DOCSLIB.ORG

Numerical Simulations of Myanmar Cyclone Nargis and the Associated Storm Surge Part I: Forecast Experiment with a Nonhydrostatic Model and Simulation of Storm Surge

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Numerical Simulations of Myanmar Cyclone Nargis and the Associated Storm Surge Part I: Forecast Experiment with a Nonhydrostatic Model and Simulation of Storm Surge Journal of the Meteorological Society of Japan, Vol. 88, No. 3, pp. 521--545, 2010. 521 DOI:10.2151/jmsj.2010-315 Numerical Simulations of Myanmar Cyclone Nargis and the Associated Storm Surge Part I: Forecast Experiment with a Nonhydrostatic Model and Simulation of Storm Surge Tohru KURODA, Kazuo SAITO, Masaru KUNII Meteorological Research Institute, Tsukuba, Japan and Nadao KOHNO Japan Meteorological Agency, Tokyo, Japan (Manuscript received 27 May 2009, in final form 25 February 2010) Abstract Numerical simulations of the 2008 Myanmar cyclone Nargis and the associated storm surge were conducted using the Japan Meteorological Agency (JMA) Nonhydrostatic Model (NHM) and the Princeton Ocean Model (POM). Although the JMA operational global analysis (GA) and the global spectral model (GSM) forecast underestimated Nargis’ intensity, downscale experiments by NHM with a horizontal resolution of 10 km using GA and GSM forecast data reproduced the development of Nargis more properly. Sensitivity experiments to study the e¤ects of ice phase, sea surface temperature (SST), and horizontal resolu- tions to Nargis’ rapid development were conducted. In a warm rain experiment, Nargis developed earlier and the eye radius became larger. It was shown that a high SST anomaly preexistent in the Bay of Bengal led to the rapid intensification of the cyclone, and that SST at least warmer than 29C was necessary for the development seen in the experiment. In a simulation with a horizontal resolution of 5 km, the cyclone exhibited more distinct develop- ment and attained a center pressure of 968 hPa. Numerical experiments on the storm surge were performed with POM whose horizontal resolution is 3.5 km. An experiment with POM using GSM forecast data could not reproduce the storm surge, while a simulation us- ing NHM forecast data predicted a rise in the sea surface level by over 3 m. A southerly sub-surface current driven by strong surface winds of the cyclone caused a storm surge in the river mouths in southern Myanmar fac- ing the Andaman Sea. Our results demonstrate that the storm surge produced by Nargis was predictable two days before landfall by a downscale forecast with a mesoscale model using accessible operational numerical weather prediction (NWP) data and application of an ocean model. 1. Introduction tion is important for preventing and mitigating me- teorological disasters. In the areas around the Bay Severe meteorological phenomena such as tropi- of Bengal, historically, there have been several cal cyclones (TCs) sometimes cause catastrophic cases in which storm surges induced by TCs gave damage to human society; therefore, their predic- rise to severe floods (Obashi 1994). In cases such as the 1970 Bohla cyclone (Frank and Husain 1971) Corresponding author: Tohru Kuroda, Meteorological and the 1991 Bangladesh cyclone (Katsura et al. Research Institute, 1-1, Nagamine Tsukuba, Ibaraki 1992; Bern et al. 1993), cyclones generated in the 305-0052, Japan. E-mail: [email protected] central area of the bay moved northward and 6 2010, Meteorological Society of Japan made landfall in Bangladesh, and the associated 522 Journal of the Meteorological Society of Japan Vol. 88, No. 3 storm surges destroyed the lowlands of that coun- experiments, in which the JMA global spectral try. In 2007, cyclone Sidr struck the same area and model (GSM) forecast data are used as the lateral caused considerable destruction (MFDM Bangla- boundary conditions are conducted. Also, the re- desh 2008; Hasegawa et al. 2008). sults are compared with a reproduction experiment, In contrast with the above cases, cyclone Nargis in which global analyses (GA) are used as the lat- that was generated at the end of April 2008, moved eral boundary conditions instead of the GSM fore- eastward. On May 2, it made landfall in southern cast in order to observe the impact of the accuracy Myanmar during its strongest period and caused a of the lateral boundary value. destructive storm surge over the Irrawaddy Delta 2) To investigate the impact of the sea surface and other low-lying areas that claimed more than temperature (SST) and the physical process on the one hundred thousand lives (Webster 2008). For di- rapid development of Nargis: saster prediction in the areas mentioned above, SST is an important factor controlling the devel- forecasts of TCs and the associated storm surges opment of tropical cyclones. McPhaden et al. (2009) based on numerical weather prediction (NWP) are pointed out that there was a preexisting warm particularly important. anomaly of SST in the Bay of Bengal in late April Since 2007, a research project called ‘‘Interna- 2008 and inferred that this had contributed to the tional Research for Prevention and Mitigation of rapid