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1.
By EOF, Power spectrum and nonlinear mapping methods, the temperature time series of May to July in Jianghuai river basins from 1948-2014 (67 years) were objectively divided into several climate stages. The time series were divided into three climate stages with similar lengths: the stage with its air temperature trend going downwards stage (1948-1970); the stage with its air temperature trend going upwards (1971-1994) and the stage with its air temperature trend going gentle upwards (1995-2014). Their climate characteristics can be quantified by a special climate index. Then, the statistic characteristics of Jianghuai cyclones in the three climate stages were compared with the cooling or warming trends. The results showed that characteristic evolutions of the frequency of yearly average of Jianhuai cyclones, the cyclones with their life cycles in the area longer than 48h, the cyclones with three types of thickness, shallow and bottom shapes classified according to the cyclone height, the cyclones with three kinds of zonal, meridional, and circular trajectory, responded to the temperature changing trends in the three climate stages. The cooling trends of the stage temperature restrained the activity of Jianghuai cyclones, and the warming trends of the stage temperature promoted the cyclone’s development, maintaining, activity, and also led cyclone moving towards to north further. The composite analysis of cyclone structures showed that the evolution characteristics in the center intensity, temperature grads, the maxima velocity of jet of the cyclones, and the intensity, length and position of the vapor flux passage of the Jianghuai cyclones, also the intensity, thickness, the positions of the warm and cold air masses within the cyclones, all responded to the trend change of stage temperature including cooling, warming and gentle warming. The results show clearly that temperature cooling reduces the intensity of cyclone structures and restrains the activity of cyclones in the temperatures trend down stage. The temperature warming enhances the stable development and strengthening of cyclone structure,and maintains the activity of cyclones in the temperature warming stages. 相似文献
2.
The cyclones over Bay of Bengal (BoB) have varied socio-economic impacts and meteorological importance. There are considerable uncertainties in predicting the track and intensity of cyclonic systems in the BoB. The present study examines the cyclogenesis characteristics over the BoB and addresses the regional impacts and their importance in terms of intensification of cyclones. An analysis of cyclone track data from 1971–2013 reveals that the cyclones generated in Andaman Sea (a regional sea of BoB) and propagating through central BoB sustain maximum life time. Furthermore, within the BoB, the cyclones originated from Andaman Sea are the most intensified and characterized by highest cyclogenesis potential index. Interestingly, we have found that higher value of mid-tropospheric relative humidity over Andaman Sea during the cyclone period is enhancing the cyclone’s intensity. Climatologically also the Andaman Sea is dominated by higher values of mid-tropospheric relative humidity compared to other regions of BoB. There is no significant distinction between Andaman Sea and rest of the BoB for other meteorological and oceanic parameters that supports cyclogenesis. Climatologically dominant east–west asymmetry in mid-tropospheric relative humidity is enhancing the intensity of cyclones from Andaman Sea. The results will be helpful in understanding the processes of cyclone intensification and useful in the statistical and dynamical prediction of cyclones. 相似文献
3.
This article estimates the non-first-order economic loss in Japan due to a future increase in tropical cyclones. One possible
effect of global warming could be the increase in intensity of tropical cyclones. Using historical storm tracks between the
years 1978 and 2007 and altering their intensities due to this potential increase in their intensity, this paper calculates
the future potential regional GDP loss in a certain area that is affected by tropical cyclones. Most of the literature is
concerned with physical damage and the loss of lives due to tropical cyclones. However, there are additional economic costs
when sustained wind speeds are higher than 30 knots (55.56 km/h), a level that generally will lead to a precautionary cessation
of many human activities. Using a Monte Carlo simulation, the paper calculates the potential economic costs for the year 2085
under a climate change scenario with a linear one-per cent yearly increase in CO2. Using a spatial distribution of economic activity in Japan, it is possible to forecast which parts of the country are likely
to experience the highest loss risk. 相似文献
4.
In recent years, tropical cyclones on the Pacific Northwest have decreased. We cannot infer that tropical cyclones impact China have reduced, because the Pacific Northwest is not homogeneous, and the variation characteristics of tropical cyclones in different sea areas are not clear. This paper uses gray relational density clustering algorithm to cluster tropical cyclone data sets between 1949 and 2008, according to the generated position of tropical cyclones, generated density and the possibility of landing. The Pacific Northwest is divided into different sea areas. Then, we analyze the risk of tropical cyclones generated in these sea areas. The results show that the probability of tropical cyclones landing generated in some sea areas is very high, reached 74 %, but the probability of tropical cyclones landing generated in other sea areas is only 2 %. Tropical cyclones generated in some sea areas are more likely to develop into typhoons, strong typhoons and so on, but the intensity of tropical cyclones generated in other sea areas is lower, there is little risk for China. Finally, according to the climate change stage trends, we divide the period 1949–2008 into three stages and analyze the tropical cyclone risk of each sea areas. 相似文献
5.
