A5055929239- Meteorological Phenomena and Simulations
- Climate variability and models
- Soil Moisture and Remote Sensing
- Precipitation Measurement and Analysis
- Flood Risk Assessment and Management
- Hydrology and Watershed Management Studies
- Cryospheric studies and observations
- Geophysics and Gravity Measurements
- Atmospheric aerosols and clouds
- Climate change and permafrost
- Atmospheric and Environmental Gas Dynamics
- Urban Heat Island Mitigation
- Plant Water Relations and Carbon Dynamics
- Tropical and Extratropical Cyclones Research
- Arctic and Antarctic ice dynamics
- Spectroscopy and Chemometric Analyses
- Coastal wetland ecosystem dynamics
- Neural Networks and Applications
- Blind Source Separation Techniques
- Oceanographic and Atmospheric Processes
- Soil and Unsaturated Flow
- Peatlands and Wetlands Ecology
- Climate change impacts on agriculture
- Calibration and Measurement Techniques
- Solar and Space Plasma Dynamics
Observatoire de Paris
2015-2024
Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Université Paris Sciences et Lettres
2008-2024
Sorbonne Université
2010-2024
Laboratoire de Météorologie Dynamique
2004-2023
The University of Tokyo
2023
Columbia University
2001-2020
Roche (France)
2018-2019
Centre National de Recherches Météorologiques
2019
Wetlands and surface waters are recognized to play important roles in climate, hydrologic biogeochemical cycles, availability of water resources. Until now, quantitative, global time series spatial temporal dynamics inundation have been unavailable. This study presents the first estimate monthly inundated areas for 1993–2000. The data set is derived from a multisatellite method employing passive microwave land emissivities calculated SSM/I ISCCP observations, ERS scatterometer responses,...
Land surface waters play a primary role in the global water cycle and climate. As consequence, there is widespread demand for accurate long‐term quantitative observations of their distribution over whole globe. This study presents first data set that quantifies monthly extent at ∼25 km sampling intervals 12 years (1993–2004). These estimates, generated from complementary multiple‐satellite observations, including passive (Special Sensor Microwave Imager) active (ERS scatterometer) microwaves...
We developed a remote sensing approach based on multi‐satellite observations, which provides an unprecedented estimate of monthly distribution and area land‐surface open water over the whole globe. Results for 1993 to 2007 exhibit large seasonal inter‐annual variability inundation extent with overall decline in global average maximum inundated 6% during fifteen‐year period, primarily tropical subtropical South America Asia. The largest declines are found where increases population have...
Abstract As the largest river basin on Earth, Amazon is of major importance to world's climate and water resources. Over past decades, advances in satellite‐based remote sensing (RS) have brought our understanding its terrestrial cycle associated hydrological processes a new era. Here, we review studies various techniques using satellite RS Amazon. We show how played role supporting research key findings regarding cycle, region became laboratory for groundbreaking investigations retrievals...
This study is the first global effort to quantify seasonality and extent of inundation with a suite satellite observations, including passive active microwave along visible infrared measurements. A clustering technique which merges observations used detect inundation. Monthly flooded areas are then calculated by estimating pixel fractional coverage flooding using signal linear mixture model end‐members calibrated radar account for vegetation cover. The results, comprising natural wetlands,...
The analysis of microwave observations over land to determine atmospheric and surface parameters is still limited due the complexity inverse problem. Neural network techniques have already proved successful as basis efficient retrieval methods for nonlinear cases; however, first guess estimates, which are used in variational assimilation avoid problems solution nonuniqueness or other forms irregularity, up now not been with neural methods. In this study, a approach developed that uses guess....
Abstract A Tool to Estimate Land Surface Emissivities at Microwave frequencies (TELSEM) has been developed for use with the Radiative Transfer Television and infrared Observation satellite operational Vertical Sounder (RTTOV) model. Its objective is provide a good estimate of microwave surface emissivity improve retrieval atmospheric profiles or direct assimilation radiances in numerical weather prediction (NWP) models using sounder data over land. TELSEM provides estimates error‐covariance...
Abstract. A new global estimate of surface turbulent fluxes, latent heat flux (LE) and sensible (H), gross primary production (GPP) is developed using a machine learning approach informed by novel remotely sensed solar-induced fluorescence (SIF) other radiative meteorological variables. This the first study to jointly retrieve LE, H, GPP SIF observations. The uses an artificial neural network (ANN) with target dataset generated from three independent data sources, weighted based on triple...
A methodology to retrieve soil moisture (SM) from Soil Moisture and Ocean Salinity (SMOS) data is presented. The method uses a neural network (NN) find the statistical relationship linking input reference SM set. are composed of passive microwaves (L-band SMOS brightness temperatures, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T_{b} $</tex-math></inline-formula> 's) complemented with active (C-band...
Abstract Climate change resulting in ocean warming, sea level rise, and ice melting has consequences for the global economy, navigation, security. The Copernicus Imaging Microwave Radiometer (CIMR) mission is a high priority candidate within European Expansion program. CIMR designed to observe more particularly Arctic environment. Sea surface temperature (SST), wind speed, salinity (SSS), concentration (SIC) are fundamental variables understanding, monitoring, predicting state of ice....
