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Chapter 14
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Important Topics are covered- cyclones- tropical and temperate, conditions required for their formation, characteristics etc.

Suhasini S
With an experience of year and half in corporate office and fire in my belly, I started to find ways to make an impact. Teaching has become

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Sir this course in Hindi plz
please provide the answers
  1. o B. tech-SRM University o 1 year of teaching experience. o 1.5 years of corporate experience. o Love to read, teach, play guitar UPSC aspirant https://unacademy.com/user/hasini.8201 Please do rate, review and share the course.


  2. CYCLONES o Develops in low pressure area- barometric gradient is steep o 2 types: 1. Tropical 2. Temperate (due to fronts)


  3. TROPICAL CYCLONES o Formed usually in oceans when temp reaches 27 C mostly near ITCZ area (low pressure) Tropical cyclones are absent at equator. Why??? Since, coriolis force is absent- necessary for cyclone movement Formed when ITCZ moves to 23.5 N or S Formed generally in early summer or autumn season Occurs in tropical latitudes 23.5 N or S Originate on the western flanks of the oceans



  4. Conditions necessary for origin of tropical cyclone 1. Continuous and abundant supply of warm and moist air 2. Sea temp 27 C in lower latitudes 3. Existence of weak tropical disturbance 4. Anti cyclonic circulation at the height of 9km to 15km above the surface.


  5. HURRICANE STRUCTURE IN THE NORTHERN HEMISPHERE Outflow cirrus shield Outflow Warm rising air Cold falling air Eye wall Eye Storm rotation COUNTERCLOCKWISE Rain bands


  6. 100 km 9N


  7. CHARACTERISTICS Diameter= 150-300 km originate on western margins of oceans where sea tem exceeds 27 C O Speed- 15 to 25 km/hr o Violent winds of hurricane speed (119 km/hr) circulate around the eye or centre of the storm o Majority of the cyclones decay when they come over land o Heavy winds continue even after winds become weak o Cyclone accompanied by torrential rainfall from heavy clouds ( clouds have vertical development) o Rainfall is absent or scanty at the centre o Strongest winds are usually recorded in the right quadrant (relative to storm's direction)


  8. TEMPERATE CYCLONES Referred as depression or low or extra tropical or wave cyclones or mid latitude cyclones o Defined as large scale low pressure weather systems that occur in middle latitudes ( 30- 60 N/S) o Depression usually passes through cycle of deepening to maturity , "filling" as it becomes less intense and finally losing its identity. In contrast to tropical cyclones, these produce rapid changes in temperature and dew point along broad lines, called weather fronts, about the center of the cyclone