Evaluation of the ERA5 reanalysis-based Universal Thermal Climate Index on mortality data in Europe

Air temperature has been the most commonly used exposure metric in assessing relationships between thermal stress and mortality. Lack of high-quality meteorological station data necessary to adequately characterize environment one main limitations for use more complex indices. Global climate reanalyses may provide an ideal platform overcome this limitation define heat cold conditions anywhere world. In study, we explored potential Universal Thermal Climate Index (UTCI) based on ERA5 – latest global reanalysis from European Centre Medium-Range Weather Forecasts (ECMWF) as a health-related tool. Employing novel ERA5-based comfort dataset ERA5-HEAT, investigated UTCI daily mortality 21 cities across 9 countries. We distributed lag nonlinear models assess exposure-response individual cities. then employed meta-regression pool results each city into four groups according zone. To evaluate performance UTCI, compared its effects with those station-based data. order additional effect ERA5-and air (T) was evaluated. Whilst generally similar heat- cold-effects were observed locations, important role wind appeared results. The largest difference any two datasets found Southern group cities, where relative risk at 1st percentile mean distribution (1.29 1.30 vs data, respectively) considerably exceeded (1.19 1.22). These differences mainly due tail distribution. comparison shows that be useful tool definition life-threatening locations are not available.