Tropical cyclones in the western north Pacific during the Last Glacial Maximum

Abstract:

Tropical cyclones (TCs) play an important role in the hydrology, sedimentology, and geomorphology of the landmasses surrounding the western north Pacific. Advances in our understanding of these processes, and how they may have influenced the tectonic evolution of sites like Taiwan and Japan, have been hampered by a lack of knowledge of the paleoclimatology of tropical cyclones, the record of which only extends back to the mid 20th century. In particular, the climatology of tropical cyclones during the Last Glacial Maximum (LGM) is poorly known but of prime interest for studies of sedimentology and landscape evolution. General circulation and regional climate modeling have been shown to provide realistic insights into the links between tropical cyclones and climate, but have not been applied to the paleoclimate periods of interest to geoscientists. We present dynamically-downscaled modeling results of tropical cyclone climatology from the Last Glacial Maximum and from the 20th century. The climatology of TCs in the LGM simulations is very similar to that from the modern control, consistent with large-scale indices that suggest that, despite lower sea-surface temperatures, the LGM in the western North Pacific was likely as favorable for TC development, if not more favorable, than the modern period. Our results suggest that tropical cyclone activity in the western North Pacific during glacial periods may have been broadly similar to that observed today.