Call with D. Maraun Statistical Downscaling Controlled

Vocabulary

5 DEC 2013

Update on the Downscaling metadata project

• NCPP extended the CIM schema to allow for the description of downscaling methods– Added StatisticalModelComponent– Added DownscalingSimulation

• Dynamical downscaling CV– The existing CMIP5 CVs for atmosphere and land are being re-

used and added to– Work under way with the help of Seth McGinnis from NARCCAP

and Shuyan Liu from University of Maryland to develop instances of dynamical downscaling

• Statistical downscaling CV– Current version is ready for comments and collaborative work

with the community – will be presented today

CIM Concepts• StatisticalModelComponent • Describe “method as implemented” (in software!)• Training• Validation (how much should be described along with the method?)• Application – describe how it is applied (if different than during

training period)

• DownscalingSimulation -- for another call!• Application Specifics for a given use• downscaled from…. which GCMs or RCMs• Ensembles of DownscalingSimulations can be grouped.

Elements of the statistical CV

Pre-processingInput variables

Output variables

Post-processing

Variables

Statistical Model

Key properties

Component details

Elements of the statistical CV

Pre-processing

Statistical Model

Post-processing

Input variables

Output variables

Pre-processingInput variables

Output variables

Post-processing

Variables

Statistical Model Component

Key properties;Variables

Child components

Abstraction

Challenges• Level of specificity when describing downscaling method (e.g. “weather

typing” vs. “hierarchical clustering”) • Variable-specific attributes hard to describe in the CV (e.g. sqrt-

precipitation pre-processing) • Variable-centric vs. method-centric description• “Key attribute” vs. method detail• Compound methods, e.g. Weather Typing + Regression + Analogs. (we

use child components as “building blocks”)• Where to describe validation? As part of StatisticalModelComponent

or as a downscalingSimulation • When is a new CIM document needed as methods evolve?

• Many more……

Guidelines• Favor description over classification.• Describe method as implemented. Build from examples of methods.

Focus (first) on method that have been used to generate available datasets.

• WWCD: What Would the Comparator Do? – Implication is to keep as much as possible at the same level in the CV Mind

Map, and properties we want to compare across methods as “leaves on the same twig”.

• How will this appear in the Questionnaire? Is this too much detail to ask for? Are the property names intuitive?

• Be flexible. A lot of the “boundaries” between concepts are not absolute. Allow multiple choices.

• When mired in complexity, use a free text box.