The aim of the present study is to understand the impact of oceanic heat potential in relation to the intensity of tropical cyclones (TC) in the Bay of Bengal during the pre-monsoon (April–May) and post-monsoon (October–November) cyclones for the period 2006–2010. To accomplish this, the two-layer gravity model (TLGM) is employed to estimate daily tropical cyclone heat potential (TCHP) utilizing satellite altimeter data, satellite sea surface temperature (SST), and a high-resolution comprehensive ocean atlas developed for Indian Ocean, subsequently validated with in situ ARGO profiles. Accumulated TCHP (ATCHP) is estimated from genesis to the maximum intensity of cyclone in terms of minimum central pressure along their track of all the cyclones for the study period using TLGM generated TCHP and six-hourly National Centre for Environmental Prediction Climate Forecast System Reanalysis data. Similarly, accumulated sea surface heat content (ASSHC) is estimated using satellite SST. In this study, the relationship between ATCHP and ASSHC with the central pressure (CP) which is a function of TC intensity is developed. Results reveal a distinct relationship between ATCHP and CP during both the seasons. Interestingly, it is seen that requirement of higher ATCHP during pre-monsoon cyclones is required to attain higher intensity compared to post-monsoon cyclones. It is mainly attributed to the presence of thick barrier layer (BL) resulting in higher enthalpy fluxes during post-monsoon period, where as such BL is non-existent during pre-monsoon period. 相似文献
6.
P. Chittibabu S. K. Dube J. B. Macnabb T. S. Murty A. D. Rao U. C. Mohanty P. C. Sinha 《Natural Hazards》2004,31(2):455-485
Storm surges generated by the strong tangential wind stressesand normal atmospheric pressure gradients at the sea surface due to tropical cyclones (TC'S)have been studied with the goal of detecting any significant and systematic changes due to climatechange. Cyclone and storm surge data for the 19th and 20th centuries for the Bay of Bengalcoast of the state of Orissa in India are available to varying degrees of quality and detail,the data being more scientific since the advent of the India Meteorological Department in 1875.Based on more precise data for the period 1971 to 2000, statistical projections have been madeon the probable intensities of tropical cyclones for various return periods. The super cyclone ofOctober 29, 1999 (SC1999) appears to have a return period of about 50 years. The cyclones of1831, 1885 and possibly the one in 1895 could have been super cyclones. During the 19th century,there were 72 flooding events associated with cyclones, whereas in the 20th century therewere only 56 events. There was no observational evidence to suggest that there was an increaseeither in the frequency or intensity of cyclones or storm surges on the coast of Orissa. However,the impact of cyclones and surges is on the increase due to increase of population and coastalinfrastructure. 相似文献
7.
Tropical cyclones are well-known extreme weather and the cause of considerable damages, injuries and loss of life. The assessment of the maximum sustained wind speed along the track of the tropical cyclones is very important for estimating the strength of the cyclones. The swarm intelligence in the form of ant colony optimization (ACO) technique is introduced in this study to compute the pheromone deposition along the track of tropical cyclones followed by neural nets to forecast the maximum sustained wind speed of the cyclones occurring over the Bay of Bengal of North Indian Ocean. The ACO is a nonlinear problem-based meta-heuristic optimization method for finding approximate solutions to discrete optimization problems and simulates the decision-making processes of ant colony similar to other adaptive learning techniques. The method has shown its application potential in various fields including the prediction of monsoon rainfall. In this study, the amount of pheromone deposition during the successive stages of the cyclones has been estimated. A range of minimum central pressure (MCP), central pressure drop (PD), maximum sustained wind speed (MSWS) and intensity (T-No) associated with the cyclones of Bay of Bengal are utilized to form the input matrix of the neural nets. The neural nets are trained to forecast the maximum sustained wind speed along the track of the tropical cyclones over Bay of Bengal. The result reveals that the errors in forecasting the MSWS along the track of tropical cyclones with 6, 12, 18 and 24 h lead time are 2.6, 2.9, 3.1 and 4.8, respectively. The result is compared with the existing dynamical, statistical and adaptive models to evaluate the skill of the present model. The result is well validated with observation. 相似文献
8.
Bangladesh is highly susceptible to tropical cyclones. Unfortunately, there is a dearth of climatological studies on the tropical
cyclones of Bangladesh. The Global Tropical Cyclone Climatic Atlas (GTCCA) lists historical storm track information for all
the seven tropical cyclone ocean basins including the North Indian Ocean. Using GIS, tropical cyclones that made landfall
in Bangladesh during 1877–2003 are identified and examined from the climatological perspective. For the convenience of study,
the coast of Bangladesh is divided into five segments and comparisons are made among the coastal segments in terms of cyclone
landfall and vulnerability. There is a large variability in the year-to-year occurrence of landfalling tropical cyclones in
Bangladesh. Most of the tropical cyclones (70%) hit in the months of May–June and October–November generally show the well-known
pattern of pre- and post-monsoon cyclone seasons in that region. 相似文献
9.
Tropical cyclones are the most hazardous weather systems, which form over warm ocean waters. The frequencies of tropical cyclones show variabilities over all the oceanic basins, during the El-Niño and El-Niño Modoki years. Recent studies have shown significant impact of air–sea interaction processes like El-Niño and El-Niño Modoki on the cyclone activity over different ocean basins. The results suggest in most cases, El-Niño events suppress the formation of cyclones over various basins. A recent study indicated that concurrent occurrence of El-Niño Modoki and positive Indian Ocean dipole (IOD) events can generate more cyclones over north-west Pacific. We propose to study the impact of El-Niño Modoki events on the formation of tropical cyclones over north Indian Ocean (NIO). Our present study suggests that the cyclogenesis over the NIO is a complex phenomenon, as it is influenced by several coupled ocean atmospheric phenomena such as El-Niño, El-Niño Modki, IOD and Madden–Julian oscillation. 相似文献
10.
P. K. Pal B. M. Rao C. M. Kishtawal M. S. Narayanan G. Rajkumar 《Journal of Earth System Science》1989,98(4):353-364
INSAT visible and infrared imageries of three cyclones in the Bay of Bengal during the period 1984–1987 were analysed with
a view to improve the cyclone track prediction in this region. It was observed that the rotation in the major structural cloud
features (as seen from the cloud-top temperature maps) associated with these cyclones in the Bay of Bengal is followed with
a change in direction of their movement. This method is seen to be particularly effective when the cyclone is severe and when
the major cloud features persist for a reasonably longer time. In the present study, only the direction of movement is forecast
assuming a uniform speed of the cyclone. 相似文献
11.
Tropical cyclones are a key climate-related hazard in South Asia. Assessment of the risk of cyclone impacts requires a comprehensive characterization of historical cyclone climatology. This study analyzes the tracks of tropical cyclones in the North Indian Ocean. Based on their spatial characteristics, cyclone tracks appear to be grouped into five well-defined clusters. These clusters correspond to distinct regions of cyclonic activity and exhibit differences in characteristics such as genesis location, probability of landfall, duration, and maximum intensity. Some of the identified clusters appear particularly important with regard to impacts because events in these clusters have greater landfall probability and are more intense. The clustering approach is likely to provide useful insights for the characterization of cyclone risk. 相似文献
12.
Chen Changsheng Lin Zhaolin Beardsley Robert C. Shyka Tom Zhang Yu Xu Qichun Qi Jianhua Lin Huichan Xu Danya 《Natural Hazards》2021,106(1):375-399
Natural Hazards - Hurricanes (tropical cyclones) and nor'easters (extratropical cyclones) are two major storm systems for flood risk over the Massachusetts coast. Severe coastal inundation... 相似文献
13.
Modeling the effects of tropical cyclones on flooding in the Santa Fe river basin,Florida 总被引：1，自引：0，他引：1
Peter R. Waylen 《GeoJournal》1991,23(4):361-373
14.
15.
对国内外5个石英脉型金矿床的研究表明,矿田中的含金石英脉往往成群出现,并呈弧形帚状分布,帚状脉群的收敛端方向一致地显示为逆时针旋转方向。这一规律可能与科里奥利力产生的涡旋作用有关。 相似文献
16.
In this paper, the main meteorological and meteorologically induced marine disasters in Shanghai are climatologically investigated on the basis of historical qualitative documentary records and quantitative data. Statistics show that disasters may be classified into six different kinds, of which three are fundamental, i.e. floods, winds, and storm surges. Emphasis is placed on the detailed analysis and discussion of floods, tropical cyclones, and Mei-yu which affect Shanghai and cause destructive calamities.Firstly, the classification of floods, their frequencies, and geographical distribution characteristics are described and the regulation of the climatic variation of floods is revealed. Secondly, the frequency, source regions, seasonal variations, tracks, and translatory speeds of tropical cyclones affecting Shanghai, and their induced strong winds, storm rainfalls, and storm surges are systematically studied. Many meaningful conclusions have been reached for providing the climatological background of Shanghai.The climatic change and its regulation of these main disasters in Shanghai have been basically clarified throughout this study. 相似文献
17.
