I Spell SSt inservice course KVGN

1. MONSOONS
K.SUGUNA.R
PGT GEO

2. MONSOON
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•
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•
MONSOON –SEASON
SEASONAL WINDS-WINDS THAT BLOW FROM A PARTICULAR AREA
TOWARDS A PARTICULAR REGION IN A PARTICULAR DIRECTION
SOUTHWEST MONSOON
– SEA
LAND
NORTHEAST MONSOON
_ LAND
SEA

3. INDIAN MONSOON
• INDIA IS LOCATED IN THE TRADE WIND BELT
• IT IS A DRY CONTINENTAL WIND BELT
• BUT FOR THE PHENOMENON OF MONSOON INDIA
WOULD HAVE BEEN A SEMI DESERT

4. SOUTHWEST MONSOON
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•
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DURING THE MONTH OF JUNE SUN IS ON THE TROPIC OF CANCER AND THE
TEMPERATURE IS HIGH IN THE NORTHERN PART OF INDIA
DUE TO VERY HIGH TEMPERATURE AIR PRESSURE IS VERY LOW
THIS LOWPRESSURE ZONE ATTRACTS THE WIND FROM THE SURROUNDING
INDIAN OCEAN
SOUTH TRADE WINDS CROSS THE EQUATOR AND BLOW FROM SOUTHWEST
DIRECTION AND SO THEY ARE CALLED SOUTHWEST MONSOON WINDS.
AS THEY MOVE FROM A VAST OCEAN PART THEIR RELATIVE HUMIDITY IS
90% AND GIVE RAINFALL TO INDIA

5. MECHANISM OF MONSOON
• DIFFERENTIAL HEATING AND COOLING OF
LAND AND WATER
• SHIFT IN THE POSITION OF ITCZ
• HIGH PRESSURE OVER MADAGASCAR
• INTENSIVE HEATING OF TIBETIAN PLATEAU
• JET STREAMS

6. DIFFERENTIAL HEATING AND
COOLING OF LAND AND WATER
• LAND ABSORBS THE HEAT VERY FAST AND RELEASES THE
HEAT VERY FAST
• WATER ABSORBS THE HEAT VERY SLOW AND RELEASES
THE HEAT VERY SLOW
• SEA BREEZE
AND
LAND BREEZE

7. POSITION OF ITCZ
• IN THE MONTH OF JUNE ITCZ IS LOCATED IN THE
TROPIC OF CANCER REGION
• INTENSIVE HEAT LEADES TO THE FORMATION OF
INTENSIVE LOW PRESSURE ZONE
• LOW PRESSURE TROUGH IS KNOWN AS MONSOON
TROUGH

8. INTENSIVE HEATING OF
TIBETIAN PLATEAU
• AS A VAST LAND MASS,TIBETIAN PLATEAU
GETS INTENSELY HEATED DURING SUMMER
• IT RESULTS IN STRONG VERTICAL AIR
CURRENTS
• FORMATION OF LOWPRESSURE OVER THE
PLATAU

9. HIGH PRESSURE OVER
MADAGASCAR
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THE PRESENCE OF THE HIGH PRESSURE AREA ,EAST OF
MADAGASCAR .
THE INTENSITY AND POSITION OF THIS HIGH PRESSURE AREA
AFFECTS THE INDIAN MONSOON

10. JET STREAMS
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FAST MOVING WINDS IN A NARROW ZONE IN THE UPPER ATMOSPHERE
WESTERLY JETSTREAM HELPS IN ARRIVAL OF MONSOON-CAUSE AND
EFFECT RELATION BETWEEN WITHDRAWAL OF WESTERLY JET STREAM AND
SHIFT OF ITCZ
EASTERLY JETSTREAM –HELPS IN SUDDEN OUTBREAK OF MONSOON

11. SOUTHERN OSCILLATION
•
Southern Oscillation, refers to the seesaw
relationship of atmospheric pressures between
Tahiti, south pacific island and Darwin, Australia’
• INDIAN OCEAN
PACIFIC OCEAN
SUMMER
WINTER

12. ELNINO CURRENT
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•
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WARM CURRENT ALONG THE PERUVIAN COAST ONCE IN TWO TO
FIVE YEARS
REPLACING PERUVIAN COLD CURRENT
INCREASES TEMPERATURE OVER EAST PACIFIC COAST AND
WEAKENS TRADE WINDS
ELNINO

13. BREAK OF MONSOON
• BREAK OF MONSOON-ONSET OF
MONSOON
• SUDDEN ARRIVAL OF MONSOON

14. BREAK IN MONSOON
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1.
2.
BREAK IN MONSOON RAINFALL
WET SPELLS ARE FOLLOWED DRY SPELLS
REASONS
WHENEVER WINDS BLOW PARALLEL TO THE COAST
POSITION OF ITCZ- MOVES TOWARDS NORTH
NO RAIN IN PLAINS MORE RAIN IN HIMALAYAS