Evaluation of ERA5-Simulated Temperature and Its Extremes for Australia

Atmospheric reanalysis products offer high-resolution and long-term gridded datasets that can often be used as an alternative or a supplement to observational data. Although more accessible than typical data deemed fit for climate change studies, show biases resulting from assimilation approaches. Thus, thorough evaluation of the product over region metric study is critical. Here, we evaluate performance latest generation ECMWF reanalysis, ERA5, in simulating mean extreme temperatures Australia 1979–2020 versus high-quality observations. We find ERA5 generally simulates maximum minimum reasonably well (mean bias ~1.5 °C), even though it underestimates/overestimates daily maximum/minimum temperatures, leading cold Tmax warm Tmin. also underestimates decadal warming trend both Tmin compared Furthermore, struggles simulate temporal variability Tmin, markedly worse skill Tmax. In terms indices, skilled at capturing spatial patterns trends extremes, albeit with presence each index. This partially attributed temperature. Overall, captures temperature indices Australian continent well, warranting its potential observations aiding change-related downscaling boundary conditions, model evaluation.