"BREATHE" art project: A journey to the origins of the air we breathe
Where does the air we breathe come from? With his installation "BREATHE" at the ETH main building, artist Khalil Berro questions the shared resource of air. His work is based on calculations from the Atmospheric Dynamics Group at ETH Zurich. The installation can be seen on the ETH Polyterrasse from 6 a.m. to 8 a.m. and between 8 p.m. and midnight until 26 October 2024.
When we breathe, we rarely think about the origin of the air – unless events such as volcanic eruptions make it necessary. In his installation "BREATHE", however, artist Khalil Berro does address precisely this question. The installation is based on real-time calculations by Hanna Joos, Michael Sprenger and Heini Wernli from the Institute for Atmospheric and Climate Science at ETH Zurich. The results of these calculations, delineating the air’s journey, complete with city names and timestamps are projected onto the façade of the ETH main building. The scrolling text is reminiscent of stock-exchange tickers that run over the skyscrapers of Wall Street. Air, clouds and water symbolically become commodities in a world determined by the capital market.
When and where
The installation "BREATHE" runs from 26 September, beginning at around 19:30 (after sunset), until 26 October 2024. It will be projected onto the ETH main building above the Polyterrasse, with viewing hours from 6 a.m. to 8 a.m. in the morning and from 8 p.m. to midnight each evening.
Location and directions to the ETH Campus Centre
Travelling with the wind
The path of an air parcel through the atmosphere is called "trajectory". Trajectories therefore describe how an air parcel, which is driven by a temporally and spatially varying wind, moves through the atmosphere. In simple terms, an air parcel can be imagined as an "imaginary balloon" in the atmosphere: If, for example, there are strong updrafts in a thunderstorm, the air parcel rises upwards. If the wind is blowing at high speed from west to east, such as in the jet stream, a band of strong winds at an altitude of around 10 kilometres, the air parcel moves eastwards at high speed and the trajectory is a "line" running from west to east. The trajectory corresponding to the scrolling text can be found here.
Forwards and backwards
Researchers are interested in both the path (trajectory) that an air parcel released at a certain location takes in the following hours and days, as well as the origin of the air at a certain location and what the air parcel experiences on its way to this location. While we call the former a forward trajectory, "BREATHE" relies on so-called backward trajectories. Both forward and backward trajectories can be calculated based on detailed wind data. "BREATHE" asks the question of where an air parcel that ultimately reaches a destination, such as ETH Zurich, originates from.
"Dance" of the air parcels
The path of the 30-day trajectories comprises a variety of patterns: Eddies, waves, fast and slow episodes, vertically ascending and descending phases, northward and southward excursions. This "dance" of an air parcel moving through the atmosphere is driven by various weather systems that result in horizontal and/or vertical air transport. In the mid-latitudes, the most prominent weather systems are the jet stream, low- and high-pressure systems and – on a smaller scale – thunderstorms.
The atmospheric wind fields required to calculate the trajectories are based on numerical weather prediction models (NWP). These models, which also form the basis for daily weather forecasts, simulate the current state of the atmosphere and its development over time. They are based on physical laws that describe the movement and thermodynamics of the atmosphere. The simulations are computationally very demanding and can only be performed on high-performance computers.
In addition to the wind fields, which form the basis for the trajectory calculation, many other meteorological fields are simulated, such as air pressure, temperature, humidity, clouds, rain and snow. For "BREATHE", global NWP simulations are used, which are provided daily by the world's leading weather forecasting centre, the European Centre for Mid-Range Weather Forecasts (ECMWF).
If one wants to calculate the path of an air parcel over the past 30 days, as in "BREATHE", one needs to know how the wind (its direction and speed) changes with height, from one place to another and also in time over the entire 30-day period. Hence, the wind data must be available for the entire atmosphere during these 30 days. This is a major challenge when realising how variable (spatially and temporally) the wind can be even in a small region.
Trajectories are used in research to analyse for example heatwaves or low-pressure systems. On smaller scales, the Alpine foehn is an example of work with trajectories. Other topics include the quantification of the transport of pollutants into the stratosphere or the transport of ozone to the earth's surface, the transport of volcanic ash clouds, Saharan dust or the investigation of moisture sources that contribute to a heavy precipitation event.
About Khalil Berro
Khalil Berro is a Swiss-Lebanese artist who questions the human perception of "nature". Many of Berro's projects involve field research trips, collaborations and conversations with scientists, researchers and experts, which provide him with the basis for his work. He is particularly interested in the "boundaries of reality" and the challenge of transcending them.
His work has been subject to multiple solo exhibitions, among them Swiss Hanok in Seoul, South Korea (2023) and public installations such as "Borderline Nature" in St. Moritz, Switzerland (2024) or research projects in Sumatra, Indonesia (2024 - 2025). "BREATHE" was previously on show at the NOI Techpark South Tyrol in Bolzano, Italy (2024).
- external page Website of Khalil Berro
- external page Scientific background of "BREATHE"
- Research of the Atmospheric Dynamics group at ETH Zurich