The northwestern Pacific Ocean and South China Sea are where tropical cyclones occur most frequently. Many climatologists also study the formation of Pacific Ocean warm pools and typhoons in this region. This study collected data of paleotyphoons found in China's official historical records over the past 2000 years that contained known typhoon activity reports. The collected data are then subjected to statistical analyses focusing on typhoon activity in coastal regions of southeastern China to garner a better understanding of the long-term evolution of moving paths and occurrence frequency, especially regarding those typhoons making landfall in mainland China. We analyzed the data with the year and month of each typhoon event, as well as the number of events in a 10-year period. The result shows that (1) north–southward migration of typhoon paths corresponds to the north–southward migration of the Intertropical Convergence Zone (ITCZ) during the Medieval Warm Period (MWP) and Little Ice Age (LIA) and (2) paleotyphoons made landfall in mainland China 1 month earlier during the MWP than during the LIA. This implies a northward shift in ITCZ during the MWP. Typhoons tend to make landfall in Japan during El Niño-like periods and strike the southern coastal regions of China during La Niña-like stages. According to paleotyphoon records over the last 2000 years, typhoons made landfall in southeastern China frequently around 490–510, 700–850, and after 1500 CE The number of typhoons striking Guangdong Province peaked during the coldest period in 1660–1680 CE; however, after 1700 CE, landfall has migrated farther north. The track of tropical cyclones (TCs) in the northwestern Pacific Ocean is affected by the North Atlantic Oscillation (NAO) and the Pacific Decadal Oscillation (PDO), which shows a nearly 30-year and a 60-year cycle during the LIA.
Tropical cyclones (TCs) are a serious hazard. According to the Federal Emergency Management Agency (FEMA) of the USA, the total amount of money spent on flood recovery programs due to TC activity was greater than that spent on any other natural catastrophe during the period 2005 to 2015. The level of destruction caused by TCs has meant they have been the focus of a great deal of current research as well as being part of the historical record of China for millennia. Among all tropical cyclones, 37 % occur in the northwestern Pacific Ocean (Liang and Ye, 1993). These TCs are of a greater intensity and make landfall more frequently in this region than those making landfall in the western Atlantic Ocean. People pay a great deal of attention to the frequency and tracks of TCs on Earth. The path of TCs in the Pacific Ocean is driven by the clockwise rotation of the subtropical North Pacific High, and it takes three paths away from this genesis region: (1) a westerly path straight toward south China; (2) a west–northwesterly path curving back to Japan; and (3) a north-oriented path that keeps them out at sea (Elsner and Liu, 2003). Most existing TC records are based on short-term research that covers the past few decades (Wu and Lau, 1992; Lander, 1994). Short-term weather records indicate that TC paths may be directly influenced by variations in the El Niño Southern Oscillation (ENSO) in the equatorial Pacific region (Chan, 1985; Lander, 1994; Wang and Chan, 2002; Elsner and Liu, 2003; Ho et al., 2004; Chu, 2004), and ENSO is highly related to the Pacific Decadal Oscillation (PDO; Pavia et al., 2006; Feng et al., 2013). Another dynamic forcing influence on the pathways of TCs is related to the Intertropical Convergence Zone (ITCZ) position and North Atlantic Oscillation (NAO) (Gil et al., 2006).
However, climate study literature is severely lacking longer-term studies with more data that cover hundreds of years. For the purpose of tracking TC pathways in the long term, we need geological records from natural sediment from lake cores and lagoons originating in a widespread coastal area. The geological records indicate that ancient TC activity were enhanced by ENSO activity after the middle Holocene, both in the Atlantic and Pacific oceans (Donnelly and Woodruff, 2007; Woodruff et al., 2009; Chen et al., 2012; McCloskey and Liu, 2012, 2013; McCloskey et al., 2013; Liu et al., 2015). Therefore, we attempted to collect more TC data from these documents and understand some of the fragmented historical records. Bossak et al. (2014) discussed the statistical records of regional TC occurrence since 1851 from the southeastern Atlantic coastal region of the United States of America. In addition, the historical record of TC occurrence in the northwestern Pacific has a longer historical record in China. Chan and Shi (2000) first published the frequency of typhoon landfall over Guangdong Province of China during the period of 1470–1931 CE, and then Liu et al. (2001) examined historical records dating back to 1000 years ago in Guangdong Province. Further research also tried to integrate statistical records of TC occurrence in southeastern coastal China over the last 400 years (Fogarty, 2004).
In this study, we attempted to collate statistics on the landfall frequency of TCs recorded in China's written historical record with typhoon intensity recorded in the geological record of lake sediments in northeastern Taiwan to investigate TC path migration in the northwestern Pacific Ocean region over the last 2 kyr.
China's historical record is a rich source of documented evidence on climatic
conditions dating back millennia. Abnormalities in climatic
conditions found in China's records have been successfully applied in the
reconstruction of regional climate changes (Liu et al., 2001; Chu et al.,
2002, 2008). Previous research revealed that the term
China's written historical record dates back 3000 years. The statistical
records used in our study include data from southeastern coastal China and
Taiwan (Fig. 1). The data source upon which our study is based is a book entitled
Southeastern coastal regions of China and Taiwan.
After thorough verification of data sources, the timing and event locations found in the record primary source reports were kept and duplicates eliminated. Zhang (2013) is, by far, the most complete and commonly accepted climate record from China's documented history.
Illustrative quotations from selected historical sources in China.
Considering the evolution of typhoon-related keywords over the years, in
addition to using the specific keywords typhoon and
The statistical data collected for the southeastern coastal regions of China include data for Hainan, Guangdong, Fujian, Taiwan, Zhejiang, Shanghai, Jiangsu and Shandong (Fig. 1). When we categorized typhoon landfall locations based on latitudes, Fujian and Taiwan are recognized as one region due to their similarities in latitude and the same applies to Jiangsu and Shanghai. It is notable that prior to 0 CE the historical record of China lacks data on typhoon activity. Consequently, this study focuses on data collected over the last 2 kyr. Furthermore, data for the period 1945–2013 CE were collected from the northwestern Pacific Ocean TC records established by the Joint Typhoon Warning Center (JTWC). The statistical results were divided into three different time frames based on keyword results and database sources: (1) 0–1000 CE; (2) 1000–1910 CE; and (3) 1945–2013 CE. To plot the number of typhoons occurring as a function of time, typhoon events in any given decade were collectively plotted to create an interdecadal bar graph dating from 1000 CE to the present (Fig. 2). The number of events which occurred in any given decade relates closely to the age of historical documents and how well they have been preserved. Records relating to TC landfall between 1945 and 2013 CE are reliant on satellite-acquired data, meaning the data source is highly reliable in terms of its location and intensity. Consequently, Fig. 2 shows extreme growth in the number of recorded TCs in the latter years of the twentieth century. Moreover, Liu et al. (2017) published TC landfall data for the northwestern Pacific Ocean region between 1945 and 2013 CE, which corresponds to the results seen here. The Fig. 2 shows clearly that TC activity grew to an extraordinary extent at around 1500 CE and has persisted to the present.
Historical paleotyphoon data compiled over the past 1000 years from China's historical record and JTWC data for southeastern China and Taiwan. Each bar in the bar graph represents the collective number of typhoons occurring in any given decade.
The term
Statistics showing the number of typhoons between 0 and 1000 CE. The red range means high-frequency periods of TCs.
Figure 4 gives a total of 408 events relating to the terms
To make sure the historical record accurately reflected climatic conditions
for the period examined, a search of the record was conducted for anomalous
climatic events such as flooding, snow storms, droughts and so on. It was
found that there were extensive gaps in the data for the periods 1270–1320
and 1400–1450 CE, which are the two periods that corresponded to the advent
of the Yuan and Ming dynasties, respectively. All original data sources are
listed in Table S5 of the Supplement. The Yuan Dynasty was established by the
foreign-led dynasty of Kublai Khan of Mongolia. It was a period characterized
by much internal strife and rebellion. The lack of good climate data in the
historical record for the period 1400–1450 CE at first glance might seem
surprising as it is the time of the Yongle Emperor and the promotion of
Admiral Zhenghe, the eunuch commander of the seven great international
tributary voyages across the South China Sea and Indian Ocean
(1405–1430 CE). It would seem likely that weather conditions, especially TC
would be of great importance to China, and this information would have been
carefully recorded. This period is well described in the book
The numbers of typhoons occurring per decade for the period 1000–1910 CE.
To further investigate any changes in the timing of annual TC landfall, TC landfall data were collected and analyzed for three different time periods: 0–1000 CE; 1000–1910 CE; and 1945–2013. The results are shown in Fig. 5, and monthly statistics are listed in Table S3 of the Supplement. Before 1000 CE, TCs in China mostly occurred in June, July and August (Fig. 5a). However, after 1000 CE, the entire trend in arrival times shifted by 1 month, with TC landfall occurring predominantly in July, August and September (Fig. 5b). The majority of statistics after 1000 CE were collected during the Little Ice Age (LIA; 1400–1850 CE). Figure 5c shows statistics for the period 1945–2013 CE The timing of recent TCs making landfall in southeastern China is quite similar to that which occurred during the LIA period. Recent data show that TC occurrence in the entire northwestern Pacific Ocean region can last until as late as October, November and December with TCs making landfall in Vietnam, the Philippines and Thailand after September (Liu et al., 2017). It is assumed that this relates to seasonal changes in the positions of the subtropical high and ITCZ of the northwestern Pacific Ocean region. The ITCZ begins migrating north away from the Equator in March or April. It reaches its northernmost position in August, before migrating south in September (Waliser and Gautier, 1993). The question this study raises is what occurrence shifted the predominant timing of TC arrival in southeastern China from between June and August between 0 and 1000 CE to between July and September after 1000 CE. One likely explanation is that the ITCZ was at a higher latitude before 1000 CE (Rehfeld et al., 2013), resulting in earlier (June–August) TC formation.
Statistics on TCs that struck China:
Not all historical records gave details on where TCs struck before 1000 CE; therefore, this study focuses solely on the landfall locations of paleotyphoons between 1000 and 1910 CE. The number of typhoons that struck each province in China is shown in Fig. 6. Table S4 of the Supplement gives additional details on landfall locations. For the period 1000–1910 CE, Guangdong was struck by the most TCs. On the whole, the number of TCs making landfall increased dramatically after 1500 CE, with the number of typhoons hitting Guangdong peaking between 1660 and 1680 CE. By contrast, regions north of Fujian did not record any increase in typhoon activity during this time period. The number of typhoons striking Zhejiang and Jiangsu, however, did start to increase after 1700 CE.
Newton et al. (2006) proved that the warmest temperatures in the Indo-Pacific Warm Pool occurred during the Medieval Warm Period while the coolest temperatures occurred during the Little Ice Age. In particular, the lowest temperatures occurred around 1660–1680 CE within the period of the Maunder Minimum (1645–1715 CE). Therefore, it is thought that the sudden change in TC tracks around 1700 CE may relate to a change in temperature lows in the Northern Hemisphere and a shift in the location of the ITCZ.
The number of typhoons that struck the southeastern regions of China and Taiwan between 1000 and 1910 CE. (Red line means the time boundary of 1700 CE. More TCs made landfall in Guandong before this time, but more TCs made landfall to northward after this time.)
Correlations between typhoon events and ENSO.
Conserving historical documents has always been a difficult task. Racial conflicts, war, rebellion and inter-court feuds could all result in precious data being damaged, destroyed or lost during certain periods in history. Consequently, statistics on paleotyphoons recorded in the historical record are only semiquantitative. On the other hand, they are very useful in terms of noting the location of landfalls and the precise timing of such events. To help overcome any anomalies in the typhoon record lost to documented history and to avoid any confusion regarding the intensity of events, this study also looked at the geological record of paleotyphoons derived from lake sediments in northeastern Taiwan (Chen et al., 2012; Yang et al., 2014; Wang et al., 2013, 2014, 2015). Since the topography of northeastern Taiwan's Yilan region is quite unique, with the summer monsoon being blocked by mountains and rainfall being mainly supplied by the winter monsoon and typhoons (Chen et al., 2012), the region is very helpful for studying TC in the northwestern Pacific. In fact, large-scale river terraces have occurred due to typhoon rainfall, and this record has been preserved in the mountain areas of Yilan since 2.7 ka (Hsieh, 2017).
In order to correlate the number of paleotyphoons from historical data with the geological record of lake sediments, the Southern Oscillation Index (SOI), the intensity of paleotyphoons determined from sedimentary particle size at Taiwan's Lake Dahu and paleotyphoon signals from lagoon sediments in Kyushu, Japan (Fig. 7), are referenced and compared. Results suggest that typhoons struck Taiwan and the southeastern coastal region of China mostly during La Niña-like stages (Fig. 7a, b, c) (Chen et al., 2012). This outcome matches that mentioned by historical maritime disaster events caused by paleotyphoons in the last 1000 years in Liu et al. (2017). According to Liang and Zhang (2007), the chances of a typhoon making landfall in the southeastern coastal region of China during La Niña years is higher than that during El Niño years. If we started entering an El Niño-like stage after 1900 CE, this means the number of typhoons striking Japan in the future will very likely increase compared to what we see now. This trend in the data since 1700 CE shows a gradual increase in typhoon numbers moving north and away from Guangdong (Fig. 6). It has also been shown that the number and intensity of typhoons recorded in Taiwan's lake sediments has grown since the LIA (1400 CE) which seems to match the general trend in the recorded number of historical events pretty well (Fig. 7a and c). This period also coincided with the timing of flooding events in southern China (Fig. 7d). Park et al. (2017) investigated the records of lake sediments in the East Asia region. Their study noted that along coastal regions including Jeju Island (Korea), lakes in Yilan (Taiwan), Lake Huguangyan in Guangdong, and lakes on Hainan Island relatively drier conditions prevailed during the MWP and wetter conditions during the LIA. This may be due to an increase in rainfall caused by typhoons along the coast.
This study, therefore, finds that the northward migration of the ITCZ during the MWP caused typhoons to move north toward Japan. In contrast, typhoons moved toward southern China during the LIA due to the southward transition of the ITCZ. This seems to be a reasonable explanation and is not out of step with other regional studies (Rehfeld et al., 2013; Chen et al., 2015; Xu et al., 2016).
Donnelly and Woodruff (2007) first suggested that the number of hurricanes in the Caribbean area has been increasing over the last 4000 years. According to ancient hurricane research along the Gulf Cost and Caribbean Sea to Puerto Rico, hurricane tracks show an antiphase in time series data (McCloskey and Liu, 2012, 2013; McCloskey et al., 2013; Liu et al., 2015). During the MWP, more TCs made landfall in the Gulf Coast as the strength of the Bermuda High enhanced and the ITCZ moved northward. During the LIA, more TCs made landfall in the Caribbean Sea (McCloskey and Knowles, 2009; McCloskey and Liu, 2012, 2013; McCloskey et al., 2013). In 1650 CE, TC frequency reached a peak, and after 1850 CE TCs began to move toward Florida and Bermuda with the northward movement of the ITCZ (Baldini et al., 2016). Ancient lake sediment data from Yilan, Taiwan, reveals the period in history when paleotyphoons occurred most frequently. This timing correlates highly with the time of paleohurricanes recorded in Belize from McCloskey and Liu (2013). This suggests that the migration paths of TCs in both the northwestern Pacific Ocean region and the northwestern Atlantic Ocean region are closely related. TC activity occurred between 200 and 600 and between 1450 and 2600 yr BP in Belize, and it occurred between 200 and 500, 1300 and 1500, and 2000 and 2300 yr BP in Taiwan's lakes (Chen et al., 2012). This phenomenon indicates a close association between TC activity in the North Pacific Ocean and the North Atlantic Ocean.
The relation between the NAO
Location factor (
The wavelet analysis of the TTC1 during the LIA.
Since the ITCZ and westerlies are both linked to the Hadley Cell, and the position
of midlatitude storms are determined by the westerlies, which are influenced
by the North Atlantic Oscillation (NAO) (Hurrell, 1995; Morley et al.,
2014), we compared the NAO record with the track of TCs. In order to compare
our tracks of TCs with the NAO, we created an index called TTC1 to represent the
track of TCs that either move toward southern China or toward northern China
(TTC1
After we performed the wavelet analysis, we found that the TTC1 shows both 30–35- and 55–65-year cycles during the LIA stage (Fig. 9). This result is also consistent with the frequency of typhoon landfall over Guangdong Province of China during the period of 1470–1931 CE based on a different data source (Chan and Shi, 2000). The 60-year cycle is clearly present in the PDO and the Atlantic Multi-decadal Oscillation (AMO), with phases coherent with a planetary signal since at least 1650 to 1850 CE (Scafeta, 2012; Solheim, 2013). This implies that the PDO also affects the TTC1 cycle.
We statistically analyzed Chinese historical documents to understand the
relationship between the MWP, LIA and movements in the ITCZ. Our conclusions
are very similar to those found in previous studies, indicating that China's
documented historical record is an invaluable asset in the study of
climatological phenomena. The conclusions are as follows:
Before 1000 CE, TCs struck China mostly in June, July and August. The
timing of TC landfall shifted to July, August and September after 1000 CE. Statistical analyses of China's historical documents show that there was
a sudden increase in the frequency of paleotyphoons in 490–510, 700–850 CE
and since the beginning of the LIA (1400 CE). Correlating lake core records from Taiwan and Japan proved that more
typhoons made landfall in Guangdong and Taiwan during the LIA, whereas,
more typhoons made landfall in Japan during the MWP. Most typhoons made landfall in Guangdong in the coldest period of the LIA.
Typhoon tracks started migrating towards Fujian and farther north after 1700 CE,
indicating that there is a northward trend in typhoons towards Japan. The track of TCs has 30–35- and 55–65-year cycles during the LIA
stage; the result is consistent with the variation in the NAO and the PDO cycles.
Paleoclimate research covering the last 2000 years since the late Holocene mainly focuses on three drastic temperature fluctuation periods, i.e., the MWP, LIA and the global warming of the past 200 years. Our study shows that the paths of paleotyphoons between the MWP and LIA are closely related to the migration of the ITCZ. The results also demonstrate that the migration paths of TCs in the northern Pacific Ocean and the northern Atlantic Ocean are highly correlated with the NAO and the PDO cycles.
We show all data in the Supplement.
The supplement related to this article is available online at:
HFC coordinated and wrote this paper; HFC conceived the present idea and explained the conclusions; YCL read all records and obtained statistical results; XL and YMC contributed original books and helped collect data; CWC and HJP drew some of the figures and did the wavelength analysis.
The authors declare that they have no conflict of interest.
This study was supported by the National Taiwan Ocean University and grants NSC103-2116-M-019-003 and NSC106-2116-M-019-004 from the National Science Council of Taiwan. We are grateful for Kam-Biu Liu at Louisiana State University, who started the research of paleotyphoons by using historical records. His research was greatly edifying. Edited by: Chantal Camenisch Reviewed by: James Elsner, David Nash, and one anonymous referee