The Arctic has warmed faster than the global average by a factor of two or more since the mid-20th century, a phenomenon known as the Arctic amplification. The recent temperature warming over the Arctic is strongly linked to a drastic reduction in sea ice extent since the 1970s. A longstanding mystery is that a pronounced Arctic warming occurred during the early 20th century when greenhouse gas radiative forcing was weak. Using observations and model simulations, a research team led by Drs. Tokinaga and Mukougawa has discovered that a concurrent interdecadal warming of the Pacific and Atlantic were the major driver of the early Arctic warming. The results are presented on May 30, 2017, online Early Edition of Proceedings of the National Academy of Sciences of the United States of America. Read here for more detail.
Tokinaga, H., S.-P. Xie, and H. Mukougawa, 2017: Early 20th-century Arctic warming intensified by Pacific and Atlantic multidecadal variability, Proceedings of the National Academy of Sciences of the United States of America, doi:10.1073/pnas.1615880114