2. ATMOSPHERE
IT IS A MANTLE OF GASES SURROUNDING
THE EARTH.
IT IS HELD CLOSE TO THE EARTH BY
GRAVITATIONAL FORCE
DIVISIONS OF ATMOSPHERE ARE
TROPOSPHERE
STRATOSPHERE
MESOSPHERE
IONOSPHERE
EXOSPHERE
6. WEATHER / CLIMATE
WEATHER –
IT IS THE STATE OF ATMOSPHERE AT A
PARTICULAR TIME.
IT IS THE CONDITION AND CHARACTERISTIC
OF THE ATMOSPHERE AT A GIVEN TIME.
i.e , A few hours to 2 weeks
CLIMATE –
THE STATE OF ATMOSPHERE OVER A PERIOD
OF TIME
7. MICROCLIMATE/MACROCLIMATE
MACROCLIMATE MICROCLIMATE
Climatic condition existing
over a large area of the crop
Climatic condition around a
plant
Indicates the climatic
conditions above the ground
surface of a cropped area
It is the climatic condition
existing over a small area of
the plant. It denotes the
climatic conditions from the
ground surface to the top of
the plant and also soil climate
upto the depth of maximum
root accumulation
Macro climate is common for
all crops in that area
Microclimate may vary
according to the growth
conditions of crop
Mesoclimate: Climatic conditions in between micro and macro climates
8. WEATHER ELEMENTS WHICH AFFECT
THE GROWTH OF PLANTS
TEMPERATURE
PRESSURE
HUMIDITY
WIND VELOCITY
CLOUDINESS/SUNLIGHT
PRECIPITATION
10. TEMPERATURE
MEASURE OF TEMPERATURE AT DIFFERENT
LAYERS OF EARTHS ATMOSPHERE
MOST IMPORTANT WEATHER ELEMENTS
AFFECTING THE GROWTH OF PLANTS
IT AFFECTS THE ACTIVITY OF MICRO
ORGANISMS
PLANTS CAN SURVIVE WIDE RANGE 1OC -
60OC
CROP PLANTS CAN SURVIVE 10OC - 40OC
11. BASED ON THE TEMPERATURE
REQUIREMENT
THREE GROUPS OF PLANTS
TEMPERATE PLANTS
GROWS WELL IN LOW RANGE OF
TEMPERATURE
Eg:- Apple, Peach
SUB TROPICAL PLANTS
GROWS WELL IN MEDIUM RANGES OF
TEMPERATURE
Eg:- Tea, Citrus
TROPICAL PLANTS
GROWS WELL IN HIGHER RANGES OF
TEMPERATURE
Eg:- Coconut, Banana
15. ATMOSPHERIC PRESSURE
IS THE FORCE PER UNIT AREA EXERTED ON
A SURFACE BY THE WEIGHT OF AIR ABOVE
THAT SURFACE
PRESSURE IS MEASURED WITH MERCURY
BAROMETERS – FORTINS BAROMETER
PRESSURE AT DIFFERENT STATIONS CAN BE
MARKED ON MAPS
LINES CONNECTING STATIONS OF SAME
PRESSURE IS KNOWN AS ISOBARS
CONTINUOUS RECORDING OF PRESSURE
OF A DAY IS MADE WITH AN INSTRUMENT
CALLED BAROGRAPH
17. WIND
MOVEMENT OF AIR IN THE HORIZONTAL
PLANE CAUSED DUE TO PRESSURE
DIFFERENCE
VERTICAL MOVEMENT OF THE AIR ALSO
CAUSED DUE TO TEMPERATURE CHANGES
IN AIR DURING DAY AND NIGHT – IT IS NOT
WIND
WIND IS NAMED AFTER THE DIRECTION
FROM WHICH IT BLOWS
THE WIND BLOWING FROM WEST TO EAST IS
CALLED WESTERLY WIND
WEST – IS CALLED WINDWARD SIDE
EAST – IS LEEWARD SIDE
18. WIND – AFFECTS ON CROPS
HOW WIND HELPS???
