A5054181583- Climate variability and models
- Meteorological Phenomena and Simulations
- Atmospheric Ozone and Climate
- Precipitation Measurement and Analysis
- Tropical and Extratropical Cyclones Research
- Environmental and biological studies
- Atmospheric and Environmental Gas Dynamics
- Atmospheric aerosols and clouds
- Geography and Environmental Studies
- Ionosphere and magnetosphere dynamics
- Hydrology and Drought Analysis
- Conservation, Biodiversity, and Resource Management
- Land Use and Ecosystem Services
- Atmospheric chemistry and aerosols
- Solar and Space Plasma Dynamics
- Indigenous Studies and Ecology
- Remote Sensing in Agriculture
- Rural Development and Agriculture
- Plant Water Relations and Carbon Dynamics
- Solar Radiation and Photovoltaics
- Plant Physiology and Cultivation Studies
- Soil Moisture and Remote Sensing
- Zoonotic diseases and public health
- Oceanographic and Atmospheric Processes
- Ecology and Vegetation Dynamics Studies
Littoral, Environnement, Télédétection, Géomatique
2015-2024
Nantes Université
2017-2024
Centre National de la Recherche Scientifique
2015-2024
Université Rennes 2
2013-2024
Institut Universitaire Européen de la Mer
2016-2024
Université de Rennes
2012-2024
Centre Nantais de Sociologie
2022
Laboratoire de Météorologie Dynamique
2007-2015
École Polytechnique
2007-2015
Laboratoire atmosphères, milieux, observations spatiales
2011-2012
Assessing the impact/adaptation of human activities on/to climate change is a key issue, especially in tropics that concentrate major anthropogenic dynamics such as deforestation and nearly two-thirds planetary rainfall. However, this task often made tough because agricultural are usually analysed at local or regional scale whereas related studies led large to global scales due lack reliable data, tropics. In article we argue increased spatial resolution remote sensing-based rainfall...
Satellite-derived estimates of precipitation are essential to compensate for missing rainfall measurements in regions where the homogeneous and continuous monitoring remains challenging due low density rain gauge networks. The Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks—Climate Data Record (PERSIANN-CDR) is a relatively new product (released 2013) but that contains data since 1983, thus enabling long-term analysis. In this work, we used three...
Abstract The connections between intrusions of stratospheric air into the upper troposphere and deep convection in tropical eastern Pacific are examined using a combination data analysis, potential vorticity (PV) inversion, numerical simulations. Analysis NCEP–NCAR reanalyses satellite measurements outgoing longwave radiation during intrusion events shows increased cloudiness, lower static stability, upward motion, buildup convective available energy (CAPE) at leading edge intruding tongue...
The Amazon Basin is undergoing extensive environmental degradation as a result of deforestation and the rising occurrence fires. caused by fires exacerbated anomalously dry periods in Basin. objectives this study were: (i) to quantify extent areas that burned between 2001 2019 relate them extreme drought events 20-year time series; (ii) identify proportion countries comprising which was strongly observed, relating spatial patterns fires; (iii) examine carbon balance following To end,...
In 2021, diarrheal diseases were responsible for around 1.17 million deaths worldwide. Sub-Saharan Africa is one of the most impacted regions, where 440,000 recorded in 2024. This high mortality rate can be explained by 1) significant bacteriological pollution surface waters pathogenic micro-organisms diseases, 2) widespread use untreated water population and3) lack sanitation and community health infrastructures. addition, ongoing climate change likely to have a negative impact on quality,...
Abstract. Subsynoptic scale vortices that have been likened to tropical cyclones or polar lows (medicanes) are occasionally observed over the Mediterranean Sea. Generated sea, they usually associated with strong winds and heavy precipitation thus can be highly destructive in islands costal areas. Only an accurate forecasting of such systems could mitigate these effects. However, at moment, predictability remains limited. Due scarcity conventional observations, use is made NOAA/MetOp...
Abstract A characterization of the large-scale environment associated with precipitating systems in Mediterranean region, based mainly on NOAA-16 Advanced Microwave Sounding Unit (AMSU) observations from 2001 to 2007, is presented. Channels 5, 7, and 8 AMSU-A are used identify upper-level features, while a simple tractable method, combinations channels 3–5 AMSU-B insensitive land–sea contrast, was precipitation. Rain occurrence widespread over wintertime reduced or short lived eastern part...
