Observed influence of anthropogenic climate change on tropical cyclone heavy rainfall

Abstract

The coastal regions of the Western North Pacific have seen large increases in tropical cyclone heavy rainfall frequency. Statistical fingerprint analysis shows that this observed geographical change in heavy rainfall is related to anthropogenic climate change. The impact of climate change on tropical cyclones (TCs) is of great concern in the Western North Pacific (WNP) region. Observations suggest that there have been recent changes in TC-related heavy rainfall. However, it has not yet been determined whether anthropogenic forcing has any contribution to such changes. Here, we show evidence that the human-induced warming has considerably changed the frequency of TC-induced heavy rainfall events in the WNP region. Observations since 1961 show that the occurrence of TC-induced heavy rainfall has significantly increased along coastal East Asia, while it has decreased in the southern part of WNP. On the basis of large ensemble climate simulations, we demonstrate that the observed changes cannot be explained solely by natural variability. This suggests that anthropogenic impacts have already significantly altered the TC-induced heavy rainfall pattern in the WNP region.