How relevant is satellite-derived land surface temperature for assessing the cooling efficiency of urban vegetation?

Over the past decade, there has been a significant increase in studies leveraging satellite-derived land surface temperature (LST) data to evaluate the cooling efficiency of urban vegetation, especially in multi-city studies. This surge reflects growing interest in understanding the role of green infrastructure in mitigating urban heat, and the computational power to easily process global satellite imagery. However, LST differs fundamentally from air temperature, the latter being more directly linked to human thermal comfort and health. Moreover, heat stress is a complex phenomenon that is influenced not only by air temperature but also by humidity, wind, and radiation.

In this presentation, I will provide a comprehensive overview of my past and ongoing research assessing urban vegetation's cooling efficiency. We will explore studies employing satellite-derived LST, gridded urban-resolving air temperature estimates, and crowdsourced air temperature and humidity measurements, highlighting the strengths and limitations of these approaches. Additionally, I will discuss the role of radiation in shaping urban heat stress and examine how vegetation interacts with radiation to modulate the urban microclimate. By synthesizing insights from multiple methodologies and considering the interplay of diverse environmental factors, this talk aims to offer a nuanced understanding of how urban vegetation contributes to thermal regulation and human well-being.