Preprints
Filtering by Subject: Biogeochemistry
High methane emissions from a eutrophic marine coastal basin driven by bubble release from the sediment
Published: 2023-10-25
Subjects: Biogeochemistry, Physical Sciences and Mathematics
The production of methane in coastal sediments and its release to the water column is intensified by anthropogenic eutrophication and bottom water hypoxia, and it is yet uncertain whether methane emissions to the atmosphere will be enhanced. Here, we assess seasonal variations in methane dynamics in a eutrophic, seasonally euxinic coastal marine basin (Scharendijke, Lake Grevelingen). In-situ [...]
Reply to: Beyond microbial carbon use efficiency
Published: 2023-10-20
Subjects: Biogeochemistry, Earth Sciences
In their commentary, Xiao et al. cautioned that the conclusions on the critical role of microbial carbon use efficiency (CUE) in global soil organic carbon (SOC) storage in a paper by Tao et al. (2023) might be too simplistic. They claimed that Tao et al.’s study lacked mechanistic consideration of SOC formation and excluded important datasets. Xiao et al. brought up important points, which can [...]
Combined genomic and imaging techniques show intense arsenic enrichment caused by detoxification in a microbial mat of the Dead Sea shore
Published: 2023-09-26
Subjects: Biogeochemistry, Environmental Microbiology and Microbial Ecology Life Sciences, Geochemistry, Paleobiology
Microbial mats and microbialites are essential tools for reconstructing early life and its environments. To better understand microbial trace element cycling, a microbial mat was collected from the sinkhole systems of the western shores of the Dead Sea, a dynamic environment exhibiting diverse extreme environments. Intense arsenic enrichment (up to 6.5 million times higher than current water [...]
No respite from permafrost-thaw impacts in absence of a global tipping point
Published: 2023-09-25
Subjects: Biogeochemistry, Climate, Earth Sciences, Geomorphology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Arctic permafrost, the largest non-seasonal component of Earth’s cryosphere, contains a significant climate-sensitive carbon pool. Its potential for loss due to climatic changes leading to a global tipping point, where thawing accelerates with disproportionate impacts, remains debated. Here, we provide an integrative perspective on this question, building on a cross-disciplinary meta-analysis of [...]
Reactive iron as an important reservoir of marine organic carbon over geological timescales
Published: 2023-09-20
Subjects: Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Microbiology
Reactive iron (FeR) has been suggested to serve as a semi-persistent sink of organic carbon (OC) in surface marine sediments, where approximately 10-20% of total OC (TOC) is associated with FeR (FeR-OC). However, the persistence of FeR-OC on geological timescales remains poorly constrained. Here, we retrieved FeR-OC records in two long sediment cores of the northern South China Sea spanning [...]
Recent methane surges reveal heightened emissions from tropical inundated areas
Published: 2023-09-05
Subjects: Atmospheric Sciences, Biogeochemistry, Earth Sciences
Beyond microbial carbon use efficiency
Published: 2023-08-16
Subjects: Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Life Sciences, Physical Sciences and Mathematics, Soil Science
Microbial carbon use efficiency (CUE) is defined as the proportion of microbial biomass growth C versus substrate C uptake, and thus provides a useful measure of microbially driven accumulation and loss of soil organic carbon (SOC) 1. In a recent study published in Nature 2, the authors use a data-driven machine learning approach to conclude that CUE promotes global SOC storage based on a [...]
High rates of rock organic carbon oxidation sustained as Andean sediment transits the Amazon foreland-floodplain
Published: 2023-07-18
Subjects: Biogeochemistry, Geochemistry
The oxidation of organic carbon contained within sedimentary rocks (“petrogenic” carbon, or hereafter OCpetro) emits nearly as much CO2 as is released by volcanism, thereby playing a key role in the long-term global C budget. High erosion rates in mountains have been shown to increase OCpetro oxidation. However, these settings also export un-weathered material that may continue to react in [...]
Functional organic matter components in mangrove soils revealed by density fractionation
Published: 2023-07-04
Subjects: Biogeochemistry, Geochemistry, Soil Science
The mechanisms underlying stabilization of soil organic matter (SOM) in coastal ecosystems, including mangrove forests, are poorly understood, limiting our ability to predict the consequences of disturbances. Here, we introduce density fractionation to mangrove soils to identify the distribution and properties of the functional components of SOM with regard to degradation state, stability, and [...]
Global 1km Land Surface Parameters for Kilometer-Scale Earth System Modeling
Published: 2023-06-28
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology
Earth system models (ESMs) are progressively advancing towards the kilometer scale (k-scale). However, the surface parameters for Land Surface Models (LSMs) within ESMs running at the k-scale are typically derived from coarse resolution and outdated datasets. This study aims to develop a new set of global land surface parameters with a resolution of 1 km for multiple years from 2001 to 2020, [...]
Innovating and networking global geochemical data resources through OneGeochemistry
Published: 2023-06-14
Subjects: Biogeochemistry, Cosmochemistry, Databases and Information Systems, Geochemistry, Geology, Planetary Biogeochemistry, Planetary Geochemistry, Planetary Geology, Volcanology
A vision of the not-to-distant future: Imagine yourself as a researcher who is making plans for fieldwork in the Andes Mountains. You are behind your computer and load a three-dimensional visualisation of the Earth and its geology to investigate the research already done in the southern Patagonian regions. You zoom in to the mountain range of interest and select various data layers to show [...]
Assessment of Oceanographic Conditions during the North Atlantic EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) Field Campaign
Published: 2023-06-07
Subjects: Biogeochemistry, Oceanography and Atmospheric Sciences and Meteorology
This manuscript presents an overview of NASA’s EXport Processes in the Ocean from Remote Sensing 2021 Field Campaign in the North Atlantic (EXPORTS NA) and provides quantitative and dynamical descriptions of the physical processes modulating water transformations during the study. A major programmatic goal was to conduct the sampling in a Lagrangian mode so that ocean ecological and [...]
Impacts of Carbonate Buffering on Atmospheric Equilibration of CO2, δ13CDIC, and Δ14CDIC in Rivers and Streams
Published: 2023-05-28
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Hydrology
Rivers and streams play an important role within the global carbon cycle, in part through emissions of CO2 to the atmosphere. However, the sources of this CO2 and their spatiotemporal variability are difficult to constrain. Recent work has highlighted the role of carbonate buffering reactions that may serve as a source of CO2 in high alkalinity systems. In this study, we seek to develop a [...]
Oxidoreductases and metal cofactors in the functioning of Earth
Published: 2023-05-15
Subjects: Biochemistry, Biophysics, and Structural Biology, Biogeochemistry, Biology, Microbiology
Life sustains itself using energy generated by thermodynamic disequilibria, commonly existing as redox disequilibria. Metals are significant players in controlling redox reactions, as they are essential components of the engine that life uses to tap into the thermodynamic disequilibria necessary for metabolism. The number of proteins that evolved to catalyze redox reactions is extraordinary, as [...]
Environmental controls on the brGDGT and brGMGT distributions across the Seine River basin (NW France): Implications for bacterial tetraethers as a proxy for riverine runoff
Published: 2023-05-07
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences
Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial lipids that have been largely used as environmental proxies in continental paleorecords. Another group of related lipids, branched glycerol monoalkyl glycerol tetraethers (brGMGTs), has recently been proposed as a potential paleotemperature proxy. Nevertheless, the sources and environmental dependencies of both brGDGTs and [...]