A5037279767- Soil Moisture and Remote Sensing
- Meteorological Phenomena and Simulations
- Precipitation Measurement and Analysis
- Cryospheric studies and observations
- Climate change and permafrost
- Climate variability and models
- Atmospheric aerosols and clouds
- Atmospheric and Environmental Gas Dynamics
- Flood Risk Assessment and Management
- Arctic and Antarctic ice dynamics
- Hydrology and Watershed Management Studies
- Geophysics and Gravity Measurements
- Peatlands and Wetlands Ecology
- Atmospheric chemistry and aerosols
- Methane Hydrates and Related Phenomena
- Urban Heat Island Mitigation
- Atmospheric Ozone and Climate
- Aeolian processes and effects
- Ocean Waves and Remote Sensing
- Plant Water Relations and Carbon Dynamics
- Tropical and Extratropical Cyclones Research
- Science and Climate Studies
- Coastal wetland ecosystem dynamics
- Calibration and Measurement Techniques
- Oceanographic and Atmospheric Processes
Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères
2016-2025
Centre National de la Recherche Scientifique
2016-2025
Université Paris Sciences et Lettres
2018-2024
Observatoire de Paris
2015-2024
Mercator Ocean (France)
2024
CY Cergy Paris Université
2022-2024
Sorbonne Université
2017-2023
Roche (France)
2019-2022
Universidade Federal do Rio Grande do Sul
2021
Pontifical Catholic University of Peru
2021
Abstract. Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. Atmospheric emissions concentrations of CH4 continue increase, making second most human-influenced greenhouse gas in terms forcing, after carbon dioxide (CO2). The relative importance compared CO2 depends on its shorter atmospheric lifetime, stronger warming potential, variations growth rate over past decade, causes which are still debated. Two...
Abstract. The global methane (CH4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due a shorter atmospheric lifetime and stronger warming potential than carbon dioxide, challenged by the still unexplained changes of CH4 over past decade. Emissions concentrations are continuing increase, making second most human-induced greenhouse gas after dioxide. Two major difficulties in reducing uncertainties come from...
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,...
[1] A global intercomparison of 12 monthly mean land surface heat flux products for the period 1993–1995 is presented. The includes some first emerging satellite-based (developed at Paris Observatory, Max Planck Institute Biogeochemistry, University California Berkeley, Maryland, and Princeton University) examples fluxes produced by reanalyses (ERA-Interim, MERRA, NCEP-DOE) off-line models (GSWP-2, GLDAS CLM/Mosaic/Noah). An latent (Qle) annual means shows a spread ∼20 W m−2 (all-product...
Abstract Increasing atmospheric methane (CH 4 ) concentrations have contributed to approximately 20% of anthropogenic climate change. Despite the importance CH as a greenhouse gas, its growth rate and dynamics over past two decades, which include stabilization period (1999–2006), followed by renewed starting in 2007, remain poorly understood. We provide an updated estimate emissions from wetlands, largest natural global source, for 2000–2012 using ensemble biogeochemical models constrained...
Abstract. The Wetland and CH4 Intercomparison of Models Project (WETCHIMP) was created to evaluate our present ability simulate large-scale wetland characteristics corresponding methane (CH4) emissions. A multi-model comparison is essential the key uncertainties in mechanisms parameters leading Ten modelling groups joined WETCHIMP run eight global two regional models with a common experimental protocol using same climate atmospheric carbon dioxide (CO2) forcing datasets. We reported main...
Abstract. Seasonal and interannual variations in global wetland area are a strong driver of fluctuations methane (CH4) emissions. Current maps extent vary their definition, causing substantial disagreement between large uncertainty estimates To reconcile these differences for large-scale CH4 modeling, we developed the Wetland Area Dynamics Methane Modeling (WAD2M) version 1.0 dataset at ∼ 25 km resolution Equator (0.25∘) monthly time step 2000–2018. WAD2M combines series surface inundation...
