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Delineating environmental control of phytoplankton biomass and phenology in the Southern Ocean
Author(s) -
Ardyna Mathieu,
Claustre Hervé,
Sallée JeanBaptiste,
D'Ovidio Francesco,
Gentili Bernard,
Dijken Gert,
D'Ortenzio Fabrizio,
Arrigo Kevin R.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl072428
Subject(s) - phytoplankton , environmental science , bloom , biomass (ecology) , phenology , climate change , oceanography , advection , algal bloom , ecology , global warming , climatology , atmospheric sciences , biology , geology , nutrient , physics , thermodynamics
The Southern Ocean (SO), an area highly sensitive to climate change, is currently experiencing rapid warming and freshening. Such drastic physical changes might significantly alter the SO's biological pump. For more accurate predictions of the possible evolution of this pump, a better understanding of the environmental factors controlling SO phytoplankton dynamics is needed. Here we present a satellite‐based study deciphering the complex environmental control of phytoplankton biomass (PB) and phenology (PH; timing and magnitude of phytoplankton blooms) in the SO. We reveal that PH and PB are mostly organized in the SO at two scales: a large latitudinal scale and a regional scale. Latitudinally, a clear gradient in the timing of bloom occurrence appears tightly linked to the seasonal cycle in irradiance, with some exceptions in specific light‐limited regimes (i.e., well‐mixed areas). Superimposed on this latitudinal scale, zonal asymmetries, up to 3 orders of magnitude, in regional‐scale PB are mainly driven by local advective and iron supply processes. These findings provide a global understanding of PB and PH in the SO, which is of fundamental interest for identifying and explaining ongoing changes as well as predicting future changes in the SO biological pump.