Chesapeake Bay Summer Review

Dissolved oxygen mapEcoCheck (NOAA-UMCES partnership) has released the 2011 summer review. This year's summer conditions were influenced by high spring river flow, hot summer air temperatures, and late summer storms. Dissolved oxygen conditions were poor this summer, with the second largest volume of anoxic waters during late July in the last 25 years. Strong winds during Hurricane Irene mixed oxygen from the surface to the bottom waters during August and the volume of anoxic waters shrunk dramatically. Tropical Storm Lee brought heavy rains to an already saturated watershed, resulting in flooding of many rivers and washing tons of dirt and debris into the system. When compared to the forecast, the anoxic volume was greater than predicted for the early summer. The late summer anoxia forecast was for larger than the observed volume, which decreased due to the hurricane-driven mixing.