In Search of the Source of Wind
Role of Wind in the Voyage
Atmospheric Pressure The Weight of Atmospheric Air on Earth Gravitational force helps Air to remain on Earth Variations in the Atmospheric Pressure are the Cause of Wind
Variations in Atmospheric Pressure Instrument Mercury Barometer
Atmospheric Pressure - Influencing Factors Temperature Altitude Humidity
Altitude Pressure Altitude & Pressure L H Less Amount of Air
Ooty Ponnmudi Munnar Paithalmala Brahmagiri
Temperature Pressure The Tropical Region Experiences Low Atmospheric Pressure than Colder Region because of the Difference in Temperature Temperature & Pressure L H Air Expands When Heated
Humidity Pressure Quantity of Water Present in the Atmosphere is Humidity H L
Activity 1 ( Answer the Following) 1. Which are the Influencing Factors of Atmospheric Pressure? 2. Find out the Relation between a) Pressure & Altitude b) Pressure & Temperature c) Pressure & Humidity
Temperature Pressure Altitude Pressure Humidity Pressure Relation with Pressure
High & Low Pressure If the Atmospheric Pressure of an Area is Higher Lower Than Surroundings
Imaginary Lines Connecting Places Having Equal Atmospheric Temperature Isotherms
H L Imaginary Lines Connecting Places Having Equal Atmospheric Pressure Isobars
Activity 2 1. Which are the Different Global Pressure Belts? 2. Write Short note on Different Global Pressure Belts
Equatorial Low Pressure Belt 5 0 N&S Latitudes Low Pressure Sun s Rays Fall Vertically through out Year High Temperature Feeble Winds Doldrums Zone with No Winds
Sub Tropical High Pressure Belt 30 0 N&S Latitudes High Pressure Hot air from Equator Cools here due to Rotation
Sub Polar Low Pressure Belt 60 0 N&S Latitudes Low Pressure Cold air is thrown up due to Rotation
Polar High Pressure Belt 90 0 N&S Latitudes High Pressure Severe Cold throughout the Year
Activity 3 ( Complete the Table) Pressure Belt Latitudinal Extent Pressure Features Equatorial Sub Tropical Sub Polar Polar
Pre. Belt L. Extent Pressure Features Equatorial 5 0 N&S Low High Temperature Sub Tropical Global Pressure Belts 30 0 N&S High Air Cools due to Rotation Sub Polar 60 0 N&S Low Cold air is thrown up Polar 90 0 N&S High Severe Cold
Basis for Formation of Pressure Belts Variations in the Amount of Solar Energy Rotation of Earth
The Pressure Belts Move According to the Apparent Movement of the Sun
Characteristics Names based on Direction Ocean Winds More Moisture
Activity 4 ( Answer the Following) 1. List the Factors Influencing the Speed and Direction of Wind? 2. Write Short Note on : a) Pressure Gradient Force b) Coriolis Force c) Friction
Pressure Gradient Force (Speed) Coriolis Effect (Direction) Friction (Speed)
Activity 5 ( Answer the Following) 1. Mark the direction of Winds 2. In which of these situations will the speed of the Wind be higher? Why?
