Modeling Coastal Hypoxia: Lessons learned and perspectives for the future Part 1

Transcription

1 Modeling Coastal Hypoxia: Lessons learned and perspectives for the future Part 1 R. Eugene Turner 1 Dubravko Justi 1 and Nancy N. Rabalais 2 1 Louisiana State University, USA 2 Louisiana Universities Marine Consortium, USA 46 th International Liege Colloquium on Ocean Dynamics: Low oxygen environments in marine, estuarine and fresh waters 5-9 May 2014 Acknowledgments: NOAA, Center for Sponsored Coastal Ocean Research

2 Macro - Scope Part 1 Telescope and Microscope Part 2

3 Chesapeake Bay N,P Scavia, Evans, Zhou, Liu; Hagy, and others N (P) Baltic Conley et al. Carstensen et al. Great Lakes Sill or no Sill P Scavia, Evans, Zhou N Turner, Justic, Rabalais; Scavia et al; Rabotyagov et al.; Forrest et al.; Greene et al. Northern Gulf of Mexico

4 The lake ocean as a chemostat (the Lake Legacy: e.g., Naumann ; Vollenweider circa 1970s) Data in Simple linear regression models Complex multiple regression models Streeter Phelps Baysian Information Criterion Leontief-type production function General linear and General additive models Description / prediction out

5 A complex set of interactions from nutrient enrichment and physical forcings; Example: the Baltic Carstensen, J., J.H. Andersen, B.G. Gustafsson and D.J. Conley Deoxygenation of the Baltic Sea during the last century. PNAS 111: /

6 Northern Gulf of Mississippi River < 2 mg l-1 up to 22,000 km2 4-5 m nearshore to m offshore 0.5 km nearshore to 100+ km offshore widespread and severe in June September

7 The area of hypoxia has increased since the 1970s A Increasing size as nitrogen (primarily nitrate) and phosphate loading from the Mississippi River increased after WW2; little hypoxia before the 1980s

8 The area of hypoxia has increased since the 1970s The size is driven by Nitrogen loading in the Mississippi River; it has become more sensitive to loading B Stratification important; 3 month lag in N loading; 30% less when storms occur before or during cruise;

9 The area of hypoxia has increased since the 1970s A The size is driven by Nitrogen loading in the Mississippi River; it has become more sensitive to loading B Model coefficients stabilized after 15 years C

10 Load Reduction Targets Government Action Plan target Goal & Target Area (km 2 ) Model Analysis Ensemble Forecast Model-driven Target target Percent N Load Reduction

11 Nice looking model visuals Model Predictions

12 Nice looking model visuals Model Predictions But.. forecasting?

13 Nice looking model visuals Model Predictions But.. forecasting? Without a parachute??

14 Implications of the models: Oceanographers crawl upstream *

15 Land use and nitrate runoff mg N L -1 Crumpton et al Percent cropland

16 Choices - what is missing? Are land-use activities degrading the global environment in ways that ultimately undermine ecosystem services, human welfare, and the long-term sustainability of human societies? (Foley et al. 2005) Will agriculture continue to move towards an industrial model that is more and more like a factory, which will ultimately fail society, or might we put more culture in agriculture and improve the nation s food security and social welfare?

17 It is complicated and worth doing Reganold et al Transforming U.S. Agriculture. Science

18 Options: Farm payments and crop choices Broussard, Turner and Westra, 2012

19 Farm payments and fertilizer applications Broussard, Turner and Westra, 2012

20 One approach: an integrated economic, ecological policy model of landuse and relationship to the hypoxic zone size Rabotyagov et al., Cost-effective targeting of conservation investments to reduce the northern Gulf of Mexico hypoxic zone, submitted

21 Ecological- Economic model of land use choices

22 Ecological- Economic model of land use choices Strategic placement of priority sites

23 Ecological- Economic model of land use choices Strategic placement of priority sites Engage science results with societal policy options AND choices

24 Calibration requires data - e.g., the coefficients did not stabilize for 15 years, and the system is evolving (climate change, system sensitivity, chaos) Simplicity facilitates communication - only if the outputs are not merely precise or visually appealing, but accurate; Expansion from simple to complex was the easy part; coupled human systems are the hard part (to describe); implementation of policy choices is well. difficult

25 Calibration requires data - e.g., the coefficients did not stabilize for 15 years, and the system is evolving (climate change, system sensitivity, chaos) Simplicity facilitates communication - only if the outputs are not merely precise or visually appealing, but accurate; Expansion from simple to complex was the easy part; coupled human systems are the hard part (to describe); implementation of policy choices is well. difficult

26 Calibration requires data - e.g., the coefficients did not stabilize for 15 years, and the system is evolving (climate change, system sensitivity, chaos) Simplicity facilitates communication - only if the outputs are not merely precise or visually appealing, but accurate; Expansion from simple to complex was the easy part; coupled human systems are the hard part (to describe); implementation of policy choices is well. difficult

27 Thank you NEXT: PART 2 The Alchemist; David Teneirs the Younger 1610 to 1690, Antwerp, Belgium (in Galleria Palatina (Palazzo Pitti), Florence, Italy)