That set the stage for an algae bloom that covered about 2,000 square miles by the time it peaked in early October 2011. That's more than three times larger than any previously observed Lake Erie algae bloom, including blooms that occurred in the 1960s and 1970s, when the lake was famously declared dead.
The 2011 spring storms included one that dumped 2 inches of rain over Ohio's Maumee River basin in 24 hours on May 26 and 6.8 inches total for the month of May 2011more than 20 percent above the long-term monthly average. The Maumee is a primary tributary to western Lake Erie, and it drains an agricultural watershed where corn, soybeans and wheat are grown.
In their study, the researchers used 12 computerized climate models to determine if rainstorms like the May 2011 events are more likely to occur in the future. The models, which incorporate the anticipated effects of human-caused climate change due to the buildup of heat-trapping greenhouse gases, showed that the frequency of spring rainstorms that drop more than 1.2 inches is likely to double in this region by the end of the century.
"The models do predict an increase in extreme springtime precipitation events, and that's driven by an increase in greenhouse gases," said Steiner, an associate professor in the Department of Atmospheric, Oceanic and Space Sciences.
Once the 2011 Lake Erie bloom formed, unusually warm water temperatures and calm winds created ideal conditions to promote summer algae growth. "All of these factors are consistent with expected future conditions," the 29 authors of the PNAS paper wrote.
An algae bloom is a rapid buildup of algae in a body of water, and harmful blooms are those that damage other organismsincluding humansthrough the production of toxins or by other means. Algae blooms c
|Contact: Jim Erickson|
University of Michigan