intensification of Nargis. Lin et al. (2009) Meteorological Disasters in Southeast Asia’’ has determined that there were warm anomalies not been conducted by the Kyoto University, the Mete- only in the SST but also in the temperatures of orological Research Institute (MRI), and other in- the subsurface layer, and showed that this situation stitutes in Southeast Asian countries (Yoden et al. reduced the cyclone-induced ocean cooling by 2008; Koh and Teo 2009). The goals of this project using numerical experiments with a one-dimensional are to demonstrate the applicability of downscale ocean mixed layer model. However, neither Mc- NWP in Southeast Asia and to propose a decision Phaden et al. (2009) nor Lin et al. (2009) have con- support tool for preventing and mitigating meteo- ducted numerical simulation of Nargis using a full- rological disasters. From this point of view, we se- scale atmospheric model. In this paper, we examine lected the devastating disasters caused by Nargis as the impact of SST on Nargis’ development through one of the most important targets that we should sensitivity experiments using di¤erent SST datasets. study in this project. We assumed a minimum lead The impact of ice phase on Nargis’ development is time of two days before the landfall in order to ef- also examined, and the results are compared with fectively mitigate Nargis’ storm surge damage and the study by Sawada and Iwasaki (2007), in which set the initial time of our simulation as 12 UTC on simplified conditions including a horizontally uni- April 30, 2008, the time when Nargis started its form background were used. The impact of hori- eastward movement and one day before its rapid zontal resolution is also examined. These sensitivity development. Considering the project’s purpose experiments are not necessarily comprehensive, but and the real-time accessibility to data required for they give us information that help us to understand downscale NWP, the Japan Meteorological Agency the magnitude of the influence of the model un- (JMA) nonhydrostatic model (NHM) and the certainty with respect to the influence of the initial JMA’s operational global data are used as the fore- and boundary conditions on Nargis’ rapid develop- cast model and for obtaining the initial and/or ment. boundary conditions, respectively; the model and 3) To examine the predictability of storm surges the data are available and accessible to registered using downscale NWP and an ocean model: users in Southeast Asia. As for storm surges on the Bay of Bengal, In this paper, we conduct numerical simulation Flather (1994) studied storm surges associated with of Nargis and the associated storm surge for the the 1970 Bohla cyclone (Frank and Husain 1971) following purposes and scientific interests: and the 1991 Bangladesh cyclone using a numerical 1) To examine the predictability of Nargis two ocean model. However, this was a two-dimensional days before its landfall by downscale NWP using open sea model, with surface winds and pressures NHM and data available to Southeast Asian re- derived from a semi-analytical cyclone model using searchers: the best track data supplied by the US Navy Joint Considering the practical availability of the ex- Typhoon Warning Center (JTWC). periment in the case of real-time operation, forecast Recently, Kim et al. (2006) conducted numerical June 2010 T. KURODA et al. 523 simulation of the storm surge of Hurricane Ka- proached southern Myanmar. The minimum center trina, which damaged the city of New Orleans pressure estimated by JTWC was 937 hPa, while in the United States of America in 2005. The RSMC estimated its intensity as 962 hPa. The rain- simulation results obtained using a sophisticated fall rate observed by the Tropical Rainfall Measur- atmosphere-wave-ocean coupled model were in ing Mission’s Microwave Imager (TRMM/TMI) at agreement with the actual observations. However, 0137 UTC on May 2 is indicated in Fig. 2, which for achieving a practical disaster prevention, sim- depicts the typical structure of a developed cyclone pler surge predictions using a downscale mesoscale with a compact central dense overcast (CDO) and NWP and a one-way nested ocean model may be distinct spiral rainbands. After landfall at around more desirable, with application to the Bay of 09–12 UTC on May 2, the cyclone moved inland Bengal as an urgent subject (Dube et al. 2009). to the northeast, passing over southern Myanmar In this study, we conduct a numerical simulation and rapidly decayed. of the storm surge of Nargis, applying the Prince- 2.2 Storm surge of Nargis ton Ocean Model (POM) to the Bay of Bengal. The destructive damage in southern Myanmar The advantages of the NHM-simulated surface during the passage of Nargis was primarily caused winds and pressures over the GSM forecast will be by the storm surge, though the estimated maximum shown. wind speed exceeded 40 m/s. Since the river deltas This paper is organized as follows: Section 2 re- in southern Myanmar are low-lying, the storm views the characteristic features of Nargis and its surge reached inland several tens of kilometers associated storm surge.
