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Climate change and the cryosphere
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Outline
• Background, climatology & variability• Role of snow in the global climate system• Contemporary observations of climate change • Cryospheric indicators of climate change• Future global & regional projections &
implications of climate change
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Background, climatology & variability
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20th Century ClimatologyObserved GFDL
Ref: Masuda
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Current snow
coverage
1 April 2013
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Departure from
average
1 April 2013
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Seasonal climatology
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Observed & GFDL Northern Hemisphere Snow Extent (x106 km2), 1973-2000
Season OBS GFDL MAE RMSE
Winter 44 42 2.4 0.55
Spring 30 35 4.8 1.00
Summer 6 4 2.3 0.51
Fall 19 20 1.7 0.40
Annual 25 25 0.9 0.22
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Mean annual maximum
monthly snow water
equivalent (mm) in
Canada, 1980-1997
(Brown et al. 2003)
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Current SWE in the Prairies
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Monthly Eurasian standardized snow cover extent anomalies
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Interannual variability
Source: Karl et al. (1993).
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Role of snow in the global climate system
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Annual cycle of daily discharge in Skeena River (1955-2004)
freshet
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Contribution of snow to river runoff
Source: Barnett et al. (2005).
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Teleconnections
Definition: Atmospheric interactions between widely separated regions that have been identified through statistical correlations (in space and time). For example, the El Niño teleconnection with the Southwest United States involves large-scale changes in climatic conditions that are linked to increased winter rainfall.
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Correlation coefficient between annual Eurasian snow extent anomalies & discharge anomalies
the following year in 64 rivers of northern Canada
Source: Déry et al. (2005), JGR.
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Observed 20th century climate change
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Warming air temperatures
Climatic Research Unit, University of East Anglia, http://www.cru.uea.ac.uk/
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20th century climate & trends
Reference: Déry and Wood (2005)
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Trends in global surface air temperature
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Trends in global surface precipitation
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Cryospheric indicators of global change
• Snow depth, swe, density, albedo & temperature (heat content)
• Duration of snow cover & growing season
• Snowmelt/spring freshet date
• Soil moisture
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Snow depth
Source: Curtis et al. (1998), Int. J.
Climatology
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Annual cycle of daily snow accumulation (SWE) at Barkerville
0
50100
150200
250300
350400
450
Date
Aver
age
annu
al c
ycle
of
dail
y SW
E (m
m)
1971-1977 1996-2005
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Trend (%) in April 1st swe, 1950-
1997
Source: Mote et al. (2005), BAMS
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Albedo
Source: Stone et al. (2002), JGR.
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Trend (days/year)
in snow cover
duration, 1972-2000
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Snowmelt Date
Source: Stone et al. (2002), JGR.
34Reference: Déry and Brown (2007)
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Annual cycle of daily runoff for the Little Swift River near Barkerville
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Trend in centre of volume in river discharge across western N. America
Source: Stewart et al. (2005), J. Climate.
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Future projections & implications of global change
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Components of the climate system
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IPC
C 4th A
ssessment
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IPCC 4th Assessment
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Expected indicators of climate change
IPCC 3rd Assessment
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IPCC 4th Assessment
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IPCC 4th Assessment
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IPCC 4th Assessment Runs
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Trends in Northern Hemisphere snow cover extent
Source: Déry et al. (2006), JGR.
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Projected change in seasonal snow cover frequency based on GFDL
CM2 simulations (21st - 20th century)
Projected change in frequency-0
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Trends in Northern Hemisphere snow mass
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Projected change in seasonal snow water equivalent (swe) based on
GFDL CM2 simulations (21st - 20th century)
Projected change in swe (mm)
-1
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Regional climate (baseline)
• Source: PCIC (http://www.pcic.uvic.ca)
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Temperature Projections
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Precipitation projections
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Regional Projections for snow
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Implications of global change
• Increase in planetary albedo (positive feedback on global warming)
• Decreasing water resources, including soil moisture
• Longer growing season
• Impacts on recreational activities
• Ecological implications
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Further reading:
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Points of Discussion:
• Which component of the cryosphere is most vulnerable to climate change?
• What are the possible environmental impacts of climate change in Prince George, B.C., Canada?
• Will there be any jobs for cryospheric scientists in the 21st century?
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