Climate driven trends in London's urban heat island intensity reconstructed over 70 years using a generalized additive model



Bassett, R, Janes-Bassett, V ORCID: 0000-0002-4882-6202, Phillipson, J, Young, PJ and Blair, GS
(2021) Climate driven trends in London's urban heat island intensity reconstructed over 70 years using a generalized additive model. URBAN CLIMATE, 40. p. 100990.

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Abstract

Long-term urban heat island (UHI) observations are uncommon and where available, are generally unable to distinguish changing climate drivers from urban expansion; neither driver is treated independently. We overcome this limitation using a generalized additive model to learn the variability in UHI intensity (UHII) at a central London weather station (St James's Park) over a 10-year observation period (2010–2019). We then use the model to reconstruct 70 years (1950–2019) of monthly night-time UHII variability using ERA5 reanalysis data both as a reference in UHII calculation and for the predictors. We find considerable variability both seasonally and annually within the UHII time series (monthly mean maximum UHIIs are 1.4–2.9 °C). Applying extreme value analysis to the time series we show that monthly mean maximum UHIIs are likely to exceed 2.75 °C once every 11 years. Considering that most studies observe or model UHIIs for less than a year, they will likely misrepresent this UHII variability. Nevertheless, despite moving to a warmer background climate, London's UHII has not significantly changed across the period of analysis (1950–2019). The data-driven methods we create in this study are easily transferable to other cities.

Item Type: Article
Uncontrolled Keywords: Climate, Generalized additive model, GAM, Extreme values, Time series, Urban heat island, UHI, Variability
Divisions: Faculty of Science and Engineering > School of Environmental Sciences
Depositing User: Symplectic Admin
Date Deposited: 06 Jul 2022 07:36
Last Modified: 18 Jan 2023 20:56
DOI: 10.1016/j.uclim.2021.100990
Open Access URL: https://doi.org/10.1016/j.uclim.2021.100990
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3157810