A daily highest air temperature estimation method and spatial–temporal changes analysis of high temperature in China from 1979 to 2018

Abstract. The daily highest air temperature (Tmax) is a key parameter for global and regional high analysis which very difficult to obtain in areas where there are no meteorological observation stations. This study proposes an estimation framework obtaining high-precision Tmax. Firstly, we build near-surface diurnal variation model estimate Tmax with spatial resolution of 0.1? China from 1979 2018 based on multi-source data. Then, order further improve the accuracy, divided into six regions according climate conditions topography established calibration models different regions. shows that mean absolute error (MAE) dataset (https://doi.org/10.5281/zenodo.6322881, Wang et al., 2021) after correction about 1.07 ?C root square (RMSE) 1.52 ?C, higher than before nearly 1 ?C. spatial–temporal variations indicated annual seasonal most showed increasing trend. In summer autumn, northeast increased fastest among regions, was 0.4?C per 10 years 0.39?C years, respectively. number days warm trend all while icing cold decreasing abnormal changes mainly occurred El Niño or La Niña years. We found influence Indian Ocean basin warming (IOBW) generally greater those North Atlantic Oscillation NINO3.4 area sea surface making ocean modal indices temperature. general, this great significance change China, especially environmental protection.