Load more

Recommended publications
  • 2.Conference-APP Disaster Impact on Sundarbans
    IMPACT: International Journal of Research in Applied, Natural and Social Sciences (IMPACT: IJRANSS) ISSN(P): 2347-4580; ISSN(E): 2321-8851 Special Edition, Sep 2016, 5-12 © Impact Journals DISASTER IMPACT ON SUNDARBANS - A CASE STUDY ON SIDR AFFECTED AREA MOHAMMAD ZAKIR HOSSAIN KHAN Institute of Disaster Management and Vulnerability Studies, Dhaka University, Bangladesh ABSTRACT The primary indicators of environmental sustainability is the biodiversity and its conservation stated by Kates et al. (2001), whereas the assessment of biomass and floristic diversity in tropical forests has been identified as a priority by many international organizations stated by Stork et al. (1997). Cyclone ‘Sidr’, a tropical cyclone, was one of the biggest cyclones in the history of Bangladesh, formed in the central Bay of Bengal hit the coast of Bangladesh in 2007 and it made landfall on 15th of November with peaking wind speed of over 260 km/h. It resulted in an estimated 4,000 human deaths and the displacement of over 3 million people stated by US Embassy Dhaka (2007). The most significant devastating impact it left behind is on the diversity of flora of the Sundarbans. One quarter of the biomass cover (which is approximately 2500 sq. km) of the Sundarbans mangrove forest was damaged by the storm directly or indirectly due to the tidal surge stated by CEGIS (2007). The study shows that the total forest area damaged by the cyclone Sidr was about 21% of the Sundarbans. It was found that highly affected forest areas were dominated by Keora ( Sonneratia apetala ). Trees of Keora are comparatively taller more than 15 m and grow on newly accreted forest land.
    [Show full text]
  • Cyclone Disaster Vulnerability and Response Experiences in Coastal
    Cyclone disaster vulnerability and response experiences in coastal Bangladesh Edris Alam Assistant Professor and Disaster and Development Centre Affiliate, Department of Geography and Environmental Studies, University of Chittagong, Bangladesh and Andrew E. Collins Reader in Disaster and Development, Disaster and Development Centre, School of Applied Sciences, Northumbria University, United Kingdom For generations, cyclones and tidal surges have frequently devastated lives and property in coastal and island Bangladesh. This study explores vulnerability to cyclone hazards using first-hand coping recollections from prior to, during and after these events. Qualitative field data suggest that, beyond extreme cyclone forces, localised vulnerability is defined in terms of response processes, infrastructure, socially uneven exposure, settlement development patterns, and livelihoods. Prior to cyclones, religious activities increase and people try to save food and valuable possessions. Those in dispersed settlements who fail to reach cyclone shelters take refuge in thatched-roof houses and big-branch trees. However, women and children are affected more despite the modification of traditional hierarchies during cyclone periods. Instinctive survival strategies and intra-community cooperation improve coping post cyclone. This study recommends that disaster reduction programmes encourage cyclone mitigation while being aware of localised realities, endogenous risk analyses, and coping and adaptation of affected communities (as active survivors rather than helpless victims). Keywords: coastal and island people of Bangladesh, coping, cyclone vulnerability, local response Introduction With the effects of natural hazards rising in terms of loss of life and injuries in poorer nations (ISDR, 2002; World Bank, 2005; CRED, 2007), institutional disaster reduction approaches (ISDR, 2004; UNDP, 2004; DFID, 2005) and approaches adaptable to individual social and livelihood experiences are required.
