Identifying a pattern of predictable decadal North Pacific SST
variability in historical observations
Abstract
Improving predictions of decadal climate variability is critical for
reducing uncertainty in near-term climate change. Here we investigate
the potential to improve prediction skill in the North Pacific by
identifying predictable patterns of sea surface temperatures (SSTs) in
climate simulations, and then applying them to observations. A
convolutional neural network (CNN) is first trained to predict
basin-wide SSTs in the North Pacific on 1-5 year time-scales in nine
global climate models (GCMs), and a pattern of high skill is identified
from the GCM data. This pattern of high skill learned from GCMs is then
skillfully predicted by the CNN when given observations as inputs. The
identified pattern is notably not the Pacific Decadal Oscillation, and
instead corresponds to basinwide warming and cooling focused in the
North Pacific Gyre. We conclude that investigating the mechanisms that
contribute to predictability (rather than variability) is an effective
avenue for improving near-term climate predictions.