scholarly journals The role of stratospheric resolution in simulating the Arctic Oscillation response to greenhouse gases

2002 ◽  
Vol 29 (10) ◽  
pp. 138-1-138-4 ◽  
Author(s):  
Nathan P. Gillett ◽  
Myles R. Allen ◽  
Keith D. Williams
Keyword(s):  
Greenhouse Gases ◽  
Arctic Oscillation ◽  
The Arctic ◽  
The Arctic Oscillation

Internal variability of the Arctic Oscillation and its projections

2020 ◽  
Author(s):  
Annalisa Cherchi ◽  
Paolo Oliveri ◽  
Aarnout van Delden
Keyword(s):  
Northern Hemisphere ◽  
Arctic Oscillation ◽  
Internal Variability ◽  
The Arctic ◽  
Positive Phase ◽  
Cmip5 Models ◽  
Modes Of Variability ◽  
The Future ◽  
The Arctic Oscillation

<p>The Arctic Oscillation (AO) is one of the main modes of variability of the Northern Hemisphere winter, also referred as Northern Annular Mode (NAM). The positive phase of the AO is characterized by warming/cooling over Northern Eurasia and the United States and cooling over Canada, especially over eastern Canada. Its positive phase is also characterized by very dry conditions over the Mediterranean and wet conditions over Northern Europe. A positive trend of the AO is observed for the period 1951-2011 and it is captured in CMIP5 models only when GHG-only forcing are included. In CMIP5 models the change expected is mostly mitigated by the effects of the aerosols. When considering AR5 scenarios, the AO is projected to become more positive in the future, though with a large spread among the models.</p><p>Overall the spread in the representation of the AO variability and trend is large also in experiments with present-day conditions, likely associated with the large internal variability. Unique tools to identify and measure the role of the internal variability in the model representation of the large-scale modes of variability are large ensembles where multiple members are built with different initial conditions.</p><p>Here we use the NCAR Community Model Large Ensemble (CESM-LE) composing the historical period (1920-2005) to the future (2006-2100) in a RCP8.5 scenario to measure the role of the internal variability in shaping AO variability and changes. Potential predictability of the AO index is quantified in the historical and future periods, evidencing how the members spread remain large without specific trends in these characteristics. Preliminary results indicate that the internal variability has large influence on the AO changes and related implications for the Northern Hemisphere climate.</p>

scholarly journals A strong phase reversal of the Arctic Oscillation in midwinter 2015/2016: Role of the stratospheric polar vortex and tropospheric blocking

2016 ◽  
Vol 121 (22) ◽  
pp. 13,443-13,457 ◽  
Author(s):  
Hoffman H. N. Cheung ◽  
Wen Zhou ◽  
Marco Y. T. Leung ◽  
C. M. Shun ◽  
S. M. Lee ◽  
...  
Keyword(s):  
Arctic Oscillation ◽  
Polar Vortex ◽  
The Arctic ◽  
Stratospheric Polar Vortex ◽  
Strong Phase ◽  
Phase Reversal ◽  
The Arctic Oscillation

scholarly journals Changes in the Arctic Oscillation under increased atmospheric greenhouse gases

2007 ◽  
Vol 34 (12) ◽  
Author(s):  
Aiming Wu ◽  
William W. Hsieh ◽  
George J. Boer ◽  
Francis W. Zwiers
Keyword(s):  
Greenhouse Gases ◽  
Arctic Oscillation ◽  
The Arctic ◽  
The Arctic Oscillation

scholarly journals Volcanic activity sparks the Arctic Oscillation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weizheng Qu ◽  
Fei Huang ◽  
Jinping Zhao ◽  
Ling Du ◽  
Yong Cao
Keyword(s):  
Volcanic Activity ◽  
Volcanic Eruption ◽  
Arctic Oscillation ◽  
Polar Vortex ◽  
Volcanic Eruptions ◽  
The Arctic ◽  
Vortex System ◽  
Significant Fluctuation ◽  
The Arctic Oscillation

AbstractThe parasol effect of volcanic dust and aerosol caused by volcanic eruption results in the deepening and strengthening of the Arctic vortex system, thus stimulating or strengthening the Arctic Oscillation (AO). Three of the strongest AOs in more than a century have been linked to volcanic eruptions. Every significant fluctuation of the AO index (AOI = ΔH_middle latitudes − ΔH_Arctic) for many years has been associated with a volcanic eruption. Volcanic activity occurring at different locations in the Arctic vortex circulation will exert different effects on the polar vortex.

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