great lakes weather and climate
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Great Lakes Weather and Climate. Introduction. Standing in for a speaker from Environment Canada that was unable to attend at the last minute Until yesterday knew almost nothing about weather and climate in the Great Lakes but have been learning fast!. Great Lakes Weather and Climate. - PowerPoint PPT PresentationTRANSCRIPT
Great Lakes Weather and Climate
Introduction
• Standing in for a speaker from Environment Canada that was unable to attend at the last minute
• Until yesterday knew almost nothing about weather and climate in the Great Lakes but have been learning fast!
Great Lakes Weather and Climate
• Forecasting weather and projecting climate
• The role of the oceans and Great Lakes
• Great Lakes climate change
4
First a bit of history
• Early ability to predict weather constrained by:– Limited understanding of
fundamentals of atmospheric circulation
– Low density of accurate and synoptic observations
– Limited capacity to communicate, integrate and interpret observations
Time Line 1848 - Volunteer Weather Observers recruited
through Smithsonian Institution
1849 - Smithsonian supplies weather instruments to telegraph companies and establishes weather observation network
1870 - President Grant signs bill establishing a national weather warning service within Army Signal Corps
1890 - Cooperative Weather Observer Network established
1891 – Weather service transferred to Department of Agriculture, becomes United States Weather Bureau
1898 – Weather Bureau begins hurricane warning network
1900 - ‘Issacs storm’ kills over 6,000, Weather Bureau establishes regional forecasting centers in response
World Weather Watch
• Established by WMO in 1963
• Creation of a globally coordinated system of observations, data communications, data processing and forecasting
Satellite observations of the atmosphere
TIROS
GOES
Computing
• Meteorology took early advantage of the revolution in computing to deliver routine operational products
11
Why are the oceans so important?
Data from Levitus et al, Science, 2001
Because, that is where most of the heat goes
Systematic observation of the global ocean became a goal in 1990
The Global Ocean Observing SystemA joint initiative of:
Technology
• Comprehensive array of technologies for in-situ measurement
57%
100%
40%
82%
43%72%48%21%
100%
Operational Systems
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• 1000 to 1861, N. Hemisphere, proxy data
• 1861 to 2007, Global, instrumental
• 2007 to 2100, SRES projections
Evidence of Climate Change in the Great Lakes Region
• Temperatures are rising, especially in winter.
• Extreme rainfall events (24-hr and 7-day) are becoming more frequent.
• Winters have become shorter.• Spring is coming earlier.• Duration of ice cover is shorter, especially on smaller lakes.
Projected Temperature Increase in the Great Lakes Region (by 2070-99)
Summer
Winter
Higher emissionsLower emissions
Deg F
16
15
14
13
12
11
10
9
8
7
6
Deg F
16
15
14
13
12
11
10
9
8
7
6
Projected Precipitation Changes in the Great Lakes Region (by 2070-99)
• Doubling of heavy precipitation events
• Seasonal shifts in precipitation -- * More rain in winter and spring (planting season)
* Less rain during the summer and fall growing seasons
• Temperature– Winter 5-12 °F (3-7 °C)– Summer 5-20 °F (3-11 °C)– Extreme heat more common– Growing season several weeks longer
• Precipitation– Winter, spring increasing– Summer, fall decreasing– Drier soils, more droughts
• More extreme events – storms, floods– Could be 50-100% more frequent than now
• Ice cover decline will continue
Projected Climate Changes in the Great Lakes Region by 2100
