worldwide integrated study of extremes (wise)
DESCRIPTION
“Extremes constitute the major stress factor on a number of environmental and socio-economic systems.” (Heino et al., 1999). WORLDWIDE INTEGRATED STUDY OF EXTREMES (WISE). - PowerPoint PPT PresentationTRANSCRIPT
“Extremes constitute the major stress factor on a number of environmental and socio-economic systems.” (Heino et al., 1999)
WORLDWIDE INTEGRATED STUDY OF EXTREMES (WISE)
Objective: To better understand the occurrence, evolution and role of extremes within the climate system (and to contribute to their better prediction)
• It is expected that the exact nature of the objective will evolve somewhat as the effort proceeds.
• The effort is initially focusing on droughts and extended
wet periods
• Extremes are an important aspect of GEWEX Phase II Roadmap
A FOCUS ON EXTREMES …
1995 First considered
2003 Ad hoc group to consider a working group
2004 Go-ahead for working group
2005 (July) I agreed to initially lead working group
2005 (now) Developing pragmatic plan
Outline of Presentation
• Objectives and Background• Initial Focal Points• Specific Examples of Extremes
CEOP period Canadian Drought Initiative
• Trends• Data Base for Extremes• Summary and Next Steps
AN OVERALL PERSPECTIVE
• What extremes have occurred?• How do extremes develop, evolve and end within the
climate system?• Have extremes changed in occurrence and
character?• Why did (or did not) the occurrence and
characteristics of extremes change?• Given our progress, how can we contribute to
assessing whether extremes may change in the future?
Issue: How wide should our scope be?
FOCAL POINTS
It is critical to develop a small number of specific, unique and do-able actions
Although complementary, two initial ones:
• GHP builds on WEBS ‘products’ and other activities
• CEOP one scientific component of a larger effort
1. WISE and WEBS …
Extremes have always been a critical part of the GHP strategy
Since:• WEBS has focused on longer-term averages• Numerous CSE-related studies have included extremes
Then capitalize on these experiences:• Synthesis effort to collectively address water and energy
budgets, flows and feedbacks during extremeslonger period than CEOP (say 1995-2004)many relevant studies completed
SPECIFIC ISSUES
• What are the ‘water and energy cycling’ characteristics of extremes?
• What processes and feedbacks were responsible for these evolving features in different regions?
Summary of MRB Annual Water and Energy Budgets
ARTICLE OUTLINE
Objective of Article: Synthesize our understanding of how droughts/extended wet periods develop, evolve, and end with emphasis on factors over land areas
Contents: Current information as a basis additional analyses to be determined
Authorship: Multi-authors
Mode of operation: Iterate …
2. WISE and CEOPObjective• Advance our understanding of extremes including their occurrence,
characteristics and inter-connections.
Approach:• Examine extremes individually over the CEOP period• Relate these individual events to each other as well as to the overall climate
system
Questions specifically associated with this approach include: • What extremes occurred during CEOP over the world? • What are the characteristics of these extremes? • How did the cycling of water and energy occur within these extremes? • To what degree were the extremes inter-connected?
Outcome:• “Synthesis’ article on addressing such issues
CONTRIBUTORS OF EXTREMES INFORMATION DURING CEOP
and counting … Drought over Australia Alan Seed and …Heat wave over Europe Christoph Schaer plus …Flooding in NZ Warren Gray/David WrattExtremes- South America Hugo Berbery Drought over Canada Ron Stewart and …
Drought over US Rick Lawford and …Drought/floods in Asia Bill Lau/Ben BurfordBrazil extremes Jose MarengoGPCC/GPCP Bruno Rudolf
…
2001 2002
2003 2004Nov/03 – Nov/04
Impact of the summer 2003 in Europe
Agricultural losses:12.3 Billion US$ (SwissRe estimate)
Serious problems with- freshwater resources (Italy)- forest fires (Portugal)- freshwater fish (Switzerland)
Shortage of electricity, peak prices on spot market (EEX, Leipzig)
Estimated 22,000 to 35,000 heat deaths (excess mortality)
August 2003 temperatures relative to 2000-2002, 2004(Reto Stöckli, ETH/NASA, MODIS)
Estimation of Return Periods
10 y10 y
1000 y1000 y
100 y100 y
mean
Average of 4 Stations: Zürich, Basel, Berne, Geneva
1864-2003
(Gra
zzin
i et
al.
200
4)
Anomaly 500 hPa Circulation(August 2003)
L H LH
L
Atmospheric Circulation
Sequence of blocking high-pressure systems• Summer Northern Hemisphere Annular Mode, wave-number 3 (Ogi et al. 2005)• Rossby wave train (Grazzini et al. 2004, Black et al. 2005, Orsolini and Nikulin 2005)
Anomaly 500 hPa Circulation(17. Juli – 6. August 2003)
(Og
i et
al.
200
5)
’=40m
H
H
H
L
L
LL
NEW ZEALAND FLOODS
Manawatu: 21 Feb Manawatu: 21 Feb
Masterton: 17 Feb Masterton: 17 Feb
February 2004
NEW ZEALAND FLOODING
• Damage estimated at $300M …probably worst flood damage on record (inflation adjusted)
• Rainfall analysis suggests an over 1:150 year event on time scales up to 72 h
Intense precipitation events
The role of the Low-level jet east of the
Andes
South American Extremes
A CANADIAN NATURAL DISASTER
The The 1999-2004 drought1999-2004 drought
was one of the worst was one of the worst natural disasters that natural disasters that Canada has ever suffered!Canada has ever suffered!
