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PRESENTATION OUTLINE1. Validation of proposed mean annual air
temperature (MAAT) value for the site
2. Overview of permafrost assessment work
3. Relationship of ground temperatures to air temperatures
4. Introduction to climate change and global warming
5. Global warming model estimates
6. Conclusions
1. MAAT VALUE FOR SITE
• Few definitions to review
• Nearby long term climate stations
• Review MAAT values from those stations
• Add mine site weather stations (slightly shorter term)
• Rationalize MAAT versus latitude
CLIMATE - DEFINITION• Climate, in a narrow sense, is usually
defined as the “average weather”.• “Climate is what you expect, weather is
what you get.”• More rigorously, as the statistical
description in terms of the mean and variability of relevant quantities, over an appropriate period of time.
• The classical time period is 30 years, as defined by the World Meteorological Organization (WMO).
• Long period to account for climate cycles.
MAAT - DEFINITION• Mean annual air temperature value is for
either one specific year (e.g. 2007) or for period of record (e.g. 1971 to 2000).
• One single temperature parameter used to define the climate of an area.
• Used to define the mean and the ranges of the expected temperature.
• Used in climate, geography and permafrost work as opposed to annual ground temperatures.
REASONABLE - DEFINITION
1. Capable of reasoning; rational: a reasonable person.
2. Governed by or being in accordance with reason or sound thinking: a reasonable solution to the problem.
3. Being within the bounds of common sense: arrive home at a reasonable hour.
4. Not excessive or extreme; fair: reasonable prices.
PROXIMAL MAAT VALUES
Station Name Distance and Direction from
High Lake
Period of Record
MAAT
Cambridge Bay 300 km NE 1929-recent -14.7oC
Coppermine 200 km WNW 1933-1977 -11.4oC
Kugluktuk 200 km WNW 1978-recent(29 years)
-10.4oC
Contwoyto Lake (65.48oN)
280 km S 1959-1981 -11.9oC
Lupin (65.76oN) 200 km S 1982-recent(25 years)
-11.0oC
MAAT vs. LATITUDE
60
62
64
66
68
70
-16-14-12-10-8-6-4-2
MAAT (oC)
La
titu
de
(oN
)
Yellowknife A
Cambridge Bay
Snap Lake
Ekati
Kugluktuk
Lupin
Notes1. Most MAAT values based on 1971 to 2000 Canadian Climate Normals, except for individual mine sites.2. Kugluktuk and Cambridge Bap stations are located proximal to major water bodies (Coronation and Queen Maud Gulfs).
High Lake '04-'05
Ulu '04-'05
Fu
rth
er
No
rth
Getting Colder
-9.3oC
RWDI
-11.8oC
MAAT CONCLUSION• Based on interpolation/extrapolation of
nearby long-term climate station, a MAAT value of -11.8oC for the High Lake site appears reasonable.
• Any warmer value is not scientifically defensible and does not appear reasonable from data trends.
PRESENTATION OUTLINE1. Validation of proposed mean annual air
temperature (MAAT) value for the site
2. Overview of permafrost assessment work
3. Relationship of ground temperatures to air temperatures
4. Introduction to climate change and global warming
5. Global warming estimates
6. Conclusions
2. PERMAFROST WORK
• Two definitions to start
• Thermistor locations
• Results – both deep and shallow
DEFINITIONS• Permafrost is ground
that remains below 0oC for at least two years.
• Definition is purely thermal – no commentary on “frozen” nature or on ground ice content.
• Permafrost types – sporadic, discontinuous and continuous.
DEFINITIONS
• Talik – unfrozen zone within continuous permafrost. Usually caused by water bodies (heat source).
• Closed, open and through types.
RESULTS• Permafrost is 440 m deep (measured at
the West Zone).• In the associated talik modeling, mean
annual ground temperature of -7oC matched permafrost depth and measured geothermal gradient at depth.
• Estimated mean annual ground temperatures of -6oC found for the site.
