scholarly journals A Tale of Two Rapidly-Intensifying Supertyphoons: Hagibis (2019) and Haiyan (2013)

2021 ◽  
pp. 1-59
Author(s):  
I.-I. Lin ◽  
Robert F. Rogers ◽  
Hsiao-Ching Huang ◽  
Yi-Chun Liao ◽  
Derrick Herndon ◽  
...  
Keyword(s):  
Negative Impact ◽  
Heat Content ◽  
Thunderstorm Activity ◽  
Sea Surface ◽  
The Pacific ◽  
Typhoon Intensity ◽  
History Of ◽  
Eyewall Replacement Cycles ◽  
Translational Speed ◽  
Intensity Evolution

AbstractDevastating Japan in October 2019, Supertyphoon (STY) Hagibis was an important typhoon in the history of the Pacific. A striking feature of Hagibis was its explosive RI (rapid intensification). In 24 h, Hagibis intensified by 100 kt, making it one of the fastest-intensifying typhoons ever observed. After RI, Hagibis’s intensification stalled. Using the current typhoon intensity record holder, i.e., STY Haiyan (2013), as a benchmark, this work explores the intensity evolution differences of these 2 high-impact STYs.We found that the extremely high pre-storm sea surface temperature reaching 30.5°C, deep/warm pre-storm ocean heat content reaching 160 kJ cm−2, fast forward storm motion of ~8 ms−1, small during-storm ocean cooling effect of ~ 0.5C, significant thunderstorm activity at its center, and rapid eyewall contraction were all important contributors to Hagibis’s impressive intensification. There was 36% more air-sea flux for Hagibis’s RI than for Haiyan’s.After its spectacular RI, Hagibis’s intensification stopped, despite favorable environments. Haiyan, by contrast, continued to intensify, reaching its record-breaking intensity of 170 kt. A key finding here is the multiple pathways that storm size affected the intensity evolution for both typhoons. After RI, Hagibis experienced a major size expansion, becoming the largest typhoon on record in the Pacific. This size enlargement, combined with a reduction in storm translational speed, induced stronger ocean cooling that reduced ocean flux and hindered intensification. The large storm size also contributed to slower eyewall replacement cycles (ERCs), which prolonged the negative impact of the ERC on intensification.

A 12-Million-Year Temperature History of the Tropical Pacific Ocean

Science ◽  
2014 ◽  
Vol 344 (6179) ◽  
pp. 84-87 ◽  
Author(s):  
Yi Ge Zhang ◽  
Mark Pagani ◽  
Zhonghui Liu
Keyword(s):  
El Niño ◽  
El Nino ◽  
Warm Pool ◽  
Sea Surface ◽  
Temperature History ◽  
Seawater Chemistry ◽  
The Pacific ◽  
Pacific Warm Pool ◽  
History Of ◽  
The Tropical Pacific

The appearance of permanent El Niño–like conditions prior to 3 million years ago is founded on sea-surface temperature (SST) reconstructions that show invariant Pacific warm pool temperatures and negligible equatorial zonal temperature gradients. However, only a few SST records are available, and these are potentially compromised by changes in seawater chemistry, diagenesis, and calibration limitations. For this study, we establish new biomarker-SST records and show that the Pacific warm pool was ~4°C warmer 12 million years ago. Both the warm pool and cold tongue slowly cooled toward modern conditions while maintaining a zonal temperature gradient of ~3°C in the late Miocene, which increased during the Plio-Pleistocene. Our results contrast with previous temperature reconstructions that support the supposition of a permanent El Niño–like state.

Impact of Typhoons on the Ocean in the Pacific

2014 ◽  
Vol 95 (9) ◽  
pp. 1405-1418 ◽  
Author(s):  
E.A. D'Asaro ◽  
P. G. Black ◽  
L. R. Centurioni ◽  
Y.-T. Chang ◽  
S. S. Chen ◽  
...  
Keyword(s):  
Surface Waves ◽  
Subsurface Layer ◽  
Sea Surface ◽  
Surface Layers ◽  
The Pacific ◽  
Typhoon Intensity ◽  
The Impact ◽  
The Western Pacific ◽  
Initial Results

