The Great Lakes are warming up!
And so are many others…
Considering we're into the lake effect snow business now, this might be an appropriate time to mention some latest research numbers that just came out.
Earth's lakes are collecting and storing more heat than they did a century or even several decades ago. One indication of this increased heat storage is a global reduction in the annual duration of lake ice cover. In mid-latitude lakes, the average annual date when enough ice has grown to cover a lake's surface is arriving 5.8 days later in the year than it did in the middle of the 19th century. The average annual "ice-out" day, or the day when the ice leaves a lake, is now arriving 6.5 days earlier in the late winter/early spring. Less ice cover indicates that the lakes have more heat to lose before they can start to freeze. A more direct measurement of heat storage comes from an analysis of large lake (larger than 193 square miles) nighttime infrared emission data collected by satellites from 1985 to 2009. This data indicates that 167 of Earth's largest lakes warmed at an average rate of two degrees Fahrenheit per decade over this 25 year period. This warming trend has been most visible in the Northern Hemisphere; lakes in the tropics and Southern Hemisphere showed little or no warming during this period. Lakes in the Southwest, such as Lake Tahoe and The Great Salt Lake, showed the most pronounced trends for United States lakes.
For Comparison: The two degree Fahrenheit warming of large inland lakes between 1985 and 2009 is noticeably larger than the global surface temperature warming of about 0.7 degrees Fahrenheit observed over this same period.
A few other links you might find of interest:
The Priscilla Mahar Animal Welfare Foundation: http://www.pmawf.org
All Weather Facebook site. Search Precision Weather Service and "like"
