1 / 20

Can Arctic Sea Ice Summer Melt be Accelerated by Changes in Spring Cloud Properties?

Can Arctic Sea Ice Summer Melt be Accelerated by Changes in Spring Cloud Properties?. I. Gorodetskaya 1 , B. Tremblay 1,2 , B. Liepert 1 , M. Cane 1. 1 Lamont-Doherty Earth Observatory, New York. 2 McGill University, Montreal. yes. surface radiative fluxes. atmosphere.

kaiya
Download Presentation

Can Arctic Sea Ice Summer Melt be Accelerated by Changes in Spring Cloud Properties?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Can Arctic Sea Ice Summer Melt be Accelerated by Changes in Spring Cloud Properties? I. Gorodetskaya1, B. Tremblay1,2, B. Liepert1, M. Cane1 1Lamont-Doherty Earth Observatory, New York 2McGill University, Montreal

  2. yes

  3. surface radiative fluxes atmosphere Data: SHEBA Atmospheric Surface Fluxes Group

  4. February March April Cloud phase and long-wave: WINTER->SPRING

  5. Cloud phase and long-wave: SPRING->SUMMER May June July

  6. Cloud LW forcing (CFL) as a function of cloud properties Chen, Aires, Francis, Miller, J Climate 2006

  7. Liquid water path: data and models Gorodetskaya et al, accepted to J Climate

  8. Total variance in the perennial ice edge attributable to anomalies in forcing parameters, 1980-2004 J. A. Francis and E Hunter also see: Francis, Hunter, Key, Wang, JRL 2005

  9. Cloud cover over the Arctic Ocean: - Spring: large positive trend - Summer: no trend … Schweiger, GRL 2004

  10. April and May have the largest trends in both Cloud % and LW flux R(LW,CLT)=0.6 TOVS

  11. Changes in Arctic (white bars) annual mean sea ice extent at the end of the 21st century Arzel, Fichefet, Goosse, Ocean Modelling 2006

  12. CCSM3: predicts a large increase in the Arctic annual mean downwelling LW flux in the 21st century

  13. CCSM3: predicts a large increase in the Arctic annual mean downwelling LW flux in the 21st century

  14. Winter&SPRING! increase in cloud liquid water path: increase in LW flux down:

  15. Total downwelling fluxdifference between the last and first decades of 21st century

  16. 0-layer thermodynamics model: sea ice thickness and concentration evolution Ta - from NP drifting stations (Lindsay, J Climate 1998) LW, SW LW, SW, Fsens, Flat Fsens(Ta-Ti), Flat Ti Fc ice: A,h Tb=-1.8

  17. Scale the forcing with the CCSM-predicted changes in downwelling LW and SW fluxes

  18. Sea ice thickness change:

  19. conclusions and outlook • Clouds increase: Apr 21%, May 12% (1980-2004) => Arctic Ocean gains ~15 W/m2 more LW radiation (TOVS data) • NCAR CCSM3: • Arctic - more liquid clouds in 2xCO2 world • spring cloud LW warming overwhelms SW cooling • with the above cloud response alone (LW forcing strongest in winter and spring), a 1D ice model reduces an equilibrium sea ice thickness from 4.5 to 2.5 m • positive feedbacks not included! e.g., snow(T) -> surface albedo

  20. Photo from Peter Minnett Arctic Sea Ice Summer Melt can be accelerated by an increase inSpring cloud liquid water path... Big Thanks: Yonghua Chen, Jennifer Francis, Kirstie Stramler, Martin Vancoppenolle, Richard Cullather

More Related