CO2 concentration and pH in the present Southern Ocean. Phytoplankton ecology in the present Southern Ocean. Southern Ocean phytoplankton are major drivers of global carbon cycling accounting for ~2 Pg [...] this production relies on large phytoplankton blooms of a few key diatom species and the prymnesiophyte Phaeocystis along the Antarctic continent while pelagic phytoplankton contributes to a smaller degree [...] typically Fe-limited. Due to this, primary production and carbon export of oceanic phytoplankton is low while inshore phytoplankton is highly productive and has a high carbon export. Next to iron, light limitation

How does seawater chemistry shape phytoplankton composition and biogeochemistry? Biological carbon pump: Influence of changes in seawater chemistry on phytoplankton community composition and organic matter [...] export. Micro- (e.g. iron, manganese, vitamins) and macronutrients (e.g. nitrate, phosphate) shape phytoplankton composition and primary production. The efficacy of the biological pump critically depends on [...] on the quality, quantity and transformation of organic matter originally produced by phytoplankton, and ultimately determines the long-term deposition of carbon at the ocean’s floor. We lack a mechanistic

Bracher A. (2011) Optical methods to study phytoplankton composition and dynamics on global scale. Results and perspectives from work within the YIG “Marine Phytoplankton Studied with Global Biooptical Methods” [...] Invited Talks since 2007 2021 Bracher A. (2021) Quantifying Phytoplankton Diversity from Space. FCUL Science Seminar, University of Lisbon, 4 Nov 2021. Bracher A., Soppa M. A., Gege P., Losa S.N., Silva [...] IEEE International Geoscience and Remote Sensing Symposium 2021; 16 Jul 2021 Bracher A. (2021) Phytoplankton Diversity from Space. HIFMB Data Science Seminar, University Oldenburg, Online Meeting, 19 May

potential driver of Southern Ocean phytoplankton ecology? The diatom Chaetoceros debilis. Photo: F. Pausch (Photo: Alfred-Wegener-Institut) Primary production by phytoplankton is governed by several factors [...] iron and manganese limitation on the physiology of Antarctic phytoplankton is valuable to understand the requirements for optimal phytoplankton growth in the Southern Ocean and will help to improve predictions [...] factors such as light and nutrient availability in different parts of the world oceans. Phytoplankton concentrations in the Southern Ocean are low despite high concentrations of macronutrients like nitrate and

Southern Ocean phytoplankton are major drivers of global carbon cycling accounting for 20% of the global annual primary production. Most of this production relies on large phytoplankton blooms of a few [...] Antarctic continent, while pelagic phytoplankton contributes to a minor degree. The focus of the EcoTrace group is to elucidate the sensitivity of Southern Ocean phytoplankton to global change, in particular [...] availability of trace metals and light are considered key factors in controlling Southern Ocean phytoplankton productivity and community structure. Until now, only little information is available on how these

through inter-comparisons with other existing satellite derived products on phytoplankton composition including phytoplankton size class (PSC), SynSenPFT, OC-PFT and PHYSAT. Preliminary experiment of the [...] OLCI-PFT Global Retrieval of Phytoplankton Functional Types (PFTs) from OLCI and Merged Ocean Colour products This collaborative AWI-ACRI-ST project funded by ACRI-ST focuses on retrieving global PFTs [...] the satellite data but also a very large (about 12,000) globally distributed field data set on phytoplankton pigments. With data of only nine spectral bands from the merged ocean color products, it is possible

strongly depends on the size and composition of phytoplankton cells, in addition to the structure of the trophic community. Therefore, information on phytoplankton composition is needed for a better estimate [...] assess the contribution of different phytoplankton functional types (PFT) to the oceanic carbon cycle. Because of the complex spatial and temporal dynamics of phytoplankton, investigations usually rely on satellite [...] Tracking phytoplankton from space in a changing Southern Ocean PhD project by Mariana Soppa (2010-2015) In recent years, the interest on quantitative estimation of the abundance and composition of different

Colour Instrument PFT Phytoplankton Functional Type PG Phytoplankton Group PhytoDOAS DOAS applied for retrieval of phytoplankton biomass PSC Phytoplankton Size Class PT Phytoplankton Type PVR Product Validation [...] chapter any grouping of phytoplankton as identified from space, either based on spectral signatures of pigments specific to certain taxons or of size of phytoplankton is named phytoplankton group (PG). 1.2 Acronyms [...] species (and ecotypes) as “Phytoplankton Groups” (PG). PG characterised by a certain taxonomic group we name phytoplankton types (PT), and by a size range we name phytoplankton size classes (PSC). Satellite

the marine phytoplankton’s role in the global marine ecosystem and biogeochemical cycles it is necessary to derive its global, in particular the distribution of major functional phytoplankton types (PFT) [...] atmospheric components, for the retrieval of the absorption and biomass of major phytoplankton groups ( PhytoDOAS ; Phytoplankton DOAS) from data of the Scanning Imaging Absorption Spectrometer for Atmospheric [...] (PFT), but also on phytoplankton physiology and its degradation products in the world oceans. Nearly all current global ocean colour products are retrieved from multi-spectral ocean colour sensors, because

Multispectral Sentinel-Measurements to Determine Phytoplankton Functional Types at Best Spatial and Temporal Resolution (SynSenPFT) Motivation: Different phytoplankton groups have different roles in the biogeochemical [...] situ data of phytoplankton pigments Diagnostic Pigment Analysis10 f-PFTs Fit function applied to satellite Chla data Chla conc. of PFTs 3 Validation and intercomparison with phytoplankton size classes [...] pigments specific to phytoplankton functional types. Biogeosciences 8, 311–327. Soppa, M. A., Hirata, T., et al. 2014. Global retrieval of diatoms abundance based on phytoplankton pigments and satellite