"Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods" by Gerald A. Meehl, Julie M. Arblaster, John T. Fasullo, Aixue Hu and Kevin Trenberth, Nature Climate Change 1 (2011)

Nature Climate Change, 1 (2011) 360-364; doi: 10.1038/nclimate1229

Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods

Gerald A. Meehl, Julie M. Arblaster, John T. Fasullo, Aixue Hu and Kevin Trenberth

Abstract

There have been decades, such as 2000–2009, when the observed globally averaged surface-temperature time series shows little increase or even a slightly negative trend¹ (a hiatus period). However, the observed energy imbalance at the top-of-atmosphere for this recent decade indicates that a net energy flux into the climate system of about 1 W m⁻² (refs 2, 3) should be producing warming somewhere in the system^{4, 5}. Here we analyse twenty-first-century climate-model simulations that maintain a consistent radiative imbalance at the top-of-atmosphere of about 1 W m⁻² as observed for the past decade. Eight decades with a slightly negative global mean surface-temperature trend show that the ocean above 300 m takes up significantly less heat whereas the ocean below 300 m takes up significantly more, compared with non-hiatus decades. The model provides a plausible depiction of processes in the climate system causing the hiatus periods, and indicates that a hiatus period is a relatively common climate phenomenon and may be linked to La Niña-like conditions.

Received June 16, 2011; accepted August 30, 2011; published online September 18, 2011.

Link:  http://www.nature.com/nclimate/journal/v1/n7/full/nclimate1229.html