scholarly journals A New View on Risk of Typhoon Occurrence in the Western North Pacific

2020 ◽  
Author(s):  
Kelvin S. Ng ◽  
Gregor C. Leckebusch
Keyword(s):  
Risk Assessment ◽  
North Pacific ◽  
Western North Pacific ◽  
High Impact ◽  
Extreme Wind ◽  
Temporal And Spatial Characteristics ◽  
Using Data ◽  
Events Data ◽  
Typhoon Event

Abstract. To study high impact tropical cyclone (TC) is of crucial importance due to its extraordinary destruction potential that leads to major losses in many coastal areas in the Western North Pacific (WNP). Nevertheless, because of the rarity of high-impact TCs, it is difficult to construct a robust risk assessment based on the historical best track records. This paper aims to address this issue by introducing a computationally simple and efficient approach, using data from the THORPEX Interactive Grand Global Ensemble (TIGGE) archive with the application of impact-oriented tracking algorithm, to build a physically consistent high impact typhoon event set with non-realised TC events – data equivalent to more than 10 000 years of TC events. The temporal and spatial characteristics of the new event set is consistent to the historical TC climatology in the WNP. It is shown that this TC event set contains ~ 100 and ~ 77 times more Very Severe Typhoons and Violent Typhoons than the historical records, respectively. Furthermore, this approach can be used to improve the return period estimation of TC-associated extreme wind. Consequently, a robust extreme TC hazard risk assessment, reflective of the current long-term climate variability phase, can be achieved using this approach.

scholarly journals A new view on the risk of typhoon occurrence in the western North Pacific

2021 ◽  
Vol 21 (2) ◽  
pp. 663-682
Author(s):  
Kelvin S. Ng ◽  
Gregor C. Leckebusch
Keyword(s):  
Hazard Assessment ◽  
North Pacific ◽  
Western North Pacific ◽  
High Impact ◽  
Crucial Importance ◽  
Extreme Wind ◽  
Period Estimation ◽  
Temporal And Spatial ◽  
Temporal And Spatial Characteristics

Abstract. To study high-impact tropical cyclones (TCs) is of crucial importance due to their extraordinary destructive potential that leads to major losses in many coastal areas in the western North Pacific (WNP). Nevertheless, because of the rarity of high-impact TCs, it is difficult to construct a robust hazard assessment based on the historical best track records. This paper aims to address this issue by introducing a computationally simple and efficient approach to build a physically consistent high-impact TC event set with non-realised TC events in the THORPEX Interactive Grand Global Ensemble (TIGGE) archive. This event set contains more than 10 000 years of TC events. The temporal and spatial characteristics of the new event set are consistent with the historical TC climatology in the WNP. It is shown that this TC event set contains ∼100 and ∼77 times more very severe typhoons and violent typhoons than the historical records, respectively. Furthermore, this approach can be used to improve the return-period estimation of TC-associated extreme wind. Consequently, a robust extreme TC hazard assessment, reflective of the current long-term climate variability phase, can be achieved using this approach.

scholarly journals Long-term and large-scale epidemiology of Brucella infection in baleen whales and sperm whales in the western North Pacific and Antarctic Oceans

2016 ◽  
Vol 78 (9) ◽  
pp. 1457-1464 ◽  
Author(s):  
Kazue OHISHI ◽  
Takeharu BANDO ◽  
Erika ABE ◽  
Yasushi KAWAI ◽  
Yoshihiro FUJISE ◽  
...  
Keyword(s):  
North Pacific ◽  
Western North Pacific ◽  
Large Scale ◽  
Sperm Whales ◽  
Baleen Whales

Parametric Modeling of Transitioning Cyclone Wind Fields for Risk Assessment Studies in the Western North Pacific

2015 ◽  
Vol 54 (3) ◽  
pp. 624-642 ◽  
Author(s):  
T. Loridan ◽  
S. Khare ◽  
E. Scherer ◽  
M. Dixon ◽  
E. Bellone
Keyword(s):  
Risk Assessment ◽  
North Pacific ◽  
Wind Field ◽  
Western North Pacific ◽  
Parametric Modeling ◽  
Transition Phase ◽  
Wind Fields ◽  
Extratropical Transition ◽  
Starting Point ◽  
Assessment Systems

AbstractProbabilistic risk assessment systems for tropical cyclone hazards rely on large ensembles of model simulations to characterize cyclones tracks, intensities, and the extent of the associated damaging winds. Given the computational costs, the wind field is often modeled using parametric formulations that make assumptions that are based on observations of tropical systems (e.g., satellite, or aircraft reconnaissance). In particular, for the Northern Hemisphere, most of the damaging contribution is assumed to be from the right of the moving cyclone, with the left-hand-side winds being much weaker because of the direction of storm motion. Recent studies have highlighted that this asymmetry assumption does not hold for cyclones undergoing extratropical transitions around Japan. Transitioning systems can exhibit damaging winds on both sides of the moving cyclone, with wind fields often characterized as resembling a horseshoe. This study develops a new parametric formulation of the extratropical transition phase for application in risk assessment systems. A compromise is sought between the need to characterize the horseshoe shape while keeping the formulation simple to allow for implementation within a risk assessment framework. For that purpose the tropical wind model developed by Willoughby et al. is selected as a starting point and parametric bias correction fields are applied to build the target shape. Model calibration is performed against a set of 37 extratropical transition cases simulated using the Weather Research and Forecasting Model. This newly developed parametric model of the extratropical transition phase shows an ability to reproduce wind field features observed in the western North Pacific Ocean while using only a restricted number of input parameters.

