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Abstract Global ocean mean salinityis a key indicator of the Earth's hydrological cycle and the exchanges of freshwater between land and ocean, but its determination remains a challenge. Aside from traditional methods based on gridded salinity fields derived from in situ measurements, we explore estimates ofbased on liquid freshwater changes derived from space gravimetry data corrected for sea ice effects. For the 2005–2019 period analyzed, the differentseries show little consistency in seasonal, interannual, and long‐term variability. In situ estimates show sensitivity to choice of product and unrealistic variations. A suspiciously large rise insince ∼2015 is enough to measurably affect halosteric sea level estimates and can explain recent discrepancies in the global mean sea level budget. Gravimetry‐basedestimates are more realistic, inherently consistent with estimated freshwater contributions to global mean sea level, and provide a way to calibrate the in situ estimates.
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North American East Coast Sea Level Exhibits High Power and Spatiotemporal Complexity on Decadal Timescales
Abstract Tide gauges provide a rich, long‐term, record of the amplitude and spatiotemporal structure of interannual to multidecadal coastal sea‐level variability, including that related to North American east coast sea level “hotspots.” Here, using wavelet analyses, we find evidence for multidecadal epochs of enhanced decadal (10–15 year period) sea‐level variability at almost all long (70 years) east coast tide gauge records. Within this frequency band, large‐scale spatial covariance is time‐dependent; notably, coastal sectors north and south of Cape Hatteras exhibit multidecadal epochs of coherence (1960–1990) and incoherence (1990‐present). Results suggest that previous interpretations of along coast covariance, and its underlying physical drivers, are clouded by time‐dependence and frequency‐dependence. Although further work is required to clarify the mechanisms driving sea‐level variability in this frequency band, we highlight potential associations with the North Atlantic sea surface temperature tripole and Atlantic Multidecadal Variability.
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- Award ID(s):
- 1805029
- PAR ID:
- 10375235
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 48
- Issue:
- 15
- ISSN:
- 0094-8276
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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