Facts for Prelims (FFP)
Source: The Print
Context: A recent study has identified the cause of the decline in Arctic Ocean Sea ice since 2007. Researchers found that the periodic reversal of an atmospheric phenomenon known as the Arctic dipole plays a significant role in driving drops in sea ice.
- The study, published in the journal Science, explores the ecosystem responses to the Arctic dipole and its impact on the Arctic Ocean climate, a phenomenon referred to as Atlantification.
- The Arctic dipole follows a roughly 15-year cycle, and data spanning several decades suggest that it is approaching the end of its current regime.
- The current “positive” phase of the Arctic dipole, which has been in place since 2007, involves high pressure over the Canadian Arctic and low pressure over the Siberian Arctic.
- This wind pattern drives upper ocean currents and has year-round impacts on air temperatures, heat exchanges, sea-ice drift, and ecological consequences.
Significance:
- The study highlights the importance of water exchanges between the Nordic seas and the Arctic Ocean for the Arctic climate system, with sea ice decline serving as a significant indicator of climate change.
- Researchers observed changes in Atlantic water flow into the Arctic Ocean, including decreased flow through the Fram Strait and increased flow into the Barents Sea, which they referred to as a “switchgear mechanism” driven by the Arctic dipole.
- This change in water flow has had a significant impact on sea ice loss, slowing it down from 2007 to 2021.
- The study also notes that these changes in water inflow have profound effects on marine life, creating more favourable conditions for sub-Arctic boreal species in certain areas.
