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

Comparison of southward shift mechanisms of equatorial westerly anomalies between EP and CP El Niño



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

Details

  • Journal Title:
    Climate Dynamics
  • Personal Author:
  • NOAA Program & Office:
    OAR (Oceanic and Atmospheric Research)
  • Description:
    A composite analysis of observational data reveals that maximum westerly anomalies associated with both the EP and CP El Niños shift southward to 5° S during their mature phase (boreal winter), with different zonal locations. A zonal momentum budget analysis indicates that leading factors to cause the southward shift of the zonal wind anomaly for both EP and CP El Niño composites are anomalous pressure gradient force and anomalous meridional advection, while anomalous Coriolis force has an opposite effect. The difference in the longitudinal locations arises from the zonal shift of maximum SST anomaly centers between EP and CP El Niño. Prior to northern winter, the westerly anomaly for both types of El Niño is approximately symmetric about the equator. The advection by the climatological mean cross-equatorial wind leads to initial southward shift of the maximum westerly and subsequent development of an antisymmetric mode through a moisture-convection-circulation feedback and a wind-evaporation-SST feedback. An EOF analysis of the tropical Pacific surface wind field indicates that both the first and second leading modes are important in contributing to the southward shift of the maximum westerly anomaly with distinctive longitudinal locations for CP and EP El Niño.
  • Keywords:
  • Source:
    Climate Dynamics, 60(3-4), 785-796
  • DOI:
  • ISSN:
    0930-7575 ; 1432-0894
  • Format:
    PDF
  • Publisher:
    Springer Science and Business Media LLC
  • Document Type:
    Journal Article
  • Funding:
    Grant no. NA18OAR4310282
  • License:
  • Rights Information:
    CC0 Public Domain
  • Compliance:
    Library
  • Main Document Checksum:
    urn:sha256:ad48b3858359ec72ac51048c680120041cecc15500bf24915fd5d0a02f66903e
  • Download URL:
  • File Type:
    Filetype[PDF - 8.67 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