    [Show full text]
  • Drew University College of Liberal Arts Analyzing Community-Based
    Drew University College of Liberal Arts Analyzing Community-based and Centralized Approaches to Natural Disaster Management: A Comparative Case Study Analysis in Southeast Asia A Thesis in Environmental Studies and Sustainability by Brett Cheadle Submitted in Partial Fulfillment of the Requirements for the Degree of Bachelor in Arts With Specialized Honors in Environmental Studies and Sustainability May 2021 Abstract Tropical cyclones are among the worst of natural disasters that occur on a regular basis, affecting millions of people annually. Although not all regions experience the threat of intense cyclonic events, certain regions are highly susceptible to the devastating effects that are present with these storms. With the growing concern regarding climate change, vulnerable countries are forced to examine disaster management policy and analyze the potential risks associated with natural disasters and how they could impact populations in an altered climate going forward. This paper addresses the mechanisms that were in place in the disaster management efforts in Bangladesh and Myanmar and to what extent they were effective in reducing risk for vulnerable populations. A comparative case study analysis was conducted using Cyclone Sidr which struck Bangladesh in 2007 and Cyclone Nargis which impacted Myanmar in 2008, both occurring within a relatively similar time frame. The contrasting disaster management approaches of top-down and bottom-up approaches were identified and results indicate that the community based approaches appeared to be more effective in reducing risk for vulnerable populations, yet a wide variety of attributable factors were also uncovered in this study. Table of Contents 1. Introduction………………………………………………………1 2. Literature Review………………………………………………..6 a.
    [Show full text]
  • Field Surveys of Recent Storm Surge Disasters
    Available online at www.sciencedirect.com ScienceDirect Procedia Engineering 116 ( 2015 ) 179 – 186 8th International Conference on Asian and Pacific Coasts (APAC 2015) Department of Ocean Engineering, IIT Madras, India. Field Surveys of Recent Storm Surge Disasters Tomoya Shibayama* Professor, Department of Civil and Environmental Engineering Director, Complex Disaster Research Institute Waseda University, Okubo, Shinjuku-ku, Tokyo 169-8555, Japan Abstract In these ten years since 2004, there were more than ten big disasters in coastal area including six storm surge events and five tsunami events. The author performed post disaster surveys on all these events as the team leaders of survey teams. Based on those experiences, the author describes lessons of these events. Tsunami is now generally well known to coastal residents. Evacuation plans gradually become common for tsunami disasters. Storm surges arise more frequently due to strong storms but coastal residents are not well protected and not informed how to evacuate in case of surge emergency. From the field surveys conducted, it appeared that the damage depend on the geographical and social conditions of each of the areas that were visited by the author. It is now clear that such issues play important roles in disaster mechanisms. Therefore disaster risk management should carefully include local topography and social conditions of each area during the formulation of disaster prevention plans. In order to establish a reliable disaster prevention system, appropriate protection structures should be constructed, and these should be accompanied by a clear and concise evacuation plan for residents of a given area. © 2015 The Authors. Published by Elsevier Ltd.
    [Show full text]
  • Country Report: Bangladesh
    The 5th International Coordination Group (ICG) Meeting GEOSS Asian Water Cycle Initiative (AWCI) Tokyo, Japan, 15-18, December 2009 Country Report: Bangladesh Monitoring and forecasting of cyclones SIDR and AILA Colonel Mohammad Ashfakul Islam Engineer Adviser Ministry of Defence Government of the People’s Republic of Bangladesh Dhaka, Bangladesh Introduction • Bangladesh is a deltaic land of about 144,000 sq. km area having great Himalayas to the north and the vast Bay of Bengal on the south. • It is a South Asian country extending from 20° 45' N to 26° 40' N and from 88°05' E to 92°40' E belonging to the South Asian Association for Regional Cooperation (SAARC). • It has a complex coast line of about 710 kms and long continental shelf with shallow bathymetry. • The Bay of Bengal forms a funneling shape towards the Meghna estuary and for that the storm surge is the highest here in the world. • Bangladesh Meteorological Department (BMD) is the national meteorological service in Bangladesh under the Ministry of Defence of the Government of the People’s Republic of Bangladesh is mandated for cyclone forecasting. • Cyclone Preparedness Programme (CPP) under Bangladesh Red Crescent Society (BDRCS) forwards cyclone warning bulletins to 42,675 coastal volunteers for saving coastal vulnerable people. Position of Bangladesh in the World Map and in the Asia Map Bangladesh Topography of Bangladesh • Land elevation of 50% of the country is within 5 m of MSL - About 68% of the country is vulnerable to flood - 20-25% of the area is inundated during normal flood Bangladesh is the most disaster prone area in the world.
    [Show full text]
  • Manual on Cyclone
    Scope of the Manual This manual is developed with wider consultations and inputs from various relevant departments/ministries, UN Agencies, INGOs, Local NGOs, Professional organizations including some independent experts in specific hazards. This is intended to give basic information on WHY, HOW, WHAT of a disaster. It also has information on necessary measures to be taken in case of a particular disaster in pre, during and post disaster scenario, along with suggested mitigation measures. It is expected that this will be used for the school teachers, students, parents, NGOs, Civil Society Organizations, and practitioners in the field of Disaster Risk Reduction. Excerpts from the speech of Ban Ki-moon, Secretary-General of the United Nations Don’t Wait for Disaster No country can afford to ignore the lessons of the earthquakes in Chile and Haiti. We cannot stop such disasters from happening. But we can dramatically reduce their impact, if the right disaster risk reduction measures are taken in advance. A week ago I visited Chile’s earthquake zone and saw how countless lives were saved because Chile’s leaders had learned the lessons of the past and heeded the warnings of crises to come. Because stringent earthquake building codes were enforced, much worse casualties were prevented. Training and equipping first responders ahead of time meant help was there within minutes of the tremor. Embracing the spirit that governments have a responsibility for future challenges as well as current ones did more to prevent human casualties than any relief effort could. Deaths were in the hundreds in Chile, despite the magnitude of the earthquake, at 8.8 on the Richter Scale, the fifth largest since records began.
    [Show full text]
  • Bangladesh Cyclone Sidr Was the Second Occasion Habitat for Humanity* Responded to a Natural Disaster in Ban- Gladesh
    Habitat for Humanity: The Work Transitional Shelters As480 of December 2008 Latrines As480 of February 2009 A Day in November On 15th November 2007, Cyclone Sidr bore down on southern Bangladesh, unleashing winds that peaked at 250 km. per hour and six-meter high tidal surges that washed away entire villages. Cyclone Sidr killed over 3,000 people, a fraction of the more destructive cyclones that struck in 1970 and 1991 which claimed more than 600,000 lives. But that was still too many. According to reports from the worst hit areas, many of the dead and injured were crushed when trees fell onto poorly constructed houses made of thatch, bam- boo or tin. Others drowned when they, together with their houses, were swept away by the torrents of water. TANGAIL Tangail 15 Nov 18.00 UCT Wind Speed 190 kmph INDIA DHAKA SHARIATPUR BANGLADESH MADARIPUR Madaripur GOPALGANJ Madaripur Gopalganj BARISAL INDIA SATKHIRA Bagrthat JHALAKTHI BAGTHAT Pirojpur PATUAKHALI PIROJPUR KHULNA BHOLA Mirzagani Patuakhali Barguna BARGUNA Bay of Bengal Badly Affected Severely Affected Most Severely Affected Storm Track Worst Affected BURMA 0 50 100 Km TANGAIL Tangail 15 Nov 18.00 UCT Wind Speed 190 kmph INDIA Extent of DHAKA the Damage SHARIATPUR BANGLADESH MADARIPUR More than eight million people in 31 districts were Madaripur reportedly affected by Cyclone Sidr. More than 9,000 GOPALGANJ Madaripur schools were flattened or swept away, with extensive Gopalganj damage reported to roads, bridges and embankments. BARISAL Some two million acres of crops were damaged and INDIA SATKHIRA Bagrthat JHALAKTHI over 1.25 million livestock killed.