HELPS IN POLLINATION OF CROPS
KEEPS DOWN ATMOSPHERIC TEMPERATURE
AIDS IN FARM OPERATIONS LIKE WINNOWING
LIFTING WATER FRO WELLS WITH WIND MILLS
HOW WIND HARMS???
PROMOTES LOSS OF SOIL MOSITURE BY EVAPORATION
AND TRANSPIRATION – INCREASES WATER
REQUIREMENT OF THE CROPS
STRONG WIND PREVENTS FRUIT SETTING
PROMOTES FRUIT FALL IN ORCHARDS
CAUSES LODGING
CAUSES SOIL EROSION
19. MEASURING WIND
WIND VELOCITY IS MEASURED BY
EQUIPMENT CALLED CUP ANEMOMETER
WIND DIRECTION IS MEASURED BY USING
WIND VANE
20. ANEMOMETERS
FOR MEASURING THE VELOCITY OF WIND
UNIT – KM/HOUR
TWO TYPES ARE THERE
ROBINSON’S CUP ANEMOMETER
HAS A VERTICAL AXIS AND FOUR CUPS WHICH
CAPTURE THE WIND.
NUMBER OF REVOLUTIONS /MIN IS REGISTERED
ELECTRONICALLY ON A CYCLOMETER
DINES PRESSURE TUBE ANEMOMETER
22. WIND VANE
INSTRUMENT THAT INDICATES WIND
DIRECTION
WIND WANE SHOULD BE PLACED AT GOOD
HEIGHT
IT SHOULD BE KEPT IN SUCH PLACES
WHERE THERE IS NO OBSTRUCTIONS FOR
THE FLOW OF WIND
i.e., away from trees, buildings etc
TWO PARTS
ARROW HEAD – Shows direction wind is flowing
from
WIDER HEAD - Shows direction wind is flowing to
26. HUMIDITY
ATMOSPHERE HOLDS WATER VAPOUR –
THIS IS KNOWN AS HUMIDITY
100% HUMID - WHEN MAXIMUM WATER
VAPOUR IS HELD BY ATMOSPHERE
THE CAPACITY OF AIR TO HOLD MOISTURE
INCREASES WITH INCREASE IN
TEMPERATURE
THE QUANTITY OF WATER VAPOUR HELD IN
ATMOSPHERE AT ANY GIVEN TIME IS
EXPRESSED AS RELATIVE HUMIDITY AND
ABSOULUTE HUMIDITY
27. ABSOULUTE HUMIDITY
IT IS THE MASS OF WATER VAPOUR
PER UNIT VOLUME OF AIR IN THE
ATMOSPHERE
28. RELATIVE HUMIDITY
IT IS THE RATIO OF HUMIDITY ACTUALLY
PRESENT IN THE ATMOSPHERE AND THE
MAXIMUM THAT CAN BE PRESENT AT A
PARTICULAR TEMPERATURE
IT IS EXPRESSED AS PERCENTAGE
o HUMIDITY ACTUALLY PRESENT
RH =-------------------------------------------- x100
o MAXIMUM HUMIDITY THAT CAN BE HELD
30. STEVENSON SCREEN
IT I S A WHITE WOODEN BOX SET AT A
HEIGHT OF 4 FEET ABOVE THE GROUND
HIT HOUSES FOUR THERMOMETERS
NAMELY
MAXIMUM THERMOMETER
MINIMUM THERMOMETER
DRY BULB THERMOMETER
WET BULB THERMOMETER
HUMIDITY IS MEASURED BY DRY BULB AND
WET BULB HOUSED INSIDE STEVENSON
SCREEN
31.
32.
33.