• Ground temperatures (10 to 25 m depth) of -4o to -5oC under three dams. Also found -3.5o to -4oC under two dams directly beside water.
PRESENTATION OUTLINE1. Validation of proposed mean annual air
temperature (MAAT) value for the site
2. Overview of permafrost assessment work
3. Relationship of ground temperatures to air temperatures
4. Introduction to climate change and global warming
5. Global warming estimates
6. Conclusions
3. GROUND TO AIR TEMPS
• Offset from air to ground temperatures
• Impact of nearby water bodies
• Validation of site ground temperatures
IMPACT OF WATER BODIES
500
550
600
650
700
750
800
850
900
950
1000
-8 -7 -6 -5 -4 -3 -2 -1 0 1 2
Temperature (°C)
Ele
vati
on
(m
)
0m 10m
20m 30m
50m 75m
100m 150m
Distance from lake:
LARGE LAKE HAS PROFOUND THERMAL IMPACT ON NEARBY TEMPERATURES
RESULTS• MAAT of -11.8oC.• Warming in the ground (3o to 6oC with
4.5oC average) = -8.8o to -5.8oC (-7.3oC) which correlates to -6oC found in the area
• Within 20 to 30 m of major water body, 2o to 3oC warming can be felt
• Ground temperatures of -4o to -5oC under three dams. Also found -3.5o to -4oC under two dams directly beside water.
• Measured ground temperatures are reasonable with MAAT of -11.8oC.
PRESENTATION OUTLINE1. Validation of proposed mean annual air
temperature (MAAT) value for the site
2. Overview of permafrost assessment work
3. Relationship of ground temperatures to air temperatures
4. Introduction to climate change and global warming
5. Global warming estimates
6. Conclusions
CLIMATE CHANGE - DEFINITION
• Changes in the variability or average state of the atmosphere over appropriate time scales relative to a given reference period.
• These changes can be caused by processes internal to the Earth, external forces (e.g. variations in sunlight intensity) and, more recently, human activities.
CLIMATE CHANGE - OBSERVATIONS• Early decline of the spring snow
cover• Arctic melt seasons are longer• Rivers and lakes are melting earlier• Permafrost is warming or
disappearing• Arctic lakes are disappearing• Shorter winter road seasons• Less sea ice• Thunder and lightning in the north
CLIMATE CHANGE - CAUSES• These changes can be caused by
processes internal to the Earth, external forces (e.g. variations in sunlight intensity) and, more recently, human activities.
1. Natural• Solar variability, volcanic dust levels,
ocean variability, geological change
2. Human related (anthropogenic)• Greenhouse gases, aerosols, ozone
depletion
PRESENTATION OUTLINE1. Validation of proposed mean annual air
temperature (MAAT) value for the site
2. Overview of permafrost assessment work
3. Relationship of ground temperatures to air temperatures
4. Introduction to climate change and global warming
5. Global warming model estimates
6. Conclusions
5. GLOBAL WARMING MODELS• To simulate the effects of human
warming, scientists formulate very large and very complex mathematical models in computers.
• General Circulation Models (GCMs) are a class of computer-driven models for understanding climate and projecting climate change.
• Models require input assumptions regarding greenhouse gases (scenarios) in terms on amount and trend.
MODEL LIMITATIONS
• Mathematical model simulating the interaction of the earth, atmosphere, oceans and ice cover (WOW!).
• Models have numerous noted errors.
• Generally, the mean of the results has relatively good agreement for temperature but not so good agreement for precipitation.
• Models also have large nodes and hence are NOT site specific.
• RGM’s
GOVERNMENT / RESEARCHERS
• GCM’s extracted from the Canadian Institute for Climate Studies (CICS) at U of Vic (average of 4 different scenarios and 7 different models) = 7.6oC/100 years
• Canadian RCM for eastern Arctic = 5.1o to 6.1oC/100 years
• Environment Canada (2007) = 3.8o and 6.8°C of warming until the period 2070 to 2099.
