EXTREMES AND CEOP

Extremes … Background: A fundamental aspect of the water and energy cycle is the occurrence of extremes. Big Issues: 1. How can we improve our understanding and prediction of extremes? 2. To what extent will the types, distributions, and impacts of extremes change in a world with an altered climate? We envision Extremes addressing both of these issues: It will address extremes within the present climate system This foundation will allow us to contribute to assessments of their future occurrence

OBJECTIVE For CEOP … To better understand the occurrence, evolution, structure and role of extremes within the climate system To contribute to their better prediction and to societal concerns

The Focus of Extremes During CEOP Extremes of Interest Drought Floods and heavy precipitation … And, in some instances Inter-meshing of these extremes

WATER AND ENERGY CYCLING Drought is an aberration in the Water and energy cycle

SIMPLE UPDATE Within CEOP: Who is carrying out some type of extremes research? What aspects of extremes are being studied? What needs to be done? How we move forward? …

WIDE INTEREST Regional Projects: drought: CPPA, DRI, LPB, MDB... heavy precipitation/flooding: CPPA, DRI, LPB, BALTEX, MAHASRI, NEESPI... Other Components: WEBS, aerosols, isotopes high elevation, semi-arid … Modelling studies

RHPs BALTEX: Provision of improved tools for water management, with an emphasis on more accurate forecasts of extreme events (and long-term changes) CPPA: Quantify the sources and limits of predictability of climate variations on intra- seasonal to interannual time scale to quantify the sources and limits of predictability of climate variations on intra-seasonal to interannual time scale

RHPs … 2 LBA: To quantify, understand and model the physical, chemical and biological processes controlling the energy, water, carbon, trace gas, and nutrient cycles found within Amazonia and to determine how these link to the global atmosphere. LPB: What climatological and hydrological factors determine the frequency of occurrence and spatial extent of floods and droughts?

RHPs … 3 MAHASRI: Develop a hydro-meteorological prediction system, particularly with the time scale up to a season, through the better scientific understanding of Asian monsoon variability MDB: Real-time surface water budget over the Murray-Darling for application by water authorities … NEESPI: Develop a comprehensive understanding of the Northern Eurasian terrestrial ecosystem dynamics, biogeochemical cycles, surface energy and water cycles …

CROSS-CUTS WEBS: Determine and understand average values … for components of the water and energy cycles, with particular attention to hydroclimate “hotspots” and extreme events EXTREMES … AEROSOLS: Provide better understanding of the mechanisms of extreme events that affect water availability in monsoon regions, and their relationships to oceanic, land, atmospheric (including aerosols) forcings ISOTOPES: Allow non-isotope studies within CEOP to be enhanced by knowledge of isotopic constraints COLD REGION: … HIGH ALTITUDE: … MONSOONS: … SEMI-ARID: …Collaboration with crosscutting group of extremes in study of frequency of extreme droughts in semi- arid regions in the aridity trend

MODELLING MAC: Developing a Multi-model Analysis for CEOP ICTS: Study the transferability of regional climate models to areas of different continental scale experiments SIEVE: Study the mechanisms by which large-scale climate anomalies are manifested as seasonal extremes on regional scales GLDAS: Develop and test large scale validation, calibration and assimilation techniques over land HAP: Developing and testing reliable, skillful hydrologic ensemble forecast procedures based on seasonal climate model forecasts

DATA MANAGEMENT DM: GPCC: GRDC:

The Canadian Prairies

Drought Occurrence – Southern Prairies ( ) SPIPDSI

BIG ISSUES Given the drought, some key issues include: 1. What maintained it over multiple years? 2. What governed its actual structure? 3. Why did it end? 4. What did prediction systems 'miss‘ and why? 5. Given this progress, how can we better cope with drought?

LARGE SCALE ACTUAL PATTERNS Summer 500 mb

JJA mean meridional flow at 850 hPa Mean meridional flow over the prairies is northerly –> mean southerly moisture transports into the Prairies must be accounted for by eddy transports

DRI (Canadian Prairie drought) 500 km 2001/02

PRECIPITATION ANOMALY EDMONTON PRECIPITATION ANOMALY (%)

SUMMERS OF 2001 and 2002 Edmonton

Prairie Hydrology - Reality Smith Creek, Saskatchewan

PRECIPITATION

WHAT FACTORS LED TO THESE CONDITIONS?

THE SAME? Drought and heavy, sustained precipitation/flooding are reported all over the world: But: To what extent are the same physical mechanisms always responsible for these extremes? How many paths are taken to produce the ‘same’ result? …

DROUGHT AND HEAVY PRECIPITATION/FLOODING Drought: Sustained lack of precipitation. Many reasons for this: Large scales, storm tracks … WV, T, vertical profiles including precipitation, aerosols... Dry surface, vegetation … Heavy, sustained precipitation/flooding: Many reasons for this: Large scales, storm tracks … WV, T, vertical profiles, precipitation systems … Wet surface, vegetation, topography …

In CEOP Lots of interest in and research on Extremes

WORKSHOP Objective: To advance our extremes activity Key issues: update the extremes work being carried out in CEOP, GEWEX and (hopefully) CLIVAR, WCRP synthesize progress to better address overall objectives chart next steps Timing: May 21-23, 2008 Location: Vancouver

In Summary … Hydrometeorological extremes are of critical importance to society Within CEOP, we are addressing some of the issues associated with these extremes A major contribution of this effort will be assessing similarities and differences between extremes (including prediction) within different conditions