EaSM2 Climate Model Verification Project

Header 1: Overview

Earth System Models (EaSMs) comprehensively encapsulate the complex interactions between physical, (geo)chemical and biological subsystems. However, their standard products are not directly useful for most planning and decision-making processes that are increasingly confronted with climate change. They are (i) not giving the necessary variables and quantities at (ii) the required temporal and spatial scales, nor are they (iii) sufficiently quality tested for application-critical characteristics. The current "hand-down" approach for providing EaSM and related data products to end users leads to substantial losses of knowledge about the scenarios, the data, and the tools involved. Yet that knowledge, accompanied by transparent and accessible information about uncertainty and best practices, is critical for ensuring effective decision-making. To realize the promise of extensive EaSM investments, the challenge is therefore to properly and effectively integrate its broad capabilities with operational applications so that it can be made relevant for users who need actionable, robust and transparent information.

We focus on water resources because of the central role of water in climate change impacts. The collaborative effort will focus on four primary tasks that will transform the use of EaSM output and related downscaled data for our selected application:

  1. Identify the variables and indices, based on water resource management needs, that threaten or otherwise influence decision-making, applying understanding of key processes and their spatial and temporal scales.
  2. Adapt and convert established quantitative weather-forecast verification tools for climate-model metrics. Accessible and transparent metrics will be the cornerstone for establishing "best practice" uses.
  3. Characterize changes seen in future climate projections, using the new tools to link the changes and their uncertainties to specific climate change impacts and needs.
  4. Implement the new validation tools in the CESM diagnostics framework, where they can inform model development and enrich the model assessment through user-developed benchmarks.

A major hindrance in linking climate-change simulations with impacts on water- resource management is the differing perspectives of the modeling community, focused on globally important earth-system processes and feedbacks, and the water operations community, focused on local- scale processes specific to a region. The project will overcome this barrier through an extensive dialogue among the team members that identifies key decision information and how to extract it from an array of global and regional (downscaled) climate data available to the project. The effort will lead to new methods for integrating climate change science and data in water resource planning and operations and also new tools and benchmarks for assessing EaSM performance, useful for guiding model development.

This project is an initiative of the new Societal Dimensions Working Group of the NCAR Community Earth System Model. The Working Group seeks to engage climate scientists and climate-information users in a dialogue leading to more effective use of climate model output. The proposed work will develop user-applicable data and improve quality control by identifying important, sector-motivated indices of climate behavior and sources of uncertainty for sector applications. The project's dialogue will provide a prototype for interactions with other water managers and open avenues for those in other operational activities (e.g., energy utilities, transportation sector, health community) to engage in substantive interaction with climate modelers on climate-change information.

Source of funding: NSF EaSM2

Project duration: 2013-2018