YaBeSH Engineering and Technology Library

    • Journals
    • PaperQuest
    • YSE Standards
    • YaBeSH
    • Login
    View Item 
    •   YE&T Library
    • AMS
    • Journal of the Atmospheric Sciences
    • View Item
    •   YE&T Library
    • AMS
    • Journal of the Atmospheric Sciences
    • 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

    The Nonlinear Effects of Orographic and Momentum Forcing in a Low-Order, Barotropic Model

    Source: Journal of the Atmospheric Sciences:;1981:;Volume( 038 ):;issue: 010::page 2150
    Author:
    Källén, E.
    DOI: 10.1175/1520-0469(1981)038<2150:TNEOOA>2.0.CO;2
    Publisher: American Meteorological Society
    Abstract: An analysis of a low-order barotropic system with orographic and momentum forcing is presented. The low-order expansion of the streamfunction is performed on a spherical geometry, the expansion functions thus being spherical harmonics. Two purely zonal components and two wave components with the same zonal wavenumber but different orders, or latitudinal wavenumbers, are described by the model. The nonlinear terms appearing in the six ODE's governing the time evolution of the system give rise to bifurcations into multiple steady-state solutions. In order to retain as many nonlinear terms as possible, however, one must be careful in the choice of components. An analysis of the different possibilities is presented and two examples having somewhat different properties are investigated. Three of the components are the same in each example, while the three others differ in their symmetry properties around the equator. For the example which is believed to be most representative of realistic conditions, it is shown that a combination of orographic forcing and zonally asymmetric momentum forcing is required to obtain multiple steady-state solutions for realistic parameter values. The forcing must exceed certain critical values for a bifurcation from one to three steady states to appeal. A stability investigation of the steady-state triplets shows that two are stable while one is unstable. Examining the energetics of the two stable steady states for a situation which corresponds to a wintertime forcing pattern, it is shown that one of the stable steady states is much more zonal than the other. The non-zonal circulation is similar to a ?blocked? flow. Another significant difference in the energetics between the two flow types is the intensity of the energy transfer between zonal and eddy kinetic energy. Comparisons with observational studies of ?blocked? and zonal flow confirms that this is a characteristic feature of the observed energetics.
    • Download: (1.077Mb)
    • Show Full MetaData Hide Full MetaData
    • Item Order
    • Go To Publisher
    • Price: 5000 Rial
    • Statistics

      The Nonlinear Effects of Orographic and Momentum Forcing in a Low-Order, Barotropic Model

    URI
    http://yetl.yabesh.ir/yetl1/handle/yetl/4154193
    Collections
    • Journal of the Atmospheric Sciences

    Show full item record

    contributor authorKällén, E.
    date accessioned2017-06-09T14:22:35Z
    date available2017-06-09T14:22:35Z
    date copyright1981/10/01
    date issued1981
    identifier issn0022-4928
    identifier otherams-18212.pdf
    identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4154193
    description abstractAn analysis of a low-order barotropic system with orographic and momentum forcing is presented. The low-order expansion of the streamfunction is performed on a spherical geometry, the expansion functions thus being spherical harmonics. Two purely zonal components and two wave components with the same zonal wavenumber but different orders, or latitudinal wavenumbers, are described by the model. The nonlinear terms appearing in the six ODE's governing the time evolution of the system give rise to bifurcations into multiple steady-state solutions. In order to retain as many nonlinear terms as possible, however, one must be careful in the choice of components. An analysis of the different possibilities is presented and two examples having somewhat different properties are investigated. Three of the components are the same in each example, while the three others differ in their symmetry properties around the equator. For the example which is believed to be most representative of realistic conditions, it is shown that a combination of orographic forcing and zonally asymmetric momentum forcing is required to obtain multiple steady-state solutions for realistic parameter values. The forcing must exceed certain critical values for a bifurcation from one to three steady states to appeal. A stability investigation of the steady-state triplets shows that two are stable while one is unstable. Examining the energetics of the two stable steady states for a situation which corresponds to a wintertime forcing pattern, it is shown that one of the stable steady states is much more zonal than the other. The non-zonal circulation is similar to a ?blocked? flow. Another significant difference in the energetics between the two flow types is the intensity of the energy transfer between zonal and eddy kinetic energy. Comparisons with observational studies of ?blocked? and zonal flow confirms that this is a characteristic feature of the observed energetics.
    publisherAmerican Meteorological Society
    titleThe Nonlinear Effects of Orographic and Momentum Forcing in a Low-Order, Barotropic Model
    typeJournal Paper
    journal volume38
    journal issue10
    journal titleJournal of the Atmospheric Sciences
    identifier doi10.1175/1520-0469(1981)038<2150:TNEOOA>2.0.CO;2
    journal fristpage2150
    journal lastpage2163
    treeJournal of the Atmospheric Sciences:;1981:;Volume( 038 ):;issue: 010
    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