Is shade truly accessible? How does shape a city? needs shade? Find ways to avoid a . is a city in Ceará, in the northeast of Brazil. It's defined by its constant, year-round sunlight. How to the shadows? How to build an ? About heat . A solar .
How Does Solar Incidence Shape a City?
Shade is a primordial infrastructure needed in many cities, but has it become a forgotten system?
This publication is part of an artistic and scientific research on shade accessibility in the city of Fortaleza, in the north of Brazil. Before targeting shade, it is important to understand solar incidence, which varies by geolocation and time. Fortaleza receives sunlight year-round, with a tropical climate and minimal temperature fluctuations, barely experiencing distinct seasons, presenting a particular solar calendar.
As a starting point, we created a digital sundial for Fortaleza to investigate how solar incidence can shape a city. Feel free to use the digital tool, alternating the day of the year, the time of the day, and the pole height to understand how solar incidence can vary. The yellow line represents the sun incidence, while the red indicates the pole shadow.
But what if, in urban planning, we consider equal amounts of sun and shadows? Based on that question, after the digital sundial, another system (with a lot of math!) was created to planify and calculate the angles of solar incidence for a fixed look height facing south. The main goal was, after these calculations, to create a square divided into equal parts of light and dark, a perfect equilibrium, a kind of yin-yang, to be later transformed into speculative data-paintings.
Interact with the tool below to create your own Spatial Shadow Calendar.
Who Needs Shade?
The excess of light reveals climate injustices. Why haven't we built cities where shadow (or shade!) is an essential service and a social-environmental right? Brazilian modern cities (and many others) were not planned for people, for animals, nor for rivers or trees.
Ms. Liduina, the woman in this photo, hides behind a thin pole shade while waiting for the bus. She commutes daily. Like many other worker citizens. Or students. Kids, elderly, people.
What if urban infrastructure were reimagined through living systems—if a specific tree species signaled a bus stop, replacing the built shelter (when there is one) with shade itself?
That image served as the primary reference for this experimental research tool. Based on it, together with a city list, we developed a platform to scan all bus stops in Fortaleza using Google Street View, applying machine learning to analyze people, trees, and shadows in more than 4.000 images.
Do not hesitate to explore the bus stops in Fortaleza and draw your own conclusions.
Find Ways to Avoid a Sunstroke
Ceará is popularly known as the Land of Light. In this territory, characterized by high sunlight incidence, intense light washes over the ground, making matter vibrate in vivid colors, while the heat rising from the pavement - commonly called mormaço - is exacerbated by the climate crisis.
Sunstroke is Mari Nagem's first solo exhibition in Ceará and presents a selection from her research project Right to Shade, developed during the international residency "Mormaço: art, climate, and resilient ways of living in cities".
Bringing together ecology, data science, architecture, cosmology, and digital technology, the artist creates photographs, videos, drawings, and paintings that transform our perception of the city. Through a poetics of data abstraction, Mari uses color and form as languages to map a metaphysical cartography in which fluorescent yellow indicates sun exposure and gray signals brutalist concrete areas. The artist appropriates technologies originally developed for mass surveillance and control, subverting their function for poetic purposes and to generate critical reflections on the present.
The series of twelve geometric paintings refers to the twelve hours of the clock, in which Mari - with the support of scientists - performs a mathematical intersection between solar incidence, building height, and shadow projection to calculate equal areas of light and darkness at a specific hour of the day in Fortaleza.
The series of graphic drawings on paper serves as a diary of the artist's personal experiences in the city, where colored lines tell stories that merge reality and speculative fiction.
In the video work, the loading symbol evokes the shape of the sun and machine thinking, which operates on a temporal scale distinct from human time.
Across her works, Mari produces an absolute synthesis of space through essential geometric forms. She draws on sacred geometry to approach a cosmology of heat, grounding her practice in the profanation of rational technologies to create intuitive, abstract, geometric, organic, and world-sensitive forms.
In this exhibition, therefore, light is not only a ray of energy and heat but also a sign through which to reflect on the Enlightenment and its modern project of colonial, rational urbanization and the climate injustice embedded in Brazilian cities. Faced with an excess of light that blinds us through overexposure, the artist proposes shade as a gesture of resistance and as a fabulation of other possible ecologies.
Text by Lucas Dilacerda | Curator, AICA - International Association of Art Critics
Photos by Pedro Bessa
How to Navigate the Shadows?
Navigating cities through their data is a complex process involving many variables, assumptions, and decision-making. Navigating cities that haven't been planned, that grow exponentially and organically, like most Brazilian cities, I would say, present even more challenges, due to their shifting structures and unpredictable changes.
In the context of increased climate instability and data accessibility, we've been working closely with Sony Computer Science Laboratories (CSL) Rome and the Center for Data Science and Artificial Intelligence (NCDIA) at Unifor, mapping shadow structures in Fortaleza and cross-referencing them with social and economic data. On the right, a study of Fortaleza's shadow map at 7 am.
From the beginning, there was a clear answer. As buildings get taller, more shadow is cast. It was easy; let's build as many tall buildings as we can to cast as much shadow as possible. Yes, but of course no. A city is a house for many living beings. Every urban decision should take into consideration a range of factors, a mesh including rising temperatures, wind directions, water flow, heat gain, air quality, transportation, accessibility, life maintenance, and many more.