Jeff Callaghan 《Natural Hazards》2003,30(2):129-153
Because of its location close to a region of tropical cyclone formation, the city ofCairns is regularly affected by tropical cyclones. Most cyclones occur in the monthsJanuary–March, although some have affected Cairns in December and April. There is a strong year-to-year variation in tropical cyclone numbers in the Cairns region, with twice as many impacts occurring during La Niña conditions than during El Niño. Several case studies are presented of cyclone impacts on Cairns. Rapidly developing cyclones are a particularly difficult forecast problem, as they can strike the city with less than 24 hours warning. Serious inundation from storm surge often occurs some time after landfall at Cairns. 相似文献
18.
Research efforts focused on assessing the potential for changes in tropical cyclone activity in the greenhouse-warmed climate
have progressed since the IPCC assessment in 1996. Vulnerability to tropical cyclones becoming more pronounced due to the
fastest population growth in tropical coastal regions makes it practically important to explore possible changes in tropical
cyclone activity due to global warming. This paper investigates the tropical cyclone activity over whole globe and also individually
over six different ocean basins. The parameters like storm frequency, storm duration, maximum intensity attained and location
of formation of storm have been examined over the past 30-year period from 1977 to 2006. Of all, the north Atlantic Ocean
shows a significant increasing trend in storm frequency and storm days, especially for intense cyclones. Lifetime of intense
tropical cyclones over south Indian Ocean has been increased. The intense cyclonic activity over north Atlantic, south-west
Pacific, north and south Indian Ocean has been increased in recent 15 years as compared to previous 15 years, whereas in the
east and west-north Pacific it is decreased, instead weak cyclone activity has been increased there. Examination of maximum
intensity shows that cyclones are becoming more and more intense over the south Indian Ocean with the highest rate. The study
of the change in the cyclogenesis events in the recent 15 years shows more increase in the north Atlantic. The Arabian Sea
experiences increase in the cyclogenesis in general, whereas Bay of Bengal witnesses decrease in these events. Shrinking of
cyclogenesis region occurs in the east-north Pacific and south-west Pacific, whereas expansion occurs in west-north Pacific.
The change in cyclogenesis events and their spatial distribution in association with the meteorological parameters like sea
surface temperature (SST), vertical wind shear has been studied for Indian Ocean. The increase in SST and decrease in wind
shear correspond to increase in the cyclogenesis events and vice versa for north Indian Ocean; however, for south Indian Ocean,
it is not one to one. 相似文献
19.
Coastal northern Australia is largely owned and occupied by Aboriginal people who are strongly connected to their traditional country. We assess the views of Aboriginal people in Arnhem Land on the impacts of climate change and their possible precautionary responses to both sea level rise and a potential increase in the intensity of tropical cyclones in coastal communities. All respondents had heard about climate change, and 48 % had already seen environmental changes, particularly sea level rise, which they attributed to climate change. Fifty-eight percent of respondents would consider relocating in the future for safety reasons, although most respondents perceived living close to the sea as highly important for their future well-being, emphasising their strong connection to their traditional sea country. Many of those willing to relocate would consider moving inland, either temporarily or permanently, provided that community facilities could also be moved. Other respondents who said they would be unlikely to relocate in the future because of climate change impacts, and would prefer to adapt in situ with government support (e.g. building more shelters for severe cyclones, building sea walls and better roads for quick evacuation if necessary). We recommend that the diversity of adaptation preferences among Aboriginal people should be accommodated in policy to minimise social impacts of climate change and to take advantage of potential opportunities that could arise from moving. 相似文献
20.
In this paper, we consider a Markov renewal process (MRP) to model tropical cyclones occurred in Bangladesh during 1877–2009. The model takes into account both the occurrence history and some physical constraints to capture the main physical characteristics of the storm surge process. We assume that the sequence of cyclones constitutes a Markov chain, and sojourn times follow a Weibull distribution. The parameters of the Weibull MRP jointly with transition probabilities are estimated using the maximum likelihood method. The model shows a good fit with the real events, and probabilities of occurrence of different types of cyclones are calculated for various lengths of time interval using the model. Stationary probabilities and mean recurrence times are also calculated. A brief comparison with a Poisson model and a marked Poisson model has also been demonstrated. 相似文献