Number Of Intense Tropical Cyclones Research Articles

A Review of Historical Changes of Tropical and Extra-Tropical Cyclones: A Comparative Analysis of the United States, Europe, and Asia.

Tropical cyclones are highly destructive weather systems, especially in coastal areas. Tropical cyclones with maximum sustained winds exceeding 74 mph (≈119 kph) are classified as typhoons in the Northwest Pacific, whilst the term ‘hurricanes’ applies to other regions. This study aims to investigate the general characteristics of the most devastating and catastrophic tropical cyclones in the USA Europe, and Asia. To achieve the study objectives, the three most devastating typical tropical cyclones in each region were selected. The tropical cyclones were examined based on various features, such as the number of deaths, minimum pressure, highest wind speed, total financial losses, and frequency per year. In contrast to Europe and Asia, the USA has recorded the highest number of catastrophic tropical cyclones. The damage induced by hurricanes Katrina, Harvey, and Maria in the USA totalled approximately USD USD 380 billion. In addition, the present research highlights the demand to improve the public attitude and behaviour toward the impact of climate change along with the enhancement of climate change alleviation strategies. The number of intense tropical cyclones is expected to rise, and the tropical cyclone-related precipitation rate is expected to increase in warmer-climate areas. Stakeholders and industrial practitioners may use the research findings to design resilience and adaptation plans in the face of tropical cyclones, allowing them to assess the effects of climate change on tropical cyclone incidents from an academic humanitarian logistics viewpoint in the forthcoming years.

Comparison of Conventional Change Detection Methodologies Using High-Resolution Imagery to Find Forest Damage Caused by Typhoons

The number of intense tropical cyclones is expected to increase in the future, causing severe damage to forest ecosystems. Remote sensing plays an important role in detecting changes in land cover caused by these tropical storms. Remote sensing techniques have been widely used in different phases of disaster risk management because they can deliver information rapidly to the concerned parties. Although remote sensing technology is already available, an examination of appropriate methods based on the type of disaster is still missing. Our goal is to compare the suitability of three different conventional classification methods for fast and easy change detection analysis using high-spatial-resolution and high-temporal-resolution remote sensing imagery to identify areas with windthrow and landslides caused by typhoons. In August 2016, four typhoons hit Hokkaido, the northern island of Japan, creating large areas of windthrow and landslides. We compared the normalized difference vegetation index (NDVI) filtering method, the spectral angle mapper (SAM) method, and the support vector machine (SVM) method to identify windthrow and landslides in two different study areas in southwestern Hokkaido. These methodologies were evaluated using PlanetScope data with a resolution of 3 m/px and validated with reference data based on Worldview2 data with a very high resolution of 0.46 m/px. The results showed that all three methods, when applied to high-spatial-resolution imagery, can deliver sufficient results for windthrow and landslide detection. In particular, the SAM method performed better at windthrow detection, and the NDVI filtering method performed better at landslide detection.

High‐Resolution Ensemble Simulations of Intense Tropical Cyclones and Their Internal Variability During the El Niños of 1997 and 2015

AbstractExtreme El Niño events affect the number of intense tropical cyclones (ITCs) over the western North Pacific (WNP). In 1997 and 2015, both extreme El Niño years, ITC numbers were above normal in the WNP. In order to clarify how, and to what extent, sea surface temperature anomaly (SSTA) distributions control the ITCs genesis, the authors conducted 50‐member ensemble simulations using a high‐resolution global nonhydrostatic model that explicitly simulates ITCs. The ensemble simulations showed a clear relationship between the number of ITCs and their genesis locations in the WNP. However, the authors found that the simulated numbers of ITCs in the WNP were also closely related to the strength of the monsoon trough, which varies under given SSTA conditions. This indicates that reliable seasonal forecasting of ITCs depends on our ability to accurately reproduce the monsoon trough, whose strength is modulated mainly by internal atmospheric variability but also by SSTA.

