IES Fellows

Eytan
Eshkol (Alumni)

Prof. Ilan Koren’s lab, Department of Earth and Planetary Sciences

Eshkol Eytan is working at the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, under a CIRES visiting fellowship (Cooperative Institute for Research in Environmental Sciences at the University of Colorado) in the group of Dr. Graham Feingold. He received his BSc in Atmospheric and Environmental Sciences from the Hebrew University of Jerusalem and his PhD through a direct track at the Weizmann Institute of Science. In his PhD, he studied how clouds mix with their environment under the supervision of Prof. Ilan Koren from the Earth and Planetary Sciences department.

Eshkol’s current research focuses on clouds’ interactions with radiation and their role in Earth’s energy budget. He uses satellite radiometric measurements and remote sensing retrievals from different instruments with different spatial and spectral resolutions to estimate the radiative effect that clouds exert on their surroundings' clear-sky. These cloud radiative effects that cause biases in remote sensing retrievals are not considered in today’s atmospheric models. He found that cloud radiative effects in their surroundings' clear-sky in the longwave infrared are equivalent to an addition of tens of ppm of carbon dioxide. He is currently expanding these findings to the solar spectrum, and developing new methods to estimate pure clear sky radiative fluxes from high-resolution satellite observations.

Where are you from?

I was born and raised on Kibbutz Palmachim in Israel.

Where does your interest in science, the environment, and sustainability come?

Growing up on the kibbutz, I was always around animals – domestic and wild, and I was always fascinated and disturbed by the effect that we have on ecological habitats. This led me to volunteer during high school with the Israel Nature and Parks Authority, which was establishing a new nature reserve near the kibbutz. The youth guide at my kibbutz, Amir Ohana, inspired me to volunteer with them and he also taught me to be an active person when it came to the environment and the things that were important to me.  

After high school I volunteered for a year of community service at the field school in Hatzeva, where I worked with youth from all over the country teaching them about environmental issues, and where I fell in love with the desert. At the field schools, we worked with Prof. Amotz Zahavi, an evolutionary biologist who was a founder of the Society for the Protection of Nature in Israel, and he and his team were a tremendous inspiration for me. 

After the army, I went on a year-long trip to the Far East where I backpacked across the Himalayan mountain range, the Mongolian plains, and South Asian tropical areas. Those travels gave me a more global perspective, and taught me the close connection between environmental issues and societies across  cultures.

What was your path to Weizmann?

After completing my BSc at the Hebrew University of Jerusalem with a double major in Earth Sciences and Environmental Science, I knew that I wanted to continue my academic studies. However, I wasn’t sure what direction to take, since I was interested in so many areas of the topics I studied. When I discovered that at WIS you have the opportunity to work with three different labs during the first year of your MSc, I knew it was the perfect fit for me.

What does your current research focus on?

Currently in my postdoc, I am developing methods that combine different satellites with different capabilities to provide a robust quantification of the net radiative effect of clouds on their near environment for the full electromagnetic spectrum. This project uses a large amount of satellite data, and is supported by machine learning and radiation transfer models to analyze the satellite data. In addition, we have started to analyze novel in-situ aircraft measurements in cloud fields to compare the quantifications coming from satellites with measurements that have very different benefits and drawbacks.

Why did you want to become a SAERI/IES Fellow?

During my PhD, being a SAERI/IES Fellow helped me learn about and be exposed to different ‘real life’ environmental issues, and to do so as part of a multi-disciplinary group (I think this is one of the main challenges for environmental sciences today, and its ability to develop solutions to real world problems). Before deciding to pursue a postdoc, I considered whether to stay in academia or do something “more practical” related to environmental issues. As a SAERI/IES Fellow, I learned that you can be practical and also have an effect on the issues from academia. Not least, being a SAERI/IES Fellow helped me pursue my postdoc at NOAA in Boulder, Colorado, U.S. – a national lab with a practical-oriented work environment.

What are your plans for the future?

After my postdoc, I plan to return to Israel and find a position in academia. I hope to become a professor who conducts interesting research and who is also involved in environmental challenges, and in decision-making for solutions for local and national issues. I also think it is important to be a teacher for the next generation of environmental scientists and activists.

How has the postdoc period (so far) given you a perspective on your PhD at WIS in general, and on the SAERI/IES fellowship in particular?

In my postdoc, I work at NOAA, which is a national agency that operates under the US Department of Commerce. This gives me a more practical perspective on scientific work in environmental science. In fact, I’d say it’s 180 degrees from WIS, where the focus is on pure basic science. During my PhD, I learned to appreciate the amazing platform that WIS offers to engage with hard basic scientific questions and the beauty of ideal pure science. However, I also felt that I was somewhat missing out on the collaborative work on real human problems. Even though I work on a more “basic science topic” in my CIRES fellowship, I like to have defined goals – where solving them has an instantaneous effect, and I also appreciate being part of a larger team effort.

To complete the picture: Formal Background

Eshkol Eytan completed his BSc in the Hebrew University of Jerusalem with a double major in Earth Sciences (specializing in Atmosphere, Ocean and Climate) and Environmental Sciences. During his first degree, he worked in the biogeochemical lab of Prof. Alon Angert and as an assistant for modeling and mapping at the Israel National Institute of Hydrology.

After his BSc, Eshkol attained a master’s degree at the Weizmann Institute of Science in the Department of Earth and Planetary Sciences in the Chemistry faculty. During his studies, he worked in rotation with Prof. Dan Yakir trying to quantify carbon assimilation by the forest using satellites, and with Prof. Ilan Koren studying clouds. He continued his MSc with Ilan Koren studying the interface zone between clouds and their environment using satellite data. For one project, they used the longwave infrared spectrum to show for the first time that clouds exert a ‘greenhouse’ radiative effect on their surrounding environment - up to a distance of 5km away from their edge. The study was published in Nature Geoscience. 

The success of that project motivated him to continue in a direct PhD track, and for the remainder of his PhD, he was interested in learning how clouds mix with their environment to understand the causes of the radiative signatures observed. During this work, he partnered with Prof. Alexander Khain from the Hebrew University, an expert in cloud modeling, and they  utilized unique high-resolution simulation to study small to large-scale turbulent mixing of convective warm clouds. This collaboration resulted in 7 papers, with Eshkol as the lead author of 3 of them.

During his PhD, Eshkol presented his work in a few international conferences and gave a longer solicited talk at EGU 2021. He was part of the organizing committee for a national student conference and volunteered as a manager of a sustainable food cooperative initiative in Rehovot.