scholarly journals Long term Aleutian Low dynamics and obliquity-controlled oceanic primary production in the mid-latitude western North Pacific (Core MD01-2421) during the last 145,000 years

2006 ◽  
Vol 53 (1-2) ◽  
pp. 21-28 ◽  
Author(s):  
Toshinori Ueshima ◽  
Masanobu Yamamoto ◽  
Tomohisa Irino ◽  
Tadamichi Oba ◽  
Masao Minagawa ◽  
...  
Keyword(s):  
Primary Production ◽  
North Pacific ◽  
Western North Pacific ◽  
Aleutian Low

Cyclone Wind Field Asymmetries during Extratropical Transition in the Western North Pacific

2014 ◽  
Vol 53 (2) ◽  
pp. 421-428 ◽  
Author(s):  
T. Loridan ◽  
E. Scherer ◽  
M. Dixon ◽  
E. Bellone ◽  
S. Khare
Keyword(s):  
Risk Assessment ◽  
North Pacific ◽  
Wind Field ◽  
Western North Pacific ◽  
North Pacific Ocean ◽  
Maximum Magnitude ◽  
Wind Fields ◽  
Extratropical Transition ◽  
Left Hand ◽  
Assessment Systems

AbstractRisk-assessment systems for wind hazards (e.g., hurricanes or typhoons) often rely on simple parametric wind field formulations. They are built using extensive observations of tropical cyclones and make assumptions about wind field asymmetry. In this framework, maximum winds are always simulated to the right of the cyclone, but analysis of the Climate Forecast System Reanalysis database for the western North Pacific Ocean suggests that wind fields from cyclones undergoing extratropical transition around Japan often present features that cannot be adequately simulated under these assumptions. These “left-hand-side contribution” (LHSC) wind fields exhibit strong winds on both sides of the moving cyclone with the maximum magnitude often located to the left. Classification of cyclones in terms of their most frequent patterns reveals that 67% of cases that make a transition around Japan are dominantly LHSC. They are more likely in autumn and have more intense maximum winds. The results from this study show the need for a new approach to the modeling of transitioning wind fields in the context of risk-assessment systems.

scholarly journals Long-term (2001–2012) trends of carbonaceous aerosols from a remote island in the western North Pacific: an outflow region of Asian pollutants

2018 ◽  
Vol 18 (2) ◽  
pp. 1291-1306 ◽  
Author(s):  
Suresh K. R. Boreddy ◽  
M. Mozammel Haque ◽  
Kimitaka Kawamura
Keyword(s):  
Organic Carbon ◽  
Long Range ◽  
North Pacific ◽  
Western North Pacific ◽  
Atmospheric Transport ◽  
Carbonaceous Aerosols ◽  
Central Pacific ◽  
Air Masses ◽  
Photochemical Formation

Abstract. The present study reports on long-term trends of carbonaceous aerosols in total suspended particulate (TSP) samples collected at Chichijima in the western North Pacific during 2001–2012. Seasonal variations of elemental carbon (EC), organic carbon (OC), and water-soluble organic carbon (WSOC) concentrations showed maxima in winter to spring and minima in summer. These seasonal differences in the concentrations of carbonaceous aerosols were associated with the outflows of polluted air masses from East Asia, which are clearly distinguishable from pristine air masses from the central Pacific. The higher concentrations of carbonaceous aerosols during winter to spring are associated with long-range atmospheric transport of East Asian continental polluted air masses, whereas lower concentrations may be due to pristine air masses from the central Pacific in summer. The annual trends of OC ∕ EC (+0.46 % yr−1), WSOC (+0.18 % yr−1) and WSOC ∕ OC (+0.08 % yr−1) showed significant (p  <  0.05) increases during the period of 2001–2012, suggesting that photochemical formation of WSOC and its contributions to secondary organic aerosols (SOAs) have increased over the western North Pacific via long-range atmospheric transport. We found a significant increase (+0.33 % yr−1) in nss-K+ ∕ EC ratios, demonstrating that concentrations of biomass-burning-derived carbonaceous aerosols have increased, while those of primary fossil-fuel-derived aerosols have decreased over the western North Pacific. Further, secondary biogenic emissions are also important over the western North Pacific as inferred from a significant increase (+0.14 % yr−1) in the concentrations of methanesulfonate (MSA−, a tracer for biogenic sources). This point was further supported by a moderate correlation (r = 0.40) between WSOC and MSA−. We also found a significant increase in OC ∕ TC (total carbon) and WSOC ∕ TC ratios, further suggesting that photochemical formation of WSOC and its contributions to SOAs have increased over the western North Pacific during 2001–2012 via long-range atmospheric transport from East Asia.

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