Generation of Quasi‐Biweekly Yanai Waves in the Equatorial Indian Ocean
2020; American Geophysical Union; Volume: 47; Issue: 16 Linguagem: Inglês
10.1029/2020gl088915
ISSN1944-8007
AutoresIsabella B. Arzeno‐Soltero, Sarah N. Giddings, Geno Pawlak, Robert Pinkel,
Tópico(s)Tropical and Extratropical Cyclones Research
ResumoAbstract The spatial and temporal structure of quasi‐biweekly Yanai waves in the Indian Ocean and their relationship to wind stress are uniquely described using satellite observations of sea level anomalies and wind velocities, previously approximated only using theory, numerical models, and discrete mooring observations. Yanai waves represent a significant contribution to equatorial antisymmetric sea level anomaly variability in the 10–20 day band. Robust climatologies produced using 17 years of data (spanning 45–95°E and 10°S to 10°N) reveal a clear spatiotemporal pattern and are consistent with Yanai wave generation in the western equatorial Indian Ocean during monsoon seasons. Spectral and correlation analyses imply that Yanai waves are linearly forced by wind stress patterns with similar wavelengths. A new method of assembling data composites shows the first full structure of a vertical mode‐2 Yanai wave moving across the equatorial Indian Ocean under westward propagating wind vortices.
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