A WISE “Case study” During CEOP

Some Thoughts

Background

Some of CEOP’s key features include:• Focus on a particular period • ‘Ready’ access to a variety of information

CEOP’s scientific effort is concerned with the water cycle:• Fluxes and reservoirs over land• Monsoon circulations

Excellent opportunity to consider extremes:• A major scientific and societal issue• Some work is already being conducted

EXAMPLES OF EXTREMES DURING A YEAR OF CEOP

GLOBAL PRECIPITATION ANOMALIESEXAMPLE DURING THE CEOP PERIOD

2002

Global Extremes … a case study

This study contributes to two main issues:

• To advance our understanding of extremes including their occurrence, characteristics, evolution and inter-connections

• To gain experience and to develop tools for later studies including prediction

The Focus of Extremes During CEOP

• Droughts and floodslocation (by globe, continent)areaseveritytiming and duration

• Other extremespotentially could be added such as …

heat waves, …

WATER AND ENERGY CYCLINGDURING EXTREMES:

AN EXAMPLE FOR DROUGHT

Drought can be considered to bean aberration in the regional cyclingof water and energy

CEOP Extremes Case Study

• Do-able WISE activity with its global perspective• Contributor to and beneficiary of CEOP• Some key aspects

coordinated collection of detailed case studies

global inter-connections

CEOP-period extremes in long-term perspective• Not all the global information on extremes is readily

available so the overall study has to be considered as a ‘pilot’ one

Scientific Issues for CEOP Extremes include …

• What extremes occurred?• What are their features that made them

‘extreme’?reference to definitions, return period, etc.

• For extremes studied in detail, why did they occur?

• Were they linked and if so how and why?• What are the implications for simulations and

trends (past and future)?

Some Measures of Extreme

Assessing whether an event is extreme is a critical issue. Some considerations and implications include:

1. Characteristics such as: location, timing, precipitation, temperature,

duration, area …

2. Statistically-based studies give guidance on how to show ‘how’ individual event case studies are extreme and to what extent

3. Such information is important to place the CEOP time period into the proper perspective from the global system down to individual events

CEOP Extremes: Some Examples

THE ‘SYSTEM’

STEPS

Pragmatic summary:

• Summarize the occurrence of extremes around the world and some of their characteristics mainly by using readily-available information

• Identify regional in-depth studies that are already focusing on particular extremes during CEOP

• Ensure that appropriate global scale studies are

carried out to fully achieve the Extremes objectives

DETAILED EXTREMES STUDIES

• Several detailed studies of extremes during CEOP are already underway including:

Effort Contact

• AMMA• BALTEX• CPPA • DRI Kit Szeto - Ron Stewart• LPB Hugo Berbery• LBA Jose Marengo• MAHASRI• MDB• …

• There are undoubtedly other efforts as well and perhaps some of the above do not have any focus on extremes …

• But, existing ‘event case studies’ form a strong foundation for the ‘overall case study’ … a case study of case studies ..?

DRI(Canadian Prairie drought)

500 km

2001/02

DRI (flooding at the end of the drought)

St. Jean de Baptiste, ManitobaJuly 2005

LBA

Circulation anomaliesDrought of 2005

Tropical North Atlantic:

Anomalously warm surface waters.

ITCZ northward displaced

Amazonia: Downward motion inSouthwestern Amazonia(less rainfall) over theHeadwaters of major Amazonian Rivers :Consequence: Low river levels in central AmazoniaSome rainfall in central andEastern Amazonia

Not all Amazonia was affected by drought in 2005.(El Niño induced droughts affect central and eastern Amazonia also) 2005 Non El Niño year

Land surface processes?.Role of smoke and aerosols in delaying onset of rainy season?

Drought

Rain

Moisture fluxes and their convergence associated with intense precipitation events

LPB

• Other examples to be added …

Specific datasets include:

• Floods: Dartmouth, GPCC, …

• Droughts: Drought/Aridity indices, …

• Heat waves: Temperature (e.g., NCDC?) …

• More datasets are listed on the WISE web site: www.meteo.mcgill.ca/wise

DATASETS

SPECIFIC ACTIONS

• Iterate on concept

• List of/contacts for detailed studies of extremes

• Acquire datasets for extremes

• Place CEOP extremes in perspective with respect to past climate

• Continual communications amongst participants

OUTCOMESSome outcomes for the WISE ‘CEOP case study’ that is basically a

‘few-year-snapshot’ based to a large extent on activities already underway:

• Inventory of extremes for this period• Placement of these extremes within a long-term context• Detailed water and energy studies of a ‘relatively small’ number of

extreme events • Documentation and interpretations of inter-connections

While significant scientific progress is expected, this ‘CEOP case study’ or ‘pilot study of global extremes’ must be viewed as a learning process so its experiences can be considered as a:

• Foundation for further research by others