Abstract Temperature changes in the lower and middle stratosphere during 2001–2016 are evaluated using measurements from GPS Radio Occultation (RO) Advanced Microwave Sounding Unit (AMSU) aboard Aqua satellite. After downsampling of GPS‐RO profiles according to AMSU weighting functions, spatially seasonally resolved trends two data sets excellent agreement. The observations indicate that has cooled time period 2002–2016 at an average rate −0.14 ± 0.12 −0.36 0.14 K/decade, while no...
The evolution and structure of stratospheric intrusions into the upper troposphere (UT) over northern tropical Pacific is examined in terms both potential vorticity (PV) ozone (O3). Analysis 20 years NCEP–NCAR reanalysis PV shows that intrusion events have remarkably similar at 350 K, with all producing narrow tongues high an almost north–south orientation last around 3 days. Nearly extend up lower stratosphere, but only for a small percentage there deep downward penetration. explain large...
Knowledge and studies on precipitation in the Amazon Basin (AB) are determinant for environmental aspects such as hydrology, ecology, well social like agriculture, food security, or health issues. Availability of rainfall data at high spatio-temporal resolution is thus crucial these purposes. Remote sensing techniques provide extensive spatial coverage compared to ground-based but it imperative assess quality estimates. Previous underline regional scale AB, some years, efficiency Tropical...
Abstract Due to its size and geographical features, different average annual rainfall regimes co‐exist in the Amazon basin, with distinct year‐to‐year variability dependent on regions within basin. In this study, we define explain seasonal regional types of regimes, that is, years similar anomalies. Our work is based a 205 rain gauge network distributed over five Amazonian countries, spanning period 30 years. Using spectral clustering method, identified seven sub‐regions basin which are...
The potential of the Advanced Microwave Sounding Unit (AMSU) observations to identify and characterize precipitating systems in Mediterranean region is explored. Single channels or combination from AMSU‐A are used detect locate upper level vorticity anomalies that often associated with intensification surface low occurrence extreme events, while AMSU‐B data areas. motivation for approach presented here direct use satellite as an alternative reanalysis sets climatological studies lows,...
ABSTRACT Mean diurnal rainfall regimes over Eastern Africa (also referred to as the Greater Horn of Africa) are studied based on 3‐hourly data from TRMM 3B42 set, averaged a 17‐year period (1998–2014). The consistency with long‐term mean raingauge data, available for partly independent periods, varies good (Sudan, Ethiopia, Eritrea and Somalia) very (Kenya, Tanzania Uganda). Over sea (Indian Ocean Red Sea), distribution is quite uniform; however, morning peak dominates there evidence...
Abstract Stratospheric temperature trends for the period 2002–2014 have been estimated using NOAA's Integrated Microwave Inter‐calibration Approach (IMICA) version of advanced microwave sounding unit (AMSU) on AQUA satellite. In this stratosphere continued cooling over most globe with a rate ranging from −0.4 ± 0.3 to −0.5 0.4 K/decade above 25 km. Considering specific latitude bands, are highly variable height. tropical region, vary channel 12 (∼30 km) −0.7 higher channels and present small...
We present a characterization of convective activity at sub‐regional scale from two sets satellite‐based microwave observations: the Advanced Microwave Sounding Unit (AMSU) and combined Tropical Rainfall Measuring Mission (TRMM) imager precipitation radar data, for period 2001 to 2011. focus on state Mato Grosso, Brazil, located southern edge so‐called “Legal Amazon” which has undergone intense land cover transformation in last 4 decades. The annual cycle mean described by AMSU TRMM are good...
Abstract. This paper investigates the role of deep convection and overshooting convective clouds in stratosphere–troposphere dynamical coupling tropics during two large major stratospheric sudden warming events January 2009 2010. During both events, activity precipitation increased equatorial Southern Hemisphere as a result strengthening Brewer–Dobson circulation induced by enhanced planetary wave activity. Correlation coefficients between variables related to vertical velocity were...
Abstract. A new precipitation and convection dataset for the Mediterranean Basin, derived from operational satellite microwave data is documented. The diagnostics that rely on brightness temperatures measured since 1999 in water vapour absorption line (183–191 GHz). consists of twice-daily (a.m. p.m.) monthly maps occurrences a 0.2° lat × long grid area 25°–60° N, 10° W–50° E. instruments used so far are AMSU-B sensor NOAA-15 to -17 satellites, MHS NOAA-18 -19 METOP-2 with available...
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