Influence of nutrient utilization and remineralization stoichiometry on phytoplankton species and carbon export: A modeling study at BATS

2008-01-01
Salihoğlu, Barış
Oschlies, A.
Lomas, M. W.
The primary objective of this research is to understand the underlying mechanisms of the time-varying flux of carbon in the Sargasso Sea. To address this objective, a one-dimensional multi-component lower trophic level ecosystem model that includes detailed algal physiology as well as nutrient cycles is used at the Bermuda Atlantic Time-series Study (BATS, 31 degrees 40'N, 64 degrees 10'W) site. In this model autotrophic growth is represented by three algal groups and the cell quota approach is used to estimate algal growth and nutrient uptake. This model is tested and evaluated for year 1998 using the bimonthly BATS cruise data. Results show that phosphorus and dissolved organic matter (DOM) are necessary compartments to correctly simulate organic elemental cycles at the BATS site. Model results show that autotrophic eukaryotes and cyanobacteria (i.e. Prochlorococcus and Synechococcus) are the most abundant algal groups and are responsible for 63% and 33% of carbon production in the region, respectively. Sensitivity analyses show that the annual contribution of nitrogen fixation and atmospheric nitrogen deposition to new production is approximately 9% and 3%, respectively. However, the recycled nitrogen and phosphorus are important components of the ecosystem dynamics because sustained growth of algal groups depends on remineralized nutrients which accounts for 75% of the annual carbon production. Nutrient uptake and remineralization stoichiometry can play an important role in determining the surface ocean nutrient distribution. Model results suggest phosphate limitation even during the spring bloom. Phosphate may thus limit the growth of all algal groups throughout the year.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS

Suggestions

Comparison of Productivity Plankton Types and Carbon Export Mechanisms in two Different Regimes of Subtropical North Atlantic a Modeling Study
Salihoğlu, Barış (2016-02-15)
Improved structure and mechanisms of carbon export and sequestration within marine ecosystem models is vital to better understand and predict changes in the global carbon cycle. We have implemented a 1D lower trophic ecosystem model at long-term time-series stations (BATS and ESTOC) in the North Atlantic for the years 1996-2000. We have investigated the dynamics of the productivity and carbon export, and mechanisms regulating them. Our simulations agree with the previous observations that show similar produ...
Effects of oxidative functionalized and aminosilanized carbon nanotubes on the crystallization behaviour of polyamide-6 nanocomposites
Kaynak, Cevdet (2014-04-01)
The purpose of this study is to investigate effects of oxidative functionalized and aminosilanized carbon nanotubes on the (1) isothermal and (2) non-isothermal crystallization kinetics of polyamide-6 by DSC analyses, and (3) crystal structure of injection molded specimens by XRD analyses. Nanocomposites were compounded by using melt mixing technique via twin screw extrusion. Due to basically very effective heterogeneous nucleation effect, both increasing amount and surface functionalization of carbon nanot...
Effects of oxidative functionalization and aminosilanization of carbon nanotubes on the mechanical and thermal properties of polyamide 6 nanocomposites
Kaynak, Cevdet (SAGE Publications, 2013-11-13)
The focus of this study is to investigate the effects of oxidative functionalized carbon nanotubes (f-CNTs) and aminosilanized carbon nanotubes (s-CNTs) on the mechanical and thermal properties of polyamide 6 nanocomposites. Oxidation of nanotube surfaces was conducted with sulfuric acid/nitric acid mixture and then aminosilanization was carried out with -aminopropyltriethoxysilane. Nanocomposites were compounded by melt mixing technique and shaped by injection molding. Scanning electron microscopy images r...
Analysis of pre-service science teachers’ systems thinking skills in the context of carbon cycle
Turan, Deniz; Öztekin, Ceren; Department of Elementary Science and Mathematics Education (2019)
The main purpose of this study is to analyze pre-service science teachers’ systems thinking skills in the context of carbon cycle. The eight systems thinking skills that is previously defined by Ben-Zvi Assaraf and Orion (2005) were used to investigate the participants’ systems thinking skills concerning the carbon cycle. Data was collected from four senior-year pre-service science teachers from elementary science education department of a state university. The data obtained through word association test, c...
Effects of nutrient and water level changes on the composition and size structure of zooplankton communities in shallow lakes under different climatic conditions: a pan-European mesocosm experiment
Tavsanoglu, Ulku Nihan; Sorf, Michal; Stefanidis, Konstantinos; Brucet, Sandra; TÜRKAN, SEMRA; Agasild, Helen; Baho, Didier L.; Scharfenberger, Ulrike; Hejzlar, Josef; Papastergiadou, Eva; Adrian, Rita; Angeler, David G.; Zingel, Priit; Cakiroglu, Ayse Idil; Ozen, Arda; Drakare, Stina; Sondergaard, Martin; Jeppesen, Erik; Beklioğlu, Meryem (Springer Science and Business Media LLC, 2017-06-01)
Lentic ecosystems act as sentinels of climate change, and evidence exists that their sensitivity to warming varies along a latitudinal gradient. We assessed the effects of nutrient and water level variability on zooplankton community composition, taxonomic diversity and size structure in different climate zones by running a standardised controlled 6-months (May to November) experiment in six countries along a European north-south latitudinal temperature gradient. The mesocosms were established with two diff...
Citation Formats
B. Salihoğlu, A. Oschlies, and M. W. Lomas, “Influence of nutrient utilization and remineralization stoichiometry on phytoplankton species and carbon export: A modeling study at BATS,” DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, pp. 73–107, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32660.