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

    Sensitivity of Hybrid ENSO Models to Unresolved Atmospheric Variability

    Source: Journal of Climate:;2008:;volume( 021 ):;issue: 015::page 3704
    Author:
    Zavala-Garay, J.
    ,
    Zhang, C.
    ,
    Moore, A. M.
    ,
    Wittenberg, A. T.
    ,
    Harrison, M. J.
    ,
    Rosati, A.
    ,
    Vialard, Jérôme
    ,
    Kleeman, R.
    DOI: 10.1175/2007JCLI1188.1
    Publisher: American Meteorological Society
    Abstract: A common practice in the design of forecast models for ENSO is to couple ocean general circulation models to simple atmospheric models. Therefore, by construction these models (known as hybrid ENSO models) do not resolve various kinds of atmospheric variability [e.g., the Madden?Julian oscillation (MJO) and westerly wind bursts] that are often regarded as ?unwanted noise.? In this work the sensitivity of three hybrid ENSO models to this unresolved atmospheric variability is studied. The hybrid coupled models were tuned to be asymptotically stable and the magnitude, and spatial and temporal structure of the unresolved variability was extracted from observations. The results suggest that this neglected variability can add an important piece of realism and forecast skill to the hybrid models. The models were found to respond linearly to the low-frequency part of the neglected atmospheric variability, in agreement with previous findings with intermediate models. While the wind anomalies associated with the MJO typically explain a small fraction of the unresolved variability, a large fraction of the interannual variability can be excited by this forcing. A large correlation was found between interannual anomalies of Kelvin waves forced by the intraseasonal MJO and the Kelvin waves forced by the low-frequency part of the MJO. That is, in years when the MJO tends to be more active it also produces a larger low-frequency contribution, which can then resonate with the large-scale coupled system. Other kinds of atmospheric variability not related to the MJO can also produce interannual anomalies in the hybrid models. However, when projected on the characteristics of Kelvin waves, no clear correlation between its low-frequency content and its intraseasonal activity was found. This suggests that understanding the mechanisms by which the intraseasonal MJO interacts with the ocean to modulate its low-frequency content may help to better to predict ENSO variability.
    • Download: (2.704Mb)
    • Show Full MetaData Hide Full MetaData
    • Item Order
    • Go To Publisher
    • Price: 5000 Rial
    • Statistics

      Sensitivity of Hybrid ENSO Models to Unresolved Atmospheric Variability

    URI
    http://yetl.yabesh.ir/yetl1/handle/yetl/4206881
    Collections
    • Journal of Climate

    Show full item record

    contributor authorZavala-Garay, J.
    contributor authorZhang, C.
    contributor authorMoore, A. M.
    contributor authorWittenberg, A. T.
    contributor authorHarrison, M. J.
    contributor authorRosati, A.
    contributor authorVialard, Jérôme
    contributor authorKleeman, R.
    date accessioned2017-06-09T16:19:03Z
    date available2017-06-09T16:19:03Z
    date copyright2008/08/01
    date issued2008
    identifier issn0894-8755
    identifier otherams-65634.pdf
    identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4206881
    description abstractA common practice in the design of forecast models for ENSO is to couple ocean general circulation models to simple atmospheric models. Therefore, by construction these models (known as hybrid ENSO models) do not resolve various kinds of atmospheric variability [e.g., the Madden?Julian oscillation (MJO) and westerly wind bursts] that are often regarded as ?unwanted noise.? In this work the sensitivity of three hybrid ENSO models to this unresolved atmospheric variability is studied. The hybrid coupled models were tuned to be asymptotically stable and the magnitude, and spatial and temporal structure of the unresolved variability was extracted from observations. The results suggest that this neglected variability can add an important piece of realism and forecast skill to the hybrid models. The models were found to respond linearly to the low-frequency part of the neglected atmospheric variability, in agreement with previous findings with intermediate models. While the wind anomalies associated with the MJO typically explain a small fraction of the unresolved variability, a large fraction of the interannual variability can be excited by this forcing. A large correlation was found between interannual anomalies of Kelvin waves forced by the intraseasonal MJO and the Kelvin waves forced by the low-frequency part of the MJO. That is, in years when the MJO tends to be more active it also produces a larger low-frequency contribution, which can then resonate with the large-scale coupled system. Other kinds of atmospheric variability not related to the MJO can also produce interannual anomalies in the hybrid models. However, when projected on the characteristics of Kelvin waves, no clear correlation between its low-frequency content and its intraseasonal activity was found. This suggests that understanding the mechanisms by which the intraseasonal MJO interacts with the ocean to modulate its low-frequency content may help to better to predict ENSO variability.
    publisherAmerican Meteorological Society
    titleSensitivity of Hybrid ENSO Models to Unresolved Atmospheric Variability
    typeJournal Paper
    journal volume21
    journal issue15
    journal titleJournal of Climate
    identifier doi10.1175/2007JCLI1188.1
    journal fristpage3704
    journal lastpage3721
    treeJournal of Climate:;2008:;volume( 021 ):;issue: 015
    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