Arctic Ocean Amplification in a warming climate in CMIP6 models

Area of Science:

• Climate Science
• Oceanography
• Arctic Studies

Background:

• Arctic Amplification describes faster warming of near-surface air temperatures compared to the global average.
• The Arctic Ocean's role in climate change, particularly its interaction with sea ice, atmosphere, and global ocean, is not fully understood.

Purpose of the Study:

• To investigate and quantify the warming rate of the Arctic Ocean.
• To identify the primary drivers of observed Arctic Ocean warming.
• To assess the future susceptibility of the Arctic region to climate change.

Main Methods:

• Utilized data from the Coupled Model Intercomparison Project Phase 6 (CMIP6).
• Analyzed the Shared Socioeconomic Pathway 585 (SSP585) scenario.
• Calculated the warming rate of the upper 2000 m of the Arctic Ocean over the 21st century.

Main Results:

• The upper 2000 m of the Arctic Ocean is warming at 2.3 times the global mean rate for the same depth range.
• This phenomenon is termed "Arctic Ocean Amplification."
• Amplified warming is driven by increased poleward ocean heat transport, exceeding sea surface heat loss.

Conclusions:

• The Arctic Ocean is experiencing amplified warming, mirroring atmospheric Arctic Amplification.
• Increased ocean heat transport is the main driver of Arctic Ocean Amplification.
• The Arctic region, encompassing both atmosphere and ocean, is exceptionally vulnerable to ongoing climate change.