the canadian climate impacts scenarios (ccis) project is funded by the climate change action fund...
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The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
Downscaling Tools
Introduction to LARS-WG and SDSM
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
LARS-WG stochastic weather generator
( http:\\www.iacr.bbsrc.ac.uk\mas-models\larswg.html )
• Generation of long weather time-series suitable for risk assessment
• Ability to extend the simulation of weather to unobserved locations
• A computationally inexpensive tool to produce climate change scenarios incorporating changes in means and in variability
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
LARS-WG stochastic weather generator
( http:\\www.lars.bbsrc.ac.uk\model\larswg.html )
• Generates precipitation, min and max temperature and solar radiation• Modelling of precipitation events is based on wet/dry series• Semi-empirical distributions are used for precipitation amounts, dry/wet
series and solar radiation• Temperature and solar radiation are conditioned on the wet/dry status
of a day• Temperature and solar radiation are cross-correlated
0
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0.1
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(mean, sd)
Parametric- e.g., WGEN
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Semi-parametric - e.g., LARS-WG
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
LARS-WG
• Model calibration - SITE ANALYSIS• Model validation - QTEST• Generation of synthetic weather data -
GENERATOR
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
SITE ANALYSIS
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
QTESTCompare observed and synthetic data to evaluate LARS-WG performance
Precipitation
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to
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mm
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Obs
WG
Minimum temperature
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°C)
Obs
WG
Maximum temperature
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imu
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WG
Solar radiation
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iati
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(M
Jm-2)
Obs
WG
Precipitation variability
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m)
Obs
WG
Minimum temperature variability
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(°C
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WG
Maximum temperature variability
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nd
ard
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(°C
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WG
Solar radiation variability
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Sta
nd
ard
de
viat
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(M
Jm-2)
Obs
WG
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
Base scenario file
GENERATORGenerate synthetic weather data: to extend time series, or
for climate change studies
Scenario file
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
GENERATORPrecipitation
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cip
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mm
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Base
2050s
Maximum temperature
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Max
imu
m t
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pe
ratu
re (
°C)
Base
2050s
Minimum temperature
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imu
m t
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°C)
Base
2050s
Days with maximum temperature > 30°C
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1.2
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mb
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of
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Base
2050s
Days with minimum temperature < 0°C
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mb
er
of
day
s
Base
2050s
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
Limitations of LARS-WG (and weather generators in
general) ...
• Temporal downscaling only
• Designed for use at individual sites only (no spatial correlation)
• Can only represent events in calibration data set
• Generally underestimate variability
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
SDSM1. A decision support
tool for assessing local climate change impacts
2. Facilitates the rapid development of multiple, low-cost, single-site scenarios of daily surface weather variables under current and future climate forcing
3. Based on a multiple regression-based method
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
SDSM Structure
7 steps:• Quality Control and Data Transformation• Screening of Predictor Variables• Model Calibration• Weather Generation (using observed
predictors)• Statistical Analyses• Graphing Model Output• Scenario Generation (using climate model
predictors)
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
Model Verification
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
Victoria: Maximum temperature
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No
v
De
c
(°C
)
1961-1990
CGCM1 GA1
Downscaled
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
Tmax > 25°C
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the
Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada
Cautionary Remarks
• SDSM provides a parsimonious technique of scenario construction that complements other methods
• SDSM should not be used uncritically as a “black box” (evaluate all relationships using independent data)
• Local knowledge is an invaluable source of information when determining sensible combinations of predictors
• Daily precipitation amount at individual stations is the most problematic variable to downscale
• The plausibility of all SDSM scenarios depends on the realism of the climate model forcing
• Try to apply multiple forcing scenarios (via different GCMs, ensemble members, time–slices, emission pathways, etc.)