The influence of tropical cyclones upon the Earth’s crust

Doklady Earth Sciences - This paper discusses the influence of tropical cyclones (TCs) upon the Earth’s crust beneath the ocean bottom, which is associated with rapid variations of pressure...     

Prediction of severe tropical cyclones over the Bay of Bengal during 2007–2010 using high-resolution mesoscale model

In this paper, the performance of a high-resolution mesoscale model for the prediction of severe tropical cyclones over the Bay of Bengal during 2007?C2010 (Sidr, Nargis, Aila, and Laila) is discussed. The advanced Weather Research Forecast (WRF) modeling system (ARW core) is used with a combination of Yonsei University PBL schemes, Kain-Fritsch cumulus parameterization, and Ferrier cloud microphysics schemes for the simulations. The initial and boundary conditions for the simulations are derived from global operational analysis and forecast products of the National Center for Environmental Prediction-Global Forecast System (NCEP-GFS) available at 1°lon/lat resolution. The simulation results of the extreme weather parameters such as heavy rainfall, strong wind and track of those four severe cyclones, are critically evaluated and discussed by comparing with the Joint Typhoon Warning Center (JTWC) estimated values. The simulations of the cyclones reveal that the cyclone track, intensity, and time of landfall are reasonably well simulated by the model. The mean track error at the time of landfall of the cyclone is 98?km, in which the minimum error was found to be for the cyclone Nargis (22?km) and maximum error for the cyclone Laila (304?km). The landfall time of all the cyclones is also fairly simulated by the model. The distribution and intensity of rainfall are well simulated by the model as well and were comparable with the TRMM estimates.     

Estimation of the compound hazard severity of tropical cyclones over coastal China during 1949–2011 with copula function

The site effect plays very important role for planning design of structures and estimating seismic damage of existing structures, especially in seismicity active regions. Alia?a, located in the northern region of the ?zmir City, is high seismically active region in western Turkey. We identified the dynamic properties of shallow soil for Alia?a district (western Turkey) in terms of the average shear-wave velocity for the top 30 m of soil (Vs₃₀), predominant period (T ₀) and vulnerability index (Kg). We created the microzonation map that classes the shallow soil according to National Earthquake Hazards Reduction Program (NEHRP). Shear-wave velocity (Vs) was evaluated using the 1-D multichannel analysis of surface waves at 34 sites. The microtremor measurements were taken at 58 stations with a grid spacing of 1000 m in Alia?a district. The acquired HVSR results show that the T ₀ values change from 0.1 to 1.9 s, while the amplification factor (A ₀) values change between 1.5 and 12. Soil classification results illustrate that northern part of the study area, located in alluvial unit, has lower Vs₃₀ values. These values are observed within the range of 100–300 m/s. This part was classified as the D and E types according to NEHRP. In addition, the weak zones of the study area due to the local site effects were indicated by the Kg values which vary from 5 to 55. The northern part of the study area is high vulnerability index zone (Kg > 20). Last of all, we can mention that the northern part of our study area is the weakest zone according to the results of geophysical and geological data.     

Species composition and forest structure in tropical moist deciduous forest of Bangladesh—a case study in Thakurgaon

This study was conducted in the tropical moist deciduous forest in Bangladesh to describe the species composition, diversity, and the forest structure. There were three plots established in Ranishonkoil, Ruhia, and Baliadangi forest beat in Thakurgaon. A total of 126 tree species, 1,991 stems (663 ha^?1) of ≥10-cm girth were listed. Tree communities in these forest region differed in dominance, composition, diversity, and structure; and tree stand density varied from 651 to 685 ha^?1. Species diversity (H¹) ranges from 3.11 to 3.48. Meliaceae, Myrtaceae, and Rubiaceae were the most abundant families within the three plot area. Study site 2 is more diverse at spatial scale and taxonomic levels due to high rainfall and favorable edaphic condition. This study will help the foresters as baseline information for monitoring and sustaining diversity of tropical moist deciduous forests in Bangladesh.     

Characteristics of the changes in tropical cyclones influencing the South Korean region over the recent 10 years (2001–2010)

Through the investigation of tropical cyclone (TC) characteristics related to climate change, this study found that the frequency of TCs occurring over the Western North Pacific has recently decreased slightly, while their average intensity has increased. The number of overall TCs that passed within the vicinity of South Korea has also been reduced, but the number of strong typhoons in the area, those with maximum wind speeds of more than 44 m/s, has significantly increased. These changes are closely related to the following phenomena. (1) The average genesis region of TCs that influence South Korea has moved eastward. Accordingly, the TCs tend to strengthen as they move westward for long distances along the Intertropical Convergence Zone (ITCZ) trade easterlies and the southern boundary of the North Pacific Subtropical High (NPSH). (2) The NPSH and Asia Monsoon trough, which are known to affect TC tracks, have extended to the northwest and southeast. This has caused TCs that travel to higher latitudes and curve back toward the Korean Peninsula to become more frequent. (3) TCs have approached the Korean Peninsula without hitting land. In addition, the sea surface temperature became higher than it was before. These factors have caused TCs to maintain their strength or become stronger than before.     

Probabilistic assessment of tropical cyclones’ extreme wind speed in the Bay of Bengal: implications for future cyclonic hazard

Natural Hazards - Tropical cyclones (TCs) of the Bay of Bengal (BoB) cause catastrophic loss over the coasts at the time of landfall in India, Bangladesh, Myanmar and Sri Lanka. To strengthen...     

Climatology of rainfall erosivity during 1961–2012 in Jiangsu Province,southeast China

Natural Hazards - Based on daily precipitation records at 52 meteorological stations in Jiangsu Province, southeast China, the space and time changes of characteristics in rainfall erosivity (RE)...     

