Transient modulation of Kuroshio upper layer flow by directly impinging typhoon Morakot in east of Taiwan in 2009

Zhe Wen Zheng, Quanan Zheng, Chia Ying Lee, Ganesh Gopalakrishnan

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

This study deals with the modulation of the Kuroshio upper layer flow (KULF) in response to the passage of Typhoon Morakot in 2009, using Regional Oceanic Modeling System (ROMS) and in situ measurements from Argos drifters and Argo floats. The analysis of the simulated current fields near the typhoon track revealed an intermittency phenomenon of the KULF, which was almost shut down for at least 6 hours. The process begun 2 days prior to the approach of typhoon center due to blockage of the KULF by the steadily northerly winds, and lasted for more than 2 days, simultaneously shifting the Kuroshio main stream (KMS) path. When the Morakot gradually moved closely to the Kuroshio, the KMS shifted vertically from the surface layer to deeper layer of 50 - 100 m depth, and the maximum current speed in the KMS decreased from more than 1.3 m s-1 to less than 1.1 m s-1. When the Morakot center approached about 100 km to the original position of the Kuroshio, the KULF spread eastward for 1.5 degrees at 24°N. When the Morakot center moved to the original position of the KMS, the Kuroshio abruptly rushed with a maximum speed near 1.4 m s -1. Meanwhile, an offshore cool jet originating from southeastern tip of Taiwan was generated and extended northward along the Kuroshio. In the cool jet, the lowest temperature reached about 5°C lower than the ambient waters. Modeled current variations and the cool jet during the Morakot passage were validated by in situ measurements. Key Points Westward impinging typhoon through Kuroshio triggers Kuroshio intermittency Morakot passage leads to a distinct offshore cool jet southeast of Taiwan Modulations are extraordinarily crucial, due to the strong conveyor, Kuroshio

Original languageEnglish
Pages (from-to)4462-4473
Number of pages12
JournalJournal of Geophysical Research: Oceans
Volume119
Issue number7
DOIs
Publication statusPublished - 2014 Jul

Fingerprint

typhoon
Taiwan
Modulation
modulation
Argo
intermittency
in situ measurement
floats
drifter
surface layer
surface layers
near fields
actuators
Water
temperature
water
modeling
Temperature
speed

Keywords

  • Argos drifters
  • Kuroshio intermittency
  • Kuroshio shift
  • ROMS
  • typhoon Morakot

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

Transient modulation of Kuroshio upper layer flow by directly impinging typhoon Morakot in east of Taiwan in 2009. / Zheng, Zhe Wen; Zheng, Quanan; Lee, Chia Ying; Gopalakrishnan, Ganesh.

In: Journal of Geophysical Research: Oceans, Vol. 119, No. 7, 07.2014, p. 4462-4473.

Research output: Contribution to journalArticle

@article{034ac6f90d754e4fbfb9dbc62a9e2d73,
title = "Transient modulation of Kuroshio upper layer flow by directly impinging typhoon Morakot in east of Taiwan in 2009",
abstract = "This study deals with the modulation of the Kuroshio upper layer flow (KULF) in response to the passage of Typhoon Morakot in 2009, using Regional Oceanic Modeling System (ROMS) and in situ measurements from Argos drifters and Argo floats. The analysis of the simulated current fields near the typhoon track revealed an intermittency phenomenon of the KULF, which was almost shut down for at least 6 hours. The process begun 2 days prior to the approach of typhoon center due to blockage of the KULF by the steadily northerly winds, and lasted for more than 2 days, simultaneously shifting the Kuroshio main stream (KMS) path. When the Morakot gradually moved closely to the Kuroshio, the KMS shifted vertically from the surface layer to deeper layer of 50 - 100 m depth, and the maximum current speed in the KMS decreased from more than 1.3 m s-1 to less than 1.1 m s-1. When the Morakot center approached about 100 km to the original position of the Kuroshio, the KULF spread eastward for 1.5 degrees at 24°N. When the Morakot center moved to the original position of the KMS, the Kuroshio abruptly rushed with a maximum speed near 1.4 m s -1. Meanwhile, an offshore cool jet originating from southeastern tip of Taiwan was generated and extended northward along the Kuroshio. In the cool jet, the lowest temperature reached about 5°C lower than the ambient waters. Modeled current variations and the cool jet during the Morakot passage were validated by in situ measurements. Key Points Westward impinging typhoon through Kuroshio triggers Kuroshio intermittency Morakot passage leads to a distinct offshore cool jet southeast of Taiwan Modulations are extraordinarily crucial, due to the strong conveyor, Kuroshio",
keywords = "Argos drifters, Kuroshio intermittency, Kuroshio shift, ROMS, typhoon Morakot",
author = "Zheng, {Zhe Wen} and Quanan Zheng and Lee, {Chia Ying} and Ganesh Gopalakrishnan",
year = "2014",
month = "7",
doi = "10.1002/2014JC010090",
language = "English",
volume = "119",
pages = "4462--4473",
journal = "Journal of Geophysical Research: Oceans",
issn = "2169-9275",
number = "7",

}

TY - JOUR

T1 - Transient modulation of Kuroshio upper layer flow by directly impinging typhoon Morakot in east of Taiwan in 2009

AU - Zheng, Zhe Wen

AU - Zheng, Quanan

AU - Lee, Chia Ying

AU - Gopalakrishnan, Ganesh

PY - 2014/7

Y1 - 2014/7

N2 - This study deals with the modulation of the Kuroshio upper layer flow (KULF) in response to the passage of Typhoon Morakot in 2009, using Regional Oceanic Modeling System (ROMS) and in situ measurements from Argos drifters and Argo floats. The analysis of the simulated current fields near the typhoon track revealed an intermittency phenomenon of the KULF, which was almost shut down for at least 6 hours. The process begun 2 days prior to the approach of typhoon center due to blockage of the KULF by the steadily northerly winds, and lasted for more than 2 days, simultaneously shifting the Kuroshio main stream (KMS) path. When the Morakot gradually moved closely to the Kuroshio, the KMS shifted vertically from the surface layer to deeper layer of 50 - 100 m depth, and the maximum current speed in the KMS decreased from more than 1.3 m s-1 to less than 1.1 m s-1. When the Morakot center approached about 100 km to the original position of the Kuroshio, the KULF spread eastward for 1.5 degrees at 24°N. When the Morakot center moved to the original position of the KMS, the Kuroshio abruptly rushed with a maximum speed near 1.4 m s -1. Meanwhile, an offshore cool jet originating from southeastern tip of Taiwan was generated and extended northward along the Kuroshio. In the cool jet, the lowest temperature reached about 5°C lower than the ambient waters. Modeled current variations and the cool jet during the Morakot passage were validated by in situ measurements. Key Points Westward impinging typhoon through Kuroshio triggers Kuroshio intermittency Morakot passage leads to a distinct offshore cool jet southeast of Taiwan Modulations are extraordinarily crucial, due to the strong conveyor, Kuroshio

AB - This study deals with the modulation of the Kuroshio upper layer flow (KULF) in response to the passage of Typhoon Morakot in 2009, using Regional Oceanic Modeling System (ROMS) and in situ measurements from Argos drifters and Argo floats. The analysis of the simulated current fields near the typhoon track revealed an intermittency phenomenon of the KULF, which was almost shut down for at least 6 hours. The process begun 2 days prior to the approach of typhoon center due to blockage of the KULF by the steadily northerly winds, and lasted for more than 2 days, simultaneously shifting the Kuroshio main stream (KMS) path. When the Morakot gradually moved closely to the Kuroshio, the KMS shifted vertically from the surface layer to deeper layer of 50 - 100 m depth, and the maximum current speed in the KMS decreased from more than 1.3 m s-1 to less than 1.1 m s-1. When the Morakot center approached about 100 km to the original position of the Kuroshio, the KULF spread eastward for 1.5 degrees at 24°N. When the Morakot center moved to the original position of the KMS, the Kuroshio abruptly rushed with a maximum speed near 1.4 m s -1. Meanwhile, an offshore cool jet originating from southeastern tip of Taiwan was generated and extended northward along the Kuroshio. In the cool jet, the lowest temperature reached about 5°C lower than the ambient waters. Modeled current variations and the cool jet during the Morakot passage were validated by in situ measurements. Key Points Westward impinging typhoon through Kuroshio triggers Kuroshio intermittency Morakot passage leads to a distinct offshore cool jet southeast of Taiwan Modulations are extraordinarily crucial, due to the strong conveyor, Kuroshio

KW - Argos drifters

KW - Kuroshio intermittency

KW - Kuroshio shift

KW - ROMS

KW - typhoon Morakot

UR - http://www.scopus.com/inward/record.url?scp=84906272112&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84906272112&partnerID=8YFLogxK

U2 - 10.1002/2014JC010090

DO - 10.1002/2014JC010090

M3 - Article

AN - SCOPUS:84906272112

VL - 119

SP - 4462

EP - 4473

JO - Journal of Geophysical Research: Oceans

JF - Journal of Geophysical Research: Oceans

SN - 2169-9275

IS - 7

ER -