Reconciling Estimates of Ocean Heating and Earth's Radiation Budget.

Purpose Of Review: The purpose of this review is to summarise the recent literature and scientific challenges on the topic of reconciling estimates of ocean heating rates with satellite-based monitoring of Earth's radiation budget (ERB), including discussion of the satellite record and in situ ocean observing system.

Recent Findings: State-of-the-art climate model simulations suggest that the global ocean becomes the dominant term the planetary heat budget on annual and longer timescales. Therefore, we expect to see a close correspondence between year-to-year variations in ocean heating rates and satellite measurements of ERB.

Multi-model attribution of upper-ocean temperature changes using an isothermal approach.

Both air-sea heat exchanges and changes in ocean advection have contributed to observed upper-ocean warming most evident in the late-twentieth century. However, it is predominantly via changes in air-sea heat fluxes that human-induced climate forcings, such as increasing greenhouse gases, and other natural factors such as volcanic aerosols, have influenced global ocean heat content. The present study builds on previous work using two different indicators of upper-ocean temperature changes for the detection of both anthropogenic and natural external climate forcings.

Earth's energy imbalance since 1960 in observations and CMIP5 models.

Unlabelled: Observational analyses of running 5 year ocean heat content trends () and net downward top of atmosphere radiation () are significantly correlated ( ∼ 0.6) from 1960 to 1999, but a spike in in the early 2000s is likely spurious since it is inconsistent with estimates of from both satellite observations and climate model simulations. Variations in between 1960 and 2000 were dominated by volcanic eruptions and are well simulated by the ensemble mean of coupled models from the Fifth Coupled Model Intercomparison Project (CMIP5).

Changes in global net radiative imbalance 1985-2012.

Combining satellite data, atmospheric reanalyses, and climate model simulations, variability in the net downward radiative flux imbalance at the top of Earth's atmosphere () is reconstructed and linked to recent climate change. Over the 1985-1999 period mean (0.34 ± 0.

Atlantic Meridional Overturning Circulation slowdown cooled the subtropical ocean.

[1] Observations show that the upper 2 km of the subtropical North Atlantic Ocean cooled throughout 2010 and remained cold until at least December 2011. We show that these cold anomalies are partly driven by anomalous air-sea exchange during the cold winters of 2009/2010 and 2010/2011 and, more surprisingly, by extreme interannual variability in the ocean's northward heat transport at 26.5°N.

Robust warming of the global upper ocean.

A large ( approximately 10(23) J) multi-decadal globally averaged warming signal in the upper 300 m of the world's oceans was reported roughly a decade ago and is attributed to warming associated with anthropogenic greenhouse gases. The majority of the Earth's total energy uptake during recent decades has occurred in the upper ocean, but the underlying uncertainties in ocean warming are unclear, limiting our ability to assess closure of sea-level budgets, the global radiation imbalance and climate models. For example, several teams have recently produced different multi-year estimates of the annually averaged global integral of upper-ocean heat content anomalies (hereafter OHCA curves) or, equivalently, the thermosteric sea-level rise.