Resolution Dependence of Future Tropical Cyclone Projections of CAM5.1 in the U.S. CLIVAR Hurricane Working Group Idealized Configurations

The four idealized configurations of the U.S. CLIVAR Hurricane Working Group are integrated using the global Community Atmospheric Model version 5.1 at two different horizontal resolutions, approximately 100 and 25 km. The publicly released 0.9° × 1.3° configuration is a poor predictor of the sign of the 0.23° × 0.31° model configuration’s change in the total number of tropical storms in a warmer climate. However, it does predict the sign of the higher-resolution configuration’s change in the number of intense tropical cyclones in a warmer climate. In the 0.23° × 0.31° model configuration, both increased CO2 concentrations and elevated sea surface temperature (SST) independently lower the number of weak tropical storms and shorten their average duration. Conversely, increased SST causes more intense tropical cyclones and lengthens their average duration, resulting in a greater number of intense tropical cyclone days globally. Increased SST also increased maximum tropical storm instantaneous precipitation rates across all storm intensities. It was found that while a measure of maximum potential intensity based on climatological mean quantities adequately predicts the 0.23° × 0.31° model’s forced response in its most intense simulated tropical cyclones, a related measure of cyclogenesis potential fails to predict the model’s actual cyclogenesis response to warmer SSTs. These analyses lead to two broader conclusions: 1) Projections of future tropical storm activity obtained by a direct tracking of tropical storms simulated by coarse-resolution climate models must be interpreted with caution. 2) Projections of future tropical cyclogenesis obtained from metrics of model behavior that are based solely on changes in long-term climatological fields and tuned to historical records must also be interpreted with caution.

Typhoon‐induced phytoplankton blooms and primary productivity increase in the western North Pacific subtropical ocean

Using multiple satellite observations and series of numerical experiments, this work systematically studied phytoplankton blooms induced by tropical cyclones in the western North Pacific subtropical ocean (WNPSO) because WNPSO is among the world oceans where most number of intense tropical cyclones are found. All eleven typhoon cases passing the study domain in 2003 were examined in detail. It was observed that only two typhoons (18%) were able to induce phytoplankton blooms (chlorophyll‐a concentration increased from ≦0.1 mg m−3 to 0.4–0.8 mg m−3) and strong sea surface temperature cooling of −2.5 to −6°C. The other nine typhoons, including the most intense tropical cyclone on Earth in 2003 (i.e., supertyphoon Maemi), were not able to induce phytoplankton blooms and the associated sea surface temperature cooling was weak (0 to −1.5°C). Using series of numerical experiments, it was found that the presence of warm ocean eddy can effectively isolate the cold, nutrient‐rich water to be entrained to the surface ocean. Under this situation, even category 5 typhoon Maemi at its peak intensity of 150 kts could not induce phytoplankton bloom in the WNPSO. The weak responses of the other eight typhoons were due to insufficient wind intensity and transit time (caused by relatively small storm size and fast translation speed) in this deep nutricline/mixed layer ocean. As a result, the total annual primary production increase induced by typhoons in the WNPSO was estimated to be ∼3.27 × 1012 g C (0.00327 Pg), equivalent to 0.15% of the global annual anthropogenic CO2 uptake. This suggests that though WNPSO has the highest number and intensity of tropical cyclones among the world oceans, tropical cyclones in the WNPSO have little contribution to enhance biological carbon fixation in the context of global carbon‐climate system.

Climatology and Landfall of Tropical Cyclones in the South- West Indian Ocean

—The climatology of cyclone formation and behaviour in the South-West Indian Ocean, including landfall in Mozambique and Madagascar, has been investigated. The records used were obtained by merging track data from the Joint Typhoon Warning Centre with data from La Reunion – Regional Specialised Meteorological Centre. During the period 1980-2007, 12.5 cyclones per year were formed; 85% of which in November-April (the cyclone season). The number of intense tropical cyclones increased from 36 during 1980-1993 to 56 during 1994-2007, parallel to a simultaneous but smaller decrease in the number of tropical storms. This increase in intense tropical cyclones occurred at the same time as an increase in the mean sea surface temperature of 0.12˚C. This temperature increase seems insufficient to explain the increased activity. In addition, investigating a longer record (1952-2007) from the same sources indicates a long-term decrease in cyclone frequency as well as in landfall, although this was simultaneous with a substantial increase (about 0.3˚C) in sea surface temperature. However, it is recognised that records before 1980 suffer from too few wind intensity data. From 1980-2007, the number of land-falling cyclones was 64 (compared to 88 from 1952-1979), 16 of which came ashore in Mozambique and 48 in Madagascar. Seasonal variations in areas of genesis and preferred tracks are presented and discussed in relation to a number of indices. Minimum and mean sea  surface temperatures for cyclone genesis are also estimated.Keywords: Tropical cyclones, Indian Ocean, Mozambique Channel, global change, sea surface temperatures, ENSO, landfall