Climatology and trends of summer high temperature days in India during 1969–2013

Journal of Earth System Science - Based on the daily maximum air temperature data from 176 stations in India from 1969 to 2013, the climatological distribution of the number of days with high...     

Households’ experience of local government during recovery from cyclones in coastal Bangladesh: resilience,equity, and corruption

Households’ links with local Government provide important support for disaster resilience and recovery on the Bangladeshi coast. Few previous studies of disaster resilience and recovery have explored how linking social networks—and in particular local government—contribute. Using household surveys, focus groups, and key informant interviews, we examine strengths and weaknesses of local government’s contribution, using two cyclone-affected coastal villages as case studies. The findings show that local government provides important support, for example relief distribution, livelihood assistance, and reconstruction of major community services. However, patronage relationships (notably favouring political supporters) and bribery play a substantial role in how those responsibilities are discharged. The equity and efficiency of these contributions to recovery are markedly diminished by corruption. Reducing corruption in UP’s contributions to disaster recovery could significantly improve resilience; however, general reform of governance in Bangladesh would needed to bring this about.     

Exposure of US counties to Atlantic tropical storms and hurricanes, 1851–2003

Exposure of counties in the continental United States to tropical storm and hurricane conditions was determined using the historic record of storm tracks for the period 1851–2003. Two approaches were used to determine exposure: (1) cumulative number of hits, with a hit occurring when the storm’s path crosses a county and (2) cumulative exposure factor, which describes how much of the county has been exposed to tropical storm, hurricane, and intense hurricane-force winds. In both approaches the top 10 counties in terms of cumulative exposure are in coastal Florida, North Carolina, and Louisiana. An explanatory model was developed to describe the patterns in the documented exposure, which included distance to coast, latitude, longitude, size, and shape of the counties. Multivariate linear regression confirmed that much of the spatial variability in exposure to storm conditions can be explained with these simple parameters.     

Citizenship,abandonment and resistance in the India–Bangladesh borderland

Drawing on ethnography in the enclaves in India and Bangladesh, this paper explores a multifaceted yet enduring relationship between citizenship, abandonment and resistance. Following the partition in 1947, the enclave residents’ citizenry was enacted like other Indian or Bangladeshi citizens’ disregarding these enclaves’ trans-territorial reality. This paper will demonstrate that enclave dwellers did not live in the ‘citizenship gap’, the difference between rights and benefits of citizenship, rather they lived without any citizenship rights. Life in these enclaves was highly complex and experiences in the enclaves challenge the usefulness of citizenship as a universal framework of analysis for the people who are ranked as citizen but never have it. In this context, a combination of the reverse conceptualisation such as citizenship and Agamben’s conceptualisation of abandonment not only allows for these dimensions of lived experiences to be addressed and explored, it also focuses on the temporal aspect of citizenship implicated in politics. Finally, the paper calls for widening the consideration of the empirical study on everyday citizenship practices and experiences around the globe to extend and intensify the citizenship literatures.     

Variability of the gravitational lens UM 673 in 2003–2005

Results of VRI photometry of two components of the gravitationally lensed quasar UM 673 in 2003–2005 are presented. The observational data were obtained on the 1.5-m telescope of the Maidanak observatory. During the monitoring of the system, considerable brightness variations in components A and B with amplitudes of about 0.2 ^m were recorded, demonstrating variability of the quasar. The increase in the brightness of the components was accompanied by reddening of their V-R color indices. Analysis of the brightness and color variations of the components shows no variations related to microlensing.     

Behaviour of REE during weathering of granite in a tropical climate

Weathering is essentially a leaching process and thus, one way of determining the extent of weathering is to monitor the mobility of different elements. Rate of loss of elements in a weathering profile can be determined by comparing the concentrations of …     

Development of Tide–Surge Interaction Model for the Coastal Region of Bangladesh

In this paper, a two-dimensional, vertically integrated hydrodynamic model is developed taking into account entrained air bubbles during storm surges as well as incorporating inverted barometer, and river and land dynamics. The model is specifically designed for the coastal region of Bangladesh. A nested scheme method with a fine mesh scheme (FMS), capable of incorporating the complex coastline and all major offshore islands accurately, nested into a coarse mesh scheme (CMS) covering up to 15° N latitude in the Bay of Bengal is used. To incorporate the small and big offshore islands in the Meghna estuarine region with its complex coastline accurately, a very fine mesh scheme (VFMS) is again nested into the FMS. Along the northeast corner of the VFMS, the Meghna river discharge is taken into account. The coastal and island boundaries are approximated through proper stair steps. The model equations are solved by a semi-implicit finite difference technique using a staggered C-grid. A stable appropriate tidal condition over the model domain is generated by applying tidal forcing with the four major tidal constituents M ₂, S ₂, K ₁, and O ₁ along the southern open boundary of the CMS. This tidal regime is introduced as the initial state of the sea for nonlinear interaction of tide and surge. The model is applied to simulate water levels due to the interaction of tide and surge associated with the cyclones April 1991 and Aila at different coastal and island locations along the coast of Bangladesh. The results are found to be quite satisfactory with root mean square error of ～0.50 m as calculated for both the storm events. Tests of sensitivities on water levels are carried out for air bubbles, offshore islands, river discharge, inverse barometer, and grid resolution. The presence of air bubbles increases simulated water levels a little bit in our model, and the contribution of air bubbles in increasing water level is found around 2 %. Further, water levels are found to be influenced by offshore islands, river discharge, inverse barometer as well as grid resolution.