Quantifying the effect of urban agglomerations on coastal sea surface temperatures

Effects of urban agglomerations on the land surface and atmospheric temperatures have been highly studied topics in recent decades. However, their effect on the temperature of adjacent water bodies has been poorly addressed. On the other hand, severe ecological and socio-economic consequences of rising water temperatures, especially in coastal ecosystems, such as harmful algal blooms, coral bleaching and fish mortality, are well-documented and huge efforts are being made to reduce negative impacts.
This study aims to improve understanding of spatio-temporal heat transfer from urban agglomerations into coastal ecosystems. We analyse coastal sea surface temperature anomalies around multiple cities in different climate zones using the Global Ocean OSTIA Sea Surface Temperature and Sea Ice Reprocessed dataset and additionally high resolution thermal infrared data acquired form Landsat 8/9. Cities are selected for comprehensive analysis based on varying latitudes and climate zones, with an additional requirement of present quantitative studies on the UHI. A quantification of the UHI propagation into coastal waters and comparison of magnitude of such localised coastal warming would not only be valuable for coastal modelling, but also enable impact evaluation of city designs on coastal warming to provide actionable knowledge for decision-makers to mitigate rising temperatures in urban coastal ecosystems.