COPPERMINE / KUGLUKTUKCombined Coppermine Kugluktuk Weather Record
y = 0.0245x - 59.29
R2 = 0.1604
-16.0
-14.0
-12.0
-10.0
-8.0
-6.0
-4.0
1928 1938 1948 1958 1968 1978 1988 1998 2008
YEAR
MA
AT
(oC
)
MAAT Value
Linear (MAAT Value)
Coppermine Kugluktukn 44 29Mean 11.5oC 10.5oCStd. Deviation 1.10oC 1.37oC
63 YEARS
2.5oC/ 100 YEARS
CONTWOYTO / LUPINCombined Contwoyto Lupin Weather Record
y = 0.0561x - 122.65
R2 = 0.3152
-14.0
-13.0
-12.0
-11.0
-10.0
-9.0
-8.0
-7.0
-6.0
-5.0
-4.0
1958 1963 1968 1973 1978 1983 1988 1993 1998 2003 2008
YEAR
MA
AT
(oC
)
MAAT Value
Linear (MAAT Value)
Contwoyto Lupinn 23 25Mean 11.9oC 10.9oCStd. Deviation 1.16oC 1.39oC
48 YEARS
5.6oC/ 100 YEARS
ALL DATA POST 1960
-18.0
-16.0
-14.0
-12.0
-10.0
-8.0
-6.0
-4.0
-2.0
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
YEAR
Mea
n A
nn
ual
Air
Tem
per
atu
re (
oC
)
Coppermine MAAT (oC)
Kugluktuk MAAT (oC)
Contwoyto MAAT (oC)
Lupin MAAT (oC)
Best Fit Line
46 YEARS
~6oC/ 100 YEARS
SUMMARY OF ESTIMATESG
CM
(4
scen
ario
s)
Plu
mm
er e
t al.
(Upp
er V
alue
)
Plu
mm
er e
t al.
(Low
er V
alue
)
Env
ironm
ent C
anad
a (U
pper
Val
ue)
Env
ironm
ent C
anad
a (L
ower
Val
ue)
Com
bine
d C
onto
ytal
/ Lu
pin
Com
bine
d C
oppe
r M
ine
/ Kug
lukt
uk
Bes
t Fit
BG
C U
pper
Val
ue
BG
C L
ower
Val
ue
INA
C C
onto
ytal
/ Lu
pin
INA
C C
oppe
r M
ine
/ Kug
lukt
uk
0
2
4
6
8
10
12
14
War
min
g V
alu
e (o
C /
100
yrs
) Government / Researcher GCM Estimates
Factual Warming Trends
BGC Proposed Allowances
INAC Proposal
WARMING ALLOWANCES ON OTHER PROJECTSProject Mean
Annual Air Temperature
Global Warming Allowances
Project Status
Polaris Mine Closure, NU
-16.5oC 3.0oC/100 years 5.1oC/100 years
Permits received Closure work completed Active monitoring
Nanisivik Mine Closure, NU
-15.1oC 2.8oC/100 years 5.0oC/100 years
Permits received Closure work almost completed
Doris North Mine, NU (2 year mine life)
-12.0oC worst case of 5.3oC over next century. Used simplying assumption of 6.5oC over next century
NIRB approval provided in September 2006.
Ekati Mine -8.5oC ~9.5oC/200 years Closure plannig
Meadowbank Mine, NU (8 year mine life)
-11.3oC 5.5oC/100 years NIRB approval provided in August 2006.
PRESENTATION OUTLINE1. Validation of proposed mean annual air
temperature (MAAT) value for the site
2. Overview of permafrost assessment work
3. Relationship of ground temperatures to air temperatures
4. Introduction to climate change and global warming
5. Global warming estimates
6. Conclusions
6. CONCLUSIONS• High Lake MAAT Value = -11.8oC is
reasonable.• Air temperatures correlate with deep
permafrost and shallow ground temperatures, allowing for heating due to large water bodies.
• Warming estimates of 5o to 6.5oC / 100 years are reasonable in light of government/researcher estimates and actual warming over climate period in the north.
• These estimates still have an additional Factor of Safety when applied to dam design.