Metadata Development in the Earth System Curator

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Metadata Development in the Earth System Curator

• Spanning the Gap Between Models and Datasets
• Rocky Dunlap, Georgia Tech
• 5th GO-ESSP Community Meeting

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Motivation

• Two primary products of the climate community
  datasets and the models used to produce them

Models
Datasets
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Motivation

• Many efforts in place to provide uniform access
  to datasets
• Additionally, groups are working to develop
  frameworks for component exchanges and
  interoperability
• But, models and datasets are currently treated as
  distinct and separate entities
• Earth System Curators claim
• This gap is actually an artificial barrier that
  inhibits access to resources and results

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What is the Earth System Curator?

• The goal of the Earth System Curator project is
  to provide a unified interface to both climate
  models and their output data
• This means a single portal will give you access
  to both

Models
Datasets
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Convergence of Models and Data

• ESC begins with a crucial insight
• the descriptors used for comprehensively
  specifying a model configuration are also needed
  for a scientifically useful description of the
  model output data
• This leads to the convergence of models and data
• There is a need for a common metadata formalism
  to unify the treatment of models and data

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Metadata

• Metadata is data about data
• Metadata that describes not only model outputs,
  but the actual model configuration used to
  produce the data
• Provenance metadata a big part of this

Model Run
Model Metadata
Output
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Use Case Scenario

• Jane Scientist has developed a malaria model
  where mosquito breeding rates are modeled as a
  function of rainfall and temperature
• Because mosquitoes provide no feedback to the
  climate model, she can run her model offline
  from an existing climate dataset

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Use Case Scenario

• Using Curator she discovers the needed dataset,
  but finds out that the model used to produce it
  systematically underestimates rainfall
• Using the configuration description in Curator,
  she is able to re-run the model with new
  parameters to correct for the rainfall bias

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Current Efforts

• Numerical Model Metadata (NMM)
• Earth System Modeling Framework (ESMF)
• Earth System Grid (ESG)
• GFDL Curator database

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ESMF Metadata Structures

• Component
• Logical entity that models a particular physical
  process or computational function
• State
• Import/Export transport data to and from a
  component
• Field
• Physical quantity
• Grid

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Metadata Needs

• What kinds of metadata do we need for Curator to
  be a success?
• Metadata to describe the complex component
  hierarchies of current climate models, especially
  components that are made up of multiple
  sub-components
• Metadata to describe applications that exist
  across multiple repositories (e.g., labs)
• Metadata to describe couplers as first class
  citizens

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Component Hierarchy
NASA GEOS-5 ESMF Application
parent/child
swappable components
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Component Hierarchy

• Parent components need to identify their children
• children are created/invoked/destroyed by the
  parent component
• parent acts as a driver
• Allow for additional types of science components
  beyond the typical atmosphere, ocean, sea ice,
  etc

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Multi-Repository Applications

• Components are highly decoupled and have
  well-defined interfaces
• This allows us to combine components from
  different labs into one model
• Components should be treated as standalone
  entities
• Components should be related to a particular
  framework (PRISM, ESMF, etc.)
• Configuration description stored separately from
  general component description

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Couplers

• Couplers are components that act as translators
  between two components
• e.g., regridding, averaging
• However, couplers may also have significant
  science code inside, and therefore should be
  treated as components
• We still need to distinguish couplers from other
  components

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Deliverables

• Allow researchers to archive and query Earth
  system models, experiments, model components, and
  model output data
• Perform technical compatibility checking
• How can we determine if two components will run
  together?
• What about scientific compatibility?
• Prototype auto-assembly of components to
  facilitate model runs
• Involves automatic code generation of simple
  couplers

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Broader Impacts

• Improve climate prediction for policy makers
• Facilitate Model Intercomparison Projects (MIPs)
  by allowing fast setup and execution of
  experiments using different model components
• Encourage Curator-like activity in other domains

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ESC Collaborators

• NSF Funded
• National Center for Atmospheric Research
• NOAA Geophysical Fluid Dynamics Laboratory
• MIT
• Georgia Tech

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Thanks!

• Website http//www.cc.gatech.edu/projects/curator
  /
• Questions?