Seasonal variation of speed and width from kinematic parameters of mode-1 nonlinear internal waves in the northeastern East China Sea

TitleSeasonal variation of speed and width from kinematic parameters of mode-1 nonlinear internal waves in the northeastern East China Sea
Publication TypeJournal Article
Year of Publication2016
AuthorsCho C, Nam SH, Song H
JournalJournal of Geophysical Research: Oceans
Volume121
Pagination5942-5958
Date Published2016/11
Type of ArticleJournal article
ISBN Number2169-9291
Keywords4219 Continental shelf and slope processes; 4544 Internal and inertial waves; east china sea; high-frequency internal waves; KdV theory; nonlinear internal waves; seasonal cycle; South of Jeju Island
Abstract

To better understand the statistical and theoretical characteristics of nonlinear internal waves (NLIWs) in the broad continental shelf of the northeastern East China Sea (ECS), historical hydrographic data collected over 50 years between 1962 and 2011 are analyzed to calculate monthly climatology. Based on KdV and extended KdV models under the two-layer approximation (i.e., mode-1 NLIWs), the monthly climatology for propagating speed and characteristic width is constructed, ranging from 0.8 to 1.2 m s−1 and from O(102) to O(103) m, respectively. The result is consistent with a few previous in situ observations in the region. When NLIWs originating in the southeastern slope area approach the shallower regime (northwestward propagation), they propagate more slowly with neither break nor extinction, but with a shorter width, since both the Iribarren and Ostrovsky numbers are small (Ir ≪ 0.45 and Os ≪ 1, respectively). Limitations of the two-layered KdV-type models are discussed (e.g., an importance of mode-2 waves) in the context of occasional extension of the low-salinity Changjiang Discharged Water onto the area, which implies distinct effects on the kinematic parameters of NLIWs in the ECS.

DOI10.1002/2016JC012035
Student Publication: 
No
Research Topics: 
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