Collaborative Research: How do Coastlines Respond to Storm Climate Shifts?

Drawn by the beauty and recreational opportunities of beaches, communities and economies have sprung up along many coastlines in the last half century. However, coastal environments tend to change more rapidly than other landscapes, posing challenges to maintaining development. Shorelines change position, often moving landward (eroding) over years and decades, bringing the shoreline and storm impacts ever closer to homes and infrastructure originally constructed at a safe distance.

The storm impacts that threaten communities range from short term beach erosion to flooding from storm surge—all driven by wind and waves and amplified by increasing rates of sea-level rise. This project will transform the understanding of what causes shorelines to move in such complicated ways, and it will create an opportunity to forecast changes in shoreline erosion and storm hazards in coming decades (and century).

The forecasting opportunity arises because winds over an ocean basin produce waves, and because changes in typical patterns of winds in the future can be forecast using global climate models. This project features further development and application of sophisticated techniques for translating forecast future weather over an entire ocean basin into the winds and waves affecting specific shorelines in coming decades.

The wind and wave forecasts will, in turn, feed into computer models representing how waves and storm surge move sand around, leading to forecasts of patterns of shoreline erosion ‘hot spots’ as well as storm hazards. This project will bring together experts in shoreline change from around the world to test what is most important in producing shoreline change over days, years, and decades, by comparing model results with observations and with each other.

The results of this model intercomparison will be shared broadly and translated into educational materials through the Community Surface Dynamics Modeling System and the Museum of Life and Science.

In the coming decades coastlines will move even more rapidly than in the past. Along with the effects of sea-level rise, changing storm behaviors—whether related to decadal-scale climate oscillations or to longer-term trends—cause magnitudes and locations of coastal erosion ‘hot spots’ to shift, compounding threats to coastal communities. This project will revolutionize the scientific community’s ability to understand and forecast coastline change patterns, over timescales ranging from a year to a century.

The project starts with the development of new, efficient approaches to downscaling Global Climate Model output to produce forecasts of the waves and winds affecting particular coastlines. This pioneering work will address the Carolina coastline as an initial case study. The downscaled wave data will then drive coupled models addressing coastline shape and position, in response to storm/wave climate shifts, sea-level rise, and inlet dynamics.

Model hindcasts will be confronted with historical observations to test the new model and the importance of large-scale coastline dynamics in long-term shoreline change. The downscaled wave, wind, and water-level data will also form the centerpiece of a workshop and community model-intercomparison effort that will bring together contrasting coastline-change models, with the common goal of hindcasting and forecasting changes, comparing the results with each other and with observations, and thereby accelerating coastal science.

This project is jointly funded by the Marine Geology and Geophysics program in the Division of Ocean Sciences and the Geomorphology and Land-use Dynamics program in the Division of Earth Sciences.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.