CLIMATE-4

Q1. CHOOSE THE CORRECT ANSWER FROM THE FOLLOWING.

i). WHICH ONE OF THE FOLLOWING PLACES RECEIVES THE HIGHEST RAINFALL IN THE WORLS?

a) SILCHAR   b) MAWSYNRAM   c) CHERRAPUNJI   d) GUWAHATI

ii) THE WIND BLOWING IN THE NORTHERN PLAINS IN SUMMERS IS KNOWN AS-

a) KAAL BAISAKHI   b) LOO    c) TRADE WINDS      d) NONE OF THE ABOVE

iii) WHICH ONE OF THE FOLLOWING CAUSES RAINFALL DURING WINTERS IN NORTH WESTERN PART OF INDIA?

a) CYCLONIC DEPRESSION     b) RETREATING MONSOON     c) WESTERN DISTURBANCES   d) SOUTH WEST MONSOON

iv) MONSOON ARRIVES IN INDIA APPROXIMATELY IN-

a) EARLY MAY    b) EARLY JULY    c) EARLY JUNE      d) EARLY AUGUST

v) WHICH ONE OF THE FOLLOWING CHARACTERISES THE COLD WEATHER SEASON IN INDIA?

a) WARM DAYS AND WARM NIGHTS   b) WARM DAYS AND COLD NIGHTS   c) COLD DAYS AND COLD NIGHTS   d) COLD DAYS AND WARM NIGHTS

Q2. ANSWER THE FOLLOWING QUESTION BRIEFLY.

i). WHAT ARE THE CONTROLS AFFECTING THE CLIMATE OF INDIA?

ANS. THE CONTROLS AFFECTING THE CLIMATE OF INDIA ARE-

  • LATITUDE,
  • ALTITUDE,
  • AIR PRESSURE AND WINDS,
  • DISTANCE FROM THE SEA,
  • OCEAN CURRENTS AND
  • RELIEF.

ii). WHY DOES INDIA HAVE A MONSOON TYPE OF CLIMATE?

ANS. THE CLIMATE OF INDIA IS STRONGLY INFLUENCED BY THE MONSOON WINDS. SO THE COUNTRY HAS A MONSOON TYPE OF CLIMATE.

iii). WHICH PART OF INDIA DOES EXPERIENCE THE HIGHEST DIURNAL RANGE OF TEMPERATURE AND WHY?

ANS.

  • THE NORTH WESTERN PART COMPRISING THE THAR DESERT EXPERIENCES THE HIGHEST DIURNAL RANGE OF TEMPERATURE.
  • HERE THE DAY TEMPERATURE MAY RISE TO 50 DEGREE C AND DROP DOWN TO NEARLY 15 DEGREE C ON THE SAME NIGHT.
  • THIS IS BECAUSE OF THE SAND THAT ABSORBS HEAT VERY QUICKLY AND LOSES THE SAME WITH SAME SPEED AT NIGHT.

iv). WHICH WINDS ACCOUNT FOR RAINFALL ALONG THE MALABAR COAST?

ANS. SOUTH WEST MONSOON WINDS.

v). WHAT ARE JET STREAMS AND HOW DO THEY AFFECT THE CLIMATE OF INDIA?

ANS.

  • JET STREAMS ARE A NARROW BELT OF HIGH ALTITUDE (ABOVE 12000 METERS) WESTERLY WINDS IN THE TROPOSPHERE.
  • THESE ARE LOCATED OVER 27 DEGREE TO 30 DEGREE NORTH LATITUDE.
  • THE WESTERN CYCLONIC DISTERBANCES EXPERIENCED IN THE NORTH AND NORTH WESTERN PARTS OF THE COUNTRY ARE BROUGHT BY THESE WINDS.

vi). DEFINE MONSOONS. WHAT DO YOU UNDERSTAND BY ‘BREAK’ IN MONSOON?

ANS.

  • THE WORD MONSOON IS DERIVED FROM THE ARABIC WORD  ’MAUSIM’ WHICH LITERALLY  MEANS SEASON.
  • IT REFERS TO THE SEASONAL REVERSAL IN THE WIND DIRECTIONS DURING A YEAR.
  •  ‘BREAK’ IN MONSOON MEANS THE ONSET OF MONSOON.

vii). WHY IS THE MONSOON CONSIDERED A UNIFYING BOND?

ANS.

  • THE INDIAN LANDSCAPE ITS ANIMAL AND PLANT LIFE, ITS ENTIRE AGRICULTURE CALENDER AND THE LIFE OF THE PEOPLE INCLUDING THEIR FESTIVALS REVOLVE AROUND THE MONSOON.
  • EVERY YEAR PEOPLE OF INDIA FROM NORTH TO SOUTH AND FROM EAST TO WEST EAGERLY AWAIT THE ADVENT OF THE MONSOON.
  • THESE MONSOON WINDS BIND THE WHOLE COUNTRY BY PROVIDING WATER TO SET THE AGRICULTURE ACTIVITIES IN MOTION.

