Diurnal evolution of urban tree temperature at a city scale

Despite the importance of urban trees' surface temperature in assessing micro-climate interactions between trees and the surrounding environment, their diurnal evolution has been largely understudied at a city-wide scale due to a lack of effective thermal observations. By downscaling ECOSTRESS land surface temperature imaginary over New York City, we provide the first diurnal analysis of city-scale canopy temperature. Research reveals a remarkable spatial variation of the canopy temperature during daytime up to 5.6 K (standard deviation, STD), while the nighttime STD remains low at 1.7 K. Further, our analysis shows that the greenspace coverage and distance to bluespaces play an important role in cooling the local canopy during daytime, explaining 25.0-41.1% of daytime spatial variation of canopy temperatures while surrounding buildings modulate canopy temperature asymmetrically diurnally: reduced daytime warming and reduced nocturnal cooling. Built on space-borne observations and a flexible yet robust statistical method, our research design can be easily transferable to explore urban trees' response to local climate across cities, highlighting the potentials of advancing the science and technologies for urban forest management.

Automated summary

Despite the lack of research on the diurnal evolution of urban trees' surface temperature at a city-wide scale, a study on New York City reveals significant spatial variation in canopy temperature during daytime, influenced by greenspace coverage and distance to bluespaces. Surrounding buildings play an asymmetric role in modulating canopy temperature, with reduced daytime warming and reduced nocturnal cooling. This study demonstrates the potential for using space-borne observations and statistical methods to explore urban trees' response to local climate across cities, advancing science and technology for urban forest management.