A5021353786- Cryospheric studies and observations
- Meteorological Phenomena and Simulations
- Climate variability and models
- Precipitation Measurement and Analysis
- Climate change and permafrost
- Landslides and related hazards
- Soil Moisture and Remote Sensing
- Arctic and Antarctic ice dynamics
- Atmospheric aerosols and clouds
- Geophysics and Gravity Measurements
- Winter Sports Injuries and Performance
- Flood Risk Assessment and Management
- Anomaly Detection Techniques and Applications
- Atmospheric Ozone and Climate
- Hydrology and Watershed Management Studies
- Atmospheric and Environmental Gas Dynamics
- Oceanographic and Atmospheric Processes
- Calibration and Measurement Techniques
- Methane Hydrates and Related Phenomena
- Remote-Sensing Image Classification
- Building Energy and Comfort Optimization
- Aeolian processes and effects
- French Urban and Social Studies
- Time Series Analysis and Forecasting
- Synthetic Aperture Radar (SAR) Applications and Techniques
Centre National de la Recherche Scientifique
2013-2024
Université Grenoble Alpes
2018-2024
Météo-France
2013-2024
Université de Toulouse
2018-2024
Centre National de Recherches Météorologiques
2005-2023
Science et Ingénierie des Matériaux et Procédés
2022
Weatherford College
2021
Institut de Mathématiques de Toulouse
2021
Collecte Localisation Satellites (France)
2019
Ecologie des Forêts de Guyane
2004-2005
Core Ideas OZCAR is a network of sites studying the critical zone. covers various disciplines. will help disciplines to work together for better representation and modeling The French zone initiative, called (Observatoires de la Zone Critique–Application et Recherche or Critical Observatories–Application Research) National Research Infrastructure (RI). OZCAR‐RI instrumented sites, bringing 21 pre‐existing research observatories monitoring different compartments situated between “the rock...
Abstract The Crocus snowpack model within the Interactions between Soil–Biosphere–Atmosphere (ISBA) land surface was run over northern Eurasia from 1979 to 1993, using forcing data extracted hydrometeorological datasets and meteorological reanalyses. Simulated snow depth, water equivalent, density open fields were compared with local observations 1000 monitoring sites, available either once a day or three times per month. best performance is obtained European Centre for Medium-Range Weather...
Ground-based multifrequency (L-band to W-band, 1.41-90 GHz) and multiangular (20°-50°) bipolarized (V H) microwave radiometer observations, acquired over a dense wheat field, are analyzed in order assess the sensitivity of brightness temperatures ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Tb</i> ) land surface properties: soil moisture xmlns:xlink="http://www.w3.org/1999/xlink">mv</i> vegetation water content (VWC). For each frequency,...
Passive microwave (PMW) satellite-based precipitation over land algorithms rely on physical models to define the most appropriate channel combinations use in retrieval, yet typically require considerable empirical adaptation of model for with satellite measurements. Although low-frequency channels are better suited measure emission due liquid associated rain, techniques date high-frequency, scattering-based schemes since methods limited highly variable surface background, whose radiometric...
Abstract. Distributed snowpack simulations in the French and Spanish Pyrenees are carried out using detailed model Crocus driven by numerical weather prediction system AROME at 2.5 km grid spacing, during four consecutive winters from 2010 to 2014. The aim of this study is assess benefits a kilometric-resolution atmospheric forcing for describing spatial variability seasonal snow cover over mountain range. evaluation performed comparisons ground-based measurements depth, water equivalent...
Atmospheric parameter retrievals over land from Advanced Microwave Sounding Unit (AMSU) measurements, such as atmospheric temperature and moisture profiles, could be possible using a reliable estimate of the emissivity. The surface emissivities have been calculated six months data, for 30 beam positions (observation zenith angles -58/spl deg/ to +58/spl deg/) 23.8-, 31.4-, 50.3-, 89-, 150-GHz channels. emissivity calculation covers large area including Africa, Eurasia, Eastern South America....
Abstract AMSU‐A and ‐B measurements are still not extensively used over land surfaces for atmospheric applications. Recent studies have shown that it should now be possible to take advantage of the information content these instruments provided emissivity skin temperature estimates improved. This paper reports on comparisons between three land‐surface schemes using Météo‐France four‐dimensional variational (4D‐Var) assimilation system. Firstly, a monthly mean estimated atlas AMSU data is...
The Concordiasi project is making innovative observations of the atmosphere above Antarctica. most important goals are as follows: To enhance accuracy weather prediction and climate records in Antarctica through assimilation situ satellite data, with an emphasis on data provided by hyperspectral infrared sounders. focus clouds, precipitation, mass budget ice sheets. improvements dynamical model analyses forecasts will be used chemical-transport models that describe links between polar vortex...
Abstract The Tool to Estimate Land Surface Emissivity from Microwave Submillimeter Waves (TELSEM 2 ) is linked a climatology of monthly emissivity estimates and provides parameterization the surface up 700 GHz, in framework preparation for Ice Cloud Imager (ICI) on board Meteorological Operational Satellite Second Generation (MetOp-SG). It an updated version Emissivities at Frequencies (TELSEM; Aires et al. 2011). This study presents continental snow ice sea emissivities TELSEM . relies upon...
The main objective of this study was to monitor wet snow conditions from Sentinel-1 over a season, examine its variation time by cross-checking with independent and weather estimates, distribution taking into account terrain characteristics such as elevation, orientation, slope. One our motivations derive useful representations daily or seasonal changes that would help easily identify elevations determine melt-out days in an area interest. In work, well-known approach the literature is used...
