Estimating high-resolution albedo for urban applications - Preprint

[Geoengineering News]

https://arxiv.org/abs/2509.25096

Authors: David Fork, Elizabeth Jane Wesley, Salil Banerjee, Vishal Batchu, Aniruddh Chennapragada, Kevin Crossan, Bryce Cronkite-Ratcliff, Ellie Delich, Tristan Goulden, Mansi Kansal, Jonas Kemp, Eric Mackres, Yael Mayer, Becca Milman, John C. Platt, Shruthi Prabhakara, Gautam Prasad, Shravya Shetty, Charlotte Stanton, Wayne Sun, Lucy R. Hutyra

29 September 2025

Abstract 

Implementation of cool roofs is a high-impact pathway for mitigating heat at both global and city scales. However, while albedo estimates derived from Sentinel-2 are free and globally-available, the 10 m resolution is insufficient to resolve individual roofs. We present methods for increasing the resolution of Sentinel-2 albedo using high-resolution satellite imagery to produce albedo inferences at a 30-cm scale. Validating against high-resolution aerial albedo measurements over Boulder, CO we find improved precision and accuracy relative to Sentinel-2 with an RMSE of 0.04. Applying these methods to 12 global cities, we evaluate the impacts of three cool roof implementation scenarios. We find that cities can see up to a 0.5°C cooling effect from full scale implementation of cool roofs and prioritizing the largest buildings for implementation is a highly effective policy pathway. While Sentinel-2 produces accurate estimates of albedo change at larger scales, high-resolution inferences are required for prioritizing buildings based on their solar radiation management potential. This research demonstrates a scalable implementation of targeted cool roof interventions in neighborhoods with the greatest potential for heat mitigation by enabling actionable, building-level insights.

Source: Cornell University