Biweekly Mixed Rossby-Gravity Waves in the Equatorial Indian Ocean
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

For very narrow results

When looking for a specific result

Best used for discovery & interchangable words

Recommended to be used in conjunction with other fields

Dates

to

Document Data
Library
People
Clear All
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

Biweekly Mixed Rossby-Gravity Waves in the Equatorial Indian Ocean

Filetype[PDF-3.50 MB]



Details:

  • Alternative Title:
    This study describes biweekly (defined as periods between 10 and 15 days) ocean variability in relation to equatorial wave theory using a comprehensive set of moored ocean current velocities as well as satellite-retrieved oceanic and atmospheric parameters in the Indian Ocean. Moored biweekly current velocities exhibit the meridional structure of mixed Rossby-gravity waves: Symmetric for meridional velocity and antisymmetric for zonal velocity around the equator with a decay scale of 228–309 km. The biweekly meridional velocity along the equator has average zonal and vertical wavelengths of 3,430 ± 550 km and 0.76 ± 0.15 km, respectively, with phase propagating westward at speeds of 2.8–3.1 m s−1 and upward at 54–56 m day−1. Conversely, wave energy is inferred to propagate eastward and downward. The range of best fit constants (1.4–2.0 m s−1) that result from the linear separation of horizontal and vertical wave structures suggests the second baroclinic wave mode is dominant over other low baroclinic modes in accounting for the velocity variability. The biweekly waves are forced by surface winds; satellite-derived wind stress, sea level, and surface current anomalies, regressed against the first principal component of the biweekly moored velocities, illustrate the basin-scale structure and temporal evolution of the waves.
  • Journal Title:
    Journal of Geophysical Research: Oceans
  • Personal Author:
  • NOAA Program & Office:
  • Description:
    This study describes biweekly (defined as periods between 10 and 15 days) ocean variability in relation to equatorial wave theory using a comprehensive set of moored ocean current velocities as well as satellite-retrieved oceanic and atmospheric parameters in the Indian Ocean. Moored biweekly current velocities exhibit the meridional structure of mixed Rossby-gravity waves: Symmetric for meridional velocity and antisymmetric for zonal velocity around the equator with a decay scale of 228–309 km. The biweekly meridional velocity along the equator has average zonal and vertical wavelengths of 3,430 ± 550 km and 0.76 ± 0.15 km, respectively, with phase propagating westward at speeds of 2.8–3.1 m s−1 and upward at 54–56 m day−1. Conversely, wave energy is inferred to propagate eastward and downward. The range of best fit constants (1.4–2.0 m s−1) that result from the linear separation of horizontal and vertical wave structures suggests the second baroclinic wave mode is dominant over other low baroclinic modes in accounting for the velocity variability. The biweekly waves are forced by surface winds; satellite-derived wind stress, sea level, and surface current anomalies, regressed against the first principal component of the biweekly moored velocities, illustrate the basin-scale structure and temporal evolution of the waves.
  • Keywords:
  • Source:
    Journal of Geophysical Research: Oceans, 126(5)
  • DOI:
  • Document Type:
  • Place as Subject:
  • Rights Information:
    Other
  • Compliance:
    Submitted
  • Main Document Checksum:
  • Download URL:
  • File Type:

Supporting Files

  • No Additional Files
More +

You May Also Like

Checkout today's featured content at repository.library.noaa.gov

Version 3.26.1