# Presentation: 415693

## Metadata Development in the Earth System Curator

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

## Motivation

- Two primary products of the climate community: **datasets** and the **models** used to produce them

- Models

- Datasets

## 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 Curator’s claim:
- This gap is actually an artificial barrier that inhibits access to resources and results

## 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

## 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

## Metadata

- Metadata is *data about data*
- Metadata that describes not only model outputs, but the actual model configuration used to produce the data

- Model Run

- Output

- ......
- ......
- ......
- .........
- .........
- ............

- Model Metadata

## 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

## 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

## Current Efforts

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

## 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

## Metadata Needs

- What kinds of metadata do we need for Curator to be a success?
**Provenance** metadata
- 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**

## Component Hierarchy

- NASA GEOS-5 ESMF Application

- parent/child

- “swappable” components

## 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...

## 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

## 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
- Users want to distinguish couplers from other types of components

## 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

## 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

## ESC Collaborators

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

## Thanks!

- Website: _[http://www.cc.gatech.edu/projects/curator/](http://www.cc.gatech.edu/projects/curator/)_
- Questions?