Article
Environmental Sciences
Tim Rixen, Niko Lahajnar, Tarron Lamont, Rolf Koppelmann, Bettina Martin, Justus E. E. van Beusekom, Claire Siddiqui, Keshnee Pillay, Luisa Meiritz
Summary: The study shows that a topographically steered nutrient trapping zone develops during the main upwelling season in the southern Benguela Upwelling System, enhancing productivity but potentially decreasing oxygen concentrations. At the end of the upwelling season, the front separating the trapped and open shelf waters weakens or collapses due to upwelling cessation and changing current regimes.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Xingchen Tony Wang, Yuwei Wang, Alexandra Auderset, Daniel M. Sigman, Haojia Ren, Alfredo Martinez-Garcia, Gerald H. Haug, Zhan Su, Yi Ge Zhang, Birger Rasmussen, Alex L. Sessions, Woodward W. Fischer
Summary: This study reveals the expansion of ODZs in the southeastern Pacific since the late Miocene, accompanied by a major increase in ocean nutrient content, indicating a connection between the formation and development of modern ODZs and historically high concentrations of seawater phosphate.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Green & Sustainable Science & Technology
Hongxiang Chai, Jingchen Ma, Haiyuan Ma, Hong Cheng, Zhongshuai Weng, Zheng Kong, Zhiyu Shao, Yunsong Yuan, Yanhong Xu, Qichang Ni, Liqing Li
Summary: Novel pyrite-based bioretention cells with agricultural waste amendment (wood chips) were developed and evaluated under simulated complex rainfall conditions. The woodchip-amended bioretention cell showed significantly higher efficiency and stability for dissolved nutrient removal compared to the pyrite bioretention cell. Microbiological analysis revealed that woodchips promoted the proliferation of autotrophic and heterotrophic microorganisms, enhancing the nitrogen removal efficiency.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Oceanography
T. B. Mashifane
Summary: The study reveals that denitrification and anammox result in changes in nutrient stoichiometry and phytoplankton community structure in the northern Benguela, with implications for phytoplankton composition and succession in the region. Denitrification limits picophytoplankton growth, leading to a dominance of flagellates and diatom succession. The interactions between denitrification, anammox, DIC uptake and primary production highlighted in the study have significant implications for the biological pump in the northern Benguela.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Astronomy & Astrophysics
Austin Ware, Patrick Young, Amanda Truitt, Alexander Spacek
Summary: Researchers used Bayesian statistical method to analyze nine potentially habitable exoplanets, as well as Venus, Earth, and Mars, to determine their continuous habitable time and age estimates of their host stars.
ASTROPHYSICAL JOURNAL
(2022)
Review
Environmental Sciences
Zouhair Lachkar, Marina Levy, Derara Hailegeorgis, Parvathi Vallivattathillam
Summary: The Arabian Sea is known for its highly productive marine ecosystem and the thickest oxygen minimum zone (OMZ) due to intense productivity and sluggish circulation. Recent evidence suggests a decline in oxygen levels in the northern Arabian Sea. However, future projections of the OMZ are uncertain due to inconsistencies in models. The limitations of current models and the sensitivity of oxygen supply and consumption to local and remote changes pose challenges in predicting future changes in the Arabian Sea OMZ.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Limnology
Natalya Evans, Juliana Tichota, James W. Moffett, Allan H. Devol
Summary: Nitrite is a crucial intermediate in the ocean's fixed nitrogen loss and accumulates in Oxygen Deficient Zones (ODZs). Recent research has found significant reoxidation of nitrite back to nitrate, impacting the global nitrogen cycle. Analysis of basin-scale data reveals extensive nitrite reoxidation across the Eastern Tropical North Pacific (ETNP) ODZ. The study also highlights metabolic switching points and high spatiotemporal variability in nitrite reoxidation. This analysis provides valuable insights into the recycling of fixed nitrogen in the ETNP.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Engineering, Environmental
Yu Zhang, Zehua Ji, Yuansheng Pei
Summary: The artificial-natural coupled wetland effectively reduced nutrient input and protected water ecological health, mainly through high removal efficiencies of COD and TN by the lotus pond within the wetland, as well as a range of microorganisms promoting and transforming carbon and nitrogen cycling.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Review
Oceanography
Josymar Torrejon-Magallanes, Luis Enrique Angeles-Gonzalez, Jorge Csirke, Marilu Bouchon, Enrique Morales-Bojorquez, Francisco Arreguin-Sanchez
Summary: This study characterized the spatiotemporal distribution of Pacific chub mackerel in the northern Peruvian Current System by analyzing ecological niche and projected future climate change effects. Models calibrated with sea surface temperature and salinity showed good performance, with predictions for El Nino and La Nina conditions. Future scenarios indicated potential changes in habitat suitability and climate refugia, highlighting the importance of considering extreme conditions in model calibration. More testing is needed to validate these findings.