Q3. WHY DOES THE RAINFALL DECREASES FROM THE EAST TO THE WWEST IN THE NORTHERN INDIA?

ANS.

  • THE RAINFALL DECREASES FROM THE EAST TO THE WEST IN THE NORTHERN INDIA BECAUSE OF THE PROGRESSIVE DECREASE IN THE HUMIDITY OF THE WINDS.
  • SINCE THE MOISTURE BEARING WINDS OF THE BAY OF BENGAL BRANCH OF THE SOUTH WEST MONSOON MOVE FURTHER AND FURTHER INLAND, THEY EXHAUST MOST OF THE MOISTURE THAT THEY CARRY ALONG WITH THEM.
  • AS A RESULT THERE OCCURS A GRADUAL DECREASE IN THE AMOUNT OF RAINFALL FROM EAST TO WEST.

Q4. GIVE REASONS AS TO WHY-

i). SEASONAL REVERSAL OF WIND DIRECTION TAKES PLACE OVER THE INDIAN SUBCONTINENT?

ANS.

  • INDIA LIES IN THE REGION OF THE NORTH EASTERLY WINDS. THESE WINDS ORIGINATE FROM SUB TROPICAL HIGH PRESSURE BELT OF THE NORTHERN HEMISPHERE.
  • THEY BLOW SOUTH, GET DEFLECTED TO THE RIGHT DUE TO THE CORIOLIS FORCE AND MOVE ON TOWARDS THE EQUATORIAL LOW PRESSURE AREA.
  • THE CORIOLIS FORCE IS RESPONSIBLE FOR DEFLECTING WINDS TOWARDS THE RIGHT IN THE NORTHERN HEMISPHERE AND TOWARDS THE LEFT IN THE SOUTHERN HEMISPHERE.

ii). THE BULK OF RAINFALL IN INDIA IS CONCENTRATED OVER A FEW MONTHS?

ANS.

  • BY EARLY JUNE THE LOW PRESSURE CONDITION OVER THE NORTHERN PLAINS INTENSIFIES. IT ATTRACTS THE TRADE WINDS OF THE SOUTHERN HEMISPHERE.
  • THESE SOUTH EAST TRADE WINDS ORIGINATE OVER THE WARM SUBTROPICAL AREAS OF THE SOUTHERN OCEAN. THEY CROSS THE EQUATOR AND BLOW IN A SOUTH WESTERLY DIRECTION ENTERING THE INDIAN PENINSULA AS THE SOUTH WEST MONSOON.
  • AS THESE WINDS BLOW OVER WARM OCEANS THEY BRING ABUNDANT MOISTURE TO THE SUB CONTINENT.
  • THESE WINDS ARE STRONG AND BLOW  AT AN AVERAGE VELOCITY OF 30 KM PER HOUR.
  • WITH THE EXCEPTION OF THE EXTREME NORTH WEST, THE MONSOON WINDS COVER THE COUNTRY IN ABOUT A MONTH.

iii). THE TAMIL NADU COAST RECEIVES WINTER RAINFALL?

ANS.

  • TAMILNADU COAST RECEIVES WINTER RAINFALL DUE TO THE NORTH EAST TRADE WINDS.
  • THESE WINDS BLOWS FROM SEA TO LAND IN THIS REGION AND THEREFORE CARRY HUGE MOISTURE ALONG WITH THEM.
  • THE MOISTURE IS TRANSFORMED IN THE WINTER RAINFALL.

iv). THE DELTA REGION OF THE EASTERN COAST IS FREQUENTLY STRUCK BY CYCLONES?

ANS.  THIS IS BECAUSE THE CYCLONIS DEPRESSIONS THAT ORIGINATE OVER THE ANDAMAN SEA ARE BROUGHT IN BY THE SUBTROPICAL EASTERLY JET STREAM FLOWING OVER PENINSULAR INDIA DURING THE MONSOON AND DURING THE PERIOD OF OCTOBER AND NOVEMBER. THESE CYLONES ARE VERY DESTRUCTIVE.

v). THE PARTS OF RAJASTHAN, GUJRAT AND THE LEEWARD SIDE OF THE WESTERN GHATS ARE DROUGHT PRONE?

ANS. WINDS CARRY MOISTURE UPWARDS OVER MOUNTAIN BUT THE LOW TEMPERATURE CAUSES THE AIR TO LOSE MUCH OF ITS MOISTURE AS PRECIPATION WHICH CAUSES RAINFALL ON THE WINDWARD SIDE OF THE WESTERN GHATS. BY THE TIME THEY REACH THE LEEWARD SIDE OF THE MOUNTAIN THEY BECOME DRY.

Q5. DESCRIBE THE REGIONAL VARIATIONS IN THE CLIMATIC CONDITIONS OF INDIA WITH HELP OF SUITABLE EXAMPLOES.

