Hot in Baltimore: linking urban form to fine-scale temperature differences

Abstract:

Better understanding how urban morphology creates microclimates can help policymakers and planners mitigate the effects of heatwaves and other negative urban heat island effects. In Baltimore, where the observed downtown-rural temperature difference (as measured by NOAA stations) can reach 5°C, low-income neighborhoods are almost entirely covered by impervious surfaces like concrete but lack trees and parks. Their urban-rural temperature difference is then expected to exceed the reported one. However, that difference is not well quantified because these areas lack weather station coverage. Additionally, high resolution satellite imagery shows only land surface temperatures (inadequate for policy and health interventions) and may miss severe heat events. To remedy this, a low-cost monitoring network was installed in East Baltimore over summer 2015 aiming to characterize spatial and temporal variability and examine how heat excess varies during heat events. Results confirm that E. Baltimore exceeds downtown temperatures and show that a dense network of low cost sensors can help attribute temperature anomalies to local features such as land cover, building density and tree canopy.