Preprints
Filtering by Subject: Climate
Past and projected weather pattern persistence with associated multi-hazards in the British Isles
Published: 2019-05-30
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Hazards such as heatwaves, droughts and floods are often associated with persistent weather patterns. Atmosphere-Ocean General Circulation Models (AOGCMs) are important tools for evaluating projected changes in extreme weather. Here, we demonstrate that 2-day weather pattern persistence, derived from the Lamb Weather Types (LWTs) objective scheme, is a useful concept for both investigating [...]
Concurrent wet and dry hydrological extremes at the global scale
Published: 2019-05-30
Subjects: Climate, Earth Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Multi-hazard events can be associated with larger socio-economic impacts than single-hazard events. Understanding the spatio-temporal interactions that characterise the former is, therefore, of relevance to disaster risk reduction measures. Here, we consider two high-impact hazards, namely wet and dry hydrological extremes, and quantify their global co-occurrence. We define these using the [...]
Lake Level Fluctuations in the Northern Great Basin for the Last 25,000 years
Published: 2019-05-30
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
During the Last Glacial Maximum (LGM; ~23,000 to 19,000 years ago or ka) and through the last deglaciation, the Great Basin physiographic region in the western United States was marked by multiple extensive lake systems, as recorded by proxy evidence and lake sediments. However, temporal constraints on the growth, desiccation, and timing of lake highstands remain poorly constrained. Studies aimed [...]
Representation of European hydroclimatic patterns with Self-Organizing Maps
Published: 2019-05-14
Subjects: Climate, Earth Sciences, Environmental Sciences, Hydrology, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics, Planetary Sciences
Self-Organizing Maps provide a powerful, non-linear technique of dimensionality reduction that can be used to identify clusters with similar attributes. Here, they were constructed from a 1000-year-long gridded palaeoclimatic dataset, namely the Old World Drought Atlas, to detect regions of homogeneous hydroclimatic variability across the European continent. A classification scheme of 10 regions [...]
A new method to study inhomogeneities in climate records: Brownian Motion or Random Deviations?
Published: 2019-05-08
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Planetary Sciences
Climate data is affected by inhomogeneities due to historical changes in the way the measurements were performed. Understanding these inhomogeneities is important for accurate estimates of long-term changes in the climate. These inhomogeneities are typically characterized by the number of breaks and the size of the jumps or the variance of the break signal, but a full characterization of the [...]
Trends of hydroclimatic intensity in Colombia
Published: 2019-05-08
Subjects: Applied Statistics, Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Hydrology, Life Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Risk Analysis, Statistics and Probability, Water Resource Management
Prediction of changes in precipitation in upcoming years and decades caused by global climate change associated with the greenhouse effect, deforestation and other anthropic perturbations is a practical and scientific problem of high complexity and huge consequences. To advance toward this challenge we look at the daily historical record of all available rain gauges in Colombia to estimate an [...]
The Incredible Lightness of Water Vapor
Published: 2019-04-24
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The molar mass of water vapor is significantly less than that of dry air. This makes a moist parcel lighter than a dry parcel of the same temperature and pressure. This effect is referred to as the vapor buoyancy effect and has often been overlooked in climate studies. We propose that this effect increases Earths outgoing longwave radiation (OLR) and stabilizes Earths climate. We illustrate this [...]
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 [...]
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, [...]
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 [...]
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 [...]