YaBeSH Engineering and Technology Library

    • Journals
    • PaperQuest
    • YSE Standards
    • YaBeSH
    • Login
    View Item 
    •   YE&T Library
    • AMS
    • Journal of Climate
    • View Item
    •   YE&T Library
    • AMS
    • Journal of Climate
    • View Item
    • All Fields
    • Source Title
    • Year
    • Publisher
    • Title
    • Subject
    • Author
    • DOI
    • ISBN
    Advanced Search
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Archive

    Indonesian Rainfall Variability: Impacts of ENSO and Local Air–Sea Interaction

    Source: Journal of Climate:;2003:;volume( 016 ):;issue: 011::page 1775
    Author:
    Hendon, Harry H.
    DOI: 10.1175/1520-0442(2003)016<1775:IRVIOE>2.0.CO;2
    Publisher: American Meteorological Society
    Abstract: Relationships between Indonesian rainfall and Indo-Pacific sea surface temperatures (SSTs) and circulation anomalies are investigated using observations for 1951?97. Indonesia receives significant rainfall year-round but experiences a wet season that peaks in January and a dry season that peaks in August. Dry season rainfall anomalies are spatially coherent, strongly correlated with SST, and tightly coupled to El Niño?Southern Oscillation (ENSO) variations in the Pacific basin. Drought conditions typically occur during El Niño, when SSTs surrounding Indonesia are cool and the Walker circulation is weakened, resulting in anomalous surface easterlies across Indonesia. The opposite tends to occur during La Niña. Broadscale Indonesian rainfall and SST anomalies tend to not persist from the dry season into the wet season. Rainfall in the heart of the wet season tends to be uncorrelated with SST and spatially incoherent. Seasonally varying feedback between Indonesian SST, winds, and rainfall explains the growth, persistence, and coherence of the local anomalies during the dry season and their decay or change in sign once the wet season commences. During the dry season anomalous surface easterlies, remotely driven by warm SSTs in the central Pacific during El Niño, act to increase local wind speed, cooling the ocean surrounding and to the east of Indonesia and thereby increasing the anomalous SST gradient across the Pacific. Hence, local rainfall and the Walker circulation are further reduced. Once the wet season commences and the climatological surface winds across Indonesia shift from southeasterly to northwesterly, the anomalous surface easterlies now act to reduce the wind speed. The initial cold SST anomaly is damped, reducing the negative rainfall anomalies and surface easterlies. The opposite scenario occurs during La Niña. Indonesian rainfall variations during the dry season are also coupled to the development of an anomalous zonal SST gradient in the equatorial Indian Ocean. This anomalous gradient is strongly related to ENSO and is most prominent during the dry season. Once the wet season commences, the entire Indian Ocean tends to have the same-signed SST anomaly (positive during El Niño and negative during La Niña). Development and decay of this anomalous zonal SST gradient in the Indian Ocean is promoted by seasonally varying air?sea interaction in the eastern Indian Ocean in response to ENSO conditions in the Pacific. The eastern Indian Ocean SST changes are driven largely by induced surface heat flux variations (primarily changes in latent heat flux and net shortwave radiation). Biennial variations in the Indonesian region may also be induced by this seasonally varying air?sea interaction associated with ENSO.
    • Download: (811.0Kb)
    • Show Full MetaData Hide Full MetaData
    • Item Order
    • Go To Publisher
    • Price: 5000 Rial
    • Statistics

      Indonesian Rainfall Variability: Impacts of ENSO and Local Air–Sea Interaction

    URI
    http://yetl.yabesh.ir/yetl1/handle/yetl/4203957
    Collections
    • Journal of Climate

    Show full item record

    contributor authorHendon, Harry H.
    date accessioned2017-06-09T16:11:36Z
    date available2017-06-09T16:11:36Z
    date copyright2003/06/01
    date issued2003
    identifier issn0894-8755
    identifier otherams-6300.pdf
    identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4203957
    description abstractRelationships between Indonesian rainfall and Indo-Pacific sea surface temperatures (SSTs) and circulation anomalies are investigated using observations for 1951?97. Indonesia receives significant rainfall year-round but experiences a wet season that peaks in January and a dry season that peaks in August. Dry season rainfall anomalies are spatially coherent, strongly correlated with SST, and tightly coupled to El Niño?Southern Oscillation (ENSO) variations in the Pacific basin. Drought conditions typically occur during El Niño, when SSTs surrounding Indonesia are cool and the Walker circulation is weakened, resulting in anomalous surface easterlies across Indonesia. The opposite tends to occur during La Niña. Broadscale Indonesian rainfall and SST anomalies tend to not persist from the dry season into the wet season. Rainfall in the heart of the wet season tends to be uncorrelated with SST and spatially incoherent. Seasonally varying feedback between Indonesian SST, winds, and rainfall explains the growth, persistence, and coherence of the local anomalies during the dry season and their decay or change in sign once the wet season commences. During the dry season anomalous surface easterlies, remotely driven by warm SSTs in the central Pacific during El Niño, act to increase local wind speed, cooling the ocean surrounding and to the east of Indonesia and thereby increasing the anomalous SST gradient across the Pacific. Hence, local rainfall and the Walker circulation are further reduced. Once the wet season commences and the climatological surface winds across Indonesia shift from southeasterly to northwesterly, the anomalous surface easterlies now act to reduce the wind speed. The initial cold SST anomaly is damped, reducing the negative rainfall anomalies and surface easterlies. The opposite scenario occurs during La Niña. Indonesian rainfall variations during the dry season are also coupled to the development of an anomalous zonal SST gradient in the equatorial Indian Ocean. This anomalous gradient is strongly related to ENSO and is most prominent during the dry season. Once the wet season commences, the entire Indian Ocean tends to have the same-signed SST anomaly (positive during El Niño and negative during La Niña). Development and decay of this anomalous zonal SST gradient in the Indian Ocean is promoted by seasonally varying air?sea interaction in the eastern Indian Ocean in response to ENSO conditions in the Pacific. The eastern Indian Ocean SST changes are driven largely by induced surface heat flux variations (primarily changes in latent heat flux and net shortwave radiation). Biennial variations in the Indonesian region may also be induced by this seasonally varying air?sea interaction associated with ENSO.
    publisherAmerican Meteorological Society
    titleIndonesian Rainfall Variability: Impacts of ENSO and Local Air–Sea Interaction
    typeJournal Paper
    journal volume16
    journal issue11
    journal titleJournal of Climate
    identifier doi10.1175/1520-0442(2003)016<1775:IRVIOE>2.0.CO;2
    journal fristpage1775
    journal lastpage1790
    treeJournal of Climate:;2003:;volume( 016 ):;issue: 011
    contenttypeFulltext
    DSpace software copyright © 2002-2015  DuraSpace
    نرم افزار کتابخانه دیجیتال "دی اسپیس" فارسی شده توسط یابش برای کتابخانه های ایرانی | تماس با یابش
    yabeshDSpacePersian
     
    DSpace software copyright © 2002-2015  DuraSpace
    نرم افزار کتابخانه دیجیتال "دی اسپیس" فارسی شده توسط یابش برای کتابخانه های ایرانی | تماس با یابش
    yabeshDSpacePersian