This study presents a methodology to detect and monitor surface water with Sentinel-1 Synthetic Aperture Radar (SAR) data within Cambodia the Vietnamese Mekong Delta. It is based on neural network classification trained Landsat-8 optical data. Sensitivity tests are carried out optimize performance of assess retrieval accuracy. Predicted SAR maps compared reference maps, showing true positive detection ∼90% at 30 m spatial resolution. also floodability derived from high resolution topography...
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...
In preparation for new observations on board the next generation of European operational meteorological satellite ( EUMETSAT Polar System—Second Generation EPS‐SG )), a parametrization sea‐surface emissivity is proposed from 10–700 GHz: Tool to Estimate Sea‐Surface Emissivity Microwaves sub‐Millimeter waves (TESSEM 2 ). It based community model FAST microwave Model (FASTEM) at frequencies up 200 GHz, where FASTEM has been calibrated and validated operationally. follows physical higher...
The Ganges–Brahmaputra (GB), a major river basin of the Indian Sub-Continent (ISC), is host more than 700 millions people. In addition to monsoons and strong climate variability, GB facing growing demands for freshwater availability by continually population rapidly developing agricultural industrial sectors. management water resources thus highest priority and, in context current over-abstraction groundwater, accurate estimates terrestrial storage are essential. We propose multi-satellite...
ABSTRACT Life on Earth vitally depends the availability of water. Human pressure freshwater resources is increasing, as human exposure to weather-related extremes (droughts, storms, floods) caused by climate change. Understanding these changes pivotal for developing mitigation and adaptation strategies. The Global Climate Observing System (GCOS) defines a suite essential variables (ECVs), many related water cycle, required systematically monitor Earth’s system. Since long-term observations...
Microwave land surface emissivities have been calculated over the globe for ~10 yr between 19 and 85 GHz at 53° incidence angle both orthogonal polarizations, using satellite observations from Special Sensor Imager (SSM/I). Ancillary data (IR meteorological reanalysis) help remove contribution atmosphere, clouds, rain measured signal separate temperature emissivity variations. The method to calculate is general can be applied other sensors. monthly mean are available community, with a 0.25°...
Given their strong interaction with both climate and the carbon cycle, wetlands surface waters need to be parameterized in global general circulation models. For this purpose, a new simple flooding river scheme is proposed evaluated over South America. The flood dynamics described through coupling between ISBA land model TRIP routing including prognostic reservoir. This reservoir fills when height exceeds critical value vice versa. interacts soil hydrology infiltration overlying atmosphere...
This study presents a systematic and integrated analysis of the sensitivity available satellite observations to in situ soil moisture measurements. Although none these satellites is optimized for land surface characterization, before launches SMOS‐ HYDROS‐dedicated missions they are only potential sources global The include passive microwave emissivities, active scatterometer data, infrared estimates diurnal amplitude skin temperature. Global Soil Moisture Data Bank provides measurements...
In this paper, a fast atmospheric and surface temperature retrieval algorithm is developed for the high-resolution Infrared Atmospheric Sounding Interferometer (IASI) spaceborne instrument. This constructed on basis of neural network technique that has been regularized by introduction information about solution problem in addition to contained (a priori information). The performance resulting accurate inverse radiative transfer model presented large diversified dataset radiosonde atmospheres...
Estimates of the aerodynamic roughness lengths z 0 in arid and semi‐arid regions are for first time provided whole globe, using satellite ERS scatterometer observations. A statistical relationship is derived between backscattering coefficients quality situ geomorphological estimates. It a practical solution to provide realistic maps with large‐scale spatial patterns that consistent independent surface characterization. In addition, it makes possible analyze seasonal interannual variations...
Abstract This study addresses in general terms the problem of optimal combination multiple observation datasets. Only satellite-retrieved geophysical parameter datasets are considered here (not raw satellite observations). focuses on terrestrial water cycle and presents methodologies to obtain a coherent dataset four key components: precipitation, evapotranspiration, runoff, storage. Various innovative “integration” introduced: simple weighting (SW), constrained linear (CL), interpolation...
Abstract A new procedure is introduced to downscale low-spatial-resolution inundation extents from Global Inundation Extent Multi-Satellites (GIEMS) a 3-arc-s (90 m) dataset (known as GIEMS-D3). The methodology based on topography and hydrography information the HydroSHEDS database. floodability index an innovative smoothing developed ensure smooth transition, in high-resolution maps, between low-resolution boxes GIEMS. Topography pertinent for natural hydrology environments controlled by...
Earth System modeling has become more complex, and its evaluation using satellite data also difficult due to model diversity. Therefore, the fundamental methodology of direct measurements with instrumental simulators should be addressed especially for community members lacking a solid background radiative transfer scattering theory. This manuscript introduces principles multisatellite, multisensor radiance-based methods fully coupled regional model: NASA-Unified Weather Research Forecasting...