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Arctic Amplification

Arctic Amplification. Nick Sakian Atmospheric Sciences Program Graduate Student. We were warned about this 118 years ago!. Svante Arrhenius (1859-1927) Physicist and chemist Acid-base theory, ions, CO 2 1903 Nobel Prize in Chemistry Arrhenius Equation.

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Arctic Amplification

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  1. Arctic Amplification Nick Sakian Atmospheric Sciences Program Graduate Student

  2. We were warned about this 118 years ago! • Svante Arrhenius (1859-1927) • Physicist and chemist • Acid-base theory, ions, CO2 • 1903 Nobel Prize in Chemistry • Arrhenius Equation

  3. Decreasing snow + ice amplifies warming Arrhenius, S., 1896

  4. Why should we care? Equator-pole temp gradient reduction from Arctic ice melt https://www.youtube.com/watch?v=RJ0LGTTSE4Y

  5. Now, the actual authors • Mark C. Serreze • Univ. of Colorado at Boulder • Director of the National Snow and Ice Data Center (NSIDC) • Roger G. Berry • Also U. Co. Boulder • Director of the International Climate Variability and Predictability (CLIVAR) Project Office • Scientist at NSIDC

  6. Seasonal variability

  7. Past observations indicate that higher latitudes are warming faster • C.E.P. Brooks: Spitzbergen vs. western & central Europe • Callendar: less warming but considered CO2 • Other studies: warmer in winter and spring, NAO and regional changes • Periods of amplified warming and cooling in 70-90°N

  8. Causes of Arctic Amplification According to S&B • Vertical heat flux • Poleward energy transport and convergence • Cloud and water vapor feedbacks • Aerosol feedback Ice Albedo Feedback

  9. Land and oceans absorb more shortwave radiation when they have less snow & ice cover Significant increase in NSF (Net Surface Flux)

  10. Ice albedo & vertical heat flux • Less sea ice = more heat absorbed (NSF) by oceans in spring and summer • Warmer, more open ocean = more heat transfer from the ocean to the atmosphere in autumn and winter (the low sun seasons)

  11. Horizontal heat flux convergence • ECMWF ERA-40 reanalysis • Most warming around 700mb level, implying factors other than ice albedo feedback • Reanalysis of satellite data for poleward energy transport, 1979-2008 • 50% of warming • 71% for winter • AMO

  12. Cloud feedback Low latitudes: sun is higher, so more low clouds would have cooling effect

  13. Water vapor & albedo feedback • Experiment showed increasing CO2 increased water vapor and cloud cover • Albedo effect increases amplification by 15% • More open ocean allows more evaporation and cloud cover

  14. Amplification in paleoclimates • Milankovitchcycles • Variability of insolation

  15. My Summery Summary • Albedo effect and interactions with other effects • Changes in jet stream patterns and NAO • Antarctica: warming in the west, but future warming will be subtle • Arctic: greater amplification, seasonal dependence, longer and faster melting

  16. Question Me Climate Change: Arctic warming pushes winter weather further south https://www.youtube.com/watch?v=HBlLP6KTrsE

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