The distinction between canopy and boundary‐layer urban heat islands

TLDR

The study uses car‑based air‑temperature measurements in Vancouver to compare an empirical and a theoretical advective urban heat island model and to reassess how city size relates to canopy heat‑island intensity. Air‑temperature data were collected by car traverses in and near Vancouver and used to evaluate an empirical model and a theoretical advective model of the urban heat island. The empirical model fits the observations well, while the advective model performs poorly, likely because it does not distinguish between canopy and boundary‑layer meteorology.

Abstract

Abstract Air temperature measurements from car traverses in and near Vancouver, B.C. are used to test two urban heat island models: one an empirical model, the other a theoretical advective model. The empirical model describes the Vancouver observations well, whereas the advective one performs rather poorly. This discrepancy may be attributed to a failure to distinguish between meteorological conditions in the urban canopy, and those in the overlying urban boundary layer. This leads to a reassessment of the explanation of the relationship between city size (as measured by population) and the heat island intensity (as measured in the urban canopy).