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,...
We describe an updated model of the dust aerosol cycle embedded within NASA Goddard Institute for Space Studies ‘ModelE’ atmospheric general circulation (AGCM). The distribution is compared to observations ranging from optical thickness and surface concentration deposition size distribution. agreement with improved previous distributions computed by either older version GISS AGCM or offline tracer transport model. largest improvement in over Atlantic due increased emission Sahara. This...
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....
Microwave emissivities of land surfaces are estimated from special sensor microwave/imager (SSM/I) observations by removing the contributions atmosphere, clouds, and rain using ancillary satellite data (International Satellite Cloud Climatology Project (ISCCP) TIROS Operational Vertical Sounder (TOVS) products). In first step, cloud‐free SSM/I isolated with help collocated visible/infrared (ISCCP data). The atmospheric contribution is then calculated, an estimate local temperature‐humidity...
Climate variability impacts CH 4 wetland sources as changes in flux density per unit area and via expansion or contraction of areas response to surface hydrological processes. This paper is a first attempt isolate the role varying on seasonal interannual emissions over past decade. Wetland extent at monthly intervals was provided period 1993–2000 by suite satellite observations from multiple sensors. The regionally variable fraction optimized using flooded estimate further adjusted match...
We have measured the permittivity of representative samples natural seawater, synthetic and aqueous NaCl solutions over frequency range 3–20 GHz, in 0.1‐GHz steps temperature −2°–30°C 1° steps. Additional measurements been made at spot frequencies (23.8, 36.5, 89 GHz) selected temperatures between −2° 3O°C. The data from these allowed us to deduce an interpolation function for ε( υ t, S ) ranges 2 ≤ 20 t 30°C, 20‰ 40‰ with a precision 1%. If is extended up 40 about 3%.The also compare...
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...
The Amazon river basin has been recently affected by extreme climatic events, such as the exceptional drought of 2005, with significant impacts on human activities and ecosystems. In spite importance monitoring freshwater stored moving in large basins, only scarce measurements stages discharges are available signatures conditions surface dynamics at scale still poorly known. Here we use continuous multisatellite observations inundation extent water levels between 2003 2007 to monitor monthly...
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...
The MEthane Remote sensing Lidar missioN (MERLIN) aims at demonstrating the spaceborne active measurement of atmospheric methane, a potent greenhouse gas, based on an Integrated Path Differential Absorption (IPDA) nadir-viewing LIght Detecting and Ranging (Lidar) instrument. MERLIN is joint French German space mission, with launch currently scheduled for timeframe 2021/22. Space Agency (DLR) responsible payload, while platform (MYRIADE Evolutions product line) developed by (CNES). main...
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....
Abstract A method has been developed to extend the Global Inundation Estimate from Multiple Satellites (GIEMS). The presented here is based on retrieval principals similar GIEMS but with an updated estimation of microwave emissivity in order be less dependent ancillary data and some changes final surface water correct a known overestimation over low vegetation areas. new methodology, GIEMS‐2, provides monthly estimates extent, including open water, wetlands, or rice paddies, it applied...
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...
[1] Global measurements of atmospheric methane (CH4) concentrations continue to show large interannual variability whose origin is only partly understood. Here we quantify the influence El Niño–Southern Oscillation (ENSO) on wetland CH4 emissions, which are thought be dominant contributor sources. We use a simple model that captures in extent and soil carbon spatial temporal dynamics emissions from 1950–2005 compare these results an ENSO index. able explain fraction global tropical through...
Abstract. The aim of this study is to evaluate the ability ORCHIDEE land surface model simulate streamflows over each sub-basin Amazon River basin. For purpose, simulations are performed with a routing module including influence floodplains and swamps on river discharge validated against on-site hydrological measurements collected within HYBAM observatory 1980–2000 period. When forced by NCC global meteorological dataset, initial version shows discrepancies ORE underestimation 15% annual...