Fortaleza occupies an area of approximately 312 km², officially divided into 121 neighborhoods. We analyzed different areas and their shadows at specific times of day. In the following image, you can see the projected shadows of Meirelles, one of the richest areas of the city. These images represent the shadows of all buildings in the neighborhood on October 20, 2025. The shadow calculation was performed using building heights and solar coordinates (altitude and azimuth) to project the rooftop geometry in a specific direction, extruding and connecting it to the base. In green, you can also see the tree canopies in the area.
As a counterpoint (using the same system and dates), we analyzed the shadows of Edson Queiroz, a neighborhood with a mixed economic profile and wide green spaces. An area with coexistence between lower-class incomes and new luxury developments, considered dangerous for some parts of the population.
In the next image, we have Pirambu, one of the city's largest favelas, with the lowest economic levels and the highest violence indices.
But again, who needs shade? Part of this research focused on the shadow accessibility of bus stops. The next animated map illustrates the solar exposure index in Fortaleza, showing the routes from each hexagon's centroid to the bus stops reachable within a 15-minute walk. This indicator maps regions with a thermal comfort deficit, aiding in the identification of segments where walkability is compromised by direct solar radiation, as indicated by higher index values. Basically, these maps represent the shadows cast by the built environment. It represents how urban density and building heights contribute to pedestrian shading, regardless of vegetation. As more yellow as it gets, the higher the solar incidence in that area.
However, buildings are not the only urban structures to cast shade; that's why we have also projected tree canopies.
Trees are a core technical challenge in urban analysis that stems from the fundamental asymmetry between built and natural landscapes. While buildings are static geometries meticulously documented in public datasets, trees are living entities in perpetual flux. Within a single year, their morphology can be reshaped by growth, pruning, or removal. This volatility means trees are not cataloged with the same precision as architecture, resulting in significant gaps in urban inventory datasets. To mitigate this data gap, most repositories rely on image recognition algorithms based on aerial orthophotos or satellite imagery. Yet, this method remains constrained, as it often fails to accurately capture height, species, or true canopy volume. Ultimately, the shelf life of these datasets is brief: in as little as six months, the physical reality of the greenery can decouple from its digital twin, underscoring the difficulty of mapping biological variables within a shifting urban fabric.
In other words, trees became a problem from a technical data urban analysis perspective. And that's where the project had an important shift. If trees became a problem, from an artistic perspective, they should be transformed into a solution.
How to Build an Ecological City?
The first artistic proposal to build an ecological city from a shadow perspective was to create a clay cobogó (a modular, geometrically perforated Brazilian brick) with an adjacent in-built structure tailored to the climate needs of Fortaleza.
Along the way, while trees become a problem for data analyses, due to their organicity and irregularity from a technocratic and binary perspective, I realized that it wasn't necessary to create another structure to generate shade, but rather to observe, with new eyes, these ancestral technologies of shade that we already possess, the trees.
In Fortaleza, there is a street named Cidade Ecológica (Ecological City), in the Edson Queiroz neighborhood, where I found Ms. Liduina, the women using a pole as a shadow shelter while waiting for the bus. This is a tropical country; trees should be our specialty, not poles. That shift of perspective turned into a game.
Welcome to Fortaleza in Cidade Ecológica, an online game that navigates the streets of Cidade Ecológica and lets you transform the space by planting local trees. A game on a shadow geography, where shade dignifies.
Full game coming soon. Watch the demo video to learn more.
About Heat Cosmologies and Technologies
In this project, Mari Nagem investigates shadow as an ancestral technology. The Right to Shadow, implemented in the Land of Light, challenges the legacy of colonial urbanism and the Enlightenment project, denouncing how the aridity of concrete and urban overheating deepen socio-environmental inequalities in tropical cities such as Fortaleza.
Anchored in the concepts of Buen Vivir and Lo-TEK, the international residency Mormaço locates a transdisciplinary nexus between art, science, and ancestral knowledge. By consolidating shadow as an ancestral cooling technology and a gesture of poetic resistance, Mari Nagem's project repositions the aesthetic experience as a critical lens for reimagining collective survival amid contemporary climate disruption. (Lucas Dilacerda)
Mormaço: Art, climate, and resilient ways of living in cities was part of S+T+ARTS Buen-Tek, co-funded by the European Union, under the STARTS - Science, Technology and Arts initiative of DG CNECT (GA no. LC- 03568052). The program was supported by Sony CSL Rome and Unifor and was held from September 2025 to March 2026.
The research and work were only possible due to the exceptional interdisciplinary team involved at every step of its development.
Sony CSL - Rome:
- Liaison Mediator & Project Coordination: Denise Lanzieri
- Scientific mentors: Matteo Bruno, Denise Lanzieri, Vittorio Loreto
Unifor:
- Scientific mentor and twin coordinator: Hygor P. M. Melo
Thanks to everyone's sparkle:
- Data analysis and computational development: Hygor P. M. Melo and Paulo Costa
- Spatial analysis in GIS and cartographic mapping: Lara Furtado and Patricía Lima
- Trans local expert and curator: Lucas Dilacerda
- Architect and art assistant: Beatriz Balduino
- Website design and development: Thiago Hersan and Kelly Su
- Game design and development: Emerson Fleming and Rodrigo Moreira
- Heatstroke exhibition team: Galeria Cave - Pedro Diógenes, Pedro Bessa, Virgínia Pinho, Dharana Vieira
- Special acknowledgements: Adriana Helena Moreira, Aliria Aiara Duarte, Breno Angelino, Geórgia Goiana, Júlio Jardim, Vasco Furtado, and Projeto Flora do Campus.
Want to know more? Get in touch:
https://marinagem.com
mari at marinagem.com
A Solar Shaded Path
Click on the photos to know more about the project process.