Impact of heat storage on remote-sensing based quantification of anthropogenic heat in urban environments

Anthropogenic heat (AH) significantly impacts urban climates. Although combining the surface energy balance (SEB) with remote sensing data (RS-SEB) is promising for AH quantification, it has been shown to yield paradoxical low AH values in urban centers. Some speculation on the causes for the underestimation has appeared in the literature; however, none has been verified or thoroughly evaluated, largely hindering the further improvement of spatial representation of AH estimated through the RS-SEB approach. Here by casting the difference in the SEB between the observed reference state and a hypothetical scenario without AH, we developed a thermal stability analysis framework to identify the primary causes. Using AH estimations from six representative US cities based on Local Climate Zone (LCZ), we find that the reduced efficiency of the pathway from AH to sensible heat flux near high-rise buildings results in greater heat storage, which is a primary contributor to the underestimation. This study highlights the importance of heat storage in AH quantification using remote sensing data and provides evidence for potentially correcting the bias in AH with improved heat storage modeling.

Automated summary

This study identifies the reduced efficiency of the pathway from anthropogenic heat (AH) to sensible heat flux near high-rise buildings as a primary contributor to the underestimation of AH in urban centers. It highlights the importance of heat storage in AH quantification using remote sensing data and provides evidence for potentially correcting the bias in AH with improved heat storage modeling.