Acceleration of U.S. Southeast and Gulf coast sea-level rise amplified by internal climate variability

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: April 10, 2023

While there is evidence for an acceleration in global mean sea level (MSL) since the 1960s, its detection at local levels has been hampered by considerable influence of natural variability on rate MSL change. Here we report a tide gauge records along U.S. Southeast and Gulf coasts that led to rates (>10 mm yr-1 2010) are unprecedented least 120 years. We show this primarily induced ocean dynamic signal exceeding externally forced response from historical climate model simulations. However, when simulated removed observations, residuals neither historically nor inconsistent with internal A large fraction consistent wind driven Rossby waves tropical North Atlantic. This indicates ongoing represents compounding effects external forcing variability.

Language: Английский

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What Forcing Mechanisms Affect the Interannual Sea Level Co‐Variability Between the Northeast and Southeast Coasts of the United States?

Journal of Geophysical Research Oceans, Journal Year: 2024, Volume and Issue: 129(1)

Published: Jan. 1, 2024

Abstract Interannual sea‐level variations between the United States (U.S.) Northeast and Southeast Coasts separated by Cape Hatteras are significantly less correlated than those within their respective sectors, but cause is poorly understood. Here we investigate atmospheric forcing mechanisms that affect interannual co‐variability these two sectors using an adjoint reconstruction decomposition approach in framework of Estimating Circulation Climate Ocean (ECCO) ocean state estimate. We compare modeled observed changes at representative locations each sector: Nantucket Island, Massachusetts for Charleston, South Carolina Southeast. The used this work allows identification quantification causal responsible coastal variability. Coherent Charleston arise from nearshore wind stress anomalies north buoyancy forcing, especially subpolar North Atlantic, while offshore anomalies, contrast, reduce co‐variability. Offshore contributes much more to variation Nantucket, causing incoherent sea level locations. Buoyancy south including over Florida shelf, Gulf Mexico, Caribbean Sea, also because they induce responses not Nantucket. However, relative impact on smaller stress.

Language: Английский

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A novel statistical approach to predict seasonal high tide flooding

Frontiers in Marine Science, Journal Year: 2022, Volume and Issue: 9

Published: Dec. 8, 2022

Sea level rise is increasing the frequency of high tide flooding in coastal communities across United States. Although occurrence and severity high-tide will continue to increase, skillful prediction on monthly-to-annual time horizons lacking most regions. Here, we present an approach predict daily likelihood at locations throughout U.S. using a novel probabilistic modeling that relies relative sea-level rise, predictions, climatological non-tidal residuals as measured by NOAA gauges. A retrospective skill assessment sea information indicates this 61 out 92 gauges where least 10 flood days occurred from 1997–2019. In case, day occurs when observed water exceeds gauge-specific threshold. For these gauges, average 35% all floods are accurately predicted model, with over half 18 The corresponding False-Alarm-Rate less than 10% for Including mean anomaly persistence leads 1 3 months further improves model many locations, especially Pacific Islands West Coast. Model shown increase substantially nearly tides more frequently exceed Assuming intermediate amount likely be 93 94 projected have regular 2040. These results demonstrate viable incorporated into decision-support products provide guidance days. Further, structure enable future incorporation predictions numerical, statistical, andmachine learning forecast systems.

Language: Английский

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Profound Changes in the Seasonal Cycle of Sea Level Along the United States Mid‐Atlantic Coast

Geophysical Research Letters, Journal Year: 2025, Volume and Issue: 52(2)

Published: Jan. 12, 2025

Abstract The monthly mean sea level along the U.S. Mid‐Atlantic Coast varies seasonally, reaching a minimum in January and maximum September during 1960–2020 period. However, this seasonal cycle has changed significantly on multi‐decadal timescales. In last two decades, annual shifted from to February. amplitude of changes increased by 65% 14.16 cm 1980–1999 23.16 2000–2020. Even more concerning, rose 82%, 6.81 12.38 cm, potentially exacerbating coastal flooding over past 20 years. A two‐layer ocean model effectively replicates both phase magnitude observed attributes these shifts wind stress near coast, with relatively minor influence deep forcing. Both alongshore cross‐shore are found contribute level's cycle.

