Spring Floods May Increase This Year’s Gulf of Mexico Dead Zone
To develop an earlier prediction of the size of the Gulf of Mexico “dead zone” this summer, NOAA’s National Weather Service and National Ocean Service combined data from the National Hydrologic Assessment U.S. Spring Flood Risk Outlook with knowledge of soil saturation and typical weather patterns throughout the Mississippi watershed this year. Based on estimates of flood risk, snow pack, and predicted precipitation, the current above-average conditions in the basin should lead to a larger than normal dead zone size in 2013.
Upper Mississippi and Ohio River watersheds supply most of the nutrients into the Gulf, so examining spring flood risk and associated discharges from these rivers, as well as for the entire Mississippi River, can help predict the size of the summer dead zone.
NOAA plans to develop a 90-day quantitative forecast for the size of the summer dead zone in 2014 using predicted river discharge rates combined with estimated nutrient concentrations; updates will be periodic until the release of the official Gulf of Mexico hypoxic zone forecast in early June. Also in 2014, the Ocean Service and the Weather Service will take the same approach to hypoxia forecasts in the Chesapeake Bay and other regions around the country. Hypoxia is the condition where oxygen concentrations in the water are too low to support life. Creatures that can flee avoid these areas, but those that can’t suffocate and die.
This effort represents a continuing and growing collaboration between the two parts of the agency to forecast ecological phenomena and hypoxia. It is also an action item in the NOAA Ecological Forecasting Roadmap initiative.
Learn more about the outlook for spring weather and hydrology in the NOAA Press Release.
NOAA’s Visualization Laboratory created a great explanation of the dead zone: