Streaming Media
Presentation Abstract
The U.S. Geological Survey Coastal Storm Modeling System (CoSMoS) is being developed for the Salish Sea to evaluate flood hazards at a scale of 1 m to support coastal planning into the next century. CoSMoS computes extreme water levels and flooding accounting for projected sea level rise and climate change effects on river floods and storms. Modeled tides and storm surge show a mean absolute error of 10 cm across NOAA and USGS tide gages over the hindcast period 2018-2019. Model forcings deconstructed over a 1985-2015 hindcast indicate that storm surge inside Puget Sound is driven primarily by atmospheric pressure anomalies (up to 45 cm), outer shelf wind and current dynamics (up to 45 cm), large-scale North Pacific Ocean dynamics and interannual phenomena like the El Niño-Southern Oscillation (up to 20 cm), and wind setup generated within the Salish Sea (up to 20 cm). Future conditions are evaluated with spatiotemporally varying fields derived from dynamically-downscaled global climate models at 12 km spatial and hourly temporal resolution. Coastal water levels, waves, sea level rise and stream flows then drive a computationally rapid 2D flood solver that calculates overland flooding to the year 2100. Significant wave heights, wave runup, and the extent, depth, and duration of flooding are estimated for hundreds of extreme events to define storm recurrence intervals and map exposure in the future based on several climate change scenarios. Initial results across Whatcom County and Whidbey Basin reveal the spatial and temporal variability of shoreline and habitat exposure to daily, King tide and 1-, 5-, 10-, 20-, 50-, and 100-yr flood recurrence events with 7 projected sea level rise scenarios. Examples of CoSMoS results, a socioeconomic tool to assess details of projected population, property, and land cover exposure, and their integration into shoreline and restoration planning are discussed.
Session Title
Climate Science 2: Water
Conference Track
SSE8: Climate Change
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-traditionals-180
Start Date
27-4-2022 9:45 AM
End Date
27-4-2022 11:15 AM
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Downscaling future climate models for local flood and socioeconomic exposure across the Salish Sea with the Coastal Storm Modeling System (CoSMoS)
The U.S. Geological Survey Coastal Storm Modeling System (CoSMoS) is being developed for the Salish Sea to evaluate flood hazards at a scale of 1 m to support coastal planning into the next century. CoSMoS computes extreme water levels and flooding accounting for projected sea level rise and climate change effects on river floods and storms. Modeled tides and storm surge show a mean absolute error of 10 cm across NOAA and USGS tide gages over the hindcast period 2018-2019. Model forcings deconstructed over a 1985-2015 hindcast indicate that storm surge inside Puget Sound is driven primarily by atmospheric pressure anomalies (up to 45 cm), outer shelf wind and current dynamics (up to 45 cm), large-scale North Pacific Ocean dynamics and interannual phenomena like the El Niño-Southern Oscillation (up to 20 cm), and wind setup generated within the Salish Sea (up to 20 cm). Future conditions are evaluated with spatiotemporally varying fields derived from dynamically-downscaled global climate models at 12 km spatial and hourly temporal resolution. Coastal water levels, waves, sea level rise and stream flows then drive a computationally rapid 2D flood solver that calculates overland flooding to the year 2100. Significant wave heights, wave runup, and the extent, depth, and duration of flooding are estimated for hundreds of extreme events to define storm recurrence intervals and map exposure in the future based on several climate change scenarios. Initial results across Whatcom County and Whidbey Basin reveal the spatial and temporal variability of shoreline and habitat exposure to daily, King tide and 1-, 5-, 10-, 20-, 50-, and 100-yr flood recurrence events with 7 projected sea level rise scenarios. Examples of CoSMoS results, a socioeconomic tool to assess details of projected population, property, and land cover exposure, and their integration into shoreline and restoration planning are discussed.
