Preprints
Filtering by Subject: Oceanography and Atmospheric Sciences and Meteorology
The El Niño – La Niña cycle and recent trends in supply and demand of net primary productivity in African drylands
Published: 2019-04-23
Subjects: Climate, Environmental Sciences, Geography, Nature and Society Relations, Oceanography and Atmospheric Sciences and Meteorology, Physical and Environmental Geography, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences
The role of El Niño-Southern Oscillation (ENSO) in the balance between supply and demand of net primary productivity (NPP) over Africa is unclear. Here, we analyze the impact of ENSO on this balance in a spatially explicit framework using gridded population data from the WorldPop project, satellite-derived data on NPP supply, and statistical data from the United Nations. Our analyses demonstrate [...]
The flow of fresh groundwater and solutes to the world’s oceans and coastal ecosystems
Published: 2019-03-31
Subjects: Earth Sciences, Hydrology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The flow of fresh groundwater towards the world oceans may provide substantial inputs of nutrients and solutes to the oceans. Here we present a spatially resolved global model of coastal groundwater discharge to show that the contribution of fresh groundwater is lower than most previous estimates and accounts for only ~0.6% of the freshwater input and ~2% of the solute input to the oceans. [...]
Preprint: Dataset of global extreme climatic indices due to an acceleration of ice sheet melting during the 21st century
Published: 2019-03-25
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Planetary Hydrology, Planetary Sciences
This article describes extreme indices maps (Data Cube, raster X Time) for different scenarios with a more important contribution to the sea level rise from Greenland and/or Antarctica during the 21st century under the Representative Concentration Pathway (RCP) 8.5 emission scenario. The indices are produced annually and globally with a resolution of 0.5°X0.5° from 1951 to 2099. The data were [...]
The Impact of Melting Ice Sheets on Future Global Climate
Published: 2019-03-22
Subjects: Climate, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics, Physics
That is a preprint of an article suubmitted at Applied Greography (20tf of March 19). Climate change studies in the last decades have been based on Global Climate Models (GCM), and the distribution of climatic regions over time extracted from these models can be represented using the Köppen climatic classification. The Köppen approach predicts the distribution of biomes worldwide on the basis of [...]
Half the worlds population already experiences years 1.5°C warmer than preindustrial
Published: 2019-03-12
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Paris Agreement aims to limit the increase in global average temperature to 1.5 °C above preindustrial. A natural question for the public to ask is “But how much warmer than preindustrial is where I live?” We develop a pattern-scaling technique to present local annually-resolved, gridded temperature anomalies prior to the industrial burning of fossil fuels. On average the past 5 years, [...]
New flow relaxation mechanism explains scour fields at the end of submarine channels
Published: 2019-03-11
Subjects: Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
In the ocean, particle-laden gravity flows, turbidity currents, flow in river-like channels across the ocean floor. These submarine channels funnel sediment, nutrients, pollutants and organic carbon into the ocean basins and can extend over 1,000’s of kilometers. At the end of these channels, turbidity currents lose their confinement, decelerate and deposit their sediment load. This is what we [...]
Technical note on the multi-GNSS, multi-frequency and near real-time ionospheric TEC monitoring system for South America
Published: 2019-02-21
Subjects: Atmospheric Sciences, Earth Sciences, Geophysics and Seismology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Development of regional services able to provide ionospheric total electron content (TEC) maps with a high spatial resolution, and in near real-time, are of high importance for applications and the research community. We provide here the methodologies, and a preliminary assessment, of such a system. The system relies on the public Global Navigational Satellite Systems (GNSS) infrastructure in [...]
Reconstruction of Cloud Vertical Structure with a Generative Adversarial Network
Published: 2019-02-19
Subjects: Artificial Intelligence and Robotics, Atmospheric Sciences, Computer Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
We demonstrate the feasibility of solving atmospheric remote sensing problems with machine learning using conditional generative adversarial networks (CGANs), implemented using convolutional neural networks (CNNs). We apply the CGAN to generating two-dimensional cloud vertical structures that would be observed by the CloudSat satellite-based radar, using only the collocated Moderate-Resolution [...]
