7Drought Research in Canada Fragmented – spatially and temporallyBased on severe drought occurrence (e.g., )Majority for Canadian PrairiesHistorical comparisons difficult due to short and variable climate station recordsCanadian droughts unique – both cold and warm season phenomenon
1116001700180019002000-22ReconstrudgialJyPalmer Drought Severity Index (Sauchyn et al. 2001)Southwestern Saskatchewanfrequent droughtdecadal droughtNorth-central Montana
12Warm, Dry Winters Over Canada 500mb Flow500mb AnomaliesEl Niño, +PNA, +PDO, Deep Aleutian Low
13Hot, Dry Summers Over Western Canada 500mb Flow500mb Anomalies+PNA, Meridional Flow, +PDO?
14Coupled SVD pattern between Global Winter SSTs and Summer PDSI (1940-2002) Winter Interannual and interdecadal ENSO-like pattern is associated with dry summer conditions in western and central Canada. Squared Covariance Fraction = 28%, Correlation between time expansion = 0.5(Shabbar and Skinner, 2004)
16Drought MonitoringReal-time information on drought conditions over agricultural regions of CanadaNational map illustrating current and historical temperature, precipitation, and drought index maps (SPI, PDSI) at various time stepsReports of lake and reservoir levels, stream flows, snowpack accumulations, water-supply volume forecasts, dugout water levels, pasture conditions (for the Prairies)The North American Drought Monitor
17Drought MonitoringSatellite and radar measurements can provide solutions to spatial-scale problems associated with drought monitoringMSC currently uses Special Sensor Microwave Imager (SSMI) to produce SWE maps for the Prairies that are made available to water resource agenciesTime series extends from 1978 through the present, using the brightness temperature standardization of Derksen and Walker (2003).
18Drought PredictionDrought prediction involves anticipating climatic anomalies that produce unusually hot, dry conditions for extended periodsEC currently produces monthly and seasonal forecasts for T & P for lead times of 3, 6, 9, and 12 months0 to 3 month forecasts are made using NWP modelsLonger lead times use a statistical (CCA) model using SST anomalies over the previous 12 monthsSkill higher for cold season and for temperature
19The frequency and severity of droughts are likely to increase in southern Canada 204060Return Period (years)10152530Length of Dry Spell (days)Central North AmericaToday~2070
21Research Needs1. A better understanding of the physical causes of drought initiation, persistence, and termination at a variety of spatial and temporal scalesLarge-scale atmospheric and oceanic oscillationsSoil moisture anomaliesMoisture sourcesPhysical causes of multi-year droughtsDrought migration
22Research Needs2. Quantification and assessment of past drought occurrencesPast trends and variabilityDrought indicesPaleo-drought studies3. Better knowledge regarding future drought occurrenceMore reliable GCM/RCM outputImproved downscaling methodsFuture changes to large-scale circulation patterns
23Research Needs4. Ability to more accurately predict drought onset, intensity, and terminationImprovements in modelling and monitoring of current drought conditionsMore reliable short term (seasonal) climate forecast5. More effective short and long-term adaptation strategies to defend against future droughts