unstable, dri and water cycling ronald stewart mcgill university
TRANSCRIPT
UNSTABLE, DRI UNSTABLE, DRI and Water Cyclingand Water Cycling
Ronald StewartMcGill University
Specific Objectives of Presentation
• To briefly review DRI and some of its science
• Comment on interactions with UNSTABLE
Prairie Drought
CONCERNS
There are many concerns associated with drought but many of these can be summarized under two broad categories
• Will there be a drought?decadelseasonal‘now’
• How do we best prepare for and cope with drought?
many perspectives
WATER AND ENERGY CYCLING
Drought is an aberration in theWater and energy cycle
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DRI Objective• To better understand and contribute to the
better prediction of drought …
• Focus mainly but not exclusively on the
recent 1999-2005 Prairiedrought
DEUTERIUM IN WATER VAPOUR
550-800 hPa layer
Tropospheric Emission Spectrometer: Aqua satellite
Days with precipitationCalgary
• The fraction of days receiving any amount of precipitation:
Climatology (1895-2004): 40%
Drought (1999-2004): 46%
Sub-Drought (2001-2002): 43%
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Climatology
Low precipitation events: 52% of total
Sub-drought 2001-2002
Low precipitation events: 60% of total
Daily Precipitation AmountsCalgary Low precipitation event:
< 10 mm
What factors led to the ≤10 mm events?
Possibilities include
• Loss due to evaporation/sublimation• Short-lived weather systems• Change in character of clouds• Fast moving weather systems• …
RADAR PROFILES1 June 2002: Calgary
• Scattered stratiform rain early
• Late in the day there is evidence of water aloft (~5 km)
• This appears to be high-level moisture as a precursor to the rainy pattern on the following day
VIRGA
Courtesy of Barrie Bonsal
VEGETATION
July 11-20, 2002
NDVI
NDVI: Normalized DifferenceVegetation Index
Healthy vegetation
UNSTABLE
Sub-objectives include …
to better understand, resolve, and quantify:
• spatial extent, depth and temporal evolution of water vapour in the atmospheric boundary layer
• Mesoscale effects on thunderstorms• effects of variable surface• …
DRI and UNSTABLE
• DRIdiverse research expertise (~ 30)datasets (atmosphere, surface …)analysis tools (DAI …)…
• UNSTABLEaspects linked with water cyclingfocused activityobservational and model products…
CONCLUDING REMARKS
• DRI is concerned with:the science of water cycling
• UNSTABLE is concerned with:overturning of the atmosphere
• DRI and UNSTABLE can benefit from collaboration
And … thank you for your attention