Journal Information

Online ISSN: 1520-0442
Print ISSN:    0894-8755
Frequency:    Semimonthly

Impacts of El Niño–Southern Oscillation Events on Tropical Cyclone Landfalling Activity in the Western North Pacific

M. C. Wu, W. L. Chang, and W. M. Leung

Hong Kong Observatory, Hong Kong, China



Abstract

The impact of El Niño–Southern Oscillation (ENSO) episodes on the variability in the landfalling pattern of tropical cyclones in the western North Pacific is studied using the bootstrap technique.

It is found that, relative to neutral years, in the months September, October, and November or the late season of El Niño years the number of tropical cyclones landfalling in the landmasses rimming the western North Pacific is significantly reduced. The exception is Japan and the Korean Peninsula. On the other hand, in the late season of La Niña years, China can expect significantly more landfalls. The predictability of the number of landfalling tropical cyclones in the western North Pacific is found to be the highest for China in the late season of La Niña years.

The reduction in the number of landfalls during the late season of El Niño years seems to be related to an eastward shift in the mean tropical cyclone genesis position and a break in the 500-hPa subtropical ridge near 130°E. In contrast, the increase in the number of landfalls during the late season of La Niña years appears to be related to a westward shift in the mean genesis position together with a contiguous 500-hPa subtropical ridge.

Received: November 12, 2002; Final Form: May 12, 2003

Corresponding author address: W. M. Leung, Hong Kong Observatory, 134A Nathan Road, Kowloon, Hong Kong, China. Email:


1. Introduction

The impacts of El Niño–Southern Oscillation (ENSO) events on tropical cyclone activity in the western North Pacific have been considered by Chan (1985), Dong (1988), Lander (1994), and Chan (2000) as well as others. However, the relationship between ENSO events and tropical cyclone landfalling activity in the western North Pacific seems to have received less attention in the literature.

Saunders et al. (2000) studied ENSO's spatial impacts on the landfalling behavior of hurricanes in the Atlantic and typhoons in the western North Pacific. Using the landfalling incidence rate ratio (IRR) they found that ENSO has a significant impact on the landfalling patterns of tropical storms in Vietnam and on typhoons in the Philippines. They also conclude that the impact of ENSO is less in the western North Pacific than in the Atlantic. Recently, Wang and Chan (2002) examined the changes in the life spans and tracks of tropical storms in the western North Pacific during strong ENSO events. Although changes in the landfalling patterns under the influence of ENSO can to some extent be inferred from the tropical cyclone tracks defined in Wang and Chan (2002), the theme of their study is tropical cyclone activity over the western North Pacific Ocean and not landfalls.

Between 1995 and 1999, damages in the Economic and Social Commission for Asia and the Pacific/World Meteorological Organization (ESCAP/WMO) Typhoon Committee1 member areas in the western North Pacific were estimated to be approximately $3,620 million (U.S. dollars) with average annual human casualties exceeding a thousand (ESCAP/WMO, 2001; more information available online at http://www.wmo.ch/web/www/TCP/ESCAP-Typhoon-Com.html). From the point of view of reducing social and economic impacts, understanding the influence of ENSO events on the variability in tropical cyclone landfalling patterns is therefore equally important.

This note extends the work of Saunders et al. (2000) and Wang and Chan (2002). Using the bootstrap technique (details given in section 2d) and data between 1961 and 2000, it provides a quantitative comparison of landfalling patterns of tropical cyclones in the western North Pacific in years with ENSO activity (hereafter called ENSO years, and El Niño years for years in which warm events occurred, La Niña years for years in which cold events occurred) with those in years without ENSO activity (hereafter called neutral years). This is an issue not specifically addressed by Wang and Chan (2002). The western North Pacific in this study includes the coastline of mainland China, an area not covered in Saunders et al. (2000). Furthermore, as prior knowledge of the number of tropical cyclones that can be expected to make landfall is useful for planning and disaster mitigation purposes, this note examines the predictability of landfall in the western North Pacific in ENSO years. This topic also seems to be barely addressed in the literature.

This note is arranged as follows. The data and methodology used are described in section 2. The ENSO years used and the delineation of study areas in the western North Pacific for the purpose of this investigation are also given in that section. The confidence intervals for the number of tropical cyclones in different study areas and different ENSO conditions are derived using the bootstrap technique in section 3. The physical basis for the variability in landfalling behavior is examined in section 4. In section 5 an attempt is made at predicting the number of tropical cyclones expected to make landfall in the western North Pacific in ENSO years from Niño-3.4 sea surface temperature anomalies (SSTAs). A summary of the results is given in section 6.


2. Data and methodology
a. Data on landfalling tropical cyclones in the western North Pacific

The number of landfalling tropical cyclones in the western North Pacific is extracted from the best-track data published by the Hong Kong Observatory. The period studied is the 40 years between 1961 and 2000. Data before 1961 are not analyzed because the number of tropical cyclones in the presatellite years of the 1950s might be underestimated (Chan 1985).

b. ENSO years

In his investigation of the relationship between ENSO and tropical cyclone activity over the western North Pacific, Chan (2000) stratified ENSO events by years and examined the variation by season within these years. His approach is followed in the present study on landfalls.

The ENSO years between 1961 and 1996 used in this paper are those listed in Trenberth (1997). ENSO years between 1997 and 2000 are identified using the criteria adopted by Trenberth (1997) and the monthly Niño-3.4 SSTA data (available from the Climate Prediction Center's Web site at http://ftp.ncep.noaa.gov/pub/cpc/wd52dg/data/indices/sstoi.indices.) Trenberth (1997) considers an El Niño event to have occurred if the 5-month running mean SSTAs in the Niño-3.4 region (the equatorial Pacific bounded by 5°S–5°N, 120°–170°W) exceed 0.4°C for 6 months or more. La Niña events are similarly defined with an SSTA threshold of −0.4°C.

Of all the ENSO years between 1961 and 2000 thus obtained, only the subset in which ENSO activity began in June or earlier, and ended in November or later are selected for the present study. This is to ensure that during the selected ENSO years the ENSO signal is evident during the June–November tropical cyclone season in the western North Pacific.

This process yields 9 El Niño years (1963, 1965, 1969, 1972, 1982, 1987, 1991, 1994, 1997), 6 La Niña years (1964, 1971, 1973, 1975, 1988, 1999), and 25 ENSO neutral years.

c. Delineation of study areas in the western North Pacific

The landmasses rimming the western North Pacific basin are divided into four study areas. Area 1 covers Japan and the Korean Peninsula; area 2 covers China; area 3 is mainly Indochina, Thailand, and the Malay Peninsula; and area 4 the Philippines (Fig. 1).

This delineation is somewhat subjective. The factors taken into account being geographical contiguity or proximity. Consideration is also given to tropical cyclone landfall or track climatologies in the different areas as given in or can be inferred from, for example, Chen and Ding (1979) and Neumann (1993). Area 1 is mainly affected by recurving tropical cyclones, and area 2 by tropical cyclones forming in both the western North Pacific and the South China Sea and generally moving in a northwest direction. Area 2 has most landfalls in June, July, and September, and area 3 in September and October. Area 4 is rarely affected by tropical cyclones forming in the South China Sea.

d. Methodology

It is first shown (section 3a) that in ENSO years, for all areas the change in landfalling pattern from neutral years is small in the early season, June–August. Large changes are found mainly in the months September–November or the late season, and only for areas 2, 3, and 4. The bootstrap technique is then used to construct the confidence intervals about the true mean of the number of landfalling tropical cyclones in the late season in these three areas in ENSO and neutral years.

The bootstrap technique belongs to the class of resampling procedures. It allows inferences about a sample to be drawn without assumptions being made on the underlying probability distribution of the data in the sample, or when assumptions about the probability distribution can be made but the confidence intervals cannot be calculated mathematically (von Storch and Zwiers 1999).

The bootstrap technique operates by replicating without replacement a large number of synthetic sets of observations from a single set of actual observations (Wilks 1995). The mean of each of the synthetic sets of observations is calculated and the confidence intervals are obtained from the distribution of these means. For example, if 10 000 synthetic sets are generated, then the 95% confidence intervals are given by the 250th (10 000 × 0.05/2) ranked mean and the 9750th ranked mean [10 000 − (10 000 × 0.05/2)].

The advantages of applying the bootstrap technique to atmospheric observations have been discussed by Nicholls (2001). In regard to tropical cyclones, this technique has been utilized by O'Brien et al. (1996) and Bove et al. (1998) to study the effect of ENSO on landfalling hurricanes in the eastern United States, as well as by Chu and Wang (1997) to study tropical cyclone occurrences in the vicinity of Hawaii.

Because inferences based on resampling techniques are sensitive to the effects of serial correlation (Zwiers 1990), lag-1 autocorrelations are first calculated for the relevant landfalling data series and tested for statistical significance using the Ljung–Box Q test (Box and Jenkins 1976; Vandaele 1983). None of the autocorrelations are found to be significant.

The results of the bootstrap analysis are interpreted in terms of the associated large-scale atmospheric circulations. The National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis data (Kalnay et al. 1996) are used to construct the composites of these circulations at 850 and 500 hPa in ENSO years.

The predictability of the number of landfalling tropical cyclones in the western North Pacific from Niño-3.4 SSTAs is attempted using linear regression methods.


3. Landfalling patterns in the western North Pacific
a. Statistics of observed landfalls

The observed mean number of landfalls in ENSO and neutral years for areas 1, 2, 3, and 4 are given in Table 1. This table shows that in the early season, the differences between the mean number of landfalls in ENSO and neutral years are small for all the four areas. These small differences may be attributed to ENSO not beginning to attain maximum development until September (Chen et al. 1998). In the late season, the differences are large with the exception of area 1.

These differences can be better demonstrated in terms of the standardized anomaly of the number of landfalling tropical cyclones, D, calculated as the ratio of the difference between the mean number of landfalls in El Niño (La Niña) years and neutral years to the standard deviation of the number in neutral years.

In the early season, for all areas D is small, no more than 0.5. In the late season, with the exception of area 1 the value of D generally exceeds 1 (Fig. 2). If D is viewed as a discriminator, then irrespective of whether the value of 0.5 or 1 is selected as the choice of threshold the late season would emerge as that in which ENSO's impacts are likely to be the most evident for all areas except area 1. In the late season, for areas 2, 3, and 4, D takes on negative values for El Niño years, and positive values for La Niña years. These values signify, respectively, fewer landfalls in El Niño years compared with neutral years, and more landfalls in La Niña years.

b. Confidence intervals

The 95% confidence intervals in ENSO and neutral years in areas 2, 3, and 4 in the late season as obtained from the bootstrap technique are shown in Table 2.

One sees that in the late season, for area 2, the confidence interval is between 1.1 and 2.2 during El Niño years, and between 2.3 and 3.2 during neutral years. For area 3, the respective confidence intervals are 1.0–2.2, and 2.4–3.4. For area 4, they are 0.7–2.1 and 2.6–3.4. The confidence intervals in El Niño years are smaller than those in neutral years. Further, there is little overlap between the confidence intervals in El Niño years and in neutral years. This is highly suggestive of the suppressing effect of El Niño on landfalling activity in the late season in areas 2, 3, and 4.

In La Niña years, during the late season the confidence interval for area 2 is between 3.3 and 4.7, for area 3 between 1.7 and 6.3, and for area 4 between 3.3 and 5.7. They are all larger than the respective confidence intervals for neutral years. In particular, for area 2 the confidence intervals do not overlap, and points to the enhancing influence La Niña has on landfalling activity in that area.

The contrast between El Niño and La Niña years is particularly marked. For area 2, the number of landfalling tropical cyclones in La Niña years is almost 2.4 times that in El Niño years. In area 3, it is about 2.2 times. In area 4, it is about 3.3 times.

Results from the permutation test, a two-sample test related to the bootstrap (see, e.g., Wilks 1995 for a description of this test) confirm that the mean number of tropical cyclones landfalling in areas 2, 3, and 4 in the late season of El Niño years differ significantly from the mean number in neutral years (at the 5% level). This test also shows that in the late season of La Niña years, the mean number of tropical cyclones landfalling in area 2 is significantly different (at the 5% level) from that in neutral years. It is insignificant in areas 3 and 4. These results are summarized in Table 3.

ENSO's impacts on landfalling activity found here are generally consistent with those of Saunders et al. (2000) as well as those that might be inferred from the tracks given in Fig. 8 of Wang and Chan (2002).

In particular, in the sense that three out of the four delineated areas see a significant impact of ENSO on the number of landfalling tropical cyclones, ENSO's influence in the western North Pacific would seem, in this regard, to be no less than in the Atlantic as found by Saunders et al. (2000). It is ventured that the conclusion reached by Saunders et al. (2000) that ENSO's impacts on landfalling patterns are less in the western North Pacific than in the Atlantic is largely due to landfalls over mainland China in area 2 not being considered in their study.


4. Atmospheric circulations associated with the different landfalling patterns

Shifts in tropical cyclone genesis positions together with changes in the steering flow are identified as some of the factors affecting landfalling patterns in the western North Pacific in the late season of ENSO years.

a. Shifts in genesis position

Figure 3 shows that in the late season, the mean tropical cyclone genesis position is at about 14.3°N, 147.3°E during El Niño years, and 14.7°N, 133.0°E during La Niña years. These mean genesis positions are shifted, respectively, eastward and westward from that of neutral years, which is at about 14.5°N, 138.7°E. The correlation coefficient between the mean longitude of the genesis positions in the late season of each year and the mean Niño-3.4 SSTAs in the late season of each year between 1961 and 2000 is 0.67, significant at the 1% level.

These results are broadly consistent with those of Chia and Ropelewski (2002). They show that during the season July–October, tropical cyclone genesis position in the western North Pacific tends to be shifted southeastward during warm ENSO conditions, and northwestward during cold conditions. However, Chia and Ropelewski (2002) note that this is not always the case, and the relationship between genesis position and ENSO is complex. It depends, for example, on the timing and evolution of individual ENSO events. Chia and Ropelewski (2002) further suggest that while ENSO is a dominant factor in changes in genesis position, it is not the only one. The 200–850-hPa wind shear, the strength and position of the western Pacific subtropical high, and the monsoon trough are also involved, all of which may be varying with ENSO in an inter-related way.

The genesis positions of tropical cyclones are closely related to the interannual variations in the monsoon trough (Lander 1994; McBride 1995). The variation in the easternmost position of the monsoon trough in the late season is clearly seen in Fig. 3 (dashed line, left panels). In El Niño years, the eastern end of the monsoon trough stretches to just beyond 170°E, that is, almost to the date line. In neutral years, the eastern end of the monsoon trough does not extend beyond 150°E. In La Niña years, it terminates at about 135°E. That is, in La Niña years the eastern end of the monsoon trough retreats westward by some 35° longitude compared with its position in El Niño years. The eastward shift in the mean genesis position in El Niño years can be explained by the eastward extension of the monsoon trough, and its westward shift in La Niña years by the westward retreat of the monsoon trough. Chen et al. (1998) have attributed the interannual variation in the monsoon trough to an anomalous wave train resulting from SSTAs in the tropical Pacific.

For warm ENSO conditions, it has also been suggested that the shifts in tropical cyclone genesis position are due to a longitudinal shifts in the ascending and descending branches of the Walker circulation (Chan 2000).

b. Changes in steering flow

ENSO-related anomalous flows at 500-hPa flows, which steer tropical cyclones away from or toward a particular region in the western North Pacific basin, have been suggested by Chan (2000) as a reason for the variability in tropical cyclone activity over the western North Pacific.

The right panels in Fig. 3 show that during the late season of El Niño years, the subtropical high at the 500 hPa is split into two separate cells at about 130°E. In contrast, during neutral and La Niña years, the subtropical ridge presents itself as a contiguous entity.

The eastward shift in mean genesis position and the break between the two cells in the subtropical ridge induces tropical cyclones to recurve north or northeast before reaching 120°E (see Carr et al. 1998; Sampson et al. 1998 for the motion of tropical cyclones under different synoptic situations). This may help to explain in part the relatively smaller number of landfalling tropical cyclones in areas 2, 3, and 4 during the late season of El Niño years. Wang and Chan (2002) also found that during the fall of strong El Niño years. Tropical storms tend to recurve northward across 35°N 2.5 times more than in strong La Niña years.

The recurvature at about 130°E is well reflected in the track densities (Fig. 4), which are constructed by counting the number of tropical cyclones passing through grid boxes of 1° latitude and dividing by the number of years. The track density over the South China Sea is, as a consequence, also much lower relative to neutral years. The relatively smaller number of tropical cyclones making landfall in areas 2, 3, and 4 in El Niño years can also be seen in Fig. 4a.

The westward shift in mean genesis position together with the strong subtropical ridge in the late season of La Niña years favor a steering toward the west-northwest. This is reflected in the much higher track densities in the South China Sea in the late season of La Niña years relative to neutral years. Figure 4b also shows the higher number of landfalling tropical cyclones over the Philippines, south China, and northern Vietnam in the late season of La Niña years.


5. Predictability

The predictability of the number of tropical cyclones landfalling in the western North Pacific is to some degree afforded by the confidence intervals given in Table 2. That is, the number of tropical cyclones that can be expected to make landfall in the late season of El Niño years is 2 or less in areas 2, 3, and 4. In the late season of neutral years, this number is likely to be between 2 and 3 for areas 2 and 3, and 3 for area 4. In the late season of La Niña years, the number is likely to be between 3 and 5 in area 2, between 2 and 6 in area 3, and between 3 and 6 in area 4.

Wang and Chan (2002) found that the number of tropical storms forming in the months July–September in the southeast (0°–17°N, 140°E–180°) and northwest (17°–30°N, 120°–140°E) quadrants of the western North Pacific is highly correlated with SSTAs in the Niño-3.4 region in that season. A preliminary study of the predictability of the number of tropical cyclones making landfall in the western North Pacific in the late season in terms of late season Niño-3.4 SSTAs for areas 2, 3, and 4 is now attempted.

A lag-correlation analysis shows that for all the three study areas, the correlations between the monthly mean Niño-3.4 SSTAs and the late season landfalling numbers become statistically significant (at the 5% level) from June onward (Fig. 5), suggesting that the summer SSTAs can be a predictive signal for the number of late season landfalling tropical cyclones. Because the highest correlations exist between the late season Niño-3.4 SSTAs and the late season landfalling numbers, the simultaneous correlation approach of Wang and Chan (2002) is adopted in attempting the predictions. This approach also allows prediction with a longer lead time.

Figure 6a shows that for area 2, overall, that is, for all years between 1961 and 2000 considered together, there is a significant (at the 5% level) linear relationship between Niño-3.4 SSTA in the late season and the number of landfalling tropical cyclones in that season. The correlation coefficient r is 0.67. The relationship seems strongest for La Niña years alone, with r = 0.87 and significant at the 1% level. It is weaker for El Niño years alone albeit still significant (at the 5% level). Figure 6a also suggests a likely nonlinear relationship between Niño-3.4 SSTAs and landfalling activity for area 2 in the late season.

For area 3, a significant (at the 5% level) relationship between Niño-3.4 SSTAs and the number of landfalling tropical cyclones in the late season for 1961–2000 taken together is also found (r = 0.37). This is shown in Fig. 6b. However, the relation is not significant for El Niño years alone (r = 0.37) nor for a La Niña years alone (r = 0.1).

The case for area 4 is similar to that for area 3 (Fig. 6c) in that the overall correlation is significant at the 5% level, but no significant relationship is found for El Niño or La Niña years alone. The values of r are, respectively, 0.57 for the overall case, 0.07 in El Niño years, and 0.26 in La Niña years.

Thus, it seems predictions for areas 2, 3, and 4 in the late season may be attempted using predicted Niño-3.4 SSTAs, with the case of area 2 in La Niña years seeming to offer the most promise. This predictability should be a subject of further study, given the importance of advance information on the likely number of landfalls in disaster mitigation–related activities. For operational applications, say predicting the likely number of landfalls in the season several months ahead, use can be made of the predicted late season Niño-3.4 SSTAs available online (http://iri.columbia.edu/climate/ENSO/currentinfo/SSTtable.html). Alternatively, the development of empirical equations for predicting late season Niño-3.4 SSTAs can be attempted in the manner of Wang and Chan (2002). This should also be subject of further study.

Wang and Chan (2002) attribute the physical basis of the predictability they found in their study to the formation of an anomalous lower-tropospheric anticyclone (cyclone) over the Philippine Sea in the fall of El Niño (La Niña) years (Wang et al. 2000; Wang and Zhang 2002). This anomalous anticyclone (cyclone) develops as a result of the combined action of ENSO, tropical–extratropical as well as monsoon-ocean interaction. It suppresses (enhances) tropical cyclone formation in El Niño (La Niña) years. Given that many of the tropical cyclones affecting areas 2, 3, and 4 either spawn in or pass through the Philippine Sea, the suppressing/enhancing effects of this anomalous Philippine Sea anticyclone (cyclone) should also be a mechanism for the limited predictability found here.


6. Conclusions

Compared with neutral years, in the late season of El Niño years significantly fewer tropical cyclones can be expected to make landfall in the western North Pacific with the exception of Japan and the Korean Peninsula. In the late season of La Niña years, China and expect significantly more landfalls relative to neutral years. For other seasons and other regions, the difference does not appear to be as prominent.

ENSO's influence on landfalling behavior in the western North Pacific can in part be attributed to an eastward shift in tropical cyclone genesis position coupled with a weaker subtropical ridge in El Niño years resulting in generally fewer landfalls, compared with a westward shift in mean genesis position and strong subtropical ridge in La Niña years resulting in generally more landfalls.

The predictability of the number of landfalling tropical cyclones is important for planning and disaster-related activities, and a degree of predictability is offered by the resampling results of this study. In terms of Nino-3.4 SSTAs, the highest predictability is found for the number of tropical cyclones making landfall over China in the late season of La Niña years. The relationship between the number of landfalls in the western North Pacific and SSTAs merits further study so as to effect better predictions, as does the related issue of the development of empirical equations for predicting SSTAs.


Acknowledgments

We thank the two anonymous reviewers for their insightful comments which strengthened the clarity and usefulness of this note.


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Fig. 1. Delineation of the four study areas. Area 1: Japan and Korean Peninsula; area 2: China; area 3: Indochina and Malay Peninsula; area 4: the Philippines





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Fig. 2. Departure (D) of the mean number of landfalling tropical cyclones in El Niño and La Niña years from the mean in neutral years, normalized by the std dev of the number in neutral years. Jun–Aug (JJA; early season); Sep–Nov (SON; late season)





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Fig. 3. Composite circulation in the late season at 850 and 500 hPa for (top) El Niño, (middle) neutral, and (bottom) La Niña years. The tropical cyclone symbol and the dashed line represent, respectively, the mean tropical cyclone genesis position and the ITCZ





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Fig. 4. Tropical cyclone track density in the late season relative to neutral years for (a) El Niño and (b) La Niña years.





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Fig. 5. Correlations of the number of landfalling tropical cyclones in the late season with the monthly Niño-3.4 SSTAs. The 5% significance levels are indicated. 12(−1) on the abscissa denotes Dec in the preceding year





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Fig. 6. Scatter diagram showing the relationship between the mean Niño-3.4 SSTA and the mean number of landfalling tropical cyclones during the late season for (a) area 2, (b) area 3, and (c) area 4






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Table 1. Average number of landfalling tropical cyclones in El Niño, La Niña, and neutral years





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Table 2. Mean and the corresponding 95% confidence intervals of the number of landfalling tropical cyclones in the late season Sep–Nov for El Niño, La Niña, and neutral years





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Table 3. Results of permutation tests. Bold denotes significance at the 5% level. Entries are “p” values, and significance at the 5% level is achieved if “p” is less than 0.05




1The ESCAP/WMO Typhoon Committee was formed in 1968 to promote and coordinate efforts to minimize tropical cyclone damage in the ESCAP region. It has 14 members: Cambodia; China; Democratic People's Republic of Korea; Hong Kong, China; Japan; Lao People's Democratic Republic; Macau, China; Malaysia; the Phillippines; Republic of Korea; Singapore; Thailand; Socialist Republic of Vietnam; and the United States.

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Wenju Cai, Agus Santoso, Guojian Wang, Sang-Wook Yeh, Soon-Il An, Kim M. Cobb, Mat Collins, Eric Guilyardi, Fei-Fei Jin, Jong-Seong Kug, Matthieu Lengaigne, Michael J. McPhaden, Ken Takahashi, Axel Timmermann, Gabriel Vecchi, Masahiro Watanabe, Lixin Wu. (2015) ENSO and greenhouse warming. Nature Climate Change 5, 849-859.
Online publication date: 17-Aug-2015.
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Dymphna Nolasco-Javier, Lalit Kumar, Arlene Mae P. Tengonciang. (2015) Rapid appraisal of rainfall threshold and selected landslides in Baguio, Philippines. Natural Hazards.
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Yuxing Yang, Ruihuang Xie, Faming Wang, Fei Huang. (2015) Impacts of decaying eastern and central Pacific El Niños on tropical cyclone activities over the western North Pacific in summer. Theoretical and Applied Climatology.
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Yi-Ting Yang, Hung-Chi Kuo, Eric A. Hendricks, Yi-Chin Liu, Melinda S. Peng. (2015) Relationship between Typhoons with Concentric Eyewalls and ENSO in the Western North Pacific Basin. Journal of Climate 28:9, 3612-3623.
Online publication date: 1-May-2015.
Abstract . Full Text . PDF (2033 KB) 
Guodong Jia, Yang Bai, Xiaoqiang Yang, Luhua Xie, Gangjian Wei, Tingping Ouyang, Guoqiang Chu, Zhonghui Liu, Ping'an Peng. (2015) Biogeochemical evidence of Holocene East Asian summer and winter monsoon variability from a tropical maar lake in southern China. Quaternary Science Reviews 111, 51-61.
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Angela J. Colbert, Brian J. Soden, Ben P. Kirtman. (2015) The Impact of Natural and Anthropogenic Climate Change on Western North Pacific Tropical Cyclone Tracks. Journal of Climate 28:5, 1806-1823.
Online publication date: 1-Mar-2015.
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Lei Yang, Yan Du, Dongxiao Wang, Chunzai Wang, Xin Wang. (2015) Impact of intraseasonal oscillation on the tropical cyclone track in the South China Sea. Climate Dynamics 44, 1505-1519.
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J. Camp, M. Roberts, C. MacLachlan, E. Wallace, L. Hermanson, A. Brookshaw, A. Arribas, A. A. Scaife. (2015) Seasonal forecasting of tropical storms using the Met Office GloSea5 seasonal forecast system. Quarterly Journal of the Royal Meteorological Society, n/a-n/a.
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Wenju Cai, Guojian Wang, Agus Santoso, Michael J. McPhaden, Lixin Wu, Fei-Fei Jin, Axel Timmermann, Mat Collins, Gabriel Vecchi, Matthieu Lengaigne, Matthew H. England, Dietmar Dommenget, Ken Takahashi, Eric Guilyardi. (2015) Increased frequency of extreme La Niña events under greenhouse warming. Nature Climate Change 5, 132-137.
Online publication date: 26-Jan-2015.
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Haikun Zhao. (2015) A downscaling technique to simulate changes in western North Pacific tropical cyclone activity between two types of El Niño events. Theoretical and Applied Climatology.
Online publication date: 14-Jan-2015.
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Wei Mei, Shang-Ping Xie, Ming Zhao, Yuqing Wang. (2014) Forced and Internal Variability of Tropical Cyclone Track Density in the Western North Pacific. Journal of Climate 28:1, 143-167.
Online publication date: 1-Jan-2015.
Abstract . Full Text . PDF (6141 KB) . Supplemental Material 
Biranchi Kumar Mahala, Birendra Kumar Nayak, Pratap Kumar Mohanty. (2015) Impacts of ENSO and IOD on tropical cyclone activity in the Bay of Bengal. Natural Hazards 75, 1105-1125.
Online publication date: 1-Jan-2015.
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FengJiao Chen, YunFei Fu. (2015) Contribution of tropical cyclone rainfall at categories to total precipitation over the Western North Pacific from 1998 to 2007. Science China Earth Sciences.
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Yao Ha, Zhong Zhong. (2014) Features of tropical cyclone landfalls over East Asia corresponding to three types of Pacific warming decaying phase. Chinese Science Bulletin 59, 4130-4136.
Online publication date: 1-Nov-2014.
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Saleh A Wasimi, Kamal K Saha. (2014) An expert system to assess the landfall propensity of a tropical cyclone in Australia. Asia-Pacific World Congress on Computer Science and Engineering, 1-6.
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Ping-Mei Liew, Kai-Zheng Du, Ting-Wei Lin, I. Ting, Shu-Yue Huang. (2014) A possible middle Pleistocene seasonal deposit in Taipei Basin, Taiwan, inferred from pollen study. Quaternary International 349, 127-134.
Online publication date: 1-Oct-2014.
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Richard C. Y. Li, Wen Zhou. (2014) Interdecadal Change in South China Sea Tropical Cyclone Frequency in Association with Zonal Sea Surface Temperature Gradient. Journal of Climate 27:14, 5468-5480.
Online publication date: 1-Jul-2014.
Abstract . Full Text . PDF (2719 KB) 
Haikun Zhao, Liguang Wu. (2014) Inter-decadal shift of the prevailing tropical cyclone tracks over the western North Pacific and its mechanism study. Meteorology and Atmospheric Physics 125, 89-101.
Online publication date: 1-Jul-2014.
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Kamal K. Saha, Saleh A. Wasimi. (2014) An index to assess the propensity of landfall in Australia of a tropical cyclone. Natural Hazards 72, 1111-1121.
Online publication date: 1-Jun-2014.
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Chunxiang Li, Chunzai Wang. (2014) Simulated impacts of two types of ENSO events on tropical cyclone activity in the western North Pacific: large-scale atmospheric response. Climate Dynamics 42, 2727-2743.
Online publication date: 1-May-2014.
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Wan-Ru Huang, Johnny C. L. Chan. (2014) Dynamical downscaling forecasts of Western North Pacific tropical cyclone genesis and landfall. Climate Dynamics 42, 2227-2237.
Online publication date: 1-Apr-2014.
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Emmi Yonekura, Timothy M. Hall. (2014) ENSO Effect on East Asian Tropical Cyclone Landfall via Changes in Tracks and Genesis in a Statistical Model. Journal of Applied Meteorology and Climatology 53:2, 406-420.
Online publication date: 1-Feb-2014.
Abstract . Full Text . PDF (1713 KB) 
Han Zhang, Yuping Guan. (2014) Impacts of four types of ENSO events on tropical cyclones making landfall over mainland china based on three best-track datasets. Advances in Atmospheric Sciences 31, 154-164.
Online publication date: 1-Jan-2014.
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Wei Zhang, Yee Leung, Jinzhong Min. (2013) North Pacific Gyre Oscillation and the occurrence of western North Pacific tropical cyclones. Geophysical Research Letters 40, 5205-5211.
Online publication date: 16-Oct-2013.
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Hye-Mi Kim, Myong-In Lee, Peter J. Webster, Dongmin Kim, Jin Ho Yoo. (2013) A Physical Basis for the Probabilistic Prediction of the Accumulated Tropical Cyclone Kinetic Energy in the Western North Pacific. Journal of Climate 26:20, 7981-7991.
Online publication date: 1-Oct-2013.
Abstract . Full Text . PDF (1530 KB) 
Zaitao Pan, Bingcheng Wan, Zhiqiu Gao. (2013) Asymmetric and heterogeneous frequency of high and low record-breaking temperatures in China as an indication of warming climate becoming more extreme. Journal of Geophysical Research: Atmospheres 118, 6152-6164.
Online publication date: 27-Jun-2013.
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Richard C. Y. Li, Wen Zhou. (2013) Modulation of Western North Pacific Tropical Cyclone Activity by the ISO. Part II: Tracks and Landfalls. Journal of Climate 26:9, 2919-2930.
Online publication date: 1-May-2013.
Abstract . Full Text . PDF (4457 KB) 
Yao Ha, Zhong Zhong, Yimin Zhu, Yijia Hu. (2013) Contributions of Barotropic Energy Conversion to Northwest Pacific Tropical Cyclone Activity during ENSO. Monthly Weather Review 141:4, 1337-1346.
Online publication date: 1-Apr-2013.
Abstract . Full Text . PDF (1402 KB) 
Wei Zhang, Yee Leung, Yuanfei Wang. (2013) Cluster analysis of post-landfall tracks of landfalling tropical cyclones over China. Climate Dynamics 40, 1237-1255.
Online publication date: 1-Mar-2013.
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Tong He, Yang Chen, William Balsam, Xiaoke Qiang, Lianwen Liu, Jun Chen, Junfeng Ji. (2013) Carbonate leaching processes in the Red Clay Formation, Chinese Loess Plateau: Fingerprinting East Asian summer monsoon variability during the late Miocene and Pliocene. Geophysical Research Letters 40, 194-198.
Online publication date: 16-Jan-2013.
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Yao Ha, Zhong Zhong, Yijia Hu, Xiuqun Yang. (2013) Influences of ENSO on Western North Pacific Tropical Cyclone Kinetic Energy and Its Meridional Transport. Journal of Climate 26:1, 322-332.
Online publication date: 1-Jan-2013.
Abstract . Full Text . PDF (1187 KB) 
Jianyun Gao, Tim Li. (2012) Interannual variation of multiple tropical cyclone events in the western North Pacific. Advances in Atmospheric Sciences 29, 1279-1291.
Online publication date: 1-Nov-2012.
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Shanshan Wang, Yuping Guan, Tingzhao Guan, Jianping Huang. (2012) Oscillation in frequency of tropical cyclones passing Taiwan and Hainan Islands and the relationship with summer monsoon. Chinese Journal of Oceanology and Limnology 30, 966-973.
Online publication date: 1-Nov-2012.
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Wei Zhang, H.-F. Graf, Yee Leung, Michael Herzog. (2012) Different El Niño Types and Tropical Cyclone Landfall in East Asia. Journal of Climate 25:19, 6510-6523.
Online publication date: 1-Oct-2012.
Abstract . Full Text . PDF (3669 KB) 
Qiang Zhang, Wei Zhang, Xiaoqin Lu, Yongqin David Chen. (2012) Landfalling tropical cyclones activities in the south China: intensifying or weakening?. International Journal of Climatology 32:10.1002/joc.v32.12, 1815-1824.
Online publication date: 1-Oct-2012.
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Richard C. Y. Li, Wen Zhou. (2012) Changes in Western Pacific Tropical Cyclones Associated with the El Niño–Southern Oscillation Cycle. Journal of Climate 25:17, 5864-5878.
Online publication date: 1-Sep-2012.
Abstract . Full Text . PDF (4127 KB) 
Lei Wang, Qiongwan Zhang, Weibiao Li. (2012) Diagnosis of the ENSO modulation of tropical cyclogenesis over the southern South China Sea using a genesis potential index. Acta Oceanologica Sinica 31, 54-68.
Online publication date: 1-Sep-2012.
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Kelvin T. F. Chan, Johnny C. L. Chan. (2012) Size and Strength of Tropical Cyclones as Inferred from QuikSCAT Data. Monthly Weather Review 140:3, 811-824.
Online publication date: 1-Mar-2012.
Abstract . Full Text . PDF (2785 KB) 
Andy Zung-Ching Goh, Johnny C. L. Chan. (2012) Variations and prediction of the annual number of tropical cyclones affecting Korea and Japan. International Journal of Climatology 32:10.1002/joc.v32.2, 178-189.
Online publication date: 1-Feb-2012.
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Hoang Anh Nguyen-Thi, Jun Matsumoto, Thanh Ngo-Duc, Nobuhiko Endo. (2012) A Climatological Study of Tropical Cyclone Rainfall in Vietnam. SOLA 8, 41-44.
Online publication date: 1-Jan-2012.
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Wenju Cai, Peter van Rensch, Tim Cowan. (2011) Influence of Global-Scale Variability on the Subtropical Ridge over Southeast Australia. Journal of Climate 24:23, 6035-6053.
Online publication date: 1-Dec-2011.
Abstract . Full Text . PDF (5669 KB) 
Cuicui TIAN, Kefu YU. (2011) ADVANCES IN THE STUDY OF PALEOTEMPESTOLOGY. Marine Geology & Quaternary Geology 31, 171-178.
Online publication date: 23-Sep-2011.
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Guanghua Chen. (2011) How Does Shifting Pacific Ocean Warming Modulate on Tropical Cyclone Frequency over the South China Sea?. Journal of Climate 24:17, 4695-4700.
Online publication date: 1-Sep-2011.
Abstract . Full Text . PDF (988 KB) 
Emmi Yonekura, Timothy M. Hall. (2011) A Statistical Model of Tropical Cyclone Tracks in the Western North Pacific with ENSO-Dependent Cyclogenesis. Journal of Applied Meteorology and Climatology 50:8, 1725-1739.
Online publication date: 1-Aug-2011.
Abstract . Full Text . PDF (4311 KB) 
Chi-Cherng Hong, Yuan-Hsing Li, Tim Li, Ming-Ying Lee. (2011) Impacts of central Pacific and eastern Pacific El Niños on tropical cyclone tracks over the western North Pacific. Geophysical Research Letters 38, n/a-n/a.
Online publication date: 1-Aug-2011.
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Hye-Mi Kim, Peter J. Webster, Judith A. Curry. (2011) Modulation of North Pacific Tropical Cyclone Activity by Three Phases of ENSO. Journal of Climate 24:6, 1839-1849.
Online publication date: 1-Mar-2011.
Abstract . Full Text . PDF (2228 KB) 
Hiroyuki Murakami, Bin Wang, Akio Kitoh. (2011) Future Change of Western North Pacific Typhoons: Projections by a 20-km-Mesh Global Atmospheric Model. Journal of Climate 24:4, 1154-1169.
Online publication date: 1-Feb-2011.
Abstract . Full Text . PDF (4201 KB) 
Ruifen Zhan, Yuqing Wang, Xiaotu Lei. (2011) Contributions of ENSO and East Indian Ocean SSTA to the Interannual Variability of Northwest Pacific Tropical Cyclone Frequency. Journal of Climate 24:2, 509-521.
Online publication date: 1-Jan-2011.
Abstract . Full Text . PDF (1554 KB) 
Haikun ZHAO, Liguang WU, Weican ZHOU. (2011) Interannual Changes of Tropical Cyclone Intensity in the Western North Pacific. Journal of the Meteorological Society of Japan 89, 243-253.
Online publication date: 1-Jan-2011.
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Doo-Sun R. Park, Chang-Hoi Ho, Joo-Hong Kim, Hyeong-Seog Kim. (2011) Strong landfall typhoons in Korea and Japan in a recent decade. Journal of Geophysical Research 116.
Online publication date: 1-Jan-2011.
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Haikun Zhao, Liguang Wu, Weican Zhou. (2010) Assessing the influence of the ENSO on tropical cyclone prevailing tracks in the western North Pacific. Advances in Atmospheric Sciences 27, 1361-1371.
Online publication date: 1-Nov-2010.
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Yizhou Yin, Marco Gemmer, Yong Luo, Yan Wang. (2010) Tropical cyclones and heavy rainfall in Fujian Province, China. Quaternary International 226, 122-128.
Online publication date: 1-Oct-2010.
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Ki-Seon Choi, Hi-Ryong Byun. (2010) Possible relationship between western North Pacific tropical cyclone activity and Arctic Oscillation. Theoretical and Applied Climatology 100, 261-274.
Online publication date: 1-May-2010.
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Andy Zung-Ching Goh, Johnny C. L. Chan. (2010) An Improved Statistical Scheme for the Prediction of Tropical Cyclones Making Landfall in South China. Weather and Forecasting 25:2, 587-593.
Online publication date: 1-Apr-2010.
Abstract . Full Text . PDF (776 KB) 
Ki-Seon Choi, Chun-Chieh Wu, Eun-Jeong Cha. (2010) Change of tropical cyclone activity by Pacific-Japan teleconnection pattern in the western North Pacific. Journal of Geophysical Research 115.
Online publication date: 1-Jan-2010.
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Guanghua Chen, Chi-Yung Tam. (2010) Different impacts of two kinds of Pacific Ocean warming on tropical cyclone frequency over the western North Pacific. Geophysical Research Letters 37, n/a-n/a.
Online publication date: 1-Jan-2010.
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Hisayuki Kubota, Bin Wang. (2010) How Much Do Tropical Cyclones Affect Seasonal and Interannual Rainfall Variability over the Western North Pacific?. Journal of Climate 22:20, 5495-5510.
Online publication date: 1-Oct-2009.
Abstract . Full Text . PDF (2944 KB) 
Andy Zung-Ching Goh, Johnny C. L. Chan. (2009) Interannual and interdecadal variations of tropical cyclone activity in the South China Sea. International Journal of Climatology, n/a-n/a.
Online publication date: 1-Jan-2009.
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Ki-Seon Choi, Baek-Jo Kim, Do-Woo Kim, Hi-Ryong Byun. (2009) Interdecadal variation of tropical cyclone making landfall over the Korean Peninsula. International Journal of Climatology, n/a-n/a.
Online publication date: 1-Jan-2009.
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Ki-Seon Choi, Baek-Jo Kim, Hi-Ryong Byun. (2008) Relationship between Korean Peninsula Landfalling Tropical Cyclones and Interannual Climate Variabilities. Journal of the Korean earth science society 29, 375-385.
Online publication date: 30-Sep-2008.
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Kin Sik Liu, Johnny C. L. Chan. (2010) Interdecadal Variability of Western North Pacific Tropical Cyclone Tracks. Journal of Climate 21:17, 4464-4476.
Online publication date: 1-Sep-2008.
Abstract . Full Text . PDF (1963 KB) 
Satoshi Iizuka, Tomonori Matsuura. (2008) ENSO and Western North Pacific tropical cyclone activity simulated in a CGCM. Climate Dynamics 30, 815-830.
Online publication date: 1-Jun-2008.
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Joo-Hong Kim, Chang-Hoi Ho, Hyeong-Seog Kim, Chung-Hsiung Sui, Seon Ki Park. (2010) Systematic Variation of Summertime Tropical Cyclone Activity in the Western North Pacific in Relation to the Madden–Julian Oscillation. Journal of Climate 21:6, 1171-1191.
Online publication date: 1-Mar-2008.
Abstract . Full Text . PDF (4414 KB) 
A. Wada, J. C. L. Chan. (2008) Relationship between typhoon activity and upper ocean heat content. Geophysical Research Letters 35.
Online publication date: 1-Jan-2008.
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Suzana J. Camargo, Kerry A. Emanuel, Adam H. Sobel. (2010) Use of a Genesis Potential Index to Diagnose ENSO Effects on Tropical Cyclone Genesis. Journal of Climate 20:19, 4819-4834.
Online publication date: 1-Oct-2007.
Abstract . Full Text . PDF (2244 KB) 
HuiJun Wang, JianQi Sun, Ke Fan. (2007) Relationships between the North Pacific Oscillation and the typhoon/hurricane frequencies. Science in China Series D: Earth Sciences 50, 1409-1416.
Online publication date: 1-Sep-2007.
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Suzana J. Camargo, Andrew W. Robertson, Scott J. Gaffney, Padhraic Smyth, Michael Ghil. (2010) Cluster Analysis of Typhoon Tracks. Part II: Large-Scale Circulation and ENSO. Journal of Climate 20:14, 3654-3676.
Online publication date: 1-Jul-2007.
Abstract . Full Text . PDF (5284 KB) 
James M. Tolan. (2007) El Niño-Southern Oscillation impacts translated to the watershed scale: Estuarine salinity patterns along the Texas Gulf Coast, 1982 to 2004. Estuarine, Coastal and Shelf Science 72, 247-260.
Online publication date: 1-Mar-2007.
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HuiJun Wang, Ke Fan. (2007) Relationship between the Antarctic oscillation in the western North Pacific typhoon frequency. Chinese Science Bulletin 52, 561-565.
Online publication date: 1-Feb-2007.
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Tetsuo NAKAZAWA, Kavirajan RAJENDRAN. (2007) Relationship between Tropospheric Circulation over the Western North Pacific and Tropical Cyclone Approach/Landfall on Japan. Journal of the Meteorological Society of Japan 85, 101-114.
Online publication date: 1-Jan-2007.
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Tsing-Chang Chen, Shih-Yu Wang, Ming-Cheng Yen. (2010) Interannual Variation of the Tropical Cyclone Activity over the Western North Pacific. Journal of Climate 19:21, 5709-5720.
Online publication date: 1-Nov-2006.
Abstract . Full Text . PDF (1952 KB) 
Emily A. Fogarty, James B. Elsner, Thomas H. Jagger, Kam-biu Liu, Kin-sheun Louie. (2006) Variations in typhoon landfalls over China. Advances in Atmospheric Sciences 23, 665-677.
Online publication date: 1-Oct-2006.
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Joo-Hong Kim, Chang-Hoi Ho, Min-Hee Lee, Jee-Hoon Jeong, Deliang Chen. (2006) Large increase in heavy rainfall associated with tropical cyclone landfalls in Korea after the late 1970s. Geophysical Research Letters 33.
Online publication date: 1-Jan-2006.
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H. Fudeyasu, S. Iizuka, T. Matsuura. (2006) Impact of ENSO on landfall characteristics of tropical cyclones over the western North Pacific during the summer monsoon season. Geophysical Research Letters 33.
Online publication date: 1-Jan-2006.
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Joo-Hong Kim, Chang-Hoi Ho, Chung-Hsiung Sui, Seon Ki Park. (2010) Dipole Structure of Interannual Variations in Summertime Tropical Cyclone Activity over East Asia. Journal of Climate 18:24, 5344-5356.
Online publication date: 1-Dec-2005.
Abstract . Full Text . PDF (2445 KB) 
Suzana J. Camargo, Adam H. Sobel. (2010) Western North Pacific Tropical Cyclone Intensity and ENSO. Journal of Climate 18:15, 2996-3006.
Online publication date: 1-Aug-2005.
Abstract . Full Text . PDF (764 KB)