34. HUMIDITY AND ITS EFFECT ON
CROPS
HIGH HUMIDITY REDUCES TRANSPIRATION
FROM PLANTS AND EVAPORATION FROM
SOIL
LOW HUMIDITY INCREASES WATER
REQUIREMENT OF CROPS
HIGH HUMIDTY ENHANCES CHANCES OF
FUNGAL DISEASES
35. LIGHT - SUNSHINE
MEASURED BY TWO CHARACTERS
INTENSITY
DURATION
INTENSITY IS THE NUMBER OF LIGHT RAYS
FALLING IN A UNIT AREA
THE MORE THE INTENSITY OF LIGHT THE
MORE THE DRY MATTER PRODUCTION
THE LESS THE INTENSITY OF LIGHT THE
LESS THE DRYMATTER PRODUCTION
INTENSITY MEASURED BY USING LUXMETER
– UNIT IS LUX
36. SUNSHINE – DURATION OF
LIGHT
DAY LENGTH OR DURATION OF LIGHT
RECEIVED BY PLANTS IS IMPORTANT
THE RESPONSE OF PLANTS TO THE
RELATIVE LENGTH OF DAY AND NIGHT IS
KNOWN AS PHOTOPERIODISM
37. PHOTOPERIODISM
SHORT DAY PLANTS
PLANTS WHICH GROW NORMALLY WHEN THE
PHOTOPERIOD IS LESS THAN 12 HOURS.
LONG DAY PLANTS
PLANTS WHICH DEVELOP AND REPRODUCE
NORMALLY WHEN PHOTOPERIOD IS MORE
THAN 12 HOURS.
DAY NEUTRAL PLANTS
PLANTS UNAFFECTED BY PHOTOPERIOD
39. SUNSHINE RECORDER
THIS SIMPLE INSTRUMENT USED FOR
MEASURING DURATION OF BRIGHT
SUNSHINE OF THE DAY
THE SOLID GLASS SPHERE FOCUSSES THE
SUN RAYS TO AN INTENSE SPOT ON A CARD
PLACED IN THE SPHERICAL MOUNT BEHIND
THE SPHERE
THE FOCUSSED SUNLIGHT BURNS A TRACE
ON THE CARD AS THE SUN MOVES ACROSS
THE SKY
47. EVAPOTRANSPIRATION
THE LOSS OF WATER FROM THE FIELD
OCCURS IN TWO WAYS
EVAPORATION
THE LOSS OF WATER FROM SOIL AND WATER
SURFEACE
TRANSPIRATION
THE LOSS OF WATER FROM THE PLANT SURFACE
THESE TWO PROCESSES TOGETHER IS
KNOWN AS EVAPOTRANSPIRATION
EVAPORATION INCREASES WITH
INCREASE IN TEMPERATURE
INSTRUMENT USED FOR MEASURING IS
OPEN PAN EVAPORIMETER
49. OPEN PAN EVAPORIMETER
CONSISTS OF A CIRCULAR PAN OF
DIAMETER 120cm AND DEPTH 25cm.
A STILL WELL IS PROVIDED TO GET AN
UNDISTURBED WATER SURFACE AROUND
THE POINT OF MEASUREMENT
THE PAN IS FILLED WITH WATER AND
EXPOSED TO REPRESENT AN OPEN BODY
OF WATER
A WIRE MESH IS PROVIDED TO PREVENT
WATER LOSS BY BIRDS AND ANIMALS
THE AMOUNT OF WATER ADDED TO FILL THE
PAN IS THE EVAPORATION OF THAT DAY
50.
51.
52.
53.
54.
55.
56. CLOUDS
CONDENSATION OF MOISTURE AROUND
DUST PARTICLES PRESENT IN ATMOSPHERE
THE DENSITY AND APPEARANCE OF CLOUDS
INFLUENCED BY NUMBER OF TINY
DROPLETS DISPERSED IN ATMOSPHERE
AND THE PATTERN OF ARRANGEMENT
CