Variability in Intense Tropical Cyclone Days in the Western North Pacific

Kamahori, Hirotaka; Yamazaki, Nobuo; Mannoji, Nobutaka; Takahashi, K.

doi:10.2151/sola.2006-027

Cited by 76 publications

(74 citation statements)

References 16 publications

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“…The result is the same if the analysis is extended to include 2005.This downward trend is statistically significant at the 5% level (all significant tests are based on t tests).The trend signifies a falling tendency in typhoon intensity in the western North Pacific in recent years, contrary to the results of Webster et al [2005].This falling trend was also noted by Kamahori et al [2006] in their recent study on the variability in intense cyclone days in the WNP using RSMC-Tokyo's best track data.…”

Section: Pages 537-538mentioning

confidence: 68%

Trends in western North Pacific tropical cyclone intensity

2006

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Using the tropical cyclone best track data from the U.S. Department of Defense's Joint Typhoon Warning Center (JTWC), Webster et al. [2005] found that between the two consecutive 15‐year periods of 1975–1989 and 1990‐2004, the percentage of typhoons in the western North Pacific meeting the definition of categories 4 and 5 on the Saffir‐Simpson Hurricane Scale has increased from 25% to 41% of all typhoons in that ocean basin. However, an analysis of the best track data from the Regional Specialized Meteorological Centre (RSMC) Tokyo (Japan) as well as that of the Hong Kong Observatory (HKO; Hong Kong, China) indicates that, in contrast to Webster et al.'s [2005] findings, there was no increase in western North Pacific category 4–5 typhoon activity. Furthermore, neither RSMC‐Tokyo nor HKO best track data suggest an increase in western North Pacific tropical cyclone destructiveness as measured by the potential destructive index (PDI).

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Section: Pages 537-538mentioning

confidence: 68%

Trends in western North Pacific tropical cyclone intensity

2006

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“…The data set provides the central position, central pressure, estimated 10 minute-averaged maximum sustained wind speed, and size (e.g., the radius of 30 knots and 50 knots). They are estimated from observations, namely, aircraft, satellite, surface, and upper air observations (Kamahori et al 2006). In this study, the central position, the central pressure, the maximum 10 minutes-averaged sustained wind speed, and the radii of 30-knot and 50-knot winds in the data set are used as an observation.…”

Section: Best-track Datamentioning

confidence: 99%

Verification of Typhoon Forecasts for a 20 km-mesh High-Resolution Global Model

Murakami

Matsumura

Sakai

et al. 2008

Journal of the Meteorological Society of Japan

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In this study, twelve tropical storms between 2002 and 2005 over the western North Pacific Ocean, namely, typhoons, were simulated through medium-range forecast experiments with the 20 km-mesh Japan Meteorological Agency (JMA) and Meteorological Research Institute (MRI) Atmospheric General Circulation Model (JM-AGCM). These simulations were compared with the 60 km-mesh JMA Global Spectral Model (GSM) to evaluate differences in resolution. They are verified with the best-track data as an observation. The verification was conducted in terms of estimating error of position, intensifying tendency, radius of 50 knot, 30 knot, and composite wind profile. This paper addresses the importance of such high resolution to predict typhoon's intensity and inner-core structure.As a result, the JM-AGCM shows slightly smaller position error than the GSM. Moreover, much improvement was seen in the intensity prediction. The JM-AGCM outstandingly can both decrease the central sea level pressure and increase maximum wind velocity, while the GSM can not simulate them because of low resolution. The JM-AGCM also shows better intensifying and decaying tendency than the GSM.The verifications of 50 knot and 30 knot radii, and the composite wind profile indicate that the typhoon structure by the JM-AGCM is quite realistic. Moreover, the JM-AGCM expresses the drastic transformation of inner-core wind profile within 100km from the typhoon center more realistically than the GSM. These results indicate that a high resolution global model, such as 20 km-mesh, is vital when discussing the intensity and wind profile of tropical storms.Corresponding author and present affiliation: Hiroyuki Murakami,

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“…Kamahori et al (2006) found that the different trends of intense-TC days in JMA and JTWC datasets were due to different intensity categories within different datasets. Kwon et al (2006) also found that the annual TC numbers were different, as were the top 10% of the records, in JMA and JTWC datasets.…”

Section: Introductionmentioning

confidence: 94%

“…of their potential negative impact on numerical weather forecasts, and the uncertainties in the TC best track The biases in the location and intensity of tropical datasets may also confuse the natural trends in TC accyclones (TCs) have received a lot of attention because tivity with spurious variabilities (Kamahori et al 2006;Landsea et al 2006;Wang et al 2008;Wu et al 2006). …”

Section: Introductionmentioning

confidence: 99%

“…This makes it possible to estimate the potential errors that may arise from the different analysis procedures based on error theories. Some studies have attempted to evaluate the differences among these datasets (Kamahori et al 2006; Kwon et al 2006;Lei 2001;Yu et al 2007;Zhang and Ying 2009) and there appears to have been positional differences of about 54 km between the JTWC and CMA-STI datasets (Lei 2001). These differences were found to be much larger in the TC genesis region and in mid-latitude westerlies, as well as in the offshore area of China, where more data were available for the CMA-STI (Zhang and Ying 2009).…”

Section: Introductionmentioning

confidence: 99%

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Comparison of Three Western North Pacific Tropical Cyclone Best Track Datasets in a Seasonal Context

Ying

Cha

Kwon

2011

Journal of the Meteorological Society of Japan

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The quality of tropical cyclone (TC) best track data has increasingly received more attention in climate research in recent years because of the rising interest in the possible effects of global warming on TC activity. In this paper, three best track datasets for the western North Pacific TCs were compared in a seasonal context. Firstly, the statistical characteristics were examined based on their distributions. Then, the potential impact of particular features within the datasets was evaluated by using contrastive cluster analyses.The mean amplitude of the annual cycle in the Japan Meteorological Agency (JMA) data is largest among the three datasets. The smallest interannual variability helped the Shanghai Typhoon Institute of China Meteorological Administration (CMA-STI) dataset to resist the negative effect of outliers. An inhomogeneity around 2003-2004 was identified in the Joint Typhoon Warning Center (JTWC) data by the outliers and was compared with the JMA and CMA-STI data.By using contrastive cluster analyses, the differences among the datasets and some effects related to particular issues, including the representation of the annual cycle, the outliers, and wind conversion were evaluated. The JTWC dataset is affected by outliers and wind conversion among the different average times, whereas the representation of the annual cycle was important for the CMA-STI data. After excluding all the outliers, the results indicated more consistent classifications of the TC annual cycle between the JMA and JTWC data.

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Variability in Intense Tropical Cyclone Days in the Western North Pacific

Cited by 76 publications

References 16 publications

Trends in western North Pacific tropical cyclone intensity

Trends in western North Pacific tropical cyclone intensity

Verification of Typhoon Forecasts for a 20 km-mesh High-Resolution Global Model

Comparison of Three Western North Pacific Tropical Cyclone Best Track Datasets in a Seasonal Context

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