Calibrating a sedimentary record of overwash from Southeastern New England using modeled historic hurricane surges

We present a 2000-year record of overwash deposits preserved in a backbarrier salt marsh from southeastern New England. The timing of recent deposits matches well with large hurricane-induced storm surge events documented by local tide gauges in 1991, 1960, 1954, and 1938. Storm surge modeling is used to evaluate the flooding history at the site as well as to assess the pre-instrumental historical record. Storms in 1815, 1727, and 1635 likely caused significant surge that overtopped the barrier, with the timing of coarse-grained overwash deposition correlating well with these events. We infer that twenty-three prehistoric layers mapped across the site were likely also deposited by landfalling hurricanes. Additional records from the area will help to evaluate whether or not temporal trends at the site are a robust representation of hurricane activity for the region. The frequency of overwash at Mattapoisett Marsh, on average 1.5 events per century, is significantly higher than many other overwash-based reconstructions from the western North Atlantic. Further, the Mattapoisett Marsh record does not contain significant multi-centennial gaps in overwash layers. This initial comparison of the data from Mattapoisett marsh with other reconstructions from the western North Atlantic may point toward relatively constant tropical cyclone frequency over the last 2000 years with significant variation in the number of intense tropical cyclones.

Thermodynamic control on the climate of intense tropical cyclones

How thermodynamic factors control the climate of intense tropical cyclones (TCs) is investigated by examining the relationship between the seasonally averaged maximum potential intensity (MPI, used as a representative index of the thermodynamic forcing) over an ocean basin where TCs form and the seasonal frequency of occurrence of intense TCs. It is found that only in the Atlantic does the MPI have a statistically significant relationship with the number of intense TCs, explaining about 40 per cent of the variance. In other ocean basins, there is either no correlation or the correlation is not statistically significant. In other words, only in the Atlantic are thermodynamic factors responsible, but still only to a certain extent, for the climate variations of intense TCs. In other ocean basins, it appears that the dynamic factors are much more dominant. Such a conclusion has important implications in considering whether global warming may influence the future climate of intense TCs for the following reason. Although it has been generally accepted that the thermodynamic energy available in the atmosphere is likely to increase under global warming, the results from this study suggest that such an increase does not necessarily imply a concomitant increase in the number of intense TCs, because how the dynamic factors will vary are still not clear. Until we can demonstrate that the dynamic factors will also become more favourable for TC intensification, it remains uncertain whether the frequency of occurrence of intense TCs will increase under a global warming scenario.

Historical deadly typhoons in the Philippines

, in China and Japan, are used. The physical mechanisms responsible for their development are complex and not fully understood, but it is known that they require high sea-surface temperatures (SST), a moderate Coriolis force, a pre-existent synoptic perturbation (normally a monsoon trough or easterly wave) and low wind shear (Fink and Speth, 1998; Galvin, 2008). The dependence on high sea tem-perature has opened the debate on a pos-sible increase in the frequency of tropical cyclones in a changing climate. It has been proposed that a rise in SST induced by the anthropogenic global warming has already led to a greater number of intense tropical cyclones in recent decades (Emanuel, 2005; Webster

Tropical Cyclone Climatology in a Global-Warming Climate as Simulated in a 20 km-Mesh Global Atmospheric Model: Frequency and Wind Intensity Analyses

Possible changes in the tropical cyclones in a future, greenhouse-warmed climate are investigated using a 20 km-mesh, high-resolution, global atmospheric model of MRI/JMA, with the analyses focused on the evaluation of the frequency and wind intensity. Two types of 10-year climate experiments are conducted. One is a present-day climate experiment, and the other is a greenhouse-warmed climate experiment, with a forcing of higher sea surface temperature and increased greenhouse-gas concentration. A comparison of the experiments suggests that the tropical cyclone frequency in the warm-climate experiment is globally reduced by about 30% (but increased in the North Atlantic) compared to the present-day-climate experiment. Furthermore, the number of intense tropical cyclones increases. The maximum surface wind speed for the most intense tropical cyclone generally increases under the greenhouse-warmed condition (by 7.3 m s−1 in the Northern Hemisphere and by 3.3 m s−1 in the Southern Hemisphere). On average, these findings suggest the possibility of higher risks of more devastating tropical cyclones across the globe in a future greenhouse-warmed climate.