Arctic Climate Change John C. Fyfe Canadian Centre for Climate Modelling and Analysis.

Arctic Climate Change

John C. Fyfe

Canadian Centre for ClimateModelling and Analysis

Questions

1. What is the scientific basis for Arctic amplification?

2. Is there a human influence on Arctic climate change?

3. How accurate are model projections of Arctic climate change?

Graversen et al. [2008]

Te

mp

era

ture

ano

mal

y (°

C)

Year

Arctic

Winter temperatures over land

NorthernHemisphere

Yang, Fyfe and Flato [2010]

°C p

er d

eca

de

(ver

tica

lly w

eig

hte

d)

Annual trends1991 to 2000

Linked to heat transport

Annual trends1991 to 2000

Linked to heat transport

°C p

er d

eca

de

(ver

tica

lly w

eig

hte

d)

Latitude

Lev

el (

hP

a)L

eve

l (h

Pa)

Yang, Fyfe and Flato [2010]

Screen and Simmonds [2010]

Lev

el (

hP

a)

Total trends Linked to sea ice

Winter temperature trends: 1989 to 2008

Summer moisture trends: 1989 to 2008

Total trends Linked to sea iceL

eve

l (h

Pa)

Screen and Simmonds [2010]

Sigmond and Fyfe [2010]

The Antarctic paradox: it’s sea ice is increasing

The ozone hole is linked to less, not more, sea ice!

Model sea ice change: 1979-2005

Gillett et al. [2008]

A human influence on Arctic warmingT

em

per

atu

re a

nom

aly

(°C

)

Year

OBS

ALL

NAT

A human influence on Arctic moistening

Min et al. [2008]

OBS ANT

ALL NAT

Arctic surface temperature projections

IPCC AR4 WG1 Report [2007]

Arctic sea ice extent projections

Boé and Hall [2009]

Bitz, Fyfe and Flato [2002]

April sea ice thickness (meters)

From observed winds From model winds

Contaminant pathways

Macdonald, Harner and Fyfe [2005]

A typical global climate model grid

IPCC AR4 WG1 Report [2007]

@Konrad Steffen

Jakobshavn Glacier

Holland et al. [2008]

Acceleration triggered by the arrival of warm ocean waters

Main messages

1. While our understanding of Arctic climate change is advancing some significant challenges remain

2. While climate models for the Arctic are continuing to improve some important shortcomings remain

Arctic Climate Change

John C. Fyfe

Canadian Centre for ClimateModelling and Analysis