North Atlantic Surface Temperature Decrease

Climate science at a glance

• As the global climate warms, isolated cooling trends can still occur, driven by disruption of regional circulation patterns or natural variability.
• Cold and fresh surface and subsurface conditions in the north Atlantic are likely linked to weakening of the Gulf Stream System and unusual atmospheric patterns.
• From the winter of 2013–2014 to 2016, there was a large region of persistently low surface temperatures accompanied by a sharp reduction in ocean heat content in the North Atlantic. The low temperatures in the North Atlantic occurred during a record hot year globally. This event is an area of active research.

North Atlantic temperature trends and climate change

• (Josey et al. 2018): Cold ocean temperature anomalies have been observed in the mid- to high-latitude North Atlantic on interannual to centennial timescales. Air-sea interactions, and anomalous weather patterns, are contributing to this cold anomaly.
• (Smeed et al. 2018): Cold and fresh surface and subsurface conditions in the north Atlantic are linked to weakened transport by the north Atlantic Current and AMOC.[3]
• (IPCC, SROCC, 2019): "Recent relatively cold and fresh surface and subsurface conditions in the north Atlantic have been attributed to anomalous atmospheric forcing or weakened transport by the north Atlantic Current and AMOC, and in turn may have contributed to an intensification of deep convection in the Labrador Sea since 2012."
• (IPCC, AR5, 2013): Such contributions to decreased density of the ocean surface layer in the North Atlantic could act to reduce deep ocean convection there and contribute to a near-term reduction of strength of Atlantic Meridional Ocean Circulation (AMOC). However, the strength of the AMOC can also be modulated by changes in temperature, such as those from changing radiative flux.”[1][2]