Can arctic sea ice summer melt be accelerated by changes in spring cloud properties
Sponsored Links
This presentation is the property of its rightful owner.
1 / 20

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


  • 73 Views
  • Uploaded on
  • Presentation posted in: General

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.

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


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


yes


surface radiative fluxes

atmosphere

Data: SHEBA Atmospheric

Surface Fluxes Group


February

March

April

Cloud phase and long-wave:

WINTER->SPRING


Cloud phase and long-wave:

SPRING->SUMMER

May

June

July


Cloud LW forcing (CFL) as a function of cloud properties

Chen, Aires, Francis, Miller, J Climate 2006


Liquid water path: data and models

Gorodetskaya et al, accepted to J Climate


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


Cloud cover over the Arctic Ocean:

- Spring: large positive trend

- Summer: no trend …

Schweiger, GRL 2004


April and May have the largest trends in both Cloud % and LW flux

R(LW,CLT)=0.6

TOVS


Changes in Arctic (white bars) annual mean sea ice extent at the end of the 21st century

Arzel, Fichefet, Goosse, Ocean Modelling 2006


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


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


Winter&SPRING!

increase in

cloud liquid

water path:

increase in

LW flux down:


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


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


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


Sea ice thickness change:


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


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


  • Login