GNR 639 : Natural Disaster And Management Atmosphere - Meteorology disasters Blizzards Cyclonic storms Droughts Thunder storms Hailstorms Heat waves Tornadoes Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Source courtesy: compoundchem.com 1.02 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Source courtesy: en.wikepedia.org 1.03 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management 1.05 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Lesson 7 Storm & Cyclone 7.01 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Lightning is an atmospheric discharge of electricity accompanied by thunder, which typically occurs during thunderstorms and sometimes during volcanic eruptions or dust storms. In the atmospheric electrical discharge, a leader of a bolt of lightning can travel at speeds of 220,000 km/h, and can reach temperatures approaching 30,000°C. Hail is a form of solid precipitation which consists of irregular lumps of ice, that are individually called hail stones. It consists of water ice and measuring in size between 5 mm and 150 mm in diameter, with the larger stones coming from severe thunderstorms. It has caused serious damage to automobiles, aircraft, skylights, glass-roofed structures, livestock, and crops (sensitive crops such as Wheat, corn, soybeans and tobacco). Blizzards are severe winter storms characterized by low temperature, strong winds, and heavy snow. The difference between a blizzard and a snow storm is the strength of the wind. The storm must have winds exceeding of 35 miles per hour and reduced visibility to 1/4 miles. 7.02 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Hurricanes bring intense wind, torrential rain, high waves, strong currents, flooding, storm surge, tornadoes, landslides, and coastal erosion. They are revolving storms originating near the equator that are accompanied by torrential rain and wind speeds exceeding 74 mph. In the Atlantic and eastern Pacific, including Hawaii, these whirling storms are called hurricanes . In the western Pacific, including East Asia and Australia, they are typhoons . In the Indian Ocean, they are cyclones . Saffir-Simpson Hurricane Scale expresses a hurricane’s strength by its sustained wind speed — Category 1: 74-95 mph; Category 2: 96-110 mph; Category 3: 111-130 mph; Category 4: 131-155 mph; Category 5: in excess of 155 mph. 7.03 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Tornado is a violently rotating column of air that is in contact with the ground, either pendant from underneath a cumuliform cloud visible as a funnel cloud. For a vortex to be classified as a tornado, it must be in contact with both the ground and the cloud base. The causes of Tornadoes are - 1. Tornadoes are formed when hot air and cold air are mixed. 2. The clouds grow larger and larger. Finally, a thunderstorm is brewed up with a strong updraft.3. The moisture in the warm air rises and condenses into large clouds. Tornado scale Wind speed Damages (km/h) F1 73-115 Light - broken tree branches and some damage to chimneys F2 116-180 Considerable - roofs flown of houses and cars lifted slightly F3 181-250 Severe - walls damaged, cars fully lifted and most trees uprooted F4 251-330 Devastating - cars and badly constructed houses thrown around F5 – Twister 331-415 Incredible - strong frame houses leveled off foundations and swept away, automobile-sized missiles fly away in excess of 100 meters F6 Super Twister 416-510 Inconceivable - top end of F5 category 7.04 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management (Source courtesy: thinglink.com) (Source courtesy: whyflies.org) 7.05 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management 7.06 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Scale Wind speed Central Damage km/hr pressure (mb) Damage to trees, foliage & poorly anchored mobile homes. Storm surge 1.2-1.5 m above 1 120-150 > 980 normal. Flooding of low-lying areas & roads. Limited damage to piers & small crafts. Broken & foliage-stripped trees. Major damage to mobile / light roofed homes. Storm surge 2 151-175 965-979 1.6-2.4 m. Flooding of coastal roads & areas prior (2-4 hrs) to arrival of storm. Piers suffer extensive damage and unprotected vessels are torn off. 3 175-210 945-964 Foliage stripped from trees blown down. Great damage to roofing material, door and windows. Structural damage to small buildings. Storm surge 2.5-3.6 m. Serious coastal area flooding (3-5 hrs before storm) and damage to buildings on coast. Flooding of areas above 2 or 3m above msl as far as 13 km. Shrubbs, tree and signs are blown down. Extensive damage roofing material and ripping off 4 211-250 920-944 roofs. Destroyed mobile & light structures. Storm surge 3.7-5.5 m. Flooding of areas 3 to 4 m above msl, 4 to 6 hrs prior storm. Beaches suffer erosion, scouring and evacuation of homes upto 500m. Total damage. Shattered window glasses & structures blown away. Storm surge > 5.5 m. 5 >250 < 920 Lower floors of structures flooded heavily. 7.07 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management A dust / sand storm is a meteorological phenomenon common in arid and semi- arid regions. It arises when strong wind blows loose sand and dust from a dry surface. It is caused by droughts and poor farming and grazing practices also from extensive deforestation and desertification in many regions. They carry not only nutrients but also microbes and pollens. Source courtesy: crystallinks.com 7.08 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management A tropical cyclone is a storm system characterized by a large low-pressure at the center with numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor contained in the moist air. The term cyclone refers to cyclonic storms' with anticlockwise rotation in the Northern Hemisphere and clockwise rotation in the Southern Hemisphere. They are known around the world by various names: hurricanes in the Atlantic and Caribbean, typhoons in the West Pacific, Baguios in the Philippines, Cordonazos in Mexico, Tainos in Haiti. It is defined as a circular storm with rotating wind speed exceeding 64 knots (32 m/sec). Life span of a tropical cyclone is, on average, about six to nine days until it enters land or re-curves into temperate latitudes. 7.09 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Super cyclone - When the maximum sustained 3 minutes surface winds are more than 119 knots, the low pressure system is called as Super Cyclone over north Indian Ocean. Eye and center - A strong tropical cyclone will harbor over large area of strong sinking air at the center of circulation, develop into a eye of the storm. Weather in the eye is normally calm and free of clouds, irrespective of extremely violent sea surface. Central Dense Overcast (CDO) is the concentrated area of strong thunderstorm activity near the center of a tropical cyclone; in weaker tropical cyclones, the CDO may cover the center completely. If the radius is less than two degrees of latitude or 222 km, then the cyclone is " very small " 7.10 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Satellite image showing 1999 Orissa Super Cyclone (Courtesy: Indian Meteorology Department) 7.11 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Source courtesy: hko.gov.hk Source courtesy: en.Wikipedia.org 7.12 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Source courtesy: thewatchers.adorraeli.com Source courtesy: pnnl.gov 7.13 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Source courtesy: geofffox.com 7.14 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management 1. Location Specific forecast (3 days - 3 hourly interval) 2. Coastal forecast (7 days - 3 hourly interval) 3. Regional forecast (7 days - 3 hourly interval) 4. Indian Ocean forecast (5 days - 6 hourly interval) 5. Global forecast (5 days - 6 hourly interval) 6. Value added services 7.15 Prof. R. Nagarajan, CSRE , IIT Bombay
GNR 639 GNR 639 : Natural Disaster And Management Source courtesy: looptonga.com 7.16 Prof. R. Nagarajan, CSRE , IIT Bombay
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