Center for Climate Research

Itay Halevy is a professor in the Department of Earth and Planetary Sciences at the Weizmann institute who studies the long-timescale evolution of Earth systems. In his research, Prof. Halevy deciphers the chemical and isotopic fingerprints of the biogeochemical processes encoded in the rock record. With a mechanistic understanding of these processes and how they have varied through geologic time, he attempts to shed light on topics ranging from the most basic controls on Earth’s surface environment to the most extreme episodes in the chemical, biological and climatic evolution of the planet.

Prof. Halevy earned BSc degrees in Geology and Computer Science from Ben-Gurion University in the Negev, and his MSc and PhD in Geochemistry from Harvard University, where he was the recipient of a Fulbright Graduate Fellowship, a Harvard University Origins of Life Initiative Fellowship, and NASA Earth and Space Science Fellowship, among other awards. For his postdoctoral work at the California Institute of Technology, he was awarded the Texaco Prize Postdoctoral Fellowship and the Sussman Center for Environmental Sciences Fellowship from the Weizmann Institute.

Prof. Halevy joined the Department of Earth and Planetary Sciences at the Weizmann Institute of Science in 2011. He was awarded the Sir Charles Clore Prize for Outstanding Appointment in the Experimental Sciences (2011), a Yigal Alon Fellowship from the Israeli Council for Higher Education (2012), the Krill Prize for Excellence in Scientific Research from the Wolf Foundation (2016), and the Scientific Council Prize for Chemistry at the Weizmann Institute (2018). 

In 2020, Prof. Halevy was elected to the Israel Young Academy, and in 2023 he was elected Chair of the Young Academy. He has been awarded two starting grants from the European Research Council and serves as Chair of the Climate Advisory Committee to the Ministry of Education. In addition, he is a member of the National Committee for Planning and Budgeting’s Climate and Energy Panel, and a member of the Steering Committee on Climate Risks on behalf of the Israeli Academy of Sciences and Humanities.

Geochemistry Clean Lab
The group focuses on discovering past environmental changes and the interaction between land and ocean by analyzing the chemical composition of sediments and water.
 

Ecophysiology Group
The group focuses on biosphere-atmosphere interactions across scales and environmental conditions to understand the processes underlying the response of ecosystems in dry climates to local and global changes. 
 

Cloud Physics
The group explores the physics of clouds and rain as well as ocean-atmosphere interactions and nonlinear dynamics. Its research ranges from theoretical exploration of differential equations through numerical simulations of clouds and cloud fields, satellite data analysis, field measurements, and remote sensing. The group develops and merges approaches from fluid dynamics, complex systems, radiation transfer,  cloud microphysics, computer vision, and statistics.
 

Dynamic Meteorology Group
Which mechanisms govern day-to-day weather variability? Why do some weather events become extreme? How do weather systems interact across scales? How predictable are high-impact events? The group aims to answer such questions by analyzing large datasets and developing novel diagnostic tools and model experiments.
 

Atmospheric, Oceanic and Climate Dynamics
The weather and climate on Earth are mostly controlled by the large-scale flow in the atmosphere and ocean. Thus, to improve our preparedness for future human-induced climate change it is critical to understand the physical mechanisms underlying the impacts of human and natural activities on the large-scale flow. To investigate this, the group uses theoretical understanding of the large-scale climate dynamics and thermodynamics states and examines observations and state-of-the-art climate models in historic and future periods.
 

Geophysical Fluid Dynamics
The group studies geophysical fluid dynamics, including the general circulation of the atmosphere; storm track dynamics; formation of zonal jets; dynamics on giant planet atmospheres and interiors; exoplanet atmospheric dynamics; geostrophic turbulence; and climate dynamics.
 

Isotope Geochemistry and Paleoclimate
The group’s research is in the general field of low temperature geochemistry of sedimentary rocks, with a focus on paleoceanography and continental paleoclimate. The main objective is to understand and quantify past global changes that have occurred in the oceans and the continents on different time scales. The group develops and applies new geochemical tools that can serve as tracers of past environmental conditions and processes in the aquatic system, with the view that actual field measurements of materials that store information about natural systems in the past provide the basis for understanding climate variability and for testing models and hypotheses in the fields of Earth Science.

Prof. Yinon Rudich is a Professor and Dean of the Faculty of Chemistry at the Weizmann Institute of Science. His research focuses on studying aerosol chemistry and physics, and the effects of aerosols on climate and human health. He has established a state-of-the-art aerosol Physics and Biology lab to study the optical properties, ice nucleation, and health effects of aerosols, and he has also created a national pollutants database to study the health effects of exposure to pollutants.

The overarching goal of Dr. Rudich’s research is to provide a mechanistic understanding of the connections between the physical and chemical properties of aerosols to their ability to nucleate ice, absorb and scatter solar radiation, and induce health effects. Dr. Rudich also studies the aerobiome – bacteria, viruses and fungi that are transported in the atmosphere by dust and winds, and their potential impacts on ecosystems and human health.

Dr. Rudich has authored more than 250 peer-reviewed articles and serves as an expert reviewer for the European Commission and ERC. He is a member of the WMO Global Atmosphere Watch Programme’s ARCH (Air Pollution, Climate Change, Health Effects Nexus) working group, is on the scientific advisory board of SPARTAN, and is a member of the international steering committee of the Tropospheric Ozone Assessment Report (TOAR II). He is a Fellow of the American Geophysical Society (AGU), the Royal Society of Chemistry (FRSC), and Academia Europea.

Prof. Assaf Vardi earned a BSc in Biology from the Hebrew University of Jerusalem, from which he also received an MSc in Environmental Sciences and PhD in Molecular Ecology. After conducting postdoctoral research at the École Normale Supérieure in Paris and at Rutgers University, he joined the Weizmann Institute faculty in 2010 where he is the incumbent of the Edith and Nathan Goldenberg Career Development Chair. He was also appointed an Adjunct Scientist at the Woods Hole Oceanographic Institution (US). Prof. Vardi has received several awards, including two Reiger Foundation awards, a Marie Curie fellowship, and a Legacy Heritage Brain Drain fund award from the Israeli Science Foundation. In addition to support from the Gordon and Betty Moore Foundation, Simons Foundation, and Israeli Science Foundation, he has been granted a Human Frontiers Award, and the prestigious ERC young, consolidator and advanced investigator grants from the European Union.

 Prof. Vardi elucidates the molecular mechanisms that drive microbial interactions in the marine environment. Microbial interactions that regulate the fate of algal blooms play a profound role in determining carbon and nutrient cycling in the ocean and feedback to the atmosphere.  Prof. Vardi studies some of the key mortality agents of algal cells such as marine viruses, bacteria, and grazers. The specific interactions between algae and their pathogens will lead to the demise of algal blooms and will have a unique footprint on the environment. Assaf and his team study how each interaction will differentially influence not only the surrounding microbial population, but also the carbon export to the deep ocean, recycling of nutrients available to the rest of the marine organisms, biodiversity, and even how they may influence the atmosphere above the decaying bloom. The latter occurs when dying algal cells produce volatile molecules that are emitted to the atmosphere as aerosols and can modulate cloud formation.

 While most of the basic science is performed in the Vardi lab and allows for interesting discoveries of the biology and chemical ecology of microbial interactions, Assaf and his team are passionate about testing their findings in the real world, in natural populations in the ocean. To measure microbial interactions within algal blooms, they study specific genetic and metabolic biomarkers that are induced during a myriad of interactions. During field campaigns, Prof. Vardi’s research group detect and measure these biomarkers and couple them with bloom dynamics and environmental parameters, to gain a holistic view on the bloom ecosystem.