Language: Английский

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Nonstationary Roles of Regional Forcings in Driving Low‐Frequency Sea Level Variability Along the U.S. East Coast Since the 1950s

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(15)

Published: Aug. 7, 2023

Abstract The nonstationary roles of regional forcings from alongshore wind stress and sea level pressure (SLP) in driving low‐frequency (interannual‐to‐decadal) variability along the U.S. east coast for 1959–2020 period are investigated. role increases with time north Cape Hatteras particularly during summer when their contributions to variance observed summertime coastal anomalies increase by approximately 58%–87% 1959–1989 1990–2020. enhanced impact recent decades results an Inverted Barometer (IB) effect that act constructively especially summer, a lesser extent Gulf Maine fall. North Atlantic Oscillation (NAO) is largely responsible increased IB effect, owing stronger NAO‐associated low SLP centered around Mid‐Atlantic Bight compared earlier decades.

Language: Английский

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A Link Between U.S. East Coast Sea Level and North Atlantic Subtropical Ocean Heat Content

Authorea (Authorea), Journal Year: 2024, Volume and Issue: unknown

Published: June 13, 2024

Using a recently developed 1/12th degree regional ocean model, we establish link between U.S. East Coast sea level variability and offshore upper-ocean heat content change. This manifests as cross-shore mass redistribution driven by an thermosteric response to subsurface warming or cooling. Approximately 50\% of simulated monthly inter-annual coastal variance south Cape Hatteras can be statistically accounted for this mechanism, realized function hypsometry, gyre scale warming, the depth-dependence density explains non-stationarity coast covariance, specifically observed modeled behavior after $\sim$ 2010. Since approximately 2010, elevated rates rise partly explained result shore-ward due sub-surface within North Atlantic subtropical gyre. These results reveal mechanism that connects local broader region identifies influence changes on level. analysis presents framework identifying new regions may susceptible enhanced helps bridge gap quantifying large change anticipating impacts like flooding storm surge.

Language: Английский

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A Link Between U.S. East Coast Sea Level and North Atlantic Subtropical Ocean Heat Content

Journal of Geophysical Research Oceans, Journal Year: 2024, Volume and Issue: 129(12)

Published: Dec. 1, 2024

Abstract Using a recently developed 1/12th degree regional ocean model, we establish link between U.S. East Coast sea level variability and offshore upper heat content change. This manifests as cross‐shore mass redistribution driven by an thermosteric response to subsurface warming or cooling. Approximately 50% of simulated monthly interannual coastal variance south Cape Hatteras can be statistically accounted for this mechanism, realized function hypsometry, gyre scale warming, the depth dependence density explains nonstationarity covariance, specifically observed modeled behavior after 2010. Since approximately 2010, elevated rates rise partly explained result shoreward due within North Atlantic subtropical gyre. These results reveal mechanism that connects local broader region identifies influence changes on level. analysis presents framework identifying new regions may susceptible enhanced helps bridge gap quantifying large change anticipating impacts make flooding storm surge more acutely damaging.

Language: Английский

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Influence of Ocean Model Horizontal Resolution on the Representation of Global Annual‐To‐Multidecadal Coastal Sea Level Variability

Journal of Geophysical Research Oceans, Journal Year: 2024, Volume and Issue: 129(12)

Published: Dec. 1, 2024

Abstract Emerging high‐resolution global ocean climate models are expected to improve both hindcasts and forecasts of coastal sea level variability by better resolving turbulence other small‐scale phenomena. To examine this hypothesis, we compare annual multidecadal over the 1993–2018 period, as observed tide gauges simulated two identically forced models, at (LR) (HR) horizontal resolution. Differences between HR LR, misfits with gauges, spatially coherent regional alongcoast scales. Resolution‐related improvements largest in, near, marginal seas. Near attached western boundary currents, variance is several times greater in than but correlations observations may be reduced, due intrinsic variability. Globally, simulations, comprises from zero 80% variance. Outside eddy‐rich regions, generally damped relative observations. We hypothesize that weak related large‐scale, remotely forced, variability; tropical underestimated 50% satellite altimetric Similar dynamical regimes (e.g., currents) exhibit a consistent sensitivity resolution, suggesting these findings generalizable regions limited

Language: Английский

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