AOS @ McGill
CEOP / GEWEX Extremes

WEBS Follow-on for Extremes

The first CEOP/GEWEX case study will be a WEBS (Water and Energy Budget Studies) type diagnostic study of a severe drought event that occurred over the Canadian Prairies from 1999-2004/05. The objectives of the study are to (a) evaluate the surface and atmospheric water and energy budgets for the region during the 1997-2002 period; (b) assess the validity and variability of the budgets that are derived from different source datasets and (c) examine the deviations of the budgets from climatological values for this extreme hydrometeorological event. In addition to these scientific objectives, this pilot study will also attempt to establish mechanisms (e.g., in data transfer and task sharing) to facilitate future CEOP/GEWEX collaborative studies. The water and energy budgets will be evaluated by using mainly global and regional (re-)analysis and model datasets (right now we have data from NCEP-R2, ERA40, CMC and the CRCM and NARR will be added) with validation data obtained from both in situ and remotely-sensed measurements. Apart from the evaluation of standard WEBS variables and parameters, diagnostics that are useful either in the characterization of drought events or in the understanding of their dynamics, such as precipitation recycling or moisture source tracing diagnostics, will also be conducted. More details on this study are available at CEOP/GEWEX Extremes members are encouraged to participate in the case study through the contribution of measured, assimilated, modeled or remotely-sensed data for, and in carrying out, the diagnostic calculations.

To participate in this study, please contact

This initial WEBS Follow-On study benefits from a comprehensive research study being carried out of the devastating 1999-2004/05 drought over the Canadian Prairies.

This study will also make use of high resolution satellite-based datasets of precipitation. One example is the CMORPH dataset.

Other extreme event focal points will be addressed in the future. Please send suggestions to