Huge impacts on:societyeconomyecosystems
Southern Saskatchewan, April 2002
IMPACTS OF THE 1999-2004 DROUGHT
• GDP (01/02) - $5.8B• Employment (01/02) - 41,000• Natural pond depth lowest on record• Largest die-back of aspen in recorded history• Negative net farm income in some provinces (1st
time in 25 years)• Huge increase in forest fires• Curtailed hydroelectric power – increase in electric
rates• 32 massive Saskatchewan dust storms• Thriving grasshopper populations• Farm and business bankruptcies• Failed water wells due to reduced groundwater• Surface water supplies depleted
OBJECTIVE OF THE STUDY
To better understand the physical characteristics of and processes influencing Canadian Prairie droughts, and to contribute to their better prediction, through a focus on the recent severe drought that began in 1999
The Team: John Pomeroy and I (co-leads) plus ~ 25 investigators
OUR STRATEGYPhysical-Dynamic Approach
• Improve understanding and model representation of processes
• Improve understanding and simulation of the whole system
• Contribute to better prediction
Focus
• Given limited resources, important to focus on a particular period to reach ‘critical mass’
• Natural focal point is the recent catastrophic drought that can be examined with unparalleled information
• Given our detailed understanding of this event, can compare it against others over the region and elsewhere at different times
QUANTIFY THE DROUGHT
Saskatoon
Swift Current
Calgary
Red Deer
Lethbridge
Drumheller
Medicine Hat
Gem
Olds
Verlo
Tyner
Orton
Hague
Cluny
Bruno
Warner
Warman
Ponoka
Instow
Elnora
Barons
Vanscoy
Swanson
Sibbald
Pakowki
Okotoks
Enchant
Duchess
Cypress
Blucher
Stettler
Mud Lake
Irricana
Elkwater
Conquest
Cessford
Shaunavon
Saskatoon
Pine LakeInnisfail
Gull LakeDuck Lake
Cavendish
Carseland
Big Stone
Oldman Dam
High River
Hand Hills
Del Bonita
Sylvan Lake
Dickson Dam
Smith Coulee
Many Springs
Buffalo LakeBuffalo Lake
Buffalo North
Sounding Creek
Crestomere Lake
Kirkpatrick Lake
Forty Mile Coulee
Legend
Observation Well Locations
0 30 60 90 12015Kilometers
Observational Networks
GRACEsatellite
MODIS and aerosols
Wells in SouthSaskatchewan
CRITICAL FACTORS
Individual storm events
“Hot spots”(Koster et al.2004)
Varying vegetation between droughtand non-drought
Snow WaterEquivalentAnomaly (mm)
PRAIRIE HYDROLOGY DROUGHT FACTORS
Non-contributing areas
Localized hydrology affected by poor drainage,storage in small depressions
UNDERSTAND THE DROUGHTV
ertic
al S
cale
S to ra ge o f W a te r
D r o u g h t
N o n - d r o u g h t
H o rizo nta l F lu x o f W a te r
N o n - d r o u g h t
D r o u g h t
3. TRENDS AND EXTREMESIt is not clear whether there needs to be a separate initiative on trends in
extremes
• Has the frequency and/or character of extremes changed over the last few decades? Why or why not?
And possibly …
• Will the frequency and/or character of extremes change over the next few decades? Why or why not?
Considerations:
pro: critical issue in many regions strong existing GHP community activities already underway (several examples here)con: being covered elsewhere?
within the scope of GEWEX?
Hans-Jörg Isemer, IBS, [email protected] GHP#11, September 2005, Melbourne, Australia
BACC (7): Selected example material from chapter 2
www.gkss.de/BACC
Variation of annual precipitation amount over Denmark, 1874-2004 (Cappelen and Christensen 2005).
4. DATA BASE FOR EXTREMES
How can we document the occurrence of extremes of interest to GHP?
• many web sites now on hazards (check our web site!)• individual inputs from CSEs and others
Suggestion:• Data base for extremes of interest to GHP
One possible step:• Using the CEOP period as a initial focus
Note: This is linked with the establishment of development of robust definition(s) of extremes
WISE “Guys”
• BK Basu• Hugo Berbery• Ben Burford• Ole Chrstensen• Hans-Joerg Isemer• John Roads• Alan Seed• Ron Stewart• Kiyatishu Takahashi• Steve Williams• Eric Wood• and others to be added
SUMMARYWe are just starting our focused activity on extremes
Natural initial focal point are:• building on WEBS and other studies (article ~ 3 y)• in combination with CEOP (article ~ 3-4 y)• trends
A challenging issue• data base for extremes
BREAK OUT• Is our present objective still appropriate?
• Are our initial issues and components OK?
• Should we include trends?
• How do we best address ‘defining’ extremes?
• To what extent should we produce an extremes data base?
• What specific actions do we have (with what outcomes)?
• Who leads these?
• What are our timelines
MEETING PLANS
Potential special sessions at international conferences
• Extremes session at 2006 CEOP workshop• Proposed WISE session at 2006 autumn AGU • Hydrological Cycle Symposium at IUGG 2007
(Italy)• …