PROGRESS IN OCEANOGRAPHY
(2021)
Article
Ecology
Cynthia Nevison, Peter Hess, Christine Goodale, Qing Zhu, Julius Vira
Summary: This study evaluates the nitrogen cycling in two Earth System Models (ESMs), finding significant differences in global mineralization, immobilization, plant N uptake, nitrification, and denitrification fluxes between the models. The study also suggests underestimated ratios of nitrification:denitrification and highlights the need for more observational constraints on soil nitrogen fluxes.
ECOLOGICAL APPLICATIONS
(2022)
Article
Environmental Sciences
Montserrat Aldunate, Peter von Dassow, Cristian A. Vargas, Osvaldo Ulloa
Summary: Anoxic marine zones have distinct characteristics compared to oxygen minimum zones, with the development of a secondary chlorophyll maximum playing an important role in the particulate organic carbon. Photosynthesis can exceed chemoautotrophic activity when sufficient light and Prochlorococcus are present.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Microbiology
Clara A. Fuchsman, Luca Cherubini, Matthew D. Hays
Summary: Ocean oxygen deficient zones (ODZs) are important areas for N-2 production in marine ecosystems, with specific distribution and abundance of photosynthetic cyanobacteria and protists. Metagenomic analysis can reveal the changes in protist communities in ODZs and identify taxonomic groups missed by amplicon sequencing.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Green & Sustainable Science & Technology
Zewei Jiang, Shihong Yang, Jie Ding, Xiao Sun, Xi Chen, Xiaoyin Liu, Junzeng Xu
Summary: The conservation of soil organic carbon (SOC) in agricultural soils is crucial for sustainable agricultural production and climate change mitigation. A modified DNDC model was used to simulate changes in SOC, dissolved organic carbon (DOC), and rice yield under different irrigation and fertilizer management systems. Climate scenarios had a significant impact on rice yield, while controlled irrigation with straw returning was found to clearly increase SOC and rice yields in paddy fields.
Article
Environmental Sciences
Natalya Evans, Juliana Tichota, Wendi Ruef, James Moffett, Allan Devol
Summary: Climate change is expected to strengthen ocean Oxygen Deficient Zones (ODZs). A 50-year time series in the Eastern Tropical North Pacific (ETNP) ODZ revealed a 30% increase in strength from 1994 to 2019, with different factors influencing fixed nitrogen loss between core and deep ODZ layers. The recent rapid increase in ODZ strength, based on sedimentary records, suggests a potential link to climate change, but further monitoring is needed.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Environmental Sciences
Praxedes Munoz, Alexis Castillo, Jorge Valdes, Boris Dewitte
Summary: This study investigates the temporal variability of bottom oxygen conditions along the Chilean continental margin in the last 2000 years, revealing a close relationship between the upper part of the OMZ and climatic oscillations. The results show a weakening trend in the upper boundary of the OMZ in recent decades, which is interpreted as a cumulative effect of ventilation processes at different time scales.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
H. Dietze, U. Loeptien, R. Hordoir, M. Heinemann, W. Huiskamp, B. Schneider
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2020)
Article
Multidisciplinary Sciences
U. Loeptien, H. Dietze, R. Preuss, U. Toussaint
Summary: Pelagic biogeochemical models have become integral components of Earth System Models, but parameter uncertainties pose a significant challenge in projections. This study uses sensitivity analysis to map parameter uncertainties onto local model entities, facilitating uncertainty reduction. The study highlights the importance of identifying and refining specific parameters for reliable projections.
