Mobile version

Brazil-Malvinas Confluence region

Image of the month - February 2005

The region of Confluence of the Brazil and Malvinas Currents (Southwest Atlantic) is a very energetic complex region. Contrasts in sea surface temperature, in Chlorophyll-a concentration and the local maximum in eddy kinetic energy make satellite infrared (IR) color imagery and satellite altimetry particularly appropriate tools to study the Confluence region.
Data from satellites provide valuable information in this area, which, like most of the southern hemisphere oceans, has few in situ time series observations. Satellite data provide information about spatial scales as small as 1 km (e.g. filaments are visible with MODIS) to several hundred of kilometers (Zapiola Rise) and from time scales of 24 hours to more than 10 years.

The variability of thermal fronts is discussed with nine years of AVHRR data (1987-1995) using a gradient based edge detector [Saraceno et al., 2004].
The time-space distribution of chlorophyll-a is examined using 6 years (1998-2003) of sea surface color images from SeaWiFS [Saraceno et al., 2005].
Root mean square of Sea Level Anomaly obtained from 11 years of Sea Surface Height from ERS + Topex/Poseidon + Jason-1. Dash-dot lines are mean position of Brazil Current Front and Subantarctic Front (SAF).

 

 

These means fields allow to establish biophysical provinces in the South West Atlantic ocean:
   - Background colors represent the six ranges of chl-a magnitudes identified with an histogram method.
   - Regions obtained (solid black lines) retrieves Longhurst (1998) Provinces (dash-dot red lines).
   - Three new provinces are identified: the Overshoot, the Patagonian Shelf Break (PSB) and the Zapiola Rise Provinces (Saraceno, 2005).
 
SATL: South Atlantic Gyral Province
SSTC: South Subtropical Convergence Province
BRAZ: Brazil Current Costal Province
FLKD: Southwest Atlantic Shelves Province
SANT: Subantartic Water Ring Province

Simultaneous high resolution (1.1 km) MODIS SST and color images document the meso- and sub-meso-scale structures [Barré et al., 2005].

References

  • Saraceno, M., C. Provost, A. R. Piola, J. Bava, and A. Gagliardini, Brazil Malvinas Frontal System as seen from 9 years of advanced very high resolution radiometer data, J. Geophys. Res., 109, C05027, doi:10.1029/2003JC002127, 2004.
  • Saraceno, M., C. Provost, A. R. Piola, On the relationship of satellite retrieved surface temperature fronts and chlorophyll-a in the Western South Atlantic, JGR, 110, C11016, doi:10.1029/2004JC002736, 2005.
EnglishFrançais
Rss feedsContactPartnersFAQLexiconLegal noticePersonal Data Protection PolicyMobile
You must enable cookies in your browser preferences to save the modifications
You are using an older version of Internet Explorer, please update to take full advantage of Aviso+ features

Customize the home page

View all widgets
Reduce display
Public profile
User profile

Select/Deselect widgets

Discover AVISO+

Customizable home, reading tools, products search guide, etc.. Discover step by step the features of the new site AVISO+.

Customizable homepage

This home page is composed of blocks called "widgets".

Rearrange the blocks with a "Click & Drop".

Hide a widget with the cross at the top right. Reset or add a widget with the "wrench" icon. The "User" and "Public" profiles offer a predefined organization.

All the modifications are automatically saved as cookies on your machine so as to enable you to have your own specific AVISO+.

Reading tools

Ease your reading by choosing the page background colour (black/white) and/or by modifying the font size.

Browsing menu and breadcrum trail

To ease your browsing through AVISO+, you can use at any time the main banner items with the interactive submenus or use the browsing menu on the left side of the screen (it is open by default). For more readiness of the page contents, you can fold and unfold the browsing menu by clicking on the tab. At any time you can know where you are thanks to the browsing menu or the breadcrum at the top of the page.

Products search guide

The first submenu of the "Data" banner item leads you to a new search form enabling you to find quickier the product that suits your needs. The list of results is updated according to your selection criteria.

AVISO+ Multimedia

The first submenu of the "Multimedia" banner item leads you to AVISO+ collections of images and videos linked to altimetry and its applications. Have a nice visit!