate observations, products, and information;

• Contributes assembled data, products and their attributes; • Cooperates with other activities (DMAC, OTI, OOPC, etc) leading data system

development;• Provides feedback on acceptable metadata and data “models”; • Help sustain current Data Assembly Centers (DACs), regional, and specialized

data centers

• CLIVAR Global Synthesis and Observations Panel (GSOP) is the CLIVAR group charged with addressing data management issues. First meeting is being planned (early 2004)

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For Consideration– CLIVAR is an important customer/user of NVODS– CLIVAR can contribute data, metadata to global

component of IOOS …help develop IOOS data system– CLIVAR can help extend NVODS technology to other

disciplines– Importance of products (very different from

observations)• Model/value-added products• Browse products• What metadata should be included?

– Importance of a data/metadata model and standards • encourage contributions of a more comprehensive set of

data/metadata• Sufficiently extensible to address stringent needs of climate

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Further Information:

www.clivar.org

www.clivar2004.org

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NVODS Activities…CLIVAR Input

1. Develop a Comprehensive IOOS Data Model2. Deliver time-critical (real-time) data to data assembly and operational modeling sites

• Characterize the need for real-time data.3. Develop DMAC Middleware

• Determine the breadth of data management solutions in use by IOOS data suppliers, which must be supported by IOOS middleware.

• Determine the breadth of legacy and new client applications that should be supported. Similarly survey and prioritize requirements for delivery of formatted subsets to users.

4. Make data available using IOOS middleware solution• Work with suppliers of data to make data available through the DMAC middleware

solution.5. Data Manipulation Services

• Prioritize Data Manipulation Services, including aggregation, re-gridding, and simple transforms such as averages and extrema.

6. Develop Metrics and Implement Performance Monitoring• Determine specifications for Metrics and Performance Monitoring.

7. Implement Middleware Security (Cross-discipline effort with all DMAC)8. Provide guaranteed geo-temporal-referenced browse for all IOOS data