Preprints
Filtering by Subject: Oceanography and Atmospheric Sciences and Meteorology
Sediment redox dynamics in an oligotrophic deep-water lake in Tierra del Fuego: insights from Fe isotopes
Published: 2020-06-10
Subjects: Earth Sciences, Fresh Water Studies, Geochemistry, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Fe speciation and Fe isotopes have been widely used to reconstruct past basin dynamics and water redox conditions. However, sedimentation and early diagenesis of such proxies eventually alter any primary climate signal. In this work, we disentangled the processes occurring at the redox front below the sediment-water interface of a ventilated deep-water lake (Lago Fagnano, Argentina/Chile). A [...]
Heat does not physically flow in the ways assumed by greenhouse-warming theory
Published: 2020-06-06
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Volcanology
Heat is currently defined as an amount of thermal energy flowing each second per unit area. Temperature is assumed to result from the net amount of heat flowing—the sum of all radiative forcings. Yet direct and unambiguous observations of Nature show that macroscopic temperature of solid matter results from a very broad spectrum of sub-microscopic oscillations of all the bonds holding matter [...]
Antarctic elevation drives hemispheric asymmetry in polar lapse-rate climatology and feedback
Published: 2020-06-06
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The lapse-rate feedback is the dominant driver of stronger warming in the Arctic than the Antarctic in simulations with increased CO2. While Antarctic surface elevation has been implicated in promoting a weaker Antarctic lapse-rate feedback, the mechanisms in which elevation impacts the lapse-rate feedback are still unclear. Here we suggest that weaker Antarctic warming under CO2 forcing stems [...]
A novel rules-based shoreface translation model for predicting future coastal change: ShoreTrans
Published: 2020-06-05
Subjects: Earth Sciences, Engineering, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Engineering, Physical Sciences and Mathematics
Predicting change to global shorelines presents an increasing challenge as sea-level rise (SLR) accelerates. Many shoreline prediction models use variations of the ‘Bruun-rule’, failing to account for relevant processes and morphologic complexity. To address this, we introduce a simple rules-based model (ShoreTrans) designed for complex, real-world profiles that predicts change across a wide [...]
Atmospheric thermal convection and strong chaotic fluctuations of global temperature on Earth and on Mars
Published: 2020-06-04
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
It is shown that the atmospheric thermal (buoyancy driven) convection plays the main role in generation of the strong chaotic fluctuations of the global temperature through the Kolmogorov-Bolgiano-Obukhov mechanism (in the frames of the distributed chaos approach). It is valid for the planets with substantial atmosphere such as the Earth and Mars. Direct numerical simulations, the Berkeley Earth [...]
Observation-based Simulations of Humidity and Temperature Using Quantile Regression
Published: 2020-05-29
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability
The human impacts of changes in heat events depend on changes in the joint behavior of temperature and humidity. Little is currently known about these complex joint changes, either in observations or projections from general circulation models (GCMs). Further, GCMs do not fully reproduce the observed joint distribution, implying a need for simulation methods that combine information from GCMs [...]
Advective sorting of silt by currents: a laboratory study
Published: 2020-05-28
Subjects: Earth Sciences, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Accumulations of fine sediments along continental shelf and deep-sea bathymetric contours, known as contourite drifts, form a sedimentary record that is dependent on oceanographic processes such as ocean-basin-scale circulation. A tool used to aid in interpretation of such deposits is the sortable silt hypothesis, which suggests that the mean size of the sortable silt (silt from 10-63 µm) within [...]
A newly reconciled data set for identifying sea level rise and variability in Dublin Bay
Published: 2020-05-28
Subjects: Applied Statistics, Climate, Earth Sciences, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Life Sciences, Physical Sciences and Mathematics, Planetary Sciences, Statistics and Probability
We provide an updated sea level dataset for Dublin for the period 1938 to 2016 at yearly resolution. Using a newly collated sea level record for Dublin Port, as well as two nearby tide gauges at Arklow and Howth Harbour, we perform data quality checks and calibration of the Dublin Port record by adjusting the biased high water level measurements that affect the overall calculation of mean sea [...]
Kilometer-scale sound speed structure that affects GNSS-A observation: Case study off the Kii channel
Published: 2020-05-28
Subjects: Earth Sciences, Geophysics and Seismology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Global Navigation Satellite System-Acoustic ranging combination technique (GNSS-A) is a recently developed technology to precisely detect seafloor crustal deformation. This method can also estimate km-scale underwater sound speed structure (SSS) as a by-product of monitoring seafloor crustal deformation. This paper evaluates the validity of the spatial gradient and its temporal variation of [...]
Shining light on priming in euphotic sediments: Nutrient enrichment stimulates export of stored organic matter
Published: 2020-05-26
Subjects: Biogeochemistry, Earth Sciences, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Estuarine sediments are important sites for the interception, processing and retention of organic matter, prior to its export to the coastal oceans. Stimulated microbial co-metabolism (priming) potentially increases export of refractory organic matter through increased production of hydrolytic enzymes. By using the microphytobenthos community to directly introduce a pulse of labile carbon into [...]
UNSEEN trends: Detecting decadal changes in 100-year precipitation extremes
Published: 2020-05-26
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Environmental Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Sample sizes of observed climate extremes are typically too small to reliably constrain non-stationary behaviour. To facilitate detection of non-stationarities in 100-year precipitation values over a short period of 35 years (1981-2015), we apply the UNprecedented Simulated Extreme ENsemble (UNSEEN) approach, by pooling ensemble members and lead times from the ECMWF seasonal prediction system [...]
A multi-control climate policy process for a trusted decision maker
Published: 2020-05-25
Subjects: Climate, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sustainability
Persistent greenhouse gas (GHG) emissions threaten global climate goals and have prompted consideration of climate controls supplementary to emissions mitigation. We present an idealized model of optimally-controlled climate change, which is complementary to simpler analytical models and more comprehensive Integrated Assessment Models. We show that the four methods of controlling climate damage– [...]
Evaporative Resistance is of Equal Importance as Surface Albedo in High Latitude Surface Temperatures Due to Cloud Feedbacks
Published: 2020-05-25
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Arctic vegetation is known to influence Arctic surface temperatures through albedo. However, it is less clear how plant evaporative resistance and albedo independently influence surface climate at high latitudes. We use surface properties derived from two common Arctic tree types to simulate the climate response to a change in land surface albedo and evaporative resistance in factorial [...]
Quantification and interpretation of the climate variability record
Published: 2020-05-25
Subjects: Applied Mathematics, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This paper is currently in review for Global and Planetary Change. \\ The spectral view of variability is a compelling and adaptable tool for understanding variability of the climate. In the Mitchell (1976) seminal paper, it was used to express, on one graph with log scales, a very wide range of climate variations from millions of years to days. The spectral approach is particularly useful for [...]
Recent water mass changes reveal mechanisms of ocean warming
Published: 2020-05-19
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Over 90% of the build up of additional heat in the earth system over recent decades is contained in the ocean. Since 2006 new observational programs have revealed heterogeneous patterns of ocean heat content change. It is unclear how much of this heterogeneity is due to heat being added to and mixed within the ocean leading to material changes in water mass properties or due to changes in [...]