Preprints
Filtering by Subject: Life Sciences
The first climate tipping point – Already in the past?
Published: 2020-01-03
Subjects: Life Sciences, Other Life Sciences
Humanity may have passed its first climate tipping point and face self-sustained melting of the permafrost for hundreds of years even if all man-made GHG emissions are stopped.
Reframing Lake Geneva ecological trajectory in a context of multiple but asynchronous drivers
Published: 2019-12-12
Subjects: Ecology and Evolutionary Biology, Life Sciences, Terrestrial and Aquatic Ecology
There are no doubts long-term observatories provide unique insight on ecosystems trajectories. Can we use earliest data to set restoration goals? We take the example of Lake Geneva, for which descriptions of the ecosystem are available for as soon as the late 19th and early 20th century. Forel writes about how the luxuriant growth of plant communities provided important habitat for aquatic [...]
Bayesian Models for Deriving Biogeochemical Information from Satellite Ocean Color
Published: 2019-12-04
Subjects: Life Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In this study, we present Bayesian machine learning approaches to predict the spectral phytoplankton absorption coefficient - a proxy of phytoplankton biomass - from top of atmosphere measurements of ocean color. This presents a significant advance in ocean color research as it permits the bypassing of conventional atmospheric correction, which is notoriously challenging in optically complex [...]
Fossil fuel combustion is driving indoor CO2 toward levels harmful to human cognition
Published: 2019-12-03
Subjects: Climate, Cognitive Neuroscience, Life Sciences, Neuroscience and Neurobiology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Human activities are elevating atmospheric carbon dioxide concentrations to levels unprecedented in human history. The majority of anticipated impacts of anthropogenic CO2 emissions are mediated by climate warming. Recent experimental studies in the fields of indoor air quality and cognitive psychology and neuroscience, however, have revealed significant direct effects of indoor CO2 levels on [...]
Plate tectonics drive deep biosphere microbial community structure
Published: 2019-10-13
Subjects: Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Life Sciences, Microbiology, Other Earth Sciences, Physical Sciences and Mathematics
The deep subsurface is one of Earth’s largest biomes. Here, microorganisms modify volatiles moving between the deep and surface Earth. However, it is unknown whether large-scale tectonic processes affect the distribution of microorganisms across this subterranean landscape. We sampled subsurface microbial ecosystems in deeply-sourced springs across the Costa Rican convergent margin. Noble gases, [...]
Climate change resilient agricultural practices: A learning experience from indigenous communities over India
Published: 2019-10-06
Subjects: Agriculture, Biodiversity, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Sustainability
The impact of climate change on agricultural practices is rising question marks on future food security of billions of people in tropical and sub-tropical region. Recently introduced, Climate Smart Agriculture (CSA) techniques encourages the practices of sustainable agriculture, increasing adaptive capacity and resilience to shocks at multiple levels. However, in reality, it is extremely [...]
Mechanisms controlling fluid break-up and reconnection during two-phase flow in porous media
Published: 2019-10-01
Subjects: Earth Sciences, Engineering, Geophysics and Seismology, Life Sciences, Physical Sciences and Mathematics
The use of Darcys law to describe steady-state multiphase flow in porous media has been justified by the assumption that the fluids flow in continuously connected pathways. However, a range of complex interface dynamics have been observed during macroscopically steady-state flow, including intermittent pathway flow where flow pathways periodically disconnect and reconnect. The physical [...]
Canopy structure explains the relationship between photosynthesis and sun-induced chlorophyll fluorescence in crops
Published: 2019-09-30
Subjects: Agricultural Science, Life Sciences, Physiology, Plant Sciences
Remote sensing of far-red sun-induced chlorophyll fluorescence (SIF) has emerged as an important tool for studying gross primary productivity (GPP) at the global scale. However, the relationship between SIF and GPP at the canopy scale lacks a clear mechanistic explanation. This is largely due to the poorly characterized role of the relative contributions from canopy structure and leaf physiology [...]
Possible Tectonic Impact of Biosphere
Published: 2019-09-19
Subjects: Environmental Microbiology and Microbial Ecology Life Sciences, Life Sciences, Microbiology
This paper explores the possibility of existence of ultra-deep biosphere (deeper than 10 km under the surface) and the biogenic earthquake hypothesis -- the idea that subsurface microorganisms might be directly related to earthquake activity. The importance of electroautotrophic type of metabolism is underlined, and the role of telluric currents in this process is explored in some detail, as well [...]
Enriching the historical meteorological information using Romanian newspaper reports
Published: 2019-09-17
Subjects: Life Sciences, Other Life Sciences
This study presents the meteorological information spanning the last two decades of the end of 19th century (1880-1900) extracted from three Romanian newspapers (România Liberă, Gazeta de Transilvania and Foaia Poporului). It describes the characteristics of the newspaper data included in the database, it offers and overview of the meteorological network and climate picture at that time in [...]
Paradoxical impact of sprawling intra-Urban Heat Islets: Reducing mean surface temperatures while enhancing local extremes
Published: 2019-09-08
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Life Sciences, Physical Sciences and Mathematics, Statistics and Probability
Cities are at the forefront of climate change impacts and face a growing burden of adaptation to ensuing natural hazards. Extreme heat is a particularly challenging hazard as persistent heatwaves are locally exacerbated by the Urban Heat Island (UHI) effect. As a result, there is an increasing scientific interest in the influence of diverse urban morphologies on UHI. However, as the temperatures [...]
Accounting for training data error in machine learning applied to Earth observations
Published: 2019-08-29
Subjects: Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics
Remote sensing, or Earth Observation (EO), is increasingly used to understand Earth system dynamics and create continuous and categorical maps of biophysical properties and land cover, especially based on recent advances in machine learning (ML). ML models typically require large, spatially explicit training datasets to make accurate predictions. Training data (TD) are typically generated by [...]
Considering the role of adaptive evolution in models of the ocean and climate system
Published: 2019-08-29
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Numerical models have been highly successful in simulating global carbon and nutrient cycles in today’s ocean, together with observed spatial and temporal patterns of chlorophyll and plankton biomass at the surface. With this success has come some confidence in projecting the century-scale response to continuing anthropogenic warming. There is also increasing interest in using such models to [...]
More than planetary-scale feedback self-regulation: A Biological-centred approach to the Gaia Hypothesis
Published: 2019-08-15
Subjects: Life Sciences, Other Life Sciences
Recent appraisals of the Gaia theory tend to focus on the claim that planetary life is a cybernetic regulator that would self-regulate Earth’s chemistry composition and climate dynamics, following either a weak (biotic and physical processes create feedback loops), or a strong (biological activity control and regulates the physical processes) interpretation of the Gaia hypothesis. Here, we [...]
Realistic and simplified models of plant and leaf area indices for a seasonally dry tropical forest
Published: 2019-08-06
Subjects: Civil and Environmental Engineering, Desert Ecology, Ecology and Evolutionary Biology, Engineering, Environmental Engineering, Forest Management, Forest Sciences, Life Sciences, Plant Sciences, Research Methods in Life Sciences
Leaf Area Index (LAI) models that consider all phenological stages have not been developed for the Caatinga, the largest seasonally dry tropical forest in South America. LAI models that are currently used show moderate to high covariance when compared to in situ data, but they often lack accuracy in the whole spectra of possible values and do not consider the impact that the stems and branches [...]