Significant elevation dependent warming over the Tibetan Plateau after removing longitude and latitude factors

As the largest plateau over China and the highest plateau over the world, the Tibetan Plateau (TP hereafter) has a vast territory spanning multiple longitude and latitude zones. Warming amplification and elevation dependent warming (EDW hereafter) are the most significant characteristics of climate change patterns over the TP. However, previous studies on the EDW over the TP have not taken the differences of longitude and latitude into consideration. Based on the observational mean, maximum and minimum temperature datasets at 118 meteorological stations over the TP, this study investigates the EDW after removing the influence of longitude and latitude factors in annual, warm season and cold season during 1961–2020 using the warming components separation method. The results show that (1) The mean warming rate over the TP during 1961–2020 is 0.33 °C·decade−1, which mainly affected by latitude and elevation. The effect of latitude on the total warming accounts for more than 65% and the effect of elevation is less than 35% on an annual basis. Moreover, the latitude factor has the greatest influence of maximum temperature in cold season (72%). (2) More robust EDW is found after removing the influences of latitude factors. In particular, the maximum temperature shows change from no feature to significant EDW (0.29 to 0.35 °C·decade−1·km−1), and the most significant change occurs in cold season (0.33 °C·decade−1·km−1) due to the removed latitude factor. It shows that stronger warming means more significant EDW, and the recent warming amplification and EDW are more intense during 1991–2020 than that during 1961–1990 when latitude factor is removed. (3) The warming components separation method effectively eliminates the differences of latitudinal warming between different stations. It mainly strengthens EDW by removing the latitudinal warming at low elevation and high latitude stations over the TP. This study highlights the importance of noise removal for the study of EDW over the TP.