Where and How the East Madagascar Current Retroflection Originates?

Abstract

The East Madagascar Current (EMC) is one of the western boundary currents of the South Indian Ocean. As such, it plays an important role in the climate system by transporting water and heat toward the pole and recirculating to the large‐scale Indian Ocean through retroflection modes of its southern extension. Five cruise data sets and remote sensing data from different sensors are used to identify three states of the southern extension of the EMC: early retroflection, canonical retroflection, and no retroflection. Retroflections occur 47% of the time. EMC strength regulates the retroflection state, although impinged mesoscale eddies also contribute to retroflection formation. Early retroflection is linked with EMC volume transport. Anticyclonic eddies drifting from the central Indian Ocean to the coast favor early retroflection formation, anticyclonic eddies near the southern tip of Madagascar promote the generation of canonical retroflection, and no retroflection appears to be associated with a lower eddy kinetic energy (EKE). Knowledge of the EMC retroflection state could help predict (a) coastal upwelling south of Madagascar, (b) the southeastern Madagascar phytoplankton bloom, and (c) the formation of the South Indian Ocean Counter Current (SICC).

Lexicostatistics of Malay and Malagasy Languages: Comparative Historical Linguistic Study

“…The most likely explanation about the ancestors of the Madagascar is that they did not sail alone but were brought as slaves by Malay sailors. Evidences from other studies say that the Madagascar community comes from approximately 30 women from Indonesia (Ramanantsoa et al, 2021) and this has been concurred by Goodman & Jungers (2018 ) and Serva (2018). The most recent study on this area was written by Serva & Pasquini (2022) who concur that Malagasy language was initially identified as a member of the Austronesian Family around the beginning of the 17 th century.…”

Chlorophyll bloom triggered by tropical storm chedza at the southern tip of madagascar island

“…A large number of eddies and upwelling cells were found in the South East Madagascar Current (SEMC) (DiMarco et al 2000, J R E Lutjeharms 2000). Increased mesoscale eddy activity in the southwestern Indian Ocean, including southern Madagascar, could lead to more southeast Madagascar blooms (Ramanantsoa et al 2021). Upwelling can stimulate surface phytoplankton production by transporting nutrients to the sea surface.…”