    [Show full text]
  • Application of Remote Sensing and Gis for Cyclone Disaster Management in Coastal Area: a Case Study at Barguna District, Bangladesh
    International Archives of the Photogrammetry, Remote Sensing and Spatial Information Science, Volume XXXVIII, Part 8, Kyoto Japan 2010 APPLICATION OF REMOTE SENSING AND GIS FOR CYCLONE DISASTER MANAGEMENT IN COASTAL AREA: A CASE STUDY AT BARGUNA DISTRICT, BANGLADESH Md. Sohel Rana1, Kavinda Gunasekara2, Manzul Kumar Hazarika2, Lal Samarakoon2 and Munir Siddiquee1 1GIS Unit, Local Government Engineering Department (LGED), Dhaka, Bangladesh emails: [email protected], [email protected]. 2GeoInformatics Center, Asian Institute of Technology, Bangkok, Thailand emails: [email protected], [email protected], [email protected] KEYWORDS: Cyclone, Disaster, Hazard, Vulnerability, Risk, Storm surge model, DEM. ABSTRACT Bangladesh is one of the top vulnerable countries to the climate change and the adverse impact on the country will be catastrophic because of convergence of climate change, poverty and large population. The frequency of natural disasters like floods, cyclones etc have increased significantly over the last decade particularly in the coastal line of Bangladesh which is asserted as the impact of climate change. The consequences of these disasters are a huge loss of lives and properties that implicates the economy of the country. So disaster management is now an important concern to minimize all those losses. Disaster management of an event like Cyclone, Flood or Earthquake etc. requires some ingredients, such as, response, incident mapping, establishing priorities, developing action plans and implementing the plan to protect lives, property and the environment. GIS in combination with Remote Sensing (RS), can be used very effectively to identify hazards and risk for cyclone. In Bangladesh, cyclone and tidal surge are considered as the most catastrophic phenomena for coastal regions.
    [Show full text]
  • D. Numerical Experiments for Tropical Cyclones D-1. Forecast Experiment with a Nonhydrostatic Model and Simulation of Storm Surge on Cyclone Nargis1 D-1-1
    TECHNICAL REPORTS OF THE METEOROLOGICAL RESEARCH INSTITUTE No.65 2012 D. Numerical experiments for tropical cyclones D-1. Forecast experiment with a nonhydrostatic model and simulation of storm surge on cyclone Nargis1 D-1-1. Introduction Severe meteorological phenomena such as tropical cyclones (TCs) sometimes cause catastrophic damage to human society; therefore, their prediction is significantly important for preventing and mitigating meteorological disasters. In the areas around the Bay of Bengal, historically, there have been several cases in which storm surges induced by TCs gave rise to severe floods (Webster 2008). At the end of April 2008, cyclone Nargis was generated in the center of the bay and moved eastward in contrast with typical northward motion of cyclone of the bay such as the 1970 Bohla cyclone or the 1991 Bangladesh cyclone. Nargis reached its maximum intensity of category 4 around 06–12 UTC on 2 May, then it made landfall in southern Myanmar, and caused a destructive storm surge over the Irrawaddy Delta and other low-lying areas that claimed more than one hundred thousand lives. Figure D-1-1 shows the development of Nargis estimated by the Regional Specialized Meteorological Center (RSMC) New Delhi and the US Navy Joint Typhoon Warning Center (JTWC). The minimum center pressure by JTWC was 937 hPa, while the RSMC New Delhi estimated its intensity as 962 hPa. For disaster prediction and mitigation in these areas, forecasts of TCs and the associated storm surges based on numerical weather prediction (NWP) are particularly important. In this study, numerical simulations of the 2008 Myanmar cyclone Nargis and the associated storm surge were conducted using the Japan Meteorological Agency (JMA) Nonhydrostatic Model (NHM; Saito et al.
    [Show full text]
  • Full Version of Global Guide to Tropical Cyclone Forecasting
    WMO-No. 1194 © World Meteorological Organization, 2017 The right of publication in print, electronic and any other form and in any language is reserved by WMO. Short extracts from WMO publications may be reproduced without authorization, provided that the complete source is clearly indicated. Editorial correspondence and requests to publish, reproduce or translate this publication in part or in whole should be addressed to: Chairperson, Publications Board World Meteorological Organization (WMO) 7 bis, avenue de la Paix P.O. Box 2300 CH-1211 Geneva 2, Switzerland ISBN 978-92-63-11194-4 NOTE The designations employed in WMO publications and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of WMO concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or products does not imply that they are endorsed or recommended by WMO in preference to others of a similar nature which are not mentioned or advertised. The findings, interpretations and conclusions expressed in WMO publications with named authors are those of the authors alone and do not necessarily reflect those of WMO or its Members. This publication has not been subjected to WMO standard editorial procedures. The views expressed herein do not necessarily have the endorsement of the Organization. Preface Tropical cyclones are amongst the most damaging weather phenomena that directly affect hundreds of millions of people and cause huge economic loss every year. Mitigation and reduction of disasters induced by tropical cyclones and consequential phenomena such as storm surges, floods and high winds have been long-standing objectives and mandates of WMO Members prone to tropical cyclones and their National Meteorological and Hydrometeorological Services.
