scholarly journals A Comparative Modeling Study of Supertyphoons Mangkhut and Yutu (2018) Past the Philippines with Ocean-Coupled HWRF

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1055
Author(s):  
Thi-Chinh Nguyen ◽  
Ching-Yuang Huang

The ocean-coupled Hurricane Weather Research and Forecasting (HWRF) system was used to investigate the evolution of Supertyphoons Mangkhut and Yutu (2018) over the Philippines Sea and near landfall in the northern Philippines. The simulation results indicate that Mangkhut at a deepening stage has a smaller track sensitivity to the use of different physics schemes but greater intensity sensitivity, which becomes reversed for Yutu at a weakening stage. When both upstream tracks are well simulated with some specific suite of physics schemes, sensitivity experiments indicate that both track deviations near the northern Philippines are only weakly modified by the air–sea interaction (ocean-coupled or uncoupled processes), the topographic effects of the Philippines terrain (retained or not), and the initial ocean temperature change along both typhoon tracks. The interactions between the internal typhoon vortex and the large-scale flow play an important role in the overall movement of both typhoons, which were explored for their structural and convective evolutions near the terrain. The wavenumber-one potential vorticity (PV) tendency budget of the typhoon vortex was analyzed to explain the induced typhoon translation from different physical processes. The west-northwestward translation for the stronger Mangkhut near the northern Philippines is primarily induced by both horizontal and vertical PV advection but with the latter further enhanced to dominate the northward deflection when closing in to the terrain. However, the northwestward translation and track deflection near landfall for the weaker Yutu are driven by the dominant horizontal PV advection. Differential diabatic heating is relatively less important for affecting the movement of both typhoons near landfall.

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 543
Author(s):  
Chih-wen Hung ◽  
Ming-Fu Shih ◽  
Te-Yuan Lin

Taiwan frequently suffers from typhoon hits in the boreal summer and fall. The location of Taiwan makes it vulnerable to the pathways of typhoons mainly determined by the position of the Pacific subtropical high. In order to clarify the linkage between typhoon invasion and associated large-scale environments from a climatological perspective, this study counts the historical typhoon invasion days for each month in the typhoon season to establish analyzed cases and then categorizes them with statistical thresholds. Besides, the categorized cases with less typhoon invasion are further sorted to distinguish different movements of tropical cyclones. Therefore, corresponding composites are applied for each category. The results reveal that when the subtropical high retreats eastward, the accompanying steering flow guides typhoons to make an early recurvature toward Japan and South Korea. While the subtropical high further extends its property to the west covering Taiwan, the steering flow on the south transfers typhoons moving westward to the South China Sea. However, when the subtropical high lies in areas between the above two scenarios, the steering flow along the periphery of the subtropical high continuously sends typhoons toward Taiwan and the vicinity, which greatly increases the threat to the island.


2015 ◽  
Vol 72 (4) ◽  
pp. 1307-1322 ◽  
Author(s):  
Jia Liang ◽  
Liguang Wu

Abstract Tropical cyclones (TCs) in the eastern semicircle of large-scale monsoon gyres (MGs) were observed to take either a northward (sudden northward and northward without a sharp turn) or a westward TC turn, but only the northward turn was previously simulated in a barotropic model. To understand what controls TC track types in MGs, idealized numerical experiments are performed using the full-physics Weather Research and Forecasting (WRF) Model. These experiments indicate that TCs initially located in the eastern semicircle of MGs can generally take three types of tracks: a sudden northward track, a westward track, and a northward track without a sharp turn. The track types depend upon the TC movement relative to the MG center. In agreement with barotropic simulations, the WRF simulation confirms that approaching and being collocated with the MG center is crucial to the occurrence of sudden northward TC track changes and that sudden northward track changes can be generally accounted for by changes in the steering flow. TCs that take westward tracks and northward tracks without a sharp turn do not experience such a coalescence process. Westward TCs move faster than MGs and are then located to the west of the MG center, while TCs move more slowly than MGs and then take a northward track without a sharp turn. This study reveals that the specific TC track in the eastern semicircle of an MG is sensitive to the initial wind profiles of both MGs and TCs, suggesting that improvement in the observation of TC and MG structures is very important for predicting TC track types in MGs.


2011 ◽  
Vol 24 (2) ◽  
pp. 488-508 ◽  
Author(s):  
Hyeong-Seog Kim ◽  
Joo-Hong Kim ◽  
Chang-Hoi Ho ◽  
Pao-Shin Chu

Abstract A fuzzy c-means clustering method (FCM) is applied to cluster tropical cyclone (TC) tracks. FCM is suitable for the data where cluster boundaries are ambiguous, such as a group of TC tracks. This study introduces the feasibility of a straightforward metric to incorporate the entire shapes of all tracks into the FCM, that is, the interpolation of all tracks into equal number of segments. Four validity measures (e.g., partition coefficient, partition index, separation index, and Dunn index) are used objectively to determine the optimum number of clusters. This results in seven clusters from 855 TCs over the western North Pacific (WNP) from June through October during 1965–2006. The seven clusters are characterized by 1) TCs striking the Korean Peninsula and Japan with north-oriented tracks, 2) TCs affecting Japan with long trajectories, 3) TCs hitting Taiwan and eastern China with west-oriented tracks, 4) TCs passing the east of Japan with early recurving tracks, 5) TCs traveling the easternmost region over the WNP, 6) TCs over the South China Sea, and 7) TCs moving straight across the Philippines. Each cluster shows distinctive characteristics in its lifetime, traveling distance, intensity, seasonal variation, landfall region, and distribution of TC-induced rainfall. The roles of large-scale environments (e.g., sea surface temperatures, low-level relative vorticity, and steering flows) on cluster-dependent genesis locations and tracks are also discussed.


