Preprints
Filtering by Subject: Biogeochemistry
Towards statistical modeling of chlorophyll-a concentrations in Balikpapan Bay, Indonesia: Implications for algal bloom detection
Published: 2024-10-26
Subjects: Artificial Intelligence and Robotics, Biogeochemistry, Environmental Monitoring, Marine Biology, Oceanography
This study presents a comprehensive statistical analysis of chlorophyll-a dynamics in Balikpapan Bay, Indonesia, combining time series analysis, extreme value modeling, and machine learning techniques to understand phytoplankton variability near Indonesia's planned new capital city. Analysis of daily chlorophyll-a concentrations (2019-2021) revealed a non-Gaussian distribution (skewness = 2.212, [...]
Potential effects of coagulation processes on phytoplankton mortality in the Elbe estuary from a Lagrangian point of view
Published: 2024-10-18
Subjects: Biogeochemistry, Environmental Health and Protection, Environmental Indicators and Impact Assessment, Environmental Monitoring, Oceanography, Water Resource Management
Within the Elbe estuary, a sudden change in depth occurs when the river enters the shipping channel in the Port of Hamburg. This change in depth correlates with a sharp decline in phytoplankton concentrations. This decline affects the estuarine food web and shifts the ecosystem from autotrophic to heterotrophic during the summer months. Previous studies have hypothesized that this collapse is [...]
Instability in the geological regulation of Earth’s climate
Published: 2024-10-06
Subjects: Biogeochemistry
Negative feedback between climate and atmospheric CO2, as mediated via weathering of silicate minerals, is thought to provide the dominant regulation of Earth’s climate on geological timescales. In contrast, we show here that faster feedbacks involving organic matter are critical and create unexpected instability in the system. Specifically, using an Earth system model, we show how organic carbon [...]
Prioritizing Safety, Advancing Efficiency: Developing a New Total Phosphorous Microwave Digestion Method for Sediment Core Nutrient Analysis
Published: 2024-09-27
Subjects: Biogeochemistry, Environmental Chemistry, Inorganic Chemistry, Soil Science
Long-term datasets are invaluable resources for understanding broad-level temporal patterns in ecosystems. For over two decades, UC Davis and Lake County Water Resources Department have collaborated on a long-term monitoring project of Clear Lake sediment nutrient concentrations, in an effort to better understand nutrient cycling in Clear Lake. When the need for a new total phosphorus digestion [...]
Contributions to the discussion of novel detection of dark oxygen production at the abyssal seafloor
Published: 2024-09-19
Subjects: Biogeochemistry, Earth Sciences
There is an overwhelming consensus between researchers based on a vast body of peer-reviewed literature that deep sea ecosystems constitute an oxygen sink. Specific studies on abyssal seafloor regions that contain polymetallic nodules have also confirmed this result. In contrast to this well-founded and longstanding paradigm, Sweetman et al. claim to provide evidence to support a hypothesis that [...]
Carbon storage in Northern Ireland’s aquatic ecosystems: an evidence synthesis to support policy development.
Published: 2024-09-06
Subjects: Biogeochemistry, Marine Biology, Oceanography
Blue carbon is defined as carbon that is naturally sequestered and stored in the world’s aquatic ecosystems. Governments around the world are currently seeking to develop a range of tools to help meet their commitments to reduce greenhouse gas emissions and potentially reverse anthropogenic climate change. As such, there is growing interest from policy makers in natural processes which may be [...]
Sensitivities of soil respiration and heterotrophic respiration to temperature in a cool-temperate forest with sika deer-induced understory vegetation alteration
Published: 2024-08-05
Subjects: Biogeochemistry, Environmental Health and Protection, Environmental Monitoring, Forest Biology, Forest Management, Soil Science, Terrestrial and Aquatic Ecology
Overpopulated ungulates reduce the biomass of understory vegetation and promote the expansion of unpalatable plants in world forests. These understory degradations possibly influence sensitivities of soil respiration (Rs) and heterotrophic respiration (Rh) to temperature and moisture. Here, we examined this possibility in a cool-temperate forest in southern Kyushu, Japan. At the study site, the [...]
Relating Multi-Scale Plume Detection and Area Estimates of Methane Emissions: A Theoretical and Empirical Analysis
Published: 2024-07-23
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Oil, Gas, and Energy, Physical Sciences and Mathematics
Methodologies for inferring surface emissions of atmospheric trace gases can be categorized into plume detection and area-scale estimation. Plume detections are observations of emissions from either individual or clustered point sources. Area estimates are derived from top-down atmospheric flux inversion models or bottom-up inventories, which infer mean emissions typically over spatial scales [...]
Excitable Dynamics of Neoproterozoic to Early Paleozoic Atmospheric and Ocean Oxygen
Published: 2024-07-05
Subjects: Biogeochemistry
The geochemical carbon isotope and redox proxy record indicates that Earth’s surface oxygenation involved a prolonged period of extreme variability in atmospheric and oceanic oxygen, spanning from the early Neoproterozoic to the early Paleozoic. This variability has been linked to external tectonic and evolutionary forcings, as well as to internal nonlinear feedbacks related to the [...]
Diversity at Goldschmidt conference
Published: 2024-06-19
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Planetary Biogeochemistry, Planetary Geochemistry, Planetary Sciences
The field of geochemistry has grown significantly over the past seventy years, contributing to our understanding of Earth's processes. However, geochemists often identify with broader fields like geology or oceanography, reflecting an identity crisis within the discipline. The Goldschmidt Conference, established in 1988, serves as a central international meeting for geochemists, promoting their [...]
Taxon-specific hydrogen isotope signals in cultures and mesocosms facilitate ecosystem and hydroclimate reconstruction
Published: 2024-06-08
Subjects: Biogeochemistry
Phytoplankton play a key role in biogeochemical cycles, impacting atmospheric and aquatic chemistry, food webs, and water quality. However, it remains challenging to reconstruct changes in algal community composition throughout the geologic past, as existing proxies are suitable only for a subset of taxa and/or influenced by degradation. Here, we investigate if compound-specific hydrogen [...]
Limited long-term cooling effects of flood basalt emplacements
Published: 2024-04-23
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Volcanology
The emplacement of large igneous provinces (LIPs) is known to have been a driver of climate change in Earth’s past, particularly during the breakup of Pangaea. However, the balance between climate warming through CO2 emission and climate cooling through increased weathering is poorly understood. To better understand the role of LIP emplacement on long-term climate change, we utilize a coupled [...]
Plant controls over tropical wetland nitrous oxide dynamics: a review
Published: 2024-03-07
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Tropical wetlands are an important global source of greenhouse gas emissions, including nitrous oxide, a potent and long-last greenhouse gas. Tropical wetland ecosystems can be highly heterogeneous, featuring a variety of vegetation types, from grasses through to palms and mangroves. A variety of plant-mediated processes can exert key controls over wetland plant/soil nitrogen transportation and [...]
Scaling High-resolution Soil Organic Matter Composition to Improve Predictions of Potential Soil Respiration Across the Continental United States
Published: 2024-02-14
Subjects: Biogeochemistry, Soil Science
Despite the importance of microbial respiration of soil organic matter (SOM) in regulating carbon flux between soils and atmosphere, soil carbon cycling models remain primarily based on climate and soil properties, leading to large uncertainty in predictions. With data from the 1000 Soils Pilot of the Molecular Observation Network (MONet), we analyzed high resolution water-extractable SOM [...]
Graph Characterization of Higher Order Structure in Atmospheric Chemical Reaction Mechanisms
Published: 2024-02-14
Subjects: Atmospheric Sciences, Biogeochemistry, Environmental Chemistry, Other Applied Mathematics, Other Environmental Sciences
Atmospheric chemical reactions play an important role in air quality and climate change. While the structure and dynamics of individual chemical reactions are fairly well understood, the emergent properties of the entire atmospheric chemical system, which can involve many different species that participate in many different reactions, are not well described. In this work, we leverage [...]