In this study, we develop a novel method to automatically detect areas of snow avalanche debris using color space segmentation technique applied synthetic aperture radar (SAR) image time series through January 2018 in the Swiss Alps. Debris zones are detected assuming that these characterized by significant and localized increase SAR signal relative surrounding environment. We undertake sensitivity study calculating products varying D-M reference images (a stable taken several weeks before...
Abstract Estimating the impact of wind-driven snow transport requires modeling wind fields with a lower grid spacing than on order 1 or few kilometers used in current numerical weather prediction (NWP) systems. In this context, we introduce new strategy to downscale from NWP systems decametric scales, using high-resolution (30 m) topographic information. Our method (named “DEVINE”) is leveraged convolutional neural network (CNN), trained replicate behavior complex atmospheric model ARPS, and...
A neural network retrieval method has been applied to investigate AMSU‐A/AMSU‐B atmospheric temperature and humidity profiling capabilities over land. The benefits from a reliable estimate of the land emissivity skin as well first guess information regarding temperature‐humidity profiles. It on large geographic area (60°W–60°E, 60°S–60°N) situations (winter summer). retrieved RMS errors are within 2 K 9% in relative humidity, respectively. Regardless scanning conditions, vegetation types,...
Abstract. Avalanches are important contributors to the mass balance of glaciers located in mountain ranges with steep topographies. result localized over-accumulation that is seldom accounted for glacier models due difficulty quantifying this contribution, let alone occurrence avalanches these remote regions. Here, we developed an approach semi-automatically map avalanche deposits over long time periods and at scales multiple glaciers, utilizing imagery from Sentinel-1 synthetic aperture...
Abstract Observations from Advanced Microwave Sounding Unit-A and -B (AMSU-A -B) have been more intensively used over sea than land because of large uncertainties about the surface emissivity skin temperature. Several methods based on a direct estimation satellite observations found to be very useful for improving assimilation sounding channels land. Feasibility studies conducted within Météo-France global system in order examine possibility assimilating low-level atmospheric receiving...
This work is in direct line with the Concordiasi international project. It aims to better constrain atmospheric analyses by improving assimilation of low-level Advanced Microwave Sounding Unit (AMSU)-A and AMSU-B microwave observations over Antarctica. So far, a very small amount available AMSU effectively assimilated To assimilate more observations, different issues have be dealt with. In this work, surface emissivity issue Antarctica examined. first step, thorough review use specular...
Abstract To improve the assimilation of Advanced Microwave Sounding Unit-A and -B (AMSU-A -B) observations over land, three methods, based either on an estimation land emissivity or skin temperature directly from satellite observations, have been developed. Some feasibility studies performed in Météo-France system order to choose most appropriate method for system. This study reports 2-month forecast experiments that use different methods estimate AMSU-A emissivities together with...
Constellations of driftsonde systems— gondolas floating in the stratosphere and able to release dropsondes upon command— have so far been used three major field experiments from 2006 through 2010. With them, high-quality, high-resolution, situ atmospheric profiles were made over extended periods regions that are otherwise very difficult observe. The measurements unique value for verifying evaluating numerical weather prediction models global data assimilation systems; they can be a valuable...
Snow and glaciers play a crucial role in various applications such as hydrology, climate avalanche risk assessment. Remote sensing is powerful tool for monitoring the snowpack melt glacier catchments. SAR imagery, which measures backscattering signal microwave spectrum, particularly useful studying snow glacier-related issues: while it almost insensitive to cloud cover, sensitive some snow/glacier properties liquid water content. In this study, we analyze snowmelt dynamics Saint-Sorlin...
Abstract The high vertical density soundings recorded during the 2006 African Monsoon Multidisciplinary Analysis (AMMA) campaign are assimilated into French numerical weather prediction Action de Recherche Petite Echelle Grande (ARPEGE) four-dimensional variational data assimilation (4DVAR) system, with and without a bias correction for relative humidity. Four different experiments carried out to assess impacts of added observations. analyses forecasts from these scenarios evaluated over...
Abstract The aim of this study is to test the feasibility assimilating microwave observations from Advanced Microwave Sounding Units (AMSU-A and AMSU-B) through implementation an appropriate parameterization sea ice emissivity. AMSU are relevant description air temperature humidity, their assimilation into numerical weather prediction (NWP) helps better constrain models in regions where very few assimilated. A emissivity model suitable for AMSU-A AMSU-B data described paper its impact...
We perform a first evaluation of the Copernicus pan-European wet snow products in mountainous terrain French Alps. Mountains are very challenging due to complexity and multiple interactions between soil, atmosphere that can impact snowpack state. focused on Sentinel-1 derived SAR Wet Snow (SWS) product with use Sentinel-2 Fractional Cover (FSC) for during periods. Comparisons were also made reanalyses from Crocus model. showed melt lines computed SWS at scale massifs show realistic...
Monitoring variations in the extent of wet snow over space and time is essential for many applications, such as hydrology, mountain ecosystems, meteorology avalanche forecasting. The Synthetic Aperture Radar (SAR) measurements from Sentinel-1 satellite help detect almost all weather conditions. Most detection methods use a fixed threshold to winter image ratio with one or two reference images (with no dry snow). This study aimed explore potential segmentation different families applied SAR...
Abstract This study describes the work performed at European Centre for Medium-Range Weather Forecasts (ECMWF) to estimate microwave land surface emissivities Advanced Microwave Sounding Unit (AMSU)-A frequencies within specific context and constraint of operational assimilation. The are directly calculated from satellite observations in clear-sky conditions using skin temperature derived ECMWF Radiative Transfer Television Infrared Observation Satellite Operational Vertical Sounder (RTTOVS)...