Optimizing Seasonal‐To‐Decadal Analog Forecasts With a Learned Spatially‐Weighted Mask

Journal Article · 29 November 2023 · Geophysical Research Letters

DOI: https://doi.org/10.1029/2023GL104983 · OSTI ID:2223010

Rader, Jamin K.  ^[1]; Barnes, Elizabeth A.  ^[1]

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1. Department of Atmospheric Science Colorado State University Fort Collins CO USA

Abstract Seasonal‐to‐decadal climate prediction is crucial for decision‐making in a number of industries, but forecasts on these timescales have limited skill. Here, we develop a data‐driven method for selecting optimal analogs for seasonal‐to‐decadal analog forecasting. Using an interpretable neural network, we learn a spatially‐weighted mask that quantifies how important each grid point is for determining whether two climate states will evolve similarly. We show that analogs selected using this weighted mask provide more skillful forecasts than analogs that are selected using traditional spatially‐uniform methods. This method is tested on two prediction problems using the Max Planck Institute for Meteorology Grand Ensemble: multi‐year prediction of North Atlantic sea surface temperatures, and seasonal prediction of El Niño Southern Oscillation. This work demonstrates a methodical approach to selecting analogs that may be useful for improving seasonal‐to‐decadal forecasts and understanding their sources of skill.

• Sponsoring Organization: USDOE
• Grant/Contract Number: NONE; SC0020347
• OSTI ID: 2223010
• Alternate ID(s): OSTI ID: 2223012
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 23 Vol. 50; ISSN 0094-8276
• Publisher: American Geophysical Union (AGU)Copyright Statement
• Country of Publication: United States
• Language: English