scholarly journals Arctic Oscillation responses to greenhouse warming and role of synoptic eddy feedback

2010 ◽  
Vol 115 (D17) ◽  
Author(s):  
Da-Hee Choi ◽  
Jong-Seong Kug ◽  
Won-Tae Kwon ◽  
Fei-Fei Jin ◽  
Hee-Jeong Baek ◽  
...  
Keyword(s):  
Arctic Oscillation ◽  
Greenhouse Warming ◽  
Synoptic Eddy

scholarly journals Methane, oxygen, photosynthesis, rubisco and the regulation of the air through time

2008 ◽  
Vol 363 (1504) ◽  
pp. 2745-2754 ◽  
Author(s):  
Euan G Nisbet ◽  
R. Ellen R Nisbet
Keyword(s):  
Greenhouse Gas ◽  
Greenhouse Warming ◽  
Biological Productivity ◽  
Stable States ◽  
Mixing Ratios ◽  
The Past ◽  
Glacial Epoch ◽  
Air Control ◽  
Carbon Gases

Rubisco I's specificity, which today may be almost perfectly tuned to the task of cultivating the global garden, controlled the balance of carbon gases and O 2 in the Precambrian ocean and hence, by equilibration, in the air. Control of CO 2 and O 2 by rubisco I, coupled with CH 4 from methanogens, has for the past 2.9 Ga directed the global greenhouse warming, which maintains liquid oceans and sustains microbial ecology. Both rubisco compensation controls and the danger of greenhouse runaway (e.g. glaciation) put limits on biological productivity. Rubisco may sustain the air in either of two permissible stable states: either an anoxic system with greenhouse warming supported by both high methane mixing ratios as well as carbon dioxide, or an oxygen-rich system in which CO 2 largely fulfils the role of managing greenhouse gas, and in which methane is necessarily only a trace greenhouse gas, as is N 2 O. Transition from the anoxic to the oxic state risks glaciation. CO 2 build-up during a global snowball may be an essential precursor to a CO 2 -dominated greenhouse with high levels of atmospheric O 2 . Photosynthetic and greenhouse-controlling competitions between marine algae, cyanobacteria, and terrestrial C3 and C4 plants may collectively set the CO 2  : O 2 ratio of the modern atmosphere (last few million years ago in a mainly glacial epoch), maximizing the productivity close to rubisco compensation and glacial limits.

scholarly journals Role of synoptic eddy feedback on polar climate responses to the anthropogenic forcing

2010 ◽  
Vol 37 (14) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jong-Seong Kug ◽  
Da-Hee Choi ◽  
Fei-Fei Jin ◽  
Won-Tae Kwon ◽  
Hong-Li Ren
Keyword(s):  
Anthropogenic Forcing ◽  
Polar Climate ◽  
Synoptic Eddy ◽  
Climate Responses

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 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

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
Sign in / Sign up

Export Citation Format

Share Document