The Madagascar bloom: what do we know / not know?
The Madagascar bloom is a southwest Indian Ocean late austral summer bloom occurring to the east of Madagascar. At its largest extent it can cover 1% of the global ocean surface. It was originally observed in satellite ocean colour data and is clearly modulated by the oceanic mesoscales eddy field. The bloom is unusual in that it propagates east away from Madagascar and displays considerable temporal and spatial variability from year-to-year. It has been hypothesised that the bloom is fertilised by iron from Madagascar. In situ observations from RRS Discovery cruise 288 in 2005 have provided some insights into the bloom. More recent work using the 1/12˚ NEMO ocean model and Lagrangian particle tracking has allowed the question of its interannual temporal and spatial variability to be addressed, together with the potential role of Madagascan iron in fertilising the bloom.