Water and Weather

Confluence of events

Attended a public meeting yesterday on the management of water levels in Glen Lake and the Crystal River.

Doc had just posted a piece on Freeman Dyson a couple of days ago
Doc Searls Weblog : Higher ground

I linked to some related materials ( last 48 hours )

Glen Lake is currently higher than usual, and part is due to our having a cool wet spring, early summer. Through early July we have had more precipitation than all of '07.
This is a regional phenomena.

Harbor Light Newspaper: Lake levels on the rise thanks to wet spring:
"The tumultuous weather, which has likely contributed to a slow start to the summer season, has, as it turns out, one major benefit – a rise in Lake Michigan water levels, which have been below average for over a decade.

Keith Kompoltowicz, meteorologist at the U.S. Army Corps of Engineers, said the lake rose five inches during the month of June – three inches above the yearly average – and is expected to continue to do so, at least through July.

“It has been rising since about the beginning of the year,” he said, on the phone from his Detroit base. “This is a direct result of active weather patterns.”

The Army Corps uses measurements provided by the National Oceanic and Atmospheric Administration, which has a number of water level gauges planted throughout the Great Lakes. As of June 30, Lake Michigan was said to have an elevation of just over 578 feet.

The lake is still 14 or 15 inches below average, added Kompoltowicz. This has been the case for over ten years. The lakes follow long-term and seasonal patterns, rising in the spring and summer and dropping in the late fall and winter. It is the magnitude of these rises and falls that changes every year."

Datum here (GIF Image, 640x480 pixels)

This all got me thinking about long term weather (not really climate) patterns and of course really long term (in human terms, not geologic time).

The Great Lakes were formed by Glaciers, carving out ancient river beds, then filling the resulting valleys.
Laurentide ice sheet - Wikipedia.

We are still undergoing Post-glacial rebound.

I checked into the news about the ongoing issue of the Arctic Ice and possible ties to changes in wind patterns. In particular the Pacific Decadal Oscillation (PDO).

From Jet Propulsion Lab/NASA:

JPL.NASA.GOV: News Releases: "The Pacific Decadal Oscillation is a long-term fluctuation of the Pacific Ocean that waxes and wanes between cool and warm phases approximately every five to 20 years. In the cool phase, higher than normal sea-surface heights caused by warm water form a horseshoe pattern that connects the north, west and southern Pacific, with cool water in the middle. During most of the 1980s and 1990s, the Pacific was locked in the oscillation's warm phase, during which these warm and cool regions are reversed"

This situation can shift the Jet Stream, both changing the Circumpolar Vortex, and allowing or forcing cooler air south over the upper Midwest.

Currently pondering if we have indeed had a shift to a different weather pattern. Mid July and we're in the mid 60's ...