Implications of temporal change in urban heat island intensity observed at Beijing and Wuhan stations

Temporal change in urbanization-induced warming at two national basic meteorological stations of China and its contribution to the overall warming are analyzed. Annual and seasonal mean surface air temperature for time periods of 1961 similar to 2000 and 1981 similar to 2000 at the two stations of Beijing and Wuhan Cities and their nearby rural stations all significantly increase. Annual and seasonal urbanization-induced warming for the two periods at Beijing and Wuhan stations is also generally significant, with the annual urban warming accounting for about 65 similar to 80% of the overall warming in 1961 similar to 2000 and about 40 similar to 61% of the overall warming in 1981 similar to 2000. This result along with the previous researches indicates a need to pay more attention to the urbanization-induced bias probably existing in the current surface air temperature records of the national basic stations.