Observational Evidence of Generation and Propagation of Barotropic Rossby Waves Induced by Tropical Instability Waves in the Northeastern Pacific

Abstract Tropical instability waves (TIWs) in the equatorial eastern Pacific exhibit 25–40‐day westward‐propagating fluctuations with seasonal and interannual variations, which are stronger during July–December and La Niña periods. There is evidence that the instability of the equatorial currents th...

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Main Authors: Kang‐Nyeong Lee, Chanhyung Jeon, YoungHo Seung, Hong‐Ryeol Shin, Seung‐Kyu Son, Jae‐Hun Park
Format: Article
Language:English
Published: Wiley 2022-08-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1029/2022GL098327
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author Kang‐Nyeong Lee
Chanhyung Jeon
YoungHo Seung
Hong‐Ryeol Shin
Seung‐Kyu Son
Jae‐Hun Park
author_facet Kang‐Nyeong Lee
Chanhyung Jeon
YoungHo Seung
Hong‐Ryeol Shin
Seung‐Kyu Son
Jae‐Hun Park
author_sort Kang‐Nyeong Lee
collection DOAJ
description Abstract Tropical instability waves (TIWs) in the equatorial eastern Pacific exhibit 25–40‐day westward‐propagating fluctuations with seasonal and interannual variations, which are stronger during July–December and La Niña periods. There is evidence that the instability of the equatorial currents that generates TIWs also induce radiation of barotropic Rossby waves (BTRWTIW). Long‐term near‐bottom current measurements at 10.5°N and 131.3°W during 2004–2013 revealed a spectral peak at 25–40 days, where significant coherences were found with satellite‐measured sea surface height with maxima approximately 5°N. Simulated deep currents from a data‐assimilated ocean model concur with the observed near‐bottom currents, and both currents vary seasonally and interannually, consistent with the typical characteristics of TIW. Further analyses using 25–40‐day bandpass‐filtered barotropic velocity data from the model revealed that they reasonably satisfied the theoretical dispersion relation of BTRWTIW. The in situ and model analysis support the conclusion that BTRWTIW propagate north of 10°N in the northeastern Pacific.
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institution OA Journals
issn 0094-8276
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language English
publishDate 2022-08-01
publisher Wiley
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series Geophysical Research Letters
spelling doaj-art-435ca14f1a9d4e1b865e1f7616c874e62025-08-20T02:11:38ZengWileyGeophysical Research Letters0094-82761944-80072022-08-014915n/an/a10.1029/2022GL098327Observational Evidence of Generation and Propagation of Barotropic Rossby Waves Induced by Tropical Instability Waves in the Northeastern PacificKang‐Nyeong Lee0Chanhyung Jeon1YoungHo Seung2Hong‐Ryeol Shin3Seung‐Kyu Son4Jae‐Hun Park5Department of Ocean Sciences Inha University Incheon South KoreaDepartment of Oceanography Pusan National University Busan South KoreaDepartment of Ocean Sciences Inha University Incheon South KoreaDepartment of Atmospheric Sciences Kongju National University Gongju‐si South KoreaDeep‐Sea and Seabed Mineral Resources Research Center Korea Institute of Ocean Science & Technology Busan South KoreaDepartment of Ocean Sciences Inha University Incheon South KoreaAbstract Tropical instability waves (TIWs) in the equatorial eastern Pacific exhibit 25–40‐day westward‐propagating fluctuations with seasonal and interannual variations, which are stronger during July–December and La Niña periods. There is evidence that the instability of the equatorial currents that generates TIWs also induce radiation of barotropic Rossby waves (BTRWTIW). Long‐term near‐bottom current measurements at 10.5°N and 131.3°W during 2004–2013 revealed a spectral peak at 25–40 days, where significant coherences were found with satellite‐measured sea surface height with maxima approximately 5°N. Simulated deep currents from a data‐assimilated ocean model concur with the observed near‐bottom currents, and both currents vary seasonally and interannually, consistent with the typical characteristics of TIW. Further analyses using 25–40‐day bandpass‐filtered barotropic velocity data from the model revealed that they reasonably satisfied the theoretical dispersion relation of BTRWTIW. The in situ and model analysis support the conclusion that BTRWTIW propagate north of 10°N in the northeastern Pacific.https://doi.org/10.1029/2022GL098327in situ near‐bottom currenttropical instability wavesbarotropic Rossby wavesinterannual variation
spellingShingle Kang‐Nyeong Lee
Chanhyung Jeon
YoungHo Seung
Hong‐Ryeol Shin
Seung‐Kyu Son
Jae‐Hun Park
Observational Evidence of Generation and Propagation of Barotropic Rossby Waves Induced by Tropical Instability Waves in the Northeastern Pacific
Geophysical Research Letters
in situ near‐bottom current
tropical instability waves
barotropic Rossby waves
interannual variation
title Observational Evidence of Generation and Propagation of Barotropic Rossby Waves Induced by Tropical Instability Waves in the Northeastern Pacific
title_full Observational Evidence of Generation and Propagation of Barotropic Rossby Waves Induced by Tropical Instability Waves in the Northeastern Pacific
title_fullStr Observational Evidence of Generation and Propagation of Barotropic Rossby Waves Induced by Tropical Instability Waves in the Northeastern Pacific
title_full_unstemmed Observational Evidence of Generation and Propagation of Barotropic Rossby Waves Induced by Tropical Instability Waves in the Northeastern Pacific
title_short Observational Evidence of Generation and Propagation of Barotropic Rossby Waves Induced by Tropical Instability Waves in the Northeastern Pacific
title_sort observational evidence of generation and propagation of barotropic rossby waves induced by tropical instability waves in the northeastern pacific
topic in situ near‐bottom current
tropical instability waves
barotropic Rossby waves
interannual variation
url https://doi.org/10.1029/2022GL098327
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