Annually resolved Northwestern Pacific tropical cyclone series since the mid-14th century: intensified activities during the Maunder Minimum

This study used Reconstructed East Asian Climate Historical Encoded Series (REACHES) database (Wang et al. 2018) to reconstruct historical tropical cyclone (TC) series documented in 1368-1911. Records documented with ‘typhoon’ (Chinese character颱) or ‘hurricane’ (颶) were retrieved, with descriptions of other compounding effects such as strong wind, torrential rain and storm surge to consist of the data set. To avoid repetition and duplicate counting of the same TC event, records that have temporal (± 1 days) and spatial (±2∘degree latitude/longitude) proximity were combined accounting for one single TC event. The method was based on a systematic database approach and data quality was checked and validated through comparison with other independent reconstructed series and IBTrACS (Tropical Cyclone Best Track Data) 1884-2020. The REACHES TC series was then merged with the IBTrACS data to form a l368-2020 long TC series for Northwestern Pacific region. The reconstructed TC series demonstrates clear multi-decadal to centennial variabilities. In the last six hundred years, there were in average 3 TC documented in every year. 1600s was the most TC active period (8 TC in 1627, 7 in 1640, 7 in 1652, 6 in 1662, 7 in 1664, 9 in 1668, 12 in 1669, 10 in 1671, and 8 in 1672). The TC series was then compared with other forcings (volcanic eruption, solar, and SST) and ENSO.  All of the forcings may have a role in the frequent TC activities during Maunder Minimum. Further research from model-data comparison and simulations will shed lights on TC behaviors in the warming climate.