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

All these words:

For very narrow results

This exact word or phrase:

When looking for a specific result

Any of these words:

Best used for discovery & interchangable words

None of these words:

Recommended to be used in conjunction with other fields

Language:

Dates

Publication Date Range:

to

Document Data

Title:

Document Type:

Library

Collection:

Series:

People

Author:

Help
Clear All

Query Builder

Query box

Help
Clear All

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

i

Transport variability of the Brazil Current from observations and a data assimilation model

Filetype[PDF-5.97 MB]


Select the Download button to view the document
This document is over 5mb in size and cannot be previewed

Details:

  • Journal Title:
    Ocean Science
  • Description:
    The Brazil Current transports from observations and the Hybrid Coordinate Model (HYCOM) model are analyzed to improve our understanding of the current's structure and variability. A time series of the observed transport is derived from a three-dimensional field of the velocity in the South Atlantic covering the years 1993 to 2015 (hereinafter called Argo & SSH). The mean transports of the Brazil Current increases from 3.8 +/- 2.2 Sv (1 Sv is 10(6) m(3) s(-1)) at 25 degrees S to 13.9 +/- 2.6 Sv at 32 degrees S, which corresponds to a mean slope of 1.4 +/- 0.4 Sv per degree. Transport estimates derived from HYCOM fields are somewhat higher (5.2 +/- 2.7 and 18.7 +/- 7.1 Sv at 25 and 32 degrees S, respectively) than those from Argo & SSH, but these differences are small when compared with the standard deviations. Overall, the observed latitude dependence of the transport of the Brazil Current is in agreement with the wind-driven circulation in the super gyre of the subtropical South Atlantic. A mean annual cycle with highest (lowest) transports in austral summer (winter) is found to exist at selected latitudes (24, 35, and 38 degrees S). The significance of this signal shrinks with increasing latitude (both in Argo & SSH and HYCOM), mainly due to mesoscale and interannual variability. Both Argo & SSH, as well as HYCOM, reveal interannual variability at 24 and 35 degrees S that results in relatively large power at periods of 2 years or more in wavelet spectra. It is found that the interannual variability at 24 degrees S is correlated with the South Atlantic Subtropical Dipole Mode (SASD), the Southern Annular Mode (SAM), and the Nino 3.4 index. Similarly, correlations between SAM and the Brazil Current transport are also found at 35 degrees S. Further investigation of the variability reveals that the first and second mode of a coupled empirical orthogonal function of the meridional transport and the sea level pressure explain 36 and 15 % of the covariance, respectively. Overall, the results indicate that SAM, SASD, and El Nifio-Southern Oscillation have an influence on the transport of the Brazil Current.
  • Source:
    Ocean Science, 14(3), 417-436.
  • Document Type:
  • Rights Information:
    CC BY
  • Compliance:
    Submitted
  • Main Document Checksum:
  • File Type:

Supporting Files

  • No Additional Files

More +

Related Documents

You May Also Like

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

Version 3.26