Preprints
Filtering by Subject: Oceanography and Atmospheric Sciences and Meteorology
Buoyancy driven distributed chaos and ensemble weather forecasting
Published: 2019-01-04
Subjects: Atmospheric Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
It is shown, using results of direct numerical simulations, that strong thermal convection in horizontal layer and on a hemisphere can be well described by the distributed chaos approach with the stretched exponential kinetic energy spectrum. Two relevant cases: the vorticity and helicity dominated distributed chaos, have been considered. The results obtained with the Weather Research and [...]
A test case for application of convolutional neural networks to spatio-temporal climate data: Re-identifying clustered weather patterns
Published: 2019-01-01
Subjects: Applied Mathematics, Computer Sciences, Earth Sciences, Engineering, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Planetary Sciences
Convolutional neural networks (CNNs) can potentially provide powerful tools for classifying and identifying patterns in climate and environmental data. However, because of the inherent complexities of such data, which are often spatio-temporal, chaotic, and non-stationary, the CNN algorithms must be designed/evaluated for each specific dataset and application. Yet to start, CNN, a supervised [...]
Comparing the Euro 2k reconstruction to a regional climate model simulation
Published: 2018-12-20
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics
We do not expect simulations and reconstructions of past climate change to agree on the exact evolution of past climate variations. Simulations with sophisticated climate models present spatially discrete but complete estimates, which are consistent relative to the implemented physics and their uncertain forcing data. Reconstruction methods statistically infer past changes from natural archives [...]
Attributing Historical and Future Evolution of Radiative Feedbacks to Regional Warming Patterns using a Green’s Function Approach: The Preeminence of the Western Pacific
Published: 2018-12-18
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Global radiative feedbacks have been found to vary in global climate model (GCM) simulations. Atmospheric GCMs (AGCMs) driven with historical patterns of sea-surface temperatures (SST) and sea-ice concentrations produce radiative feedbacks that trend toward more negative values, implying low climate sensitivity, over recent decades. Freely-evolving coupled GCMs driven by increasing CO2 produce [...]
Intensity-Duration-Frequency curves at the global scale
Published: 2018-12-18
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Hydraulic Engineering, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Water Resource Management
Intensity-Duration-Frequency (IDF) curves usefully quantify extreme precipitation over various durations and return periods for engineering design. Unfortunately, sparse, infrequent or short observations hinder the creation of robust IDF curves in many locations. This paper presents the first global, multi-temporal (1 to 360 hours) dataset of Generalized Extreme Value (GEV) parameters at 31 km [...]
Separating the impact of individual land surface properties on the terrestrial surface energy budget in both the coupled and un-coupled land-atmosphere system
Published: 2018-12-12
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Changes in the land surface can drive large responses in the atmosphere on local, regional, and global scales. Surface properties control the partitioning of energy within the surface energy budget to fluxes of shortwave and longwave radiation, sensible and latent heat, and ground heat storage. Changes in surface energy fluxes can impact the atmosphere across scales through changes in [...]
Extreme weather events in early Summer 2018 connected by a recurrent hemispheric wave-7 pattern.
Published: 2018-11-28
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The summer of 2018 witnessed a number of extreme weather events such as heatwaves in North America, Western Europe and the Caspian Sea region and rainfall extremes in South-East Europe and Japan that occurred near-simultaneously. Here we show that these extremes were connected by an amplified hemisphere-wide wavenumber 7 circulation pattern. We show that this pattern constitutes a teleconnection [...]
Analysis of atmospheric thermodynamics using the R package aiRthermo
Published: 2018-11-26
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This is a non-peer reviewed preprint submitted to EarthArxiv. It corresponds to the version initially submitted to Computers and Geosciences corresponding to final paper "Analysis of atmospheric thermodynamics using the R package aiRthermo", describing a new package for R which has been designed for computations of quantities related to atmospheric thermodynamics. The paper was finally accepted [...]
Applications of Deep Learning to Ocean Data Inference and Sub-Grid Parameterisation
Published: 2018-11-20
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Oceanographic observations are limited by sampling rates, while ocean models are limited by finite resolution and high viscosity and diffusion coefficients. Therefore both data from observations and ocean models lack information at small-scales. Methods are needed to either extract information, extrapolate, or up-scale existing oceanographic datasets, to account for the unresolved physical [...]
Spatial variability of late Holocene and 20th century sea-level rise along the Atlantic coast of the United States
Published: 2018-11-06
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Geomorphology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Accurate estimates of global sea-level rise in the pre-satellite era provide a context for 21st century sea-level predictions, but the use of tide-gauge records is complicated by the contributions from changes in land level due to glacial isostatic adjustment (GIA). We have constructed a rigorous quality-controlled database of late Holocene sea-level indices from the U.S. Atlantic coast, [...]
Guidance on the homogenization of climate station data
Published: 2018-11-06
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Draft guidance on the homogenisation of climate station data of the World Meteorological Organisation.
Implications of ambiguity in Antarctic ice sheet dynamics for future coastal erosion estimates: a probabilistic assessment
Published: 2018-11-02
Subjects: Earth Sciences, Engineering, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Probability, Statistical Models, Statistics and Probability
Sea-level rise (SLR) can amplify the episodic erosion from storms and drive chronic erosion on sandy shorelines, threatening many coastal communities. One of the major uncertainties in SLR projections is the potential rapid disintegration of large fractions of the Antarctic ice sheet (AIS). Quantifying this uncertainty is essential to support sound risk management of coastal areas, although it is [...]
Volume transports and temperature distributions in the main Arctic Gateways: A comparative study between an ocean reanalysis and mooring-derived data
Published: 2018-10-24
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Oceanic transports through the Arctic gateways represent an integral part of the polar climate system, but comprehensive in-situ-based estimates of this quantity have been lacking in the past. New observation-based estimates of oceanic volume, temperature and freshwater transports have recently become available. Those estimates have been derived from moored observations in the four major gateways [...]
Estimating Transient Climate Response in a large-ensemble global climate model simulation
Published: 2018-10-11
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The transient climate response (TCR), defined to be the warming in near-surface air temperature after 70 years of a 1% per year increase in CO2, can be estimated from observed warming over the 19th and 20th centuries. Such analyses yield lower values than TCR estimated from global climate models (GCMs). This disagreement has been used to suggest that GCMs’ climate may be too sensitive to [...]
Lake area constraints on past hydroclimate in the western United States: Application to Pleistocene Lake Bonneville
Published: 2018-10-09
Subjects: Climate, Earth Sciences, Environmental Sciences, Fresh Water Studies, Geology, Geomorphology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Lake shoreline remnants found in basins of the western United States reflect wetter conditions during Pleistocene glacial periods. The size distribution of paleolakes, such as Lake Bonneville, provide a first-order constraint on the competition between regional precipitation delivery and evaporative demand. In this contribution we downscale previous work using lake mass balance equations and [...]