Influences of surface heat flux on twin cyclone structure during their explosive development over the East Asian marginal seas on 23 January 2008

The formation of explosively developing twin extratropical cyclones is investigated for background conditions involving a transition from double jets to a single jet. Upper-level double jets produced a latitudinally wide baroclinic zone before formation of the twin cyclones. In the early development...

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Main Authors: Yutaro Yokoyama, Masaru Yamamoto
Format: Article
Language:English
Published: Elsevier 2019-03-01
Series:Weather and Climate Extremes
Online Access:http://www.sciencedirect.com/science/article/pii/S2212094717300063
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author Yutaro Yokoyama
Masaru Yamamoto
author_facet Yutaro Yokoyama
Masaru Yamamoto
author_sort Yutaro Yokoyama
collection DOAJ
description The formation of explosively developing twin extratropical cyclones is investigated for background conditions involving a transition from double jets to a single jet. Upper-level double jets produced a latitudinally wide baroclinic zone before formation of the twin cyclones. In the early development stage, those double jets merged into the single jet with a strong potential vorticity (PV) streamer that moved to the Japan Sea and coupled with lower-level PV of the northernmost of the twin cyclones. Subsequently, the area of high PV associated with the single jet migrated to the northwestern Pacific, and the upper-level trough coupled with the southernmost of the twin cyclones. The northern low over the Japan Sea then merged with the developing southern low over the Pacific. For this case, sensitivity experiments suggest that sea surface turbulent heat flux before formation of the cyclones is crucial to formation of the twin cyclone structure, via development of a latitudinally elongated trough. Both Eady growth rate and water vapor mixing ratio near the surface were maintained by a strong sea surface turbulent heat flux and contributed to the development of the latitudinally elongated trough around Japan, where diabatic PV production strengthening the two lows separated into two distinct areas. The twin cyclone structure was formed when the lower-level trough extended from the humid Pacific region was developed by the surface turbulent heat flux. While the upper-level PV coupled with the northernmost low over the Japan Sea, the southernmost low developed independently in the lower-level Pacific region. Keywords: Twin extratropical cyclones, Explosively developing cyclone, East-Asian marginal seas, Potential vorticity
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spelling doaj.art-a16cb90197b440c1a7c7760669b027562022-12-21T18:57:50ZengElsevierWeather and Climate Extremes2212-09472019-03-0123Influences of surface heat flux on twin cyclone structure during their explosive development over the East Asian marginal seas on 23 January 2008Yutaro Yokoyama0Masaru Yamamoto1Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka, JapanResearch Institute for Applied Mechanics, Kyushu University, Fukuoka, Japan; Corresponding author. Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-kouen, Kasuga, 816-8580, Japan.The formation of explosively developing twin extratropical cyclones is investigated for background conditions involving a transition from double jets to a single jet. Upper-level double jets produced a latitudinally wide baroclinic zone before formation of the twin cyclones. In the early development stage, those double jets merged into the single jet with a strong potential vorticity (PV) streamer that moved to the Japan Sea and coupled with lower-level PV of the northernmost of the twin cyclones. Subsequently, the area of high PV associated with the single jet migrated to the northwestern Pacific, and the upper-level trough coupled with the southernmost of the twin cyclones. The northern low over the Japan Sea then merged with the developing southern low over the Pacific. For this case, sensitivity experiments suggest that sea surface turbulent heat flux before formation of the cyclones is crucial to formation of the twin cyclone structure, via development of a latitudinally elongated trough. Both Eady growth rate and water vapor mixing ratio near the surface were maintained by a strong sea surface turbulent heat flux and contributed to the development of the latitudinally elongated trough around Japan, where diabatic PV production strengthening the two lows separated into two distinct areas. The twin cyclone structure was formed when the lower-level trough extended from the humid Pacific region was developed by the surface turbulent heat flux. While the upper-level PV coupled with the northernmost low over the Japan Sea, the southernmost low developed independently in the lower-level Pacific region. Keywords: Twin extratropical cyclones, Explosively developing cyclone, East-Asian marginal seas, Potential vorticityhttp://www.sciencedirect.com/science/article/pii/S2212094717300063
spellingShingle Yutaro Yokoyama
Masaru Yamamoto
Influences of surface heat flux on twin cyclone structure during their explosive development over the East Asian marginal seas on 23 January 2008
Weather and Climate Extremes
title Influences of surface heat flux on twin cyclone structure during their explosive development over the East Asian marginal seas on 23 January 2008
title_full Influences of surface heat flux on twin cyclone structure during their explosive development over the East Asian marginal seas on 23 January 2008
title_fullStr Influences of surface heat flux on twin cyclone structure during their explosive development over the East Asian marginal seas on 23 January 2008
title_full_unstemmed Influences of surface heat flux on twin cyclone structure during their explosive development over the East Asian marginal seas on 23 January 2008
title_short Influences of surface heat flux on twin cyclone structure during their explosive development over the East Asian marginal seas on 23 January 2008
title_sort influences of surface heat flux on twin cyclone structure during their explosive development over the east asian marginal seas on 23 january 2008
url http://www.sciencedirect.com/science/article/pii/S2212094717300063
work_keys_str_mv AT yutaroyokoyama influencesofsurfaceheatfluxontwincyclonestructureduringtheirexplosivedevelopmentovertheeastasianmarginalseason23january2008
AT masaruyamamoto influencesofsurfaceheatfluxontwincyclonestructureduringtheirexplosivedevelopmentovertheeastasianmarginalseason23january2008