Preprints
Filtering by Subject: Meteorology
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 [...]
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 [...]
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 [...]
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 [...]
Modeling the effects of future urban planning scenarios on the Urban Heat Island in a complex region
Published: 2018-10-02
Subjects: Civil and Environmental Engineering, Construction Engineering and Management, Engineering, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Because of the global warming, urban planning strategies must be investigated to reduce the building energy consumption and increase the thermal comfort in cities. In the framework of Energy Strategy 2050 of Switzerland, this research aim to highlight the impact of future climate change on urban planning and proposes strategies to help urban planners and policymakers face this new challenge [...]
Detecting lightning infrasound using a high-altitude balloon
Published: 2018-04-17
Subjects: Atmospheric Sciences, Earth Sciences, Geophysics and Seismology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Acoustic waves with a wide range of frequencies are generated by lightning strokes during thunderstorms, including infrasonic waves (0.1 to 20 Hz). The source mechanism for these low frequency acoustic waves is still debated and studies have so far been limited to ground-based instruments. Here we report the first confirmed detection of lightning generated infrasound with acoustic instruments [...]
The role of upper level diffluence in the Tropical Easterly Jet in the formation of the recent strongest Atlantic hurricanes
Published: 2018-04-08
Subjects: Atmospheric Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In this paper we report the evidence of the potential role of diffluence in the 200hPa wind field off the coast of West Africa in the formation of a significant number of Category 4 and Category 5 hurricanes in the recent decade. It is shown that on an average of 65% cases of hurricanes at Category 4 and above is preceded by upper level diffluence in the Tropical Easterly Jet (TEJ) by 0–3 days. [...]
Moisture balance over the Iberian Peninsula according to a regional climate model: The impact of 3DVAR data assimilation.
Published: 2018-01-10
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
An analysis of the atmospheric branch of the hydrological cycle by means of a 15 km resolution numerical integration performed using WRF nested in ERA Interim is presented. Two WRF experiments covering the period 2010-2014 were prepared. The first one (N) was configured as in standard numerical downscaling experiments. The second one (D), with the same parameterizations, included a step of 3DVAR [...]
Decreasing cloud cover drives the recent mass loss on the Greenland Ice Sheet
Published: 2017-11-13
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Glaciology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Greenland Ice Sheet (GrIS) has been losing mass at an accelerating rate since the mid-1990s. This has been due to both increased ice discharge into the ocean and melting at the surface, with the latter being the dominant contribution. This change in state has been attributed to rising temperatures and a decrease in surface albedo. We show, using satellite data and climate model output, that [...]