Title: Characterizing the Relative Importance Assigned to Physical Variables by Climate Scientists when Assessing Atmospheric Climate Model Fidelity

Abstract

Evaluating a climate model’s fidelity (ability to simulate observed climate) is a critical step in establishing confidence in the model’s suitability for future climate projections, and in tuning climate model parameters. Model developers use their judgement in determining which trade-offs between different aspects of model fidelity are acceptable. However, little is known about the degree of consensus in these evaluations, and whether experts use the same criteria when different scientific objectives are defined. Here, we report on results from a broad community survey studying expert assessments of the relative importance of different output variables when evaluating a global atmospheric model’s mean climate. We find that experts adjust their ratings of variable importance in response to the scientific objective, for instance, scientists rate surface wind stress as significantly more important for Southern Ocean climate than for the water cycle in the Asian watershed. There is greater consensus on the importance of certain variables (e.g., shortwave cloud forcing) than others (e.g., aerosol optical depth). We find few differences in expert consensus between respondents with greater or less climate modeling experience, and no statistically significant differences between the responses of climate model developers and users. In conclusion, the concise variable lists and communitymore » ratings reported here provide baseline descriptive data on current expert understanding of certain aspects of model evaluation, and can serve as a starting point for further investigation, as well as developing more sophisticated evaluation and scoring criteria with respect to specific scientific objectives.« less

Authors:

Burrows, Susannah M. ^[1]; Dasgupta, Aritra ^[1]; Reehl, Sarah ^[1]; Bramer, Lisa ^[1]; Ma, Po -Lun ^[1]; Rasch, Philip J. ^[1]; Qian, Yun ^[1]

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+ Show Author Affiliations

1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Publication Date:

2018-07-05

Research Org.:

Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1459662

Alternate Identifier(s):

OSTI ID: 1510431

Report Number(s):

PNNL-SA-129346
Journal ID: ISSN 0256-1530; PII: 7300

Grant/Contract Number:  

AC05-76RL01830

Resource Type:

Accepted Manuscript

Journal Name:

Advances in Atmospheric Sciences

Additional Journal Information:

Journal Volume: 35; Journal Issue: 9; Journal ID: ISSN 0256-1530

Publisher:

Springer

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; climate; climate model; model evaluation; numerical model skill; expert elicitation