Effects of Balanced Motions and Unbalanced Internal Waves on Steric Height in the Mid‐Latitude Ocean
Type | Article | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Date | 2024-03 | ||||||||||||
Language | English | ||||||||||||
Author(s) | Zhang Xiujie1, Yu Xiaolong1, 2, 3, Ponte Aurelien4, Gong Wenping1, 2 | ||||||||||||
Affiliation(s) | 1 : School of Marine Sciences Sun Yat‐sen University Zhuhai, China 2 : Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Zhuhai ,China 3 : Fujian Provincial Key Laboratory of Marine Physical and Geological Processes Third Institute of Oceanography Xiamen ,China 4 : Ifremer Université de Brest CNRS IRD Laboratoire D’Océanographie Physique et Spatiale IUEM Brest ,France |
||||||||||||
Source | Geophysical Research Letters (0094-8276) (American Geophysical Union (AGU)), 2024-03 , Vol. 51 , N. 6 , P. e2023GL106480 (10p.) | ||||||||||||
DOI | 10.1029/2023GL106480 | ||||||||||||
Keyword(s) | steric height, submesoscale motions, internal waves, SWOT | ||||||||||||
Abstract | The baroclinic component of the sea surface height, referred to as steric height, is governed by geostrophically balanced motions and unbalanced internal waves, and thus is an essential indicator of ocean interior dynamics. Using yearlong measurements from a mooring array, we assess the distribution of upper‐ocean steric height across frequencies and spatial scales of O (1–20 km) in the northeast Atlantic. Temporal decomposition indicates that the two largest contributors to steric height variance are large‐scale atmospheric forcing (32.8%) and mesoscale eddies (34.1%), followed by submesoscale motions (15.2%), semidiurnal internal tides (8%), super‐tidal variability (6.1%) and near‐inertial motions (3.8%). Structure function diagnostics further reveal the seasonality and scale dependence of steric height variance. In winter, steric height is dominated by balanced motions across all resolved scales, whereas in summer, unbalanced internal waves become the leading‐order contributor to steric height at scales of O (1 km). |
||||||||||||
Licence | |||||||||||||
Full Text |
|