Heavy rainfall in Paraguay during the 2015-2016 austral summer: causes and sub-seasonal-to-seasonal predictive skill
Published: 2019-02-11
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Water Resource Management
During the austral summer 2015/16, severe flooding displaced over 170 000 people on the Paraguay River system in Paraguay, Argentina, and southern Brazil. These floods were driven by repeated heavy rainfall events in the lower Paraguay River basin. Alternating sequences of enhanced moisture inflow from the South American low-level jet and local convergence associated with baroclinic systems were [...]
The Urban Heat Island (UHI) is a major source of uncertainty in projections of population-weighted surface temperature under climate change.
Published: 2019-02-06
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Rising global mean temperatures and an increase in the fraction of the population living in urban areas is leading to a number of grand challenges. Contrasting area-weighted and population-weighted trends in an ensemble of CMIP5 climate model simulations under a range of climate and population change scenarios (RCPs and SSPs) shows that population-weighted changes in future surface temperature [...]
Factor Analysis by R Programming to Assess Variability Among Environmental Determinants of the Mariana Trench
Published: 2019-01-28
Subjects: Computer Sciences, Earth Sciences, Education, Engineering, Environmental Monitoring, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Graphics and Human Computer Interfaces, Life Sciences, Marine Biology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Geography, Other Oceanography and Atmospheric Sciences and Meteorology, Physical and Environmental Geography, Physical Sciences and Mathematics, Programming Languages and Compilers, Remote Sensing, Science and Mathematics Education, Sedimentology, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure, Water Resource Management
The aim of this work is to identify main impact factors affecting variations in the geomorphology of the Mariana Trench which is the deepest place of the Earth, located in the west Pacific Ocean: steepness angle and structure of the sediment compression. The Mariana Trench presents a complex ecosystem with highly interconnected factors: geology (sediment thickness and tectonics including four [...]
Hierarchical Cluster Analysis by R language for Pattern Recognition in the Bathymetric Data Frame: a Case Study of the Mariana Trench, Pacific Ocean
Published: 2019-01-25
Subjects: Applied Statistics, Earth Sciences, Environmental Education, Environmental Monitoring, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Geology, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Oceanography and Atmospheric Sciences and Meteorology, Other Statistics and Probability, Physical and Environmental Geography, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Statistics and Probability, Tectonics and Structure
The geographic focus of the current study Mariana trench, the deepest point of the Earth located in the west Pacific Ocean. Mariana trench has unique structure and features formed in the complex process of the trench development. There is a range of the environmental factors affecting trench structure and functioning: bathymetry, geography, geology and tectonics. Current research aimed to study [...]
Dynamics of ITCZ width: Ekman processes, non-Ekman processes and links to sea-surface temperature
Published: 2019-01-22
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The dynamical processes controlling the width of the intertropical convergence zone (ITCZ) are investigated using idealized simulations. ITCZ width is defined in terms of boundary-layer vertical velocity. The tropical boundary layer is approximately in Ekman balance suggesting that wind stress places a strong constraint on ITCZ width. A scaling based on Ekman balance predicts that ITCZ width is [...]
A statistics-based reconstruction of high-resolution global terrestrial climate for the last 800,000 years
Published: 2019-01-18
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistical Models, Statistics and Probability
Curated global climate data have been generated from climate model outputs for the last 120,000 years, whereas reconstructions going back even further have been lacking due to the high computational cost of climate simulations. Here, we present a statistically-derived global terrestrial climate dataset for every 1,000 years of the last 800,000 years. It is based on a set of linear regressions [...]
Utilising the flexible generation potential of tidal range power plants to optimise economic value
Published: 2019-01-08
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Tidal range renewable power plants have the capacity to deliver predictable energy to the electricity grid, subject to the known variability of the tides. Tidal power plants inherently feature advantages that characterise hydro-power more generally, including a lifetime exceeding alternative renewable energy technologies and relatively low Operation & Maintenance costs. Nevertheless, the [...]