21st century change in ocean response to climate forcing

TL;DR

This paper models the ocean's response to climate forcing using surface temperature data, revealing that recent deviations in SST are due to increased heat transfer into deeper ocean layers, not IPO phases.

Contribution

It introduces a model linking SST changes to heat diffusion, demonstrating consistent accuracy over the 20th century and identifying a shift in ocean behavior in the last 15 years.

Findings

Model accurately captures 20th-century SST variations

Recent SST decline linked to increased heat transfer to deep ocean

Slower recent warming not caused by IPO phases

Abstract

Modeling globally averaged information on climate forcing from the land surface temperature data, the sea surface temperatures (SST) and the empirically determined relationship between the changes in SST and the turbulent diffusion of heat into the upper ocean demonstrates a consistent link. The modeling is accurate throughout the 20th century despite the different phases of the Interdecadal Pacific Oscillation (IPO) or the strong divergence between land and ocean surface warming. It only fails during the last 15 years when SST drops well below the trend. The finding reinforces the view that slower global warming over the previous 15 years is not a caused by a negative phase of the IPO or by the variations in the upper ocean (top 700 m) warming but results from a change in the ocean behavior leading to increased heat transfer into the deeper ocean.