Pressure Gradient Force High Speed Wind Isobars are shown Closely Less Speed Wind Isobar s are not shown Closely
William Ferrel (1817 1891) American Meteorologist (Meteorology is the interdisciplinary scientific study of the atmosphere)
Freely moving Bodies get Deflected : Right NH Left SH Earth s Rotation is the Reason Increases as it moves from Equator Poles Ferrel s Law
Winds
The Wind Formed between the Global Pressure Belts are Planetary Winds 1. Trade Winds 2. Westerlies 3. Polar Easterlies
Subtropical Equatorial High pressure Low North East Winds N Hemisphere South East Winds S Hemisphere Same Direction & Velocity Rainfall in Eastern Cost No Rain in Western-->Desert Helped Sea Travelers
Subtropical Subpolar High pressure Low Westerlies Direction from West Stronger in S H due to Vast Oceans N Hemisphere S W N E S Hemisphere N W S E Different Names Roaring 40s, Furious 50s, Shrieking 60s
Polar Sub Polar High pressure Low Colder & Stronger Blow from East in both Hemisphere due to Coriolis Force (Polar Easterlies) Role in the Climate of N America, Eastern European Countries & Russia
Activity 6 ( Complete the Table) Planetary Winds Area they Blow High Pressure Low Pressure Northern Hemisphere Direction of Wind Southern Hemisphere Features Trade Winds Westerlies Polar Easterlies
Planetary Winds Area they Blow High Pressure Low Pressure Direction of Wind Northern Hemisphere Southern Hemisphere Features Trade Winds Sub Tropical Equato rial North East South East Same Direction & Velocity Westerli es Sub Tropical Sub Polar South West North West Stronger in S H due to Vast Oceans Polar Easterli es Polar Sub Polar North East South East Colder & Stronger
Periodic Winds o For a Short Period o At Certain Places o Examples are Monsoon Winds Land & Sea Breeze Mountain & Valley Breeze
Monsoon Winds Due to Seasonal Changes Seasonal Reversal in a year o o S W Monsoon Winds N E Monsoon Winds Hippalus Formation of Monsoon Winds Factors The Apparent Movement of Sun Coriolis Force Differences in Heating
Monsoon Winds
Arctic Circle Tropic of Cancer Equator Tropic of Capricorn Antarctic Circle N Polar HP June 21Sub Tropical HP Mar 21 Sub Polar LP SE Trade Wind Equatorial LP Sub Tropical HP Sub Polar LP Polar HP S Sep 23 NE Trade Wind Dec 22 Southwest Monsoon Sun Northern H Pressure Belts Shift to North Summer NH - HTemperature As SE Trade Wind cross Equator, Deflected (Coriolis Force) and Transform into Southwest Monsoon Northeast Monsoon Winter HP on Asia & LP on Indian Ocean Northeast Trade Wind Strengthened & they are Northeast Monsoon
N Polar HP Sub Polar LP June Sub 21 Tropical HP SE Trade Wind Mar 21Equatorial LP Sub Tropical HP Sep 23 NE Trade Wind Dec 22 Monsoon Doesn t Occur in N Europe o The Planetary Winds In North European Region blow on the Opposite Direction o Winds are not From the Oceans o Temperature difference between Land & Sea is less Vasco da Gama Sub Polar LP Polar HP S Reached Kerala with the help of Monsoon Winds On Return he went against its Direction & it Troubled him
Activity 7 (Comparison) 1. Make a Comparison Between Southwest & Northeast Monsoon Winds 2. Make a Comparison Between Sea Breeze & Land Breeze 3. Make a Comparison Between Valley Breeze & Mountain Breeze
Direction Southwest Monsoon South West From Indian Ocean Temperature NH High SH Low (Indian Ocean) Pressure Season NH Low SH High NH Summer SH Winter Northeast Monsoon North East To Indian Ocean NH Low SH High NH High SH Low NH Winter SH Summer
L H H L
Valley Breeze Day Time Air in the Valley Heated up & Blows upslope the Mountain Mountain Breeze At Night Air in the Mountain Cools & Blows towards the valley
Local Winds Smaller Locality Result of Local Pressure Difference E.g. (India) Loo, Mango showers, Kalbaisakhi E.g. (World) Chinook, Harmattan & Foehn
Activity 8 Prepare a Table Showing the Name, Region and Specialties of Local Winds Wind Region Specialties Chinook Foehn Harmattan Loo
Wind Region Specialties Chinook Foehn Harmattan Loo Eastern Slopes of Rockies Mountains Southern Valley of Alps Sahara Desert W Africa North Indian Plains Melting Snow Reduce Severity of Cold Wheat Cultivation in Canadian lowlands Reduce Severity of Cold Dry Wind Humidity & Sultry Conditions Improved Hot Wind Rise in Temperature
Activity 9 ( Complete the Flow Chart)
Planetary Winds Periodic Winds Trade Winds Westerlies Polar Easterlies Monsoon Winds Land & Sea Breeze Mountain & Valley Breeze Local Winds Loo Foehn Chinook Harmattan
Without the Sun s Energy there would have been Nothing
Additional Activities 1. Difference between Isotherms & Isobars 2. Name the different Global Pressure Belts 3. What is Inter Tropical Convergence Zone (ITCZ)? 4. Which are the different names Westerly Winds? 5. Explain Doldrum 6. 7. 8. 9. 10.
Michael Angelo M.A. MA (Phi.,His.) HSA(Social Science) St. Mary s H.S. Palliport mamichaelma@gmail.com 9746953695