Published in Climatic Change 95, 231-248, doi:10.1007/s10584-009-9563-9 in 2009
Masumi Zaiki, Gunther P. Können, Keiji Kimura, Takehiko Mikami, and Togo Tsukahara
The temperature and pressure differences between Tokyo and Nagasaki were used to reconstruct past climate conditions. January and July in each available year since the 1820s were classified into several types with characteristic sea level atmospheric pressure patterns. This results in 18 years of pre-1881 data and a continuous series thereafter. The series indicate that the warming after 1900 (after the end of the so-called Little Ice Age) and again after 1960 can at least partly be attributed to an increase in the frequency of warm circulation pattern types at the expense of cold types. The difference in nature of the shifts in circulation types that occurred in the late 19th century compared with that in the late 20th centuries suggests that the mechanism behind the warming in the late 19th century differs from that in the late 20th century.