SCIENTIFIC REPORTS
(2021)
Article
Oceanography
Robinson Hordoir, Oystein Skagseth, Randi B. Ingvaldsen, Anne Britt Sando, Ulrike Loeptien, Heiner Dietze, Andrea M. U. Gierisch, Karen M. Assmann, Oyvind Lundesgaard, Sigrid Lind
Summary: Climate change has a significant impact on the Arctic Ocean, affecting its thermo-haline structure. Analysis of a 3D ocean model simulation from 1970 to 2019 shows a decrease in stratification, decrease in fresh water inputs, and increase in momentum inputs. The winter mixed layer becomes deeper while the summer mixed layer shows a less evident deepening pattern. Regional exceptions include areas where the mixed layer becomes shallower. The results highlight the non-linear dynamics of the Arctic Ocean.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Multidisciplinary Sciences
U. Loeptien, H. Dietze
Summary: Massive blooms of cyanobacteria regularly occur in the Baltic Sea during late summer, which can negatively impact water quality. Understanding the controls on cyanobacteria blooms is crucial for better management efforts. By combining satellite data, ocean circulation models, and nutrient observations, this study identifies offshore, nutrient-depleted areas as the primary origins of blooms.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
U. Loeptien, H. Dietze
Summary: Nitrogen fixers, or diazotrophs, play a vital role in the nitrogen and carbon cycle of the world oceans by utilizing atmospheric dinitrogen. This study examines the effects of preferential grazing and high-affinity diazotrophic phosphorus uptake on an Earth System Model, and finds that these factors significantly impact estimated nitrogen fixation rates.
SCIENTIFIC REPORTS
(2022)
Article
Oceanography
Ahmad Fehmi Dilmahamod, Johannes Karstensen, Heiner Dietze, Ulrike Loeptien, Katja Fennel
Summary: This study investigates the physical processes driving the cyclonic and anticyclonic eddies originating from the Mauritanian coastal current system. The results show that a baroclinically unstable state of the boundary current during the intensification phase in summer drives the generation of eddies. The interaction between the coastal flow and the sloping topography, as well as flow separation and transport of different water masses, play important roles in the generation and intensification of the eddies.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Ecology
Heiner Dietze, Ulrike Loeptien
Summary: This study aims to analyze the mechanisms of hypoxia in the Eckernförde Bight in the Baltic Sea, explore the potential of existing monitoring programs to predict hypoxia, and develop a workflow applicable to other regions facing similar challenges. The research utilizes a highly detailed ocean circulation model to examine the factors contributing to hypoxic events.
Review
Ecology
Britta Munkes, Ulrike Loeptien, Heiner Dietze
Summary: The ecosystem of the Baltic Sea is endangered by eutrophication, with international management efforts hindered by factors like cyanobacteria blooms. The lack of comprehensive understanding of controlling cyanobacteria blooms contributes to uncertainties in model-based projections for the Baltic Sea's warming future.
Article
Geosciences, Multidisciplinary
Sabine Mathesius, Julia Getzlaff, Heiner Dietze, Andreas Oschlies, Markus Schartau
EARTH SYSTEM SCIENCE DATA
(2020)
Article
Geosciences, Multidisciplinary
Heiner Dietze, Ulrike Loeptien, Julia Getzlaff
GEOSCIENTIFIC MODEL DEVELOPMENT
(2020)
Article
Ecology
Ulrike Loeptien, Heiner Dietze
Article
Geosciences, Multidisciplinary
Robinson Hordoir, Lars Axell, Anders Hoglund, Christian Dieterich, Filippa Fransner, Matthias Groger, Ye Liu, Per Pemberton, Semjon Schimanke, Helen Andersson, Patrik Ljungemyr, Petter Nygren, Saeed Falahat, Adam Nord, Anette Jonsson, Irene Lake, Kristofer Doos, Magnus Hieronymus, Heiner Dietze, Ulrike Loeptien, Ivan Kuznetsov, Antti Westerlund, Laura Tuomi, Jari Haapala
GEOSCIENTIFIC MODEL DEVELOPMENT
(2019)
Article
Geosciences, Multidisciplinary
Karin F. Kvale, Samar Khatiwala, Heiner Dietze, Iris Kriest, Andreas Oschlies
GEOSCIENTIFIC MODEL DEVELOPMENT
(2017)
Article
Ecology
Yonss Saranga Jose, Heiner Dietze, Andreas Oschlies
Article
Ecology
Heiner Dietze, Julia Getzlaff, Ulrike Loeptien