Welcome to DU!
The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards.
Join the community:
Create a free account
Support DU (and get rid of ads!):
Become a Star Member
Latest Breaking News
General Discussion
The DU Lounge
All Forums
Issue Forums
Culture Forums
Alliance Forums
Region Forums
Support Forums
Help & Search
Lake Michigan and Lake Huron hit all-time low water levels
The record-low water levels on Lake Michigan and Lake Huron are due, in part, to dredging operations in their outflow channel, the St. Clair River. The dredging, which stopped in the 1960s, is blamed for a long-term 10 - 16" decrease in water levels.
The record low water levels on Lake Michigan and Lake Huron in January occurred despite the fact that precipitation over their watershed was 61% above average during the month. However, precipitation over the past 12 months was only 91% of average, and runoff into the lakes depends upon precipitation over longer than a 1-month period.
Furthermore, evaporation over these lakes was much higher than average during January, making the net water supplied to the lakes (runoff into the lakes, plus precipitation over the lakes, minus evaporation from the lakes) only 63% of average. What caused the increased evaporation? Well, very warm water temperatures, for one. According to NOAA's Great Lakes Environmental Research Laboratory (GLERL), water temperatures over Lake Michigan are currently about 2.5°F above average, and are about 1°F above average over Lake Huron.
These warm water temperatures are the lingering effects of the extraordinary warmth of 2012, which was the warmest year on record over much of the Great Lakes region. Also increasing the evaporation from the lakes during January was the presence of less ice cover than average, which exposed more open water to the air.
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2343
The record low water levels on Lake Michigan and Lake Huron in January occurred despite the fact that precipitation over their watershed was 61% above average during the month. However, precipitation over the past 12 months was only 91% of average, and runoff into the lakes depends upon precipitation over longer than a 1-month period.
Furthermore, evaporation over these lakes was much higher than average during January, making the net water supplied to the lakes (runoff into the lakes, plus precipitation over the lakes, minus evaporation from the lakes) only 63% of average. What caused the increased evaporation? Well, very warm water temperatures, for one. According to NOAA's Great Lakes Environmental Research Laboratory (GLERL), water temperatures over Lake Michigan are currently about 2.5°F above average, and are about 1°F above average over Lake Huron.
These warm water temperatures are the lingering effects of the extraordinary warmth of 2012, which was the warmest year on record over much of the Great Lakes region. Also increasing the evaporation from the lakes during January was the presence of less ice cover than average, which exposed more open water to the air.
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2343
