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A recent pause in Antarctic Peninsula warming
https://www.bas.ac.uk/media-post/a-recent-pause-in-antarctic-peninsula-warming/[font face=Serif][font size=5]A recent pause in Antarctic Peninsula warming[/font]
20 July, 2016
[font size=4]The rapid warming of the Antarctic Peninsula, which occurred from the early-1950s to the late 1990s, has paused. Stabilisation of the ozone hole along with natural climate variability were significant in bringing about the change. Together these influences have now caused the northern part of the peninsula to enter a temporary cooling phase. Temperatures remain higher than measured during the middle of the 20th Century and glacial retreat is still taking place. However, scientists predict that if greenhouse gas concentrations continue to rise at the current rate, temperatures will increase across the Antarctic Peninsula by several degrees Centigrade by the end of this century.[/font]
[font size=3]Reporting this week (Wednesday 20 July) in the journal Nature researchers from British Antarctic Survey (BAS) describe how the stabilisation of the ozone hole and changing wind patterns has driven a regional cooling phase that is temporarily masking the warming influence of greenhouse gases.
…
A wide range of climate data was analysed for this study, including atmospheric circulation fields, sea-ice records, ocean surface temperatures and meteorological observations from six Antarctic Peninsula research stations with near-continuous records extending back to the 1950s.
During the Twentieth Century, Antarctic Peninsula temperatures increased by up to 0.5⁰ C per decade, helping to trigger the dramatic collapse of ice shelves and causing many glaciers to retreat. Whilst there was a decrease in sea ice extent around the Antarctic Peninsula towards the end of the last century it has been increasing in recent years, particularly in the north-east of the region. The cold easterly winds observed in the 21st Century have had a greater impact on the region because the sea ice has prevented ocean heat from entering the atmosphere.
To set their observations in a longer-term context, the research team looked at a 2,000 year climate reconstruction using the chemical signals in ice cores. As previously reported, analysis suggests that peninsula warming over the whole twentieth century was unusual, but not unprecedented in the context of the past 2,000 years. The reconstruction shows a warming starting in the 1920s, which is consistent with the warming trends recorded by the meteorological stations. The ice core records also reveal periods of warming and cooling over the last several centuries that were comparable to those observed in the post-1950s instrumental record. This highlights the large natural variability of temperatures in this region of Antarctica that has influenced more recent climate changes.
…[/font][/font]
http://dx.doi.org/10.1038/nature1864520 July, 2016
[font size=4]The rapid warming of the Antarctic Peninsula, which occurred from the early-1950s to the late 1990s, has paused. Stabilisation of the ozone hole along with natural climate variability were significant in bringing about the change. Together these influences have now caused the northern part of the peninsula to enter a temporary cooling phase. Temperatures remain higher than measured during the middle of the 20th Century and glacial retreat is still taking place. However, scientists predict that if greenhouse gas concentrations continue to rise at the current rate, temperatures will increase across the Antarctic Peninsula by several degrees Centigrade by the end of this century.[/font]
[font size=3]Reporting this week (Wednesday 20 July) in the journal Nature researchers from British Antarctic Survey (BAS) describe how the stabilisation of the ozone hole and changing wind patterns has driven a regional cooling phase that is temporarily masking the warming influence of greenhouse gases.
…
A wide range of climate data was analysed for this study, including atmospheric circulation fields, sea-ice records, ocean surface temperatures and meteorological observations from six Antarctic Peninsula research stations with near-continuous records extending back to the 1950s.
During the Twentieth Century, Antarctic Peninsula temperatures increased by up to 0.5⁰ C per decade, helping to trigger the dramatic collapse of ice shelves and causing many glaciers to retreat. Whilst there was a decrease in sea ice extent around the Antarctic Peninsula towards the end of the last century it has been increasing in recent years, particularly in the north-east of the region. The cold easterly winds observed in the 21st Century have had a greater impact on the region because the sea ice has prevented ocean heat from entering the atmosphere.
To set their observations in a longer-term context, the research team looked at a 2,000 year climate reconstruction using the chemical signals in ice cores. As previously reported, analysis suggests that peninsula warming over the whole twentieth century was unusual, but not unprecedented in the context of the past 2,000 years. The reconstruction shows a warming starting in the 1920s, which is consistent with the warming trends recorded by the meteorological stations. The ice core records also reveal periods of warming and cooling over the last several centuries that were comparable to those observed in the post-1950s instrumental record. This highlights the large natural variability of temperatures in this region of Antarctica that has influenced more recent climate changes.
…[/font][/font]