Tropical cyclones (TCs) change the ocean by mixing deeper water into the surface layers, by the direct air–sea exchange of moisture and heat from the sea surface, and by inducing currents, surface waves, and waves internal to the ocean. In turn, the changed ocean influences the intensity of the TC, primarily through the action of surface waves and of cooler surface temperatures that modify the air–sea fluxes. The Impact of Typhoons on the Ocean in the Pacific (ITOP) program made detailed measurements of three different TCs (i.e., typhoons) and their interaction with the ocean in the western Pacific. ITOP coordinated meteorological and oceanic observations from aircraft and satellites with deployments of autonomous oceanographic instruments from the aircraft and from ships. These platforms and instruments measured typhoon intensity and structure, the underlying ocean structure, and the long-term recovery of the ocean from the storms' effects with a particular emphasis on the cooling of the ocean beneath the storm and the resulting cold wake. Initial results show how different TCs create very different wakes, whose strength and properties depend most heavily on the nondimensional storm speed. The degree to which air–sea fluxes in the TC core were reduced by ocean cooling varied greatly. A warm layer formed over and capped the cold wakes within a few days, but a residual cold subsurface layer persisted for 10–30 days.

Estimation of Tropical Cyclone Heat Potential From Oceanic Measurements

2011 ◽  
Author(s):  
Chung-Ru Ho ◽  
Yen-Hsuan Tsao ◽  
Nan-Jung Kuo ◽  
Shih-Jen Huang
Keyword(s):  
Tropical Cyclone ◽  
North Pacific Ocean ◽  
Heat Content ◽  
Remote Sensing Data ◽  
Sea Surface ◽  
Tropical Cyclone Heat Potential ◽  
Heat Potential ◽  
Typhoon Intensity ◽  
Intensity Changes

The primary purpose of this study is to estimate the tropical cyclone heat potential (TCHP) in the western North Pacific Ocean using in-situ measurements and satellite remote sensing data, as well as to explore the influence of TCHP on the genesis and intensification of typhoon in this region. The TCHP is defined as the integration of heat content from the depth of 26°C isotherm to the sea surface. Sea surface height and sea surface temperature data are used to estimate the TCHP based on a two-layer reduced gravity model. Totally 35 typhoons from 2006 to 2009 are analyzed in this study. The result shows that the typhoon is dramatically developed when it goes through the area with more TCHP than surroundings. From the result of regression analysis, the correlation coefficient between typhoon intensity and accumulated TCHP is above 0.8. It implies that the typhoon intensity changes might be controlled by the TCHP conditions of tropical cyclone formation region.

Examining the entry of Walmart into South Africa: A stakeholder management perspective

2019 ◽  
Vol 38 (2) ◽  
pp. 78-89
Author(s):  
Tembinkosi Bonakele ◽  
Dave Beaty ◽  
Fathima Rasool ◽  
Drikus Kriek
Keyword(s):  
South Africa ◽  
Trade Unions ◽  
Negative Impact ◽  
Stakeholder Management ◽  
Sources Of Information ◽  
Key Stakeholders ◽  
Management Perspective ◽  
Labour Standards ◽  
History Of ◽  
Primary Focus

The recent entry of the US multinational Walmart into South Africa has proved to be a source of controversy. Key stakeholders in South Africa objected to the merger and attempted to block it unless certain conditions were met. The aim of this study was to examine the controversy and the conditions surrounding the merger. The research employed a qualitative archival analysis to examine publicly available sources of information with regard to the merger. The findings revealed key stakeholders’ concerns that Walmart’s entry would lead to an increase in imports which would displace local producers, increase unemployment, marginalise trade unions and lower labour standards unless certain conditions were met. The results also revealed problems relating to the firm’s primary focus on “business” while neglecting “public interest” issues, naively relying on their “local retailer” to manage key stakeholders, and assuming that their perceived controversial reputation regarding treatment of trade unions and their views about unemployment as well as the controversies surrounding their history of entry into other global markets would not have the major negative impact it did on stakeholders in South Africa.

A Short history of the post-graduate surgical training in Fiji - where to from here?

2018 ◽  
Vol 21 (2) ◽  
pp. 103-107 ◽  
Author(s):  
Jitoko Kelepi Cama ◽  
Sonal Singh Nagra
Keyword(s):  
Surgical Training ◽  
Training Programme ◽  
Post Graduate ◽  
School Of Medicine ◽  
Postgraduate Training Programme ◽  
The Pacific ◽  
National University ◽  
History Of ◽  
Training Of Surgeons ◽  
Pacific Island Nations

Post-graduate surgical training at the Fiji National University (FNU), previously known as the Fiji School of Medicine) has recently been updated by incorporating elements from the Royal Australasian College of Surgeons (RACS) training curriculum. The revised curriculum maintains strong contextual relevance to the needs and pathologies of the Pacific Island nations.  This paper outlines why the FNU surgical postgraduate training programme should be applauded as a successful programme in the training of surgeons for the region.

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