Summer warming 1895-2023 in U.S. cities exaggerated by 100% from the urban heat island effect
September 26th, 2023 by Roy W. Spencer, Ph. D.
We are now getting close to finalizing our methodology for computing the urban heat island (UHI) effect as a function of population density, and will be submitting our first paper for publication in the next few weeks. I’ve settled on using the CONUS (Lower 48) U.S. region as a demonstration since that is where the most dense network of weather stations is. We are using NOAA’s V4 of the GHCN monthly dataset.
I’ve previously described the methodology, where I use many thousands of closely-spaced station pairs to compute how temperature between stations change with population density at 10×10 km resolution. This is done for 22 classes of 2-station average population density, and the resulting cumulative UHI curves are shown in Fig. 1.
Fig. 1. Cumulative urban heat island effect in different multidecadal periods for the contiguous U.S. (CONUS), June/July/August, for GHCN monthly average ([Tmax+Tmin/2]) temperatures calculated from regression of station-pair differences in temperature vs. population density in 22 classes of 2-station average population density. The number of station pairs used to compute these relationships ranges from 210,000 during 1880-1920 to 480,000 during 2000-2010.
https://www.drroyspencer.com/2023/09/summer-warming-1895-2023-in-u-s-cities-exaggerated-by-100-from-the-urban-heat-island-effect/