ANS.

  • TEMPERATURE- IN SUMMER THE TEMPERATURE OCCASIONALLY TOUCHES 50 DEGREE C. IN SOME PARTS OF RAJASTHAN DESERT WHEREAS IT MAY BE AROUND 20 DEGREE C. IN PAHALGAM IN JAMMU AND KASHMIR. IN WINTER TEMPERATURE IN DRASS IN JAMMU AND KASHMIR MAY BE AS LOW AS MINUS 45 DEGREE C. WHEREAS IN THIRUVANANTHAPURAM IT MAY BE 22 DEGREE C.
  • PRECIPITATION- .PRECIPITATION IS MOSTLY IN THE FORM OF SNOWFALL IN THE UPPER PARTS OF HIMALAYAS. THE ANNUAL PRECIPITATION VARIES FROM OVER 400 CM IN MEGHALAYA TO LESS THAN 10 CM IN LADAKH AND WESTERN RAJASTHAN.

Q6. DISCUSS THE MECHANISM OF MONSOONS.

ANS.

  • THE DIFFERENTIAL HEATING AND COOLING OF LAND AND WATER CREATES LOW PRESSURE ON LANDMASS OF INDIA WHILE THE SEAS AROUND EXPERIENCE COMPARATIVELY HIGH PRESSURE.
  • THE SHIFT OF THE POSITION OF (ITCZ) IN SUMMER OVER GANGA PLAIN THIS EQUATORIAL TROUGH NORMALLY POSITIONED ABOUT 5 DEGREE NORTH OF THE EQUATOR IT ALSO KNOWN AS THE MONSOON TROUGH DURING MONSOON SEASON.
  • THE PRESENCE OF THE HIGH PRESSURE AREA AT EAST OF MADAGASCAR AFFECTS THE INDIAN MONSOON.
  • THE TIBETAN PLATEAU GETS INTENSELY HEATED DURING SUMMER WHICH RESULTS IN STRONG VERTICAL AIR CURRENTS AND THE FORMATION OF LOW PRESSURE OVER PLATEAU AT ABOUT 9 KM ABOVE SEA LEVEL.
  • THE MOVEMENT OF THE WESTERLY JET STREAM TO THE NORTH OF THE HIMALAYAS AND THE PRESENCE OF THE TROPICAL EASTERLY JET STREAMS OVER THE INDIAN PENINSULAR DURING SUMMER.

Q7. GIVE AN ACCOUNT OF WEATHER CONDITIONS AND CHARACTERISTICS OF THE COLD SEASON.

ANS.

  • THE COLD WEATHER SEASON BEGINS FROM MID NOVEMBER AND STAYS TILL FEBRUARY.
  • DECEMBER AND JANUARY ARE THE COLDEST MONTHS IN THE NORTHERN PART OF INDIA.
  • THE TEMPERATURE DECREASES FROM SOUTH TO THE NORTH.
  • DAYS ARE WARM AND NIGHTS ARE COLD. FROST IS COMMON IN THE NORTH AND THE HIGHER SLOPES OF THE HIMALAYAS EXPERIENCE SNOWFALL.
  • THE WEATHER IS NORMALLY MARKED BY CLEAR SKY, LOW TEMPERATURE AND LOW HUMIDITY.

Q8. GIVE THE CHARACTERISTICS AND EFFECTS OF THE MONSOON RAINFALL IN INDIA.

ANS.

  • THE MONSOONS ARE PULSATING IN NATURE, AFFECTED BY DIFFERENT ATMOSPHERIC CONDITIONS.
  • THE DURATION OF THE MONSOON IS BETWEEN 100-120 DAYS FROM EARLY JUNE TO MID SEPTEMBER.
  • THE MONSOON ARRIVES AT THE SOUTHERN TIP OF THE INDIAN PENINSULA GENERALLY BY THE FIRST WEEK OF JUNE. SUBSEQUENTLY IT PROCEEDS INTO TWO BRANCHES, THE ABABIAN SEA BRANCH AND THE BAY OF BENGAL BRANCH.
  • BY MID JULY THE MONSOON REACHES HIMACHAL PRADESH AND THE REST OF THE COUNTRY.
  • THE ISLAND RECEIVE THE VERY FIRST MONSOON SHOWERS FROM THE LAST WEEK OF APRIL TO THE FIRST WEEK OF MAY.

EFFECTS OF THE MONSOON RAINFALL-

i). THE MONSOON IS KNOWN FOR ITS UNCERTAINTIES. IT CAUSES HEAVY FLOODS IN ONE PART AND MAY BE RESPONSIBLE FOR DROUGHTS IN THE OTHER.

IT IS OFTEN IRREGULAR IN ITS ARRIVAL AND ITS RETREAT. HENCE IT SOMETIMES DISTURBS THE FARMING SCHEDULE IN THE COUNTRY.