Modeling the Chequamegon Bay Ecosystem to Assess Climate Change Impacts

Dr. Randy Lehr, Sigurd Olson Environmental Institute, Northland College, Ashland, WI
Presentation at the Chequamegon Bay Research Symposium, April 14, 2015

Transcript

1. Randy Lehr and Matt Hudson Modeling the Chequamegon Bay Ecosystem to Assess Climate Change Impacts
2. Chequamegon Bay Ecosystem
3. Climate Change Vulnerability • Latitude, bathymetry, isolation, precipitation
4. Climate Change Impacts Warmer Wetter
5. Climate Change Impact Assessment • Integrated Approach – Monitoring – Modeling • Magnitude – Changes in chlorophyll concentration/water clarity • Mechanism – Temperature vs. altered hydrology
6. Watershed/Tributary Monitoring • Continuous discharge gage stations – 15-minute water levels • Continuous data – Temp, SpCond, TSS • Parameter loads (Grab/integrated samples) – TP, SRP, TN, NO3, TOC, DOC, TSS, SSC, E. Coli, DO • Biweekly(ish) sampling
7. Nearshore Monitoring • Physical-chemical measurements – Vertical 1-m profiles: • Temp, pH, SpCond, DO, chl-a, turbidity, cDOM – Vertical profile: • (E) TP, SRP, TN, Chl-a, TSS, DOC, TOC, BOD • (M) TP, SRP, TSS • (H) TP, SRP, TSS – Transect tows (?) • Monthly plankton tows • Current profiles (?) – ADCP • Biweekly sampling
8. Modeling Systems – Climate Response • Food Web Interactions and Aquatic Response – AQUATOX
9. AQUATOX • Food Web Interactions and Aquatic Response – Mechanistic, physical model (mostly) Bioenergetics Bioenergetics and Biogeochemistry
10. Modeling Systems - Hydrodynamic Physically-based • Nearshore Hydrodynamics – Regional Ocean Modeling System • Set-up – Locally bounded – Boundary Forcing = NARR • 5-yr average (2009-2013) – Bathymetry = NOAA – Grid size • 200 meter, 6 Sigma Layers – Time step • 30 sec quant cycle • 1-day average – One month “spin-up” Lake Superior – Open Water
11. Hydrodynamics – Temperature oC (1m)
12. Hydrodynamics – Passive Tracer
13. Hydrodynamics – Buoyant object
14. Tributary Phosphorus
15. Research and Monitoring Directions • Lake-wide Model – SELFE 1. 2014 Validation (USGS) 2. Integration of AQUATOX 3. Hydraulic Retention 4. Sediment-water- precipitation interactions 5. Climate Change Adaptation Planning
16. Chequamegon Bay System • Model Social Ecological System – Science – Decision Support
17. Discussion Questions How can we create better linkages between current and ongoing research and monitoring activities to move us toward better: Science 1. What processes shape and define nearshore ecosystems in Lake Superior? 2. How are aquatic and upland system interconnected in the Lake Superior basin? Management and Decision-making 1. Where and how to deliver conservation and management strategies on the landscape to lead to positive outcomes in the lake? 2. Assisting local communities in preparing and adapting to climate impacts?