Week 12: Climate change and the cryosphere

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Climate change and the cryosphere
1
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 &
2
implications of climate change
Background, climatology & variability
3
20th Century Climatology
Observed
Ref: Masuda
GFDL
4
Current
snow
coverage
5
1 April 2013
Departure
from
average
6
1 April 2013
Seasonal
climatology
7
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
8
Mean annual
maximum
monthly snow
water
equivalent
(mm) in
Canada, 19801997
(Brown et al.
2003)
9
Current SWE in the Prairies
10
Monthly Eurasian standardized snow cover
extent anomalies
11
Interannual variability
12
Source: Karl et al. (1993).
Role of snow in the global climate
system
13
Annual cycle of daily discharge in
Skeena River (1955-2004)
freshet
14
Contribution of snow to river runoff
15
Source: Barnett et al. (2005).
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.
16
17
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.
18
Observed 20th century climate
change
19
Warming air temperatures
Climatic Research Unit, University of East Anglia, http://www.cru.uea.ac.uk/
20
20th century climate & trends
Reference: Déry and Wood (2005)
21
Trends in global surface air temperature
22
Trends in global surface precipitation
23
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
24
Snow depth
Source: Curtis et
al. (1998), Int. J.
Climatology
25
26
Se
p.
1
Oc
t.
1
Oc
t.
31
No
v.
30
De
c.
30
Ja
n.
29
Fe
b.
28
Ma
r.
29
Ap
r.
28
Ma
y.
28
Ju
n.
27
Ju
l.
27
Au
g.
26
Average annual cycle of daily
SWE (mm)
Annual cycle of daily snow
accumulation (SWE) at Barkerville
1971-1977
1996-2005
450
400
350
300
250
200
150
100
50
0
Date
27
28
Trend (%)
in April 1st
swe, 19501997
Source: Mote et al.
(2005), BAMS
29
Albedo
Source: Stone et al. (2002), JGR.
30
Trend
(days/year)
in snow
cover
duration,
1972-2000
31
32
Snowmelt
Date
Source: Stone et al. (2002), JGR.
33
Reference: Déry and Brown (2007)
34
Annual cycle of daily runoff for the
Little Swift River near Barkerville
35
Trend in centre of volume in river
discharge across western N. America
36
Source: Stewart et al. (2005), J. Climate.
Future projections & implications of
global change
37
Components of the climate system
38
IPCC 4th Assessment
39
40
IPCC 4th Assessment
Expected
indicators
of climate
change
IPCC 3rd Assessment
41
42
IPCC 4th Assessment
43
IPCC 4th Assessment
IPCC 4th Assessment Runs
44
Trends in Northern Hemisphere snow cover extent
Source: Déry et al. (2006), JGR.
45
Projected change
in seasonal snow
cover frequency
based on GFDL
CM2 simulations
(21st - 20th
century)
46
-0
Projected change in frequency
Trends in Northern Hemisphere snow mass
47
Projected change
in seasonal snow
water equivalent
(swe) based on
GFDL CM2
simulations
(21st - 20th
century)
-1
48
Projected change in swe (mm)
49
Regional climate (baseline)
• Source: PCIC (http://www.pcic.uvic.ca)
50
Temperature Projections
51
Precipitation projections
52
Regional
Projections
for snow
53
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
54
Further reading:
55
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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