U.S. flag An official website of the United States government.
Official websites use .gov

A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS

A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

i

Wave Packets and Life Cycles of Troughs in the Framework of Local Finite-Amplitude Wave Activity



Select the Download button to view the document
Please click the download button to view the document.

Details

  • Journal Title:
    Journal of the Atmospheric Sciences
  • Personal Author:
  • NOAA Program & Office:
    OAR (Oceanic and Atmospheric Research)
  • Description:
    Synoptic eddies embedded in a westerly flow undergo downstream developments due to their dispersive nature. This paper examines the finite-amplitude aspects of downstream development with the budget of local wave activity (LWA), including explicit contributions from diabatic heating. LWA captures well individual troughs/ridges and the wave packet, and its column budget affords simplified interpretations. In the LWA framework, (linear) downstream development demonstrated in previous analyses is represented by the LWA advection by the zonal reference flow plus LWA flux induced by the radiation of Rossby waves. In addition, convergence of nonlinear advective LWA flux, baroclinic sources at the lower boundary, meridional redistribution by eddy momentum flux, and diabatic sources and sinks complete the column budget of LWA. When applied to the life cycles of troughs within coherent wave packets in the Southern Hemisphere, the LWA budget reveals that individual troughs grow mainly through downstream development, convergence of nonlinear advective flux by eddies, and diabatic heating. Downstream development and divergence of nonlinear flux also dominate trough decay. Contributions from nonlinear advective eddy flux are large in the presence of a strong ridge either immediately upstream or downstream of the trough. Furthermore, anticyclonic components of advective LWA fluxes associated with the upstream or downstream ridge transfer LWA into or out of the trough. Diabatic contributions are significant when the heating exhibits a tilted vertical structure that gives rise to enhanced vertical gradient in heating.
  • Source:
    Journal of the Atmospheric Sciences, 82(4), 789-808
  • DOI:
  • ISSN:
    0022-4928 ; 1520-0469
  • Format:
    PDF
  • Publisher:
    American Meteorological Society
  • Document Type:
    Journal Article
  • Funding:
  • Rights Information:
    Other
  • Compliance:
    Submitted
  • Main Document Checksum:
    urn:sha-512:f0cc0646e19301a140321aaaca3658d9fe9c646fb1b149e2aebc32cbf0427d4918fc9cc6468811e6ac009e78f7c11de4d991313cfe6a0d6aefeb4a7d5e9c2641
  • Download URL:
  • File Type:
    Filetype[PDF - 27.91 MB ]
PREVIOUS
ON THIS PAGE
Details
The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners. As a repository, the NOAA IR retains documents in their original published format to ensure public access to scientific information.
BACK TO TOP