    [Show full text]
  • 17 Deb and Ferreira.Pdf
    Journal of Hydro-environment Research xxx (2016) xxx–xxx Contents lists available at ScienceDirect Journal of Hydro-environment Research journal homepage: www.elsevier.com/locate/JHER Research papers Potential impacts of the Sunderban mangrove degradation on future coastal flooding in Bangladesh ⇑ Mithun Deb a, , Celso M. Ferreira a a Department of Civil, Environmental & Infrastructure Engineering, George Mason University, Fairfax, VA 22030, USA article info abstract Article history: The coastal areas of Bangladesh are recognized by the United Nations (UN) as the most vulnerable areas Received 30 June 2015 in the world to tropical cyclones and also the sixth most vulnerable country to floods around the world. Revised 27 July 2016 Cyclone Sidr (2007) was one of the most catastrophic natural disasters in Bangladesh causing nearly Accepted 14 November 2016 10,000 deaths and $1.7 billion damage. During cyclone Sidr, mangrove forests in coastal areas played a Available online xxxx crucial role in the mitigation of these deadly effects. Sunderban mangrove, the world’s largest mangrove ecosystem with 7900 sq. miles, forms the seaward frontier of the bay and is now facing significant degra- Keywords: dation. The Sunderban mangrove ecosystem is increasingly being degraded for a variety of purposes such Bangladesh as agriculture, fishing, farming and settlement. In this study, we evaluate the potential impacts from the Sunderban mangrove Cyclone degradation of the Sunderban mangrove on storm surge flooding. We evaluate two hypothetical and Storm surge extreme scenarios: 1) the conversion of the entire mangrove land cover to an estuarine forested wetland; Coastal hazard and 2) by considering a full degradation scenario where the entire mangrove is converted to grassland.
    [Show full text]
  • Growth of Cyclone Viyaru and Phailin – a Comparative Study
    Growth of cyclone Viyaru and Phailin – a comparative study SDKotal1, S K Bhattacharya1,∗, SKRoyBhowmik1 and P K Kundu2 1India Meteorological Department, NWP Division, New Delhi 110 003, India. 2Department of Mathematics, Jadavpur University, Kolkata 700 032, India. ∗Corresponding author. e-mail: [email protected] The tropical cyclone Viyaru maintained a unique quasi-uniform intensity during its life span. Despite beingincontactwithseasurfacefor>120 hr travelling about 2150 km, the cyclonic storm (CS) intensity, once attained, did not intensify further, hitherto not exhibited by any other system over the Bay of Bengal. On the contrary, the cyclone Phailin over the Bay of Bengal intensified into very severe cyclonic storm (VSCS) within about 48 hr from its formation as depression. The system also experienced rapid intensification phase (intensity increased by 30 kts or more during subsequent 24 hours) during its life time and maximum intensity reached up to 115 kts. In this paper, a comparative study is carried out to explore the evolution of the various thermodynamical parameters and possible reasons for such converse features of the two cyclones. Analysis of thermodynamical parameters shows that the development of the lower tropospheric and upper tropospheric potential vorticity (PV) was low and quasi-static during the lifecycle of the cyclone Viyaru. For the cyclone Phailin, there was continuous development of the lower tropospheric and upper tropospheric PV, which attained a very high value during its lifecycle. Also there was poor and fluctuating diabatic heating in the middle and upper troposphere and cooling in the lower troposphere for Viyaru. On the contrary, the diabatic heating was positive from lower to upper troposphere with continuous development and increase up to 6◦C in the upper troposphere.
    [Show full text]