Advanced Research Computing


Aiding the Development of Sustainable Urban Environments: Improving the Sustainability of SuPy

Aiding the development of sustainable urban environments: improving the sustainability of SuPy, an open-source urban climate model, with funding from the UCL Open Source Software Sustainability call.

SuPy simulation of near-surface air temperature in central urban area of New York

2 July 2024

Figure 1 (above) SuPy simulated the near-surface air temperature in a central urban area of New York during an afternoon of a heatwave day, demonstrating the potential of urban greening to reduce extreme city heat. Note the cooler area - Central Park - indicated by bluish hexagons. This is part of the results of the collaboration between Dr Ting Sun and the advanced digital tech team at ARUP.


The project focused on improving the sustainable development of SuPy, an open-source urban climate model. SuPy plays a crucial role in understanding and predicting urban climate patterns, aiding in the development of sustainable urban environments.

What we did


Three individual workshops were held with the project leader, Dr Ting Sun (UCL Institute for Risk and Disaster Reduction) and ARC Research Software Engineer Dr David Stansby. The focus of these workshops was on sustainable development strategies for SuPy, encompassing a variety of aspects such as development workflow, documentation, and deployment strategies, leading to a more sustainable development practice for the SuPy project.

Student Assistance

Approximately 200 hours of student assistance were provided to improve documentation and enhance the underlying code structure of SuPy. This assistance significantly contributed to the overall development and usability of the model.

Code Development

SuPy was successfully merged with SUEWS, simplifying the development workflow and enhancing collaboration between the two models. The code structure of SuPy was improved by adopting a derived-type-based data structure, allowing for more flexible future enhancements. In addition, a new open urban climate tool, supy-lcz-global, was jointly developed, enabling users to conduct urban climate simulations easily and efficiently.

Collaborative Project

SuPy, as the cornerstone tool, supported ARUP in delivering a global campaign called the "Global Urban Heat Map." The campaign aims to communicate the risks of overheating in global cities under changing climate conditions and promote nature-based solutions, such as green roofs.

Next steps

Building on the achievements of the project, the following next steps are planned:

1. Research:

  - Coupling SuPy with a larger scale numerical weather prediction system, WRF (Weather Research and Forecasting Model), to understand heat-flood compound weather extremes in cities.

  - Enhancing the code structure to improve the performance of SUEWS in characterising the urban radiation balance, particularly in the context of high buildings.

2. Impact:

   - Further collaboration with ARUP to establish long-term integration of SUEWS in their workflow for urban climate-related projects.

   - Exploring new collaboration opportunities with Argonne National Laboratory to conduct large-scale urban climate simulations considering human mobility allowed by their agent-based model Repast.


The UCL OSSS grant has provided invaluable support for me to engage in one-on-one workshops with ARC scientist David Stansby, fostering knowledge exchange and sustainable development strategies for SuPy. Additionally, the grant has facilitated approximately 200 hours of student assistance, which has significantly contributed to the improvement of documentation and code structure. In particular, this was the first research grant awarded to me since I joined UCL in May 2022, which has greatly boosted the development of my research portfolio." - Dr Ting Sun, Project Lead


The impact

The project funded by the UCL OSSS grant has successfully enhanced the sustainable development of SuPy. The project achieved several milestones, including workshops, student assistance, and development achievements. The next steps include further research on urban climate modelling with SuPy and collaboration to advance its integration into real-world projects with ARUP. The long-term impact of the project is expected to contribute to the understanding and mitigation of urban climate challenges. The support from the UCL OSSS grant has been instrumental in the success of this project, enabling the project lead and student assistants to dedicate their time and expertise to the development and improvement of SuPy.