Group Leader · Chair of Building Physics · ETH Zürich

Yongling Zhao
Understanding urban heat, cooling cities with nature.

I lead a research group developing nature-inspired solutions for urban climate — combining fluid mechanics, multiscale heat transfer, and machine learning to understand how wind, water, and vegetation cool cities. My goal: science that helps cities beat the heat.

Explore research Google Scholar ↗
64
Peer-reviewed journal publications
IPCC
Invited expert, Special Report on Climate Change and Cities
6,022 cities
Global insights on urban heat & vegetation
CHF 700k
Research funding as PI / co-I
01 / about

About

I am a Group Leader and Lecturer at the Chair of Building Physics (CBP), Department of Mechanical and Process Engineering, ETH Zürich. My group has established an emerging line of research on nature-inspired urban climate solutions — featured in Swiss media — asking how the physics of flow and heat, and the strategies nature itself uses to stay cool, can make cities more livable in a warming world.

The foundations are in fluid mechanics: my PhD at the University of Sydney (Certificate of Research Excellence — sole recipient in the school) uncovered how natural convection boundary layers transition to turbulence, published in the Journal of Fluid Mechanics, and an SNSF-funded Visiting Fellowship at the University of Cambridge broadened that foundation toward urban-scale flows.

My work now spans 64 peer-reviewed publications — including first- and corresponding-author papers in Annual Review of Environment and Resources, Nature Communications, and Journal of Fluid Mechanics — combining fluid-tunnel PIV–LIF experiments, multiscale OpenFOAM and WRF modelling, and machine learning. As an IPCC-invited expert, I co-drafted the outline of the Special Report on Climate Change and Cities (Riga, 2024). Our research has been funded by the Australian Research Council, Singapore's National Research Foundation, and the Swiss National Science Foundation, alongside a multi-year ABB–ETH Academy industry partnership.

I serve as Guest Editor of the Philosophical Transactions of the Royal Society A theme issue Urban heat spreading above and below ground, on the editorial boards of Results in Engineering and City and Built Environment, and as a reviewer for journals including Nature Climate Change and Nature Cities. I am always open to multidisciplinary collaboration.

02 / research

Research

From fundamental transition physics to machine-learning-assisted urban climate science — six threads, one goal: cooler, more livable cities.

R·01

Urban heat mitigation pathways

Prioritizing nature-based solutions and technological innovations to accelerate cooling — and aligning urban cooling strategies with global warming trends across Hong Kong, Sydney, Montreal, Zurich, and London.

trend analysis · cooling degree hours · policy
R·02

Buoyant flows in street canyons

Quantifying how thermal buoyancy interacts with wind and canyon morphology to govern heat removal, pollutant dispersion, thermal comfort, and building energy use.

water tunnel · CFD · scaling analysis
R·03

Cooling power of urban trees

Coupled airflow–heat–moisture–radiation simulations of vegetation in street canyons, including tree-size effects on nighttime microclimate under real heatwave conditions.

OpenFOAM · 2019 Zurich heatwave data
R·04

Machine learning for urban heat

Validated WRF simulations combined with ML to disentangle how urban morphology, anthropogenic heat, and wind dynamics drive heat islands during heatwaves — and to map city-scale air temperature.

WRF · ML · city-scale mapping
R·05

PIV–LIF flow & heat diagnostics

Concurrent velocity–temperature field measurements with non-toxic dyes in large water tunnels — decisive progress enabling laboratory modelling of urban heat.

PIV · LIF · experimental methods
R·06

Transition of thermal boundary layers

DNS-based stability analysis and laser diagnostics of laminar–turbulent transition in natural convection — resonance-triggered heat transfer enhancement and controlled transitions.

DNS · stability analysis · J. Fluid Mech.
03 / publications

Selected publications

64 peer-reviewed journal articles across urban physics and heat transfer. A selection below — full list on Google Scholar ↗

2026

Asymmetric global urban cooling potential demands accelerated and context-specific actions

Ding X, Fan Y, Zhao Y, Ürge-Vorsatz D, Ge J, Carmeliet J et al. · Nature Communications 17, 4239
2023

The time-evolving impact of tree size on nighttime street canyon microclimate

Zhao Y*, Li H, Bardhan R, Kubilay A, Li Q, Carmeliet J · Urban Climate 49, 101528
2023

Machine learning-assisted mapping of city-scale air temperature

Ding X, Zhao Y, Fan Y, Li Y, Ge J · Building and Environment 234, 110211
2023

Urban heat dome flow deflected by the Coriolis force

Zhang Y, Wang X, Fan Y, Zhao Y*, Carmeliet J, Ge J · Urban Climate 49, 101449
2022

Enhancement of heat removal from street canyons due to buoyant approaching flow

Zhao Y*, Xue Y, Mei S, Chao Y, Carmeliet J · Building and Environment 226, 109757
2022

Impact of green walls on ventilation and heat removal from street canyons

Li H, Zhao Y*, Sützl B, Kubilay A, Carmeliet J · Building and Environment 214, 108945
04 / teaching

Teaching & supervision

course · ETH Zürich · since 2020

Urban Physics — Lead Lecturer

The state of the art in urban climate research: urban heat islands, urban wind, vegetation, thermal comfort, and climate mitigation strategies. Each semester includes hands-on workshops with laboratory tests and field measurements, plus invited speakers — including Prof. Diana Ürge-Vorsatz (2023).

supervision & resources

PhD & Master's supervision

Five PhD students supervised or co-supervised to completion; currently supervising two PhD candidates, plus Master's projects on topics such as:

  • Machine learning for urban climate and heat mitigation
  • Aerodynamic and thermal effects of urban vegetation

I also share PIV learning resources — code, particle images, lecture notes, and video demonstrations.

05 / contact

Let's collaborate

Open to multidisciplinary research and collaboration across fluid mechanics, urban climate, heat mitigation, and data-driven approaches to sustainable cities.

LEO C 2 · Leonhardstrasse 27 · 8092 Zürich · Switzerland
Dept. of Mechanical and Process Engineering, ETH Zürich