Abstract:
Although anthropogenic global warming is the main driver of the recent Artic warming, internal climate variability is a major contributor. Here we show that Atlantic multi-decadal variability is an important driver of the two most recent major Arctic warming events.
The early 20th century Arctic warming, comparable to the recent warming, provides a baseline for natural climate variability. Using a new physically based sea ice reconstruction and atmospheric model experiments, we show that two-thirds of the winter warming during this period was driven by increased ocean heat release, amplified further by the lapse-rate feedback. This is linked to the extensive sea ice loss, present in the new reconstruction, and enhanced poleward heat transport from the Atlantic.
For the recent warming, we focus on Northeastern Canada and western Greenland (NCWG), as this region shows has warmed much faster than the rest of the Arctic. Multi-model coordinated atmospheric model simulations show that this warming is largely driven by local SST and sea-ice changes associated with Atlantic multi-decadal variability. In total, we find about half of the warming of NCWG could result from internal climate dynamics.
Considering that Atlantic multi-decadal variability may be shifting towards its negative phase, our finding suggest that we may see suppression of warming and potentially even cooling trends in the Arctic, including Greenland over the next decade.
What is the Joint Oslo Seminar (JOS):
- Atmospheric and climate sciences have a stronghold in Oslo among the four institutions University of Oslo, the Meteorological Institute, CICERO and NILU.
- This joint seminar invites renowned international experts to contribute to an informal series of lectures, meant to create interaction with the Oslo atmospheric and climate science community on recent highlights and analysis in the field.
- Normally seminars will be held on Thursdays (12:15 pm -1pm).