scholarly journals Different El Niño Types and Tropical Cyclone Landfall in East Asia

2012 ◽  
Vol 25 (19) ◽  
pp. 6510-6523 ◽  
Author(s):  
Wei Zhang ◽  
H.-F. Graf ◽  
Yee Leung ◽  
Michael Herzog

Abstract This study examines whether there exist significant differences in tropical cyclone (TC) landfall between central Pacific (CP) El Niño, eastern Pacific (EP) El Niño, and La Niña during the peak TC season (June–October) and how and to what extent CP El Niño influences TC landfall over East Asia for the period 1961–2009. The peak TC season is subdivided into summer [June–August (JJA)] and autumn [September–October (SO)]. The results are summarized as follows: (i) during the summer of CP El Niño years, TCs are more likely to make landfall over East Asia because of a strong easterly steering flow anomaly induced by the westward shift of the subtropical high and northward-shifted TC genesis. In particular, TCs have a greater probability of making landfall over Japan and Korea during the summer of CP El Niño years. (ii) In the autumn of CP El Niño years, TC landfall in most areas of East Asia, especially Indochina, the Malay Peninsula, and the Philippines, is likely to be suppressed because the large-scale circulation resembles that of EP El Niño years. (iii) During the whole peak TC season [June–October (JJASO)] of CP El Niño years, TCs are more likely to make landfall over Japan and Korea. TC landfall in East Asia as a whole has an insignificant association with CP El Niño during the peak TC season. In addition, more (less) TCs are likely to make landfall in China, Indochina, the Malay Peninsula, and the Philippines during the peak TC season of La Niña (EP El Niño) years.

2016 ◽  
Vol 29 (5) ◽  
pp. 1877-1897 ◽  
Author(s):  
Irenea L. Corporal-Lodangco ◽  
Lance M. Leslie ◽  
Peter J. Lamb

Abstract This study investigates the El Niño–Southern Oscillation (ENSO) contribution to Philippine tropical cyclone (TC) variability, for a range of quarterly TC metrics. Philippine TC activity is found to depend on both ENSO quarter and phase. TC counts during El Niño phases differ significantly from neutral phases in all quarters, whereas neutral and La Niña phases differ only in January–March and July–September. Differences in landfalls between neutral and El Niño phases are significant in January–March and October–December and in January–March for neutral and La Niña phases. El Niño and La Niña landfalls are significantly different in April–June and October–December. Philippine neutral and El Niño TC genesis cover broader longitude–latitude ranges with similar long tracks, originating farther east in the western North Pacific. In El Niño phases, the mean eastward displacement of genesis locations and more recurving TCs reduce Philippine TC frequencies. Proximity of La Niña TC genesis to the Philippines and straight-moving tracks in April–June and October–December increase TC frequencies and landfalls. Neutral and El Niño accumulated cyclone energy (ACE) values are above average, except in April–June of El Niño phases. Above-average quarterly ACE in neutral years is due to increased TC frequencies, days, and intensities, whereas above-average El Niño ACE in July–September is due to increased TC days and intensities. Below-average La Niña ACE results from fewer TCs and shorter life cycles. Longer TC durations produce slightly above-average TC days in July–September El Niño phases. Fewer TCs than neutral years, as well as shorter TC durations, imply less TC days in La Niña phases. However, above-average TC days occur in October–December as a result of higher TC frequencies.


2020 ◽  
Vol 47 (15) ◽  
Author(s):  
Shan He ◽  
Jin‐Yi Yu ◽  
Song Yang ◽  
Shih‐Wei Fang
Keyword(s):  
El Niño ◽  
El Nino ◽  
La Niña ◽  
La Nina ◽  

2014 ◽  
Vol 53 (2) ◽  
pp. 406-420 ◽  
Author(s):  
Emmi Yonekura ◽  
Timothy M. Hall

AbstractImprovements on a statistical tropical cyclone (TC) track model in the western North Pacific Ocean are described. The goal of the model is to study the effect of El Niño–Southern Oscillation (ENSO) on East Asian TC landfall. The model is based on the International Best-Track Archive for Climate Stewardship (IBTrACS) database of TC observations for 1945–2007 and employs local regression of TC formation rates and track increments on the Niño-3.4 index and seasonally varying climate parameters. The main improvements are the inclusion of ENSO dependence in the track propagation and accounting for seasonality in both genesis and tracks. A comparison of simulations of the 1945–2007 period with observations concludes that the model updates improve the skill of this model in simulating TCs. Changes in TC genesis and tracks are analyzed separately and cumulatively in simulations of stationary extreme ENSO states. ENSO effects on regional (100-km scale) landfall are attributed to changes in genesis and tracks. The effect of ENSO on genesis is predominantly a shift in genesis location from the southeast in El Niño years to the northwest in La Niña years, resulting in higher landfall rates for the East Asian coast during La Niña. The effect of ENSO on track propagation varies seasonally and spatially. In the peak activity season (July–October), there are significant changes in mean tracks with ENSO. Landfall-rate changes from genesis– and track–ENSO effects in the Philippines cancel out, while coastal segments of Vietnam, China, the Korean Peninsula, and Japan show enhanced La Niña–year increases.


2009 ◽  
Vol 22 (14) ◽  
pp. 3877-3893 ◽  
Author(s):  
Savin S. Chand ◽  
Kevin J. E. Walsh

Abstract This study examines the variations in tropical cyclone (TC) genesis positions and their subsequent tracks for different phases of the El Niño–Southern Oscillation (ENSO) phenomenon in the Fiji, Samoa, and Tonga region (FST region) using Joint Typhoon Warning Center best-track data. Over the 36-yr period from 1970/71 to 2005/06, 122 cyclones are observed in the FST region. A large spread in the genesis positions is noted. During El Niño years, genesis is enhanced east of the date line, extending from north of Fiji to over Samoa, with the highest density centered around 10°S, 180°. During neutral years, maximum genesis occurs immediately north of Fiji with enhanced genesis south of Samoa. In La Niña years, there are fewer cyclones forming in the region than during El Niño and neutral years. During La Niña years, the genesis positions are displaced poleward of 12°S, with maximum density centered around 15°S, 170°E and south of Fiji. The cyclone tracks over the FST region are also investigated using cluster analysis. Tracks during the period 1970/71–2005/06 are conveniently described using three separate clusters, with distinct characteristics associated with different ENSO phases. Finally, the role of large-scale environmental factors affecting interannual variability of TC genesis positions and their subsequent tracks in the FST region are investigated. Favorable genesis positions are observed where large-scale environments have the following seasonal average thresholds: (i) 850-hPa cyclonic relative vorticity between −16 and −4 (×10−6 s−1), (ii) 200-hPa divergence between 2 and 8 (×10−6 s−1), and (iii) environmental vertical wind shear between 0 and 8 m s−1. The subsequent TC tracks are observed to be steered by mean 700–500-hPa winds.


2016 ◽  
Vol 29 (4) ◽  
pp. 1391-1415 ◽  
Author(s):  
Wei Zhang ◽  
Gabriel A. Vecchi ◽  
Hiroyuki Murakami ◽  
Thomas Delworth ◽  
Andrew T. Wittenberg ◽  
...  

Abstract This study aims to assess whether, and the extent to which, an increase in atmospheric resolution of the Geophysical Fluid Dynamics Laboratory (GFDL) Forecast-Oriented Low Ocean Resolution version of CM2.5 (FLOR) with 50-km resolution and the High-Resolution FLOR (HiFLOR) with 25-km resolution improves the simulation of the El Niño–Southern Oscillation (ENSO)–tropical cyclone (TC) connections in the western North Pacific (WNP). HiFLOR simulates better ENSO–TC connections in the WNP including TC track density, genesis, and landfall than FLOR in both long-term control experiments and sea surface temperature (SST)- and sea surface salinity (SSS)-restoring historical runs (1971–2012). Restoring experiments are performed with SSS and SST restored to observational estimates of climatological SSS and interannually varying monthly SST. In the control experiments of HiFLOR, an improved simulation of the Walker circulation arising from more realistic SST and precipitation is largely responsible for its better performance in simulating ENSO–TC connections in the WNP. In the SST-restoring experiments of HiFLOR, more realistic Walker circulation and steering flow during El Niño and La Niña are responsible for the improved simulation of ENSO–TC connections in the WNP. The improved simulation of ENSO–TC connections with HiFLOR arises from a better representation of SST and better responses of environmental large-scale circulation to SST anomalies associated with El Niño or La Niña. A better representation of ENSO–TC connections in HiFLOR can benefit the seasonal forecasting of TC genesis, track, and landfall; improve understanding of the interannual variation of TC activity; and provide better projection of TC activity under climate change.


2017 ◽  
Vol 30 (7) ◽  
pp. 2621-2638 ◽  
Author(s):  
Chen Li ◽  
Jing-Jia Luo ◽  
Shuanglin Li

The impacts of different types of El Niño–Southern Oscillation (ENSO) on the interannual negative correlation (seesaw) between the Somali cross-equatorial flow (CEF) and the Maritime Continent (MC) CEF during boreal summer (June–August) are investigated using the ECMWF twentieth-century reanalysis (ERA-20C) dataset and numerical experiments with a global atmospheric model [the Met Office Unified Model global atmosphere, version 6 (UM-GA6)]. The results suggest that ENSO plays a prominent role in governing the CEF-seesaw relation. A high positive correlation (0.86) exists between the MC CEF and Niño-3.4 index and also in the case of eastern Pacific (EP) El Niño, central Pacific (CP) El Niño, EP La Niña, and CP La Niña events. In contrast, a negative correlation (−0.35) exists between the Somali CEF and Niño-3.4 index, and this negative relation is significant only in the EP El Niño years. Further, the variation of the MC CEF is highly correlated with the local north–south sea surface temperature (SST) gradient, while the variation of the Somali CEF displays little relation with the local SST gradient. The Somali CEF may be remotely influenced by ENSO. The model results confirm that the EP El Niño plays a major role in causing the weakened Somali CEF via modifying the Walker cell. However, the impact of the EP El Niño on the Somali CEF differs with different seasonal background. It is also found that the interannual CEF seesaw displays a multidecadal change before and after the 1950s, which is linked with the multidecadal strengthening of the intensity of the EP ENSO.


2017 ◽  
Author(s):  
Shuyun Zhao ◽  
Hua Zhang ◽  
Bing Xie

Abstract. It is reported in previous studies that El Niño-South Oscillation (ENSO) influences not only the summer monsoon, but also the winter monsoon over East Asia. This contains some clues that ENSO may affect the winter haze pollution of China, which has become a serious problem in recent decades, through influencing the winter climate of East Asia. In this work, we explore the effects of ENSO on the winter (from December to February) haze pollution of China statistically and numerically. Statistical results reveal that the haze days of southern China tend to be less (more) than normal in El Niño (La Niña) winter; whereas the winter haze days of northern and eastern China have no significant relationship with ENSO. Results from numerical simulations show that under the emission level of aerosols for the year 2010, the winter-average atmospheric contents of anthropogenic aerosols over southern China are generally more (less) than normal in El Niño (La Niña) winter. It is because that the transports of aerosols from South and Southeast Asia to southern China are enhanced (weakened), which mask the better (worse) scavenging conditions for aerosols in El Niño (La Niña) winter. The probability density function (PDF) of the simulated daily surface concentrations of aerosols over southern China indicates that the region tends to have less clean and moderate (heavy) haze days, but more heavy (moderate) haze days in El Niño (La Niña) winter.


1999 ◽  
Vol 15 (4) ◽  
pp. 437-449 ◽  
Author(s):  
Masatoshi Yasuda ◽  
Jun Matsumoto ◽  
Noriyuki Osada ◽  
San'ei Ichikawa ◽  
Naoki Kachi ◽  
...  

The mechanism of general flowering in Dipterocarpaceae in the Malay Peninsula is revealed through field survey and meteorological data analyses. The regions of general flowering coincide with those which experienced a low night-time temperature (LNT) c. 2 mo before flowering. This supports the hypothesis that low air temperature induces the development of floral buds of dipterocarps. LNT was found to be caused by radiative cooling during dry spells in winter when the northern subtropical ridge (STR) occasionally migrates southwards with a dry air mass into the equatorial region. LNT events usually occur in La Niña episodes, not in El Niño episodes as believed previously. This is because the southward migration of the STR is associated with the intensification of local meridional Hadley Circulation in the western Pacific, which is strengthened in a La Niña episode. Results suggest that El Niño-like climate change in increased atmospheric carbon dioxide concentrations may be critical for the tropical rain forest biome in south-east Asia.


2017 ◽  
Vol 197 ◽  
pp. 150-166 ◽  
Author(s):  
Upal Saha ◽  
Devendraa Siingh ◽  
S.K. Midya ◽  
R.P. Singh ◽  
A.K. Singh ◽  
...  

2012 ◽  
Vol 25 (21) ◽  
pp. 7702-7722 ◽  
Author(s):  
Yuan Yuan ◽  
Song Yang

Using multiple datasets and a partial correlation method, the authors analyze the different impacts of eastern Pacific (EP) and central Pacific (CP) El Niño on East Asian climate, focusing on the features from El Niño developing summer to El Niño decaying summer. Unlike the positive–negative–positive (+/−/+) anomalous precipitation pattern over East Asia and the equatorial Pacific during EP El Niño, an anomalous −/+/− rainfall pattern appears during CP El Niño. The anomalous dry conditions over southeastern China and the northwestern Pacific during CP El Niño seem to result from the anomalous low-level anticyclone over southern China and the South China Sea, which is located more westward than the Philippine Sea anticyclone during EP El Niño. The continuous anomalous sinking motion over southeastern China, as part of the anomalous Walker circulation associated with CP El Niño, also contributes to these dry conditions. During the developing summer, the impact of CP El Niño on East Asian climate is more significant than the influence of EP El Niño. During the decaying summer, however, EP El Niño exerts a stronger influence on East Asia, probably due to the long-lasting anomalous warming over the tropical Indian Ocean accompanying EP El Niño. Temperatures over portions of East Asia and the northwestern Pacific tend to be above normal during EP El Niño but below normal from the developing autumn to the next spring during CP El Niño. A possible reason is the weakened (enhanced) East Asian winter monsoon related to EP (CP) El Niño.


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