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Research Scientist at CNRS
Laboratoire de Météorologie Dynamique (LMD)
Address:
LMD
Case postale 99
4, place Jussieu
75252 Paris Cedex 05
France
Tel:0033-1-44-27-52-62
Mail: xxx
Curriculum Vitae
News
New project Paleotempesto: january 2025-December 2028: web page
Research interests
Stable water isotopes
Stable isotopes of water (H218O, HDO) are tracers of the water cycle and its phase changes. I explore to what extent water isotope observations in vapor or rain can help to better understand convective and cloud processes and better evaluate their representation in climate models (Risi et al 2012, Tuinenburg et al 2015), better understand the continental hydrological cycle and evaluate its representation in climate models (Risi et al 2013a, 2017). I study how to interpret isotopic records to reconstruct paleo-climates, especially in tropical regions for a recent (Risi et al 2010a, Lee et al 2012) or distant past (Botsyun et al 2019). With this aim, I study how convection affects the water isotopic composition from observations (Risi et al 2008b, 2010b), simple models (Risi et al 2008a), atmospheric general circulation models (Risi et al 2010a), storm-resolving models (Risi et al 2020, 2021, 2023). I am mainly interested in tropical regions, including West Africa (Risi et al 2008b, 2010b, 2010c, Tremoy et al 2014), South America (Vimeux et al 2011, 2019), the Tibetan Plateau (Yao et al 2013, Gao et al 2013, He et al 2015, Shi et al 2020, 2022).
Deep convection and convective organization
Deep convection is the mechanisms that creates storms. I have long studied deep convection from the perspective of water isotopes, through observations (Risi et al 2010b) or storm-resolving models (Risi et al 2020, 2021, 2023). More recently, I am interested in convection as such, in particular the factors controlling its mesoscale organization (Abramian et al 2022, papers in preparation) and the impact of convection organization on its environment (papers submitted and in preparation).
Changes in tropical rainfall
Projections of rainfall changes in the tropics are associated with high uncertainties, especially in monsoon regions. I focus on the mechanisms of rainfall change and why climate models disagree with each other (Oueslati et al 2016). I explore how past rainfall reconstructions can help refine rainfall change projections (Schmidt et al 2014). This is an activity I hope to develop in the coming years. Refining rainfall change projections is my main motivation for my work on interpreting isotope records in the tropics in terms of past rainfall changes (Risi et al 2020) or convective organization (Risi et al 2023).
Publications
Science outreach
Research experience
- Habilitation to advise PhD students
- Post-doc at CIRES (Boulder, USA) under the direction of David Noone.
- PhD thesis at Laboratoire de Météorologie Dynamique (Paris, France) under the direction of Sandrine Bony and Jean Jouzel, on water stable isotopes and their applications to study the water cycle and climate variations.