Light absorption by marine cyanobacteria affects  tropical climate mean state and variability

Paulsen, Hanna; Ilyina, Tatiana; Jungclaus, Johann; Six, Katharina; Stemmler, Irene

doi:10.5194/esd-9-1283-2018

Cited by 13 publications

(20 citation statements)

References 58 publications

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“…The modeled aggregate excess densities in diatomdominated regions compare well to former field and laboratory measurements, where marine aggregates showed excess densities of about 0 to ∼ 10 kg m −3 (Alldredge and Gotschalk, 1988;Ploug et al, 2008;Iversen and Ploug, 2013;Laurenceau-Cornec et al, 2019). In calcifier-dominated regions, aggregate excess densities are about ∼ 35 kg m −3 , which is in the upper range of measured values of 2.1 to 41 kg m −3 (Engel et al, 2009).…”

Section: Spatial Distribution Of Marine Aggregate Propertiessupporting

confidence: 81%

“…6) can be deduced from aggregate size, primaryparticle size and d f . Porosity is frequently calculated for aggregates (Alldredge and Gotschalk, 1988;Ploug et al, 2008). Its potential dependency on the microstructure and primary-particle size is, however, seldom covered.…”

Section: Discussionmentioning

confidence: 99%

“…Diazotrophs assimilate gaseous dinitrogen under nitrate limitation and compete for phosphorus with bulk phytoplankton. Diazotrophs grow slower than bulk phytoplankton and have their optimal growth temperature at about 28 • C (Paulsen et al, 2017(Paulsen et al, , 2018. Zooplankton feeds on bulk phytoplankton and releases POM, which enters the common detritus pool.…”

Section: Model Descriptionmentioning

confidence: 99%

“…Diazotrophs in HAMOCC can grow independently of nitrate on phosphate. They are regionally confined to warm tropical and subtropical regions (Paulsen et al, 2017(Paulsen et al, , 2018. Diazotrophs modulate the phosphate concentration in the subtropical gyres.…”

Section: Sensitivity Analysismentioning

confidence: 99%

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Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean

et al. 2020

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Abstract. Marine aggregates are the vector for biogenically bound carbon and nutrients from the euphotic zone to the interior of the oceans. To improve the representation of this biological carbon pump in the global biogeochemical HAMburg Ocean Carbon Cycle (HAMOCC) model, we implemented a novel Microstructure, Multiscale, Mechanistic, Marine Aggregates in the Global Ocean (M4AGO) sinking scheme. M4AGO explicitly represents the size, microstructure, heterogeneous composition, density and porosity of aggregates and ties ballasting mineral and particulate organic carbon (POC) fluxes together. Additionally, we incorporated temperature-dependent remineralization of POC. We compare M4AGO with the standard HAMOCC version, where POC fluxes follow a Martin curve approach with (i) linearly increasing sinking velocity with depth and (ii) temperature-independent remineralization. Minerals descend separately with a constant speed. In contrast to the standard HAMOCC, M4AGO reproduces the latitudinal pattern of POC transfer efficiency, as recently constrained by Weber et al. (2016). High latitudes show transfer efficiencies of ≈0.25±0.04, and the subtropical gyres show lower values of about 0.10±0.03. In addition to temperature as a driving factor for remineralization, diatom frustule size co-determines POC fluxes in silicifier-dominated ocean regions, while calcium carbonate enhances the aggregate excess density and thus sinking velocity in subtropical gyres. Prescribing rising carbon dioxide (CO2) concentrations in stand-alone runs (without climate feedback), M4AGO alters the regional ocean atmosphere CO2 fluxes compared to the standard model. M4AGO exhibits higher CO2 uptake in the Southern Ocean compared to the standard run, while in subtropical gyres, less CO2 is taken up. Overall, the global oceanic CO2 uptake remains the same. With the explicit representation of measurable aggregate properties, M4AGO can serve as a test bed for evaluating the impact of aggregate-associated processes on global biogeochemical cycles and, in particular, on the biological carbon pump.

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Section: Spatial Distribution Of Marine Aggregate Propertiessupporting

confidence: 81%

Section: Discussionmentioning

confidence: 99%

Section: Model Descriptionmentioning

confidence: 99%

Section: Sensitivity Analysismentioning

confidence: 99%

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Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean

et al. 2020

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Section: Sensitivity Analysismentioning

confidence: 99%

Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean

Maerz¹,

Six²,

Stemmler³

et al. 2019

Preprint

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Abstract. Marine aggregates are the vector for biogenically bound carbon and nutrients from the euphotic zone to the interior of the oceans. To improve the representation of this biological carbon pump in the global biogeochemical HAMburg Ocean Carbon Cycle (HAMOCC) model, we implemented a novel Microstructure, Multiscale, Mechanistic, Marine Aggregates in the Global Ocean (M4AGO) sinking scheme. M4AGO explicitly represents the size, microstructure, heterogeneous composition, density, and porosity of aggregates, and ties ballasting mineral and particulate organic carbon (POC) fluxes together. Additionally, we incorporated temperature-dependent remineralization of POC. We compare M4AGO with the standard HAMOCC version, where POC fluxes follow a Martin curve approach with linearly increasing sinking velocity with depth, and temperature-independent remineralization. Minerals descend separately with a constant speed. In contrast to the standard HAMOCC, M4AGO reproduces the latitudinal pattern of POC transfer efficiency which has been recently constrained by Weber et al. (2016). High latitudes show transfer efficiencies of &#8776;&#8201;0.25&#8201;&#177;&#8201;0.04 and the subtropical gyres show lower values of about 0.10&#8201;&#177;&#8201;0.03. In addition to temperature as a driving factor, diatom frustule size co-determines POC fluxes in silicifiers-dominated ocean regions while calcium carbonate enhances the aggregate excess density, and thus sinking velocity in subtropical gyres. In ocean standalone runs and rising carbon dioxide (CO2) without CO2 climate feedback, M4AGO alters the regional ocean-atmosphere CO2 fluxes compared to the standard model. M4AGO exhibits higher CO2 uptake in the Southern Ocean compared to the standard run while in subtropical gyres, less CO2 is taken up. Overall, the global oceanic CO2 uptake remains the same. With the explicit representation of measurable aggregate properties, M4AGO can serve as a testbed for evaluating the impact of aggregate-associated processes on global biogeochemical cycles, and, in particular, on the biological carbon pump.

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Deep Proteogenomics of a Photosynthetic Cyanobacterium

et al. 2023

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Cyanobacteria, the evolutionary ancestors of plant chloroplasts, contribute substantially to the Earth's biogeochemical cycles and are of great interest for a sustainable economy. Knowledge of protein expression is the key to understanding cyanobacterial metabolism; however, proteome studies in cyanobacteria are limited and cover only a fraction of the theoretical proteome.Here, we performed a comprehensive proteogenomic analysis of the model cyanobacterium Synechocystis sp. PCC 6803 to characterize the expressed (phospho)proteome, re-annotate known and discover novel open reading frames (ORFs). By mapping extensive shotgun mass spectrometry proteomics data onto a six-frame translation of the Synechocystis genome, we refined the genomic annotation of 64 ORFs, including eight completely novel ORFs. Our study presents the largest reported (phospho)proteome dataset for a unicellular cyanobacterium, covering the expression of about 80% of the theoretical proteome under various cultivation conditions, such as nitrogen or carbon limitation. We report 568 phosphorylated S/T/Y sites that are present on numerous regulatory proteins, including the transcriptional regulators cyAbrB1 and cyAbrB2. We also catalogue the proteins that have never been detected under laboratory conditions and found that a large portion of them is plasmid-encoded. This dataset will serve as a resource, providing dedicated information on growth condition-dependent protein expression and phosphorylation.

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Light absorption by marine cyanobacteria affects tropical climate mean state and variability

Cited by 13 publications

References 58 publications

Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean

Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean

Microstructure and composition of marine aggregates as co-determinants for vertical particulate organic carbon transfer in the global ocean

Deep Proteogenomics of a Photosynthetic Cyanobacterium

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