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The State of Climate Modeling in the Great Lakes Basin - a Synthesis in Support of a Workshop Held on June 27, 2019 in Ann Arbor, MI

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The State of Climate Modeling in the Great Lakes Basin - a Synthesis in Support of a Workshop Held on June 27, 2019 in Ann Arbor, MI The State of Climate Modeling in the Great Lakes Basin A Synthesis in Support of a Workshop held on June 27, 2019 in Ann Arbor, MI Report By: Ontario Climate Consortium Date: September 13, 2019 Acknowledgements: This synthesis report has been prepared in partnership by the Ontario Climate Consortium (OCC), and Environment and Climate Change Canada. The authors wish to acknowledge the following individuals for their contributions to this project: Kristina Dokoska, Ontario Climate Consortium Nishal Shah, Ontario Climate Consortium Greg Mayne, Environment and Climate Change Canada Wendy Leger, Environment and Climate Change Canada Frank Seglenieks, Environment and Climate Change Canada Armin Dehghan, Environment and Climate Change Canada Shaffina Kassam, Environment and Climate Change Canada Heather Arnold, Environment and Climate Change Canada Shivani Vigneswaran, Environment and Climate Change Canada Recommended Citation: Delaney, F. and Milner, G. 2019. The State of Climate Modeling in the Great Lakes Basin - A Synthesis in Support of a Workshop held on June 27, 2019 in Ann Arbor, MI. Toronto, Canada. www.climateconnections.com | 2 Table of Contents Executive Summary .......................................................................................................................................................................... 4 1. Introduction ................................................................................................................................................................................... 7 1.1 The Great Lakes Basin ........................................................................................................................................................ 7 1.2 Climate Change Impacts and the Need for Climate Modeling in the Great Lakes Basin ..................................................... 7 1.3 Objectives of this Report and Workshop .............................................................................................................................. 8 2. Background ................................................................................................................................................................................... 8 2.1 Global Circulation Models (GCMs) and Regional Climate Models (RCMs) ......................................................................... 8 2.2 Downscaling Methods ........................................................................................................................................................ 10 2.3 Ensemble Approach .......................................................................................................................................................... 11 2.4 Climate Change Scenarios ................................................................................................................................................ 12 3. An Overview of Climate Models that Incorporate Great Lakes Conditions .................................................................................. 14 3.1 Taking Stock of Models in the Great Lakes: An Inventory ................................................................................................. 14 3.1.1 Global Circulation Models (GCMs) ................................................................................................................................ 14 3.1.2. Regional Climate Models (RCMs) ................................................................................................................................ 16 3.1.2.1.Ensembles Available for Use in the Great Lakes Basin ............................................................................................. 19 3.1.3. Hydrodynamic Models .................................................................................................................................................. 29 3.2 Limitations, Gaps and Uncertainties .................................................................................................................................. 32 4. Applying Climate Model Information across the Great Lakes Basin ........................................................................................... 35 4.1 Users of Climate Model Information ................................................................................................................................... 35 4.2 Climate Service Providers across the Great Lakes Basin .................................................................................................. 37 4.3 Common Approaches Applied in Great Lakes Basin ......................................................................................................... 38 5. Recommendations for Climate Modelers, Translators, and Users .............................................................................................. 41 6. Conclusions and Next Steps ....................................................................................................................................................... 45 7. References ................................................................................................................................................................................. 46 Appendix A: Stakeholder Workshop Agenda .................................................................................................................................. 58 Appendix B: Overview of Climate Change Modeling Experts Workshop, June 27, 2019 ................................................................ 60 Appendix C: Detailed Inventory of 1-Dimensional Climate Models in the Great Lakes ................................................................... 70 Appendix D: Detailed Inventory of 3-Dimensional Climate Models in the Great Lakes ................................................................... 72 Appendix E: List of 41 Studies Reviewed for Analysis of Climate Models Uses by Practitioners in the Great Lakes Basin ........... 73 Appendix F: Comparison of Projected Changes in the Great Lakes Basin for RCP8.5 - representative of Southwestern, ON, Canada* .......................................................................................................................................................................................... 78 www.climateconnections.com | 3 Executive Summary The Great Lakes Basin (GLB) is one of the planet's largest freshwater ecosystems and is a vital source of drinking water for over 20 million people. In recent decades, the GLB has felt the impacts of climate change. These changes include higher temperatures, increased precipitation, reduced snow cover, abrupt lake warming, decreased annual lake ice coverage, increased wind speeds and waves, fluctuating lake levels, changes in timing and quantity of precipitation events, and an increased number of extreme weather events (Wang et al., 2017). These changes are and will continue to have a significant impact on the GLB’s natural assets and population including but not limited to increased flooding, erosion of shorelines, contamination of water, and/or the loss and alterations of habitats for a variety of aquatic species (Mortsch, 1998). It is thus important that sound scientific projections of these climatic changes exist to assess the extent of the impacts of climate change within the GLB, and to communicate these impacts with GLB communities and residents. This report provides a summary of the state of climate modeling in the GLB and assesses model strengths and limitations, the knowledge gaps climate modelers face, the state of climate model users and translators, and recommendations for modelers, users, and translators moving forward. The state of climate modeling in the Great Lakes has enhanced significantly in the past few decades. Global Climate Models (GCMs) have traditionally been used to characterize the Earth's climate through the modeling of the ocean-atmosphere circulation. The coarse spatial resolution that these models operate on creates challenges for the GLB. Most climatological studies in the GLB now use Regional Climate Models (RCMs) which offer higher resolution, dynamically downscaled GCM output under a more regional climate context. This increased resolution allows for a more accurate representation of climatological variables across hydrological features, which are typically represented as land surfaces on GCMs. Efforts have been made in creating one- and three-dimensional hydrodynamic models for specific phenomena of the Great Lakes, and many modelers have started to couple these models with RCMs or GCMs to better predict climate impacts across the GLB. While there have been significant strides in climate change projections for the GLB, there exist numerous gaps in data collection, model development, and in the general understanding of the Great Lakes and their interactions from outside influences, such as large teleconnection patterns from the Gulf of Mexico and the Atlantic Ocean. www.climateconnections.com | 4 Current State of Knowledge Gaps in Data and Monitoring, Model Development, and of the Great Lakes themselves: The following provides a summary of the gaps identified in the literature review undertaken on climate modeling for the Great Lakes: 1. Data and Monitoring Gaps ➢ Urban and agricultural land use ➢ Lake surface and profile temperatures ➢ Ice cover and ice thickness (e.g., areas of ridging and rafting) ➢ Energy exchanges and interfaces of land, lakes, ice, atmosphere, and hydrologic
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