A5060468243- Meteorological Phenomena and Simulations
- Ionosphere and magnetosphere dynamics
- Climate variability and models
- Ocean Waves and Remote Sensing
- Tropical and Extratropical Cyclones Research
- Target Tracking and Data Fusion in Sensor Networks
- Atmospheric Ozone and Climate
- Geophysics and Gravity Measurements
- Wind and Air Flow Studies
- Gaussian Processes and Bayesian Inference
- Hydrological Forecasting Using AI
- Coastal and Marine Dynamics
- Geochemistry and Geologic Mapping
- Atmospheric aerosols and clouds
- COVID-19 epidemiological studies
- Soil Geostatistics and Mapping
- Atmospheric and Environmental Gas Dynamics
- Solar and Space Plasma Dynamics
- Complex Systems and Time Series Analysis
- Plant Water Relations and Carbon Dynamics
- Markov Chains and Monte Carlo Methods
- Aeolian processes and effects
- Model Reduction and Neural Networks
- Bayesian Modeling and Causal Inference
- Image and Signal Denoising Methods
Centro Científico Tecnológico - Nordeste
2018-2024
National University of the Northeast
2013-2022
Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos
2013-2022
Institute of Astronomy and Space Physics
2022
Consejo Nacional de Investigaciones Científicas y Técnicas
2011-2021
University of Reading
2002-2019
Fundación Ciencias Exactas y Naturales
2005-2018
Laboratoire des Sciences et Techniques de l’Information de la Communication et de la Connaissance
2014
Universidad Nacional de Córdoba
1998-2013
University of Toronto
2010-2011
Abstract Recent observational and theoretical studies of the global properties small‐scale atmospheric gravity waves have highlighted effects these on circulation from surface to middle atmosphere. The large‐scale long been treated via parametrizations in both climate weather‐forecasting applications. In parametrizations, key parameters describe distributions gravity‐wave momentum flux, wavelengths frequencies. Until recently, observations could not define required because are small scale...
Abstract Flow in a stably stratified environment is characterized by anisotropic and intermittent turbulence wavelike motions of varying amplitudes periods. Understanding intermittency wave‐turbulence interactions flow remains challenging issue geosciences including planetary atmospheres oceans. The stable atmospheric boundary layer (SABL) commonly occurs when the ground surface cooled longwave radiation emission such as at night over land surfaces, or even daytime snow ice warm air advected...
For modelling geophysical systems, large-scale processes are described through a set of coarse-grained dynamical equations while small-scale represented via parameterizations. This work proposes method for identifying the best possible stochastic parameterization from noisy data. State-the-art sequential estimation methods such as Kalman and particle filters do not achieve this goal succesfully because both suffer collapse parameter posterior distribution. To overcome intrinsic limitation,...
In this work, a novel sequential Monte Carlo filter is introduced which aims at an efficient sampling of the state space. Particles are pushed forward from prediction to posterior density using sequence mappings that minimizes Kullback-Leibler divergence between and intermediate densities. The represents gradient flow based on principles local optimal transport. A key ingredient they embedded in reproducing kernel Hilbert space, allows for practical algorithm. embedding provides direct means...
Abstract Recent work has shown that the parameters controlling parametrizations of physical processes in climate models can be estimated from observations using filtering techniques. In this article, we propose an offline parameter estimation approach, without estimating state model. It is based on Ensemble Kalman Filter (EnKF) and iterative error covariance matrices background a maximum likelihood algorithm. The technique implemented subgrid‐scale orography (SSO) parametrization scheme...
One of the most critical tools to mitigate impact urban flash floods is having an effective and timely early-warning system. The Argentine National Meteorological Service (SMN) actively working in this direction through PREVENIR Argentina-Japan cooperation project, which aims develop impact-based emergency management system for two target basins by 2027. As current SMN operational consists 4-km resolution deterministic warm-start probabilistic forecasts, provide a more accurate precipitation...
Extreme weather events associated with deep moist convection pose significant social risks, requiring advanced technologies for anticipatory measures. Numerical forecasting, particularly at convection-resolving scales, relies heavily on high-quality initial conditions obtained through the assimilation of complex remote-sensing-based observations. Integrating these observations into systems presents challenges due to nonlinear relationships between observed quantities and model variables....
The extraction of information about traffic accidents from legal documents is crucial for quantifying insurance company costs. Extracting entities such as percentages physical and/or psychological disability and the involved compensation amounts a challenging process, even experts, due to subtle arguments reasoning in court decision. A two-step procedure proposed: first, segmenting document identifying most relevant segments, then extracting entities. For text segmentation, two methodologies...
In this work, various methods for the estimation of parameter uncertainty and covariance between parameters state variables are investigated using local ensemble transform Kalman filter (LETKF). Two compared covariances parameters: one a single simultaneous model parameters, other two separate ensembles; initial conditions parameters. It is found that method which uses ensembles produces more accurate representation observed although does not produce an improvement or estimation. The...
To represent the complex individual interactions in dynamics of disease spread informed by data, coupling an epidemiological agent-based model with ensemble Kalman filter is proposed. The statistical inference propagation a means ensemble-based data assimilation systems has been studied previous works. models used are mostly compartmental representing mean field evolution through ordinary differential equations. These techniques allow to monitor infections from and estimate several...
There is a current need to constrain the parameters of gravity wave drag (GWD) schemes in climate models using observational information instead tuning them subjectively. In this work, an inverse technique developed data assimilation principles estimate parameters. Because most GWD assume instantaneous vertical propagation waves within column, observations single column can be used formulate one-dimensional problem unknown We define cost function that measures differences between unresolved...
Abstract A simple technique to infer the missing momentum forcing in a general circulation model is developed and evaluated. The response of large-scale dynamic equations an external presents nonlocal zonal meridional wind. On other hand, potential vorticity (PV) local growing geostrophic mode, so that there direct relationship between PV. In this work, fact exploited diagnose extratropics using model. capability estimate concentrated gravity wave dynamical evolved with prescribed sources...
Abstract The role of planetary wave drag and gravity in the breakdown stratospheric polar vortex its associated final warming Southern Hemisphere is examined using reanalyses from MERRA a middle-atmosphere dynamical model. focus this work on identifying causes delay found current general circulation models. Sensitivity experiments were conducted by changing launched momentum flux parameterization. Increasing produces date with respect to control integration more than 2 weeks. sensitivity...
Related DatabasesWeb of Science You must be logged in with an active subscription to view this.Article DataHistorySubmitted: 4 November 2019Accepted: 16 February 2021Published online: 20 May 2021Keywordsparticle filters, state-space models, model error covariance, EM algorithmAMS Subject Headings62M05, 62M20, 60G25, 93E10, 93E11Publication DataISSN (online): 2166-2525Publisher: Society for Industrial and Applied MathematicsCODEN: sjuqa3
Abstract Ray techniques are a promising tool for developing orographic gravity wave drag schemes. However, the modeling of propagation waves using standard ray theory in realistic background wind conditions usually encounters several regions, called caustics, where first-order approximation breaks down. In this work authors develop higher-order than theory, named Gaussian beam approximation, that depends on height. The analytical results show formulation is free singularities arise theory....
Abstract Covariance inflation is one of the necessary tools enabling success ensemble Kalman filters (EnKFs) in high‐dimensional spaces and presence model error. Inflation maintains variance to a sufficiently large value, counteracting damping at analysis times its underestimation arising from sampling errors. In this work, we investigate effect on dynamics EnKF ensemble. When focus recursive full cycle forecast–analysis–forecast, an apparently counterintuitive multiplicative appears span...
Stochastic parameterizations are increasingly being used to represent the uncertainty associated with model errors in ensemble forecasting and data assimilation. One of challenges use these is optimization properties stochastic forcings within their formulation. In this work a hierarchical assimilation approach based on two nested Kalman filters proposed for inferring parameters parameterization. The technique Rao-Blackwellization parameter estimation problem. consists using an filters, each...
Abstract The Antarctic peninsula and Patagonia region (the south of South America) have recently been identified as the regions with highest gravity‐wave activity in world. In this work, generation propagation gravity waves an event strong wave from 30 October 1995–1 November 1995 is examined by means radiosonde measurements simulations Weather Research Forecasting (WRF) model. are generated surface winds found near Andes mountains at a latitude 49–51°S. low‐level related to extratropical...
Abstract The impact of gravity wave drag on the Antarctic sudden stratospheric warming (SSW) in 2002 is examined through a mechanistic middle atmosphere model combined with variational data assimilation system. Significant differences SSW representation are found between integration that uses reference parameters and one estimated using assimilation. Upon identical forcings at 100 hPa, vortex breakdown may arise as either splitting event or displacement depending parameters. A local...
Ensemble forecasting is, so far, the most successful approach to produce relevant forecasts with an estimation of their uncertainty. The main limitations ensemble are high computational cost and difficulty capture quantify different sources uncertainty, particularly those associated model errors. In this work we perform toy-model state-of-the-art experiments analyze what extent artificial neural networks (ANNs) able uncertainty present in a forecast. particular accuracy initial conditions...
In this work, a novel sequential Monte Carlo filter is introduced which aims at efficient sampling of high-dimensional state spaces with limited number particles. Particles are pushed forward from the prior to posterior density using sequence mappings that minimizes Kullback-Leibler divergence between and intermediate densities. The represents gradient flow. A key ingredient they embedded in reproducing kernel Hilbert space, allows for practical algorithm. embedding provides direct means...
Abstract A continuous superposition of gravity waves, propagating upward in a shearing background wind, is analyzed. Starting from the wave equations, it proven, analytically and numerically, that uniform spectrum has resultant Doppler‐shifted power with −3 law at large vertical wavenumber contrasting −1 characterizes monochromatic perturbation profile. The preliminary results presented here show that, assuming conservative propagation (no dissipative processes), Doppler shifting effect can...
Abstract A climatological characterization of Rossby wave generation events in the middle atmosphere Southern Hemisphere is conducted using 20 years Modern‐Era Retrospective Analysis for Research and Applications (MERRA) reanalysis. An automatic detection technique developed applied to MERRA The with period 1.25 5.5 days zonal number from one three dominate Eliassen‐Palm flux divergence around stratopause at high latitudes examined year period. These produce an eastward forcing general...