2014 ◽  
Vol 81 (2) ◽  
Author(s):  
S. Yoshimura ◽  
K. Terasaka ◽  
E. Tanaka ◽  
M. Aramaki ◽  
A. Okamoto ◽  
...  

HYPER-I (High Density Plasma Experiment-I) is a linear device that combines a wide operation range of plasma production with flexible diagnostics. The plasmas are produced by the electron cyclotron resonance (ECR) heating with parallel injection of right-handed circularly polarized microwaves of 2.45 GHz from the high-field side. The maximum attainable electron density is more than two orders of magnitude higher than the cutoff density of ordinary waves. Spontaneous formation of a variety of large-scale flow structures, or vortices, has been observed in the HYPER-I plasmas. Flow-velocity field measurements using directional Langmuir probes (DLPs) and laser-induced fluorescence (LIF) method have clarified the physical processes behind such vortex formations. Recently, a new intermittent behavior of local electron temperature has also been observed. Statistical analysis of the floating potential changes has revealed that the phenomenon is characterized by a stationary Poisson process.


Author(s):  
Celine Parreñas Shimizu

Transnational films representing intimacy and inequality disrupt and disgust Western spectators. When wounded bodies within poverty entangle with healthy wealthy bodies in sex, romance and care, fear and hatred combine with desire and fetishism. Works from the Philippines, South Korea, and independents from the United States and France may not be made for the West and may not make use of Hollywood traditions. Rather, they demand recognition for the knowledge they produce beyond our existing frames. They challenge us to go beyond passive consumption, or introspection of ourselves as spectators, for they represent new ways of world-making we cannot unsee, unhear, or unfeel. The spectator is redirected to go beyond the rapture of consuming the other to the rupture that arises from witnessing pain and suffering. Self-displacement is what proximity to intimate inequality in cinema ultimately compels and demands so as to establish an ethical way of relating to others. In undoing the spectator, the voice of the transnational filmmaker emerges. Not only do we need to listen to filmmakers from outside Hollywood who unflinchingly engage the inexpressibility of difference, we need to make room for critics and theorists who prioritize the subjectivities of others. When the demographics of filmmakers and film scholars are not as diverse as its spectators, films narrow our worldviews. To recognize our culpability in the denigration of others unleashes the power of cinema. The unbearability of stories we don’t want to watch and don’t want to feel must be borne.


2020 ◽  
Vol 60 (4) ◽  
pp. 612-622
Author(s):  
Rosina Lozano

The twenty-first century has seen a surge in scholarship on Latino educational history and a new nonbinary umbrella term, Latinx, that a younger generation prefers. Many of historian Victoria-María MacDonald's astute observations in 2001 presaged the growth of the field. Focus has increased on Spanish-surnamed teachers and discussions have grown about the Latino experience in higher education, especially around student activism on campus. Great strides are being made in studying the history of Spanish-speaking regions with long ties to the United States, either as colonies or as sites of large-scale immigration, including Puerto Rico, Cuba, and the Philippines. Historical inquiry into the place of Latinos in the US educational system has also developed in ways that MacDonald did not anticipate. The growth of the comparative race and ethnicity field in and of itself has encouraged cross-ethnic and cross-racial studies, which often also tie together larger themes of colonialism, language instruction, legal cases, and civil rights or activism.


2001 ◽  
Vol 9 (1) ◽  
pp. 3-7
Author(s):  
Damon Liu ◽  
Mark Burgin ◽  
Walter Karplus ◽  
Daniel Valentino

2021 ◽  
pp. 001139212110246
Author(s):  
Walid Habbas ◽  
Yael Berda

This article delves into the everyday dynamics of colonial rule to outline a novel way of understanding colonized–colonizer interactions. It conceives colonial management as a social field in which both the colonized and colonizers negotiate and exchange resources, despite their decidedly unequal positions within a racial hierarchy. Drawing their example from the West Bank, the authors argue that a Palestinian economic elite has proactively participated in the co-production of the colonial management of spatial mobility, a central component of Israeli colonial rule. The study employs interviews and document analysis to investigate how the nexus between Palestine’s commercial-logistical needs and Israel’s security complex induced large-scale Palestinian producers to exert agency and reorder commercial mobility. The authors describe and explain the evolution of a ‘Door-to-Door’ logistical arrangement, in which large-scale Palestinian traders participate in extending Israeli’s system of spatial control in exchange for facilitating logistical mobility. This horizontal social encounter that entails pay-offs is conditioned, but not fully determined, by vertical relations of domination and subordination.


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