An Improved Statistical Scheme for the Prediction of Tropical Cyclones Making Landfall in South China

2010 ◽  
Vol 25 (2) ◽  
pp. 587-593 ◽  
Author(s):  
Andy Zung-Ching Goh ◽  
Johnny C. L. Chan
Keyword(s):  
South China Sea ◽  
Tropical Cyclones ◽  
South China ◽  
North Pacific ◽  
Western North Pacific ◽  
Empirical Orthogonal Functions ◽  
Annual Number ◽  
Orthogonal Functions ◽  
Factors Affecting ◽  
Using Data

Abstract This study describes an improved statistical scheme for predicting the annual number of tropical cyclones (TCs) making landfall along the coast of south China using data from 1965 to 2005. Based on the factors affecting TC behavior inside the South China Sea (SCS), those responsible for TCs making landfall are identified. Equations are then developed using the coefficients of empirical orthogonal functions of these factors to predict, in April, the number of these TCs in the early (May–August) and late (September–December) seasons, and in June, the number in the period between July to December. The new scheme achieves a forecast skill of 51% over climatology, or an improvement of about 11% compared to previous studies, when predicting landfalling TC for the whole season, and it seems to be able to capture the decrease in their number in the recent years. Analyses of the flow patterns suggest that the conditions inside the SCS are apparently the major factor affecting the number of landfalling TCs. In years in which this number is above normal, conditions inside the SCS are favorable for TC genesis, and vice versa. The strength of the 500-hPa subtropical high also seems to be a factor in determining whether TCs from the western North Pacific (WNP) could enter the SCS and make landfall.

Hong Kong Harbour as a Typhoon Haven

1975 ◽  
Vol 28 (2) ◽  
pp. 202-208
Author(s):  
D. J. Malone
Keyword(s):  
Hong Kong ◽  
South China Sea ◽  
Tropical Cyclones ◽  
South China ◽  
North Pacific ◽  
Western North Pacific ◽  
The South China Sea ◽  
China Sea ◽  
Size And Shape ◽  
The Many

In the western North Pacific and the South China Sea the typhoon is one of the most fearsome elements a ship can encounter and one of the major decisions that must often be considered is whether to seek, or remain in, the shelter of a harbour or to take evasive action and ride out the storm at sea. With the many variables involved, such as topography, the different directions of approach of tropical cyclones, type of holding ground, size and shape of the ship, &c, it is often not possible to stamp a particular harbour as safe or unsafe. This paper deals with some of the many factors that a Master should consider when deciding to remain in, or sail from, Hong Kong on the approach of a typhoon.

scholarly journals Two Distinctive Processes for Abnormal Spring to Summer Transition over the South China Sea

2017 ◽  
Vol 30 (23) ◽  
pp. 9665-9678 ◽  
Author(s):  
Renguang Wu ◽  
Zhuoqi He
Keyword(s):  
South China Sea ◽  
South China ◽  
North Pacific ◽  
Western North Pacific ◽  
The South China Sea ◽  
The South ◽  
Maritime Continent ◽  
China Sea ◽  
Tropical Western North Pacific ◽  
Sst Anomalies

The period from April to June signifies the transition from spring to summer over the South China Sea (SCS). The present study documents two distinct processes for abnormal spring to summer transition over the SCS. One process is related to large-scale sea surface temperature (SST) anomalies in the tropical Indo-Pacific region. During spring of La Niña decaying years, negative SST anomalies in the equatorial central Pacific (ECP) and the southwestern tropical Indian Ocean (TIO) coexist with positive SST anomalies in the tropical western North Pacific. Negative ECP SST anomalies force an anomalous Walker circulation, negative southwestern TIO SST anomalies induce anomalous cross-equatorial flows from there, and positive tropical western North Pacific SST anomalies produce a Rossby wave–type response to the west. Together, they contribute to enhanced convection and an anomalous lower-level cyclone over the SCS, leading to an advanced transition to summer there. The other process is related to regional air–sea interactions around the Maritime Continent. Preceding positive ECP SST anomalies induce anomalous descent around the Maritime Continent, leading to SST increase in the SCS and southeast TIO. An enhanced convection region moves eastward over the south TIO during spring and reaches the area northwest of Australia in May. This enhances descent over the SCS via an anomalous cross-equatorial overturning circulation and contributes to further warming in the SCS. The SST warming in turn induces convection over the SCS, leading to an accelerated transition to summer. Analysis shows that the above two processes are equally important during 1979–2015.

scholarly journals Climate shift of the South China Sea summer monsoon onset in 1993/1994 and its physical causes

2019 ◽  
Vol 54 (3-4) ◽  
pp. 1819-1827
Author(s):  
Ailan Lin ◽  
Renhe Zhang
Keyword(s):  
South China Sea ◽  
South China ◽  
North Pacific ◽  
Early Onset ◽  
Western North Pacific ◽  
The South China Sea ◽  
The South ◽  
Climate Shift ◽  
China Sea ◽  
Zonal Winds

AbstractThe characteristics of anomalous circulations during spring associated with the climate shift of the South China Sea summer monsoon (SCSSM) onset in 1993/1994 and its physical causes are investigated. It is found that the interdecadal shift of SCSSM onset happened in 1993/1994 is related closely to the 850 hPa zonal wind anomalies over the area around Kalimantan Island. Easterly (westerly) anomalies over Kalimantan Island enhance (weaken) subtropical high over the western North Pacific, leading to the late (early) onset of SCSSM in 1979–1993 (1994–2013). The sea surface temperature anomalies (SSTAs) in the key region 140°–150° E, 5° S–2.5° N influence the interdecadal change of zonal winds over Kalimantan Island. The positive SSTAs over this key region in 1994–2013 force convergence toward the region at low-level and form significant westerly anomalies near Kalimantan Island located to the west of the key region. The negative anomalies of meridional gradient of zonal winds over the South China Sea region increase the atmospheric vorticity over there significantly and result in the weakening and retreating eastward of the subtropical high over the western North Pacific, which is conducive to the early onset of SCSSM.

scholarly journals Predictability of Tropical Cyclone Intensity over the Western North Pacific Using the IBTrACS Dataset

2018 ◽  
Vol 146 (9) ◽  
pp. 2741-2755 ◽  
Author(s):  
Quanjia Zhong ◽  
Jianping Li ◽  
Lifeng Zhang ◽  
Ruiqiang Ding ◽  
Baosheng Li
Keyword(s):  
Spatial Distribution ◽  
Life Cycle ◽  
Tropical Cyclone ◽  
South China Sea ◽  
South China ◽  
North Pacific ◽  
Western North Pacific ◽  
Maximum Intensity ◽  
Tropical Cyclone Intensity ◽  
Cyclone Intensity

Abstract The predictability limits of tropical cyclone (TC) intensity over the western North Pacific (WNP) are investigated using TC best track data. The results show that the predictability limit of the TC minimum central pressure (MCP) is ~102 h, comparable to that of the TC maximum sustained wind (MSW). The spatial distribution of the predictability limit of the TC MCP over the WNP is similar to that of the TC MSW, and both gradually decrease from the eastern WNP (EWNP) to the South China Sea (SCS). The predictability limits of the TC MCP and MSW are relatively high over the southeastern WNP where the modified accumulated cyclone energy (MACE) is relatively large, whereas they are relatively low over the SCS where the MACE is relatively small. The spatial patterns of the TC lifetime and the lifetime maximum intensity (LMI) are similar to that of the TC MACE. Strong and long-lived TCs, which have relatively long predictability, mainly form in the southwestern WNP. In contrast, weak and short-lived TCs, which have relatively short predictability, mainly form in the SCS. In addition to the dependence of the predictability limit on genesis location, the predictability limits of TC intensity also evolve in the TC life cycle. The predictability limit of the TC MCP (MSW) gradually decreases from 102 (108) h at genesis time (00 h) to 54 (84) h 4 days after TC genesis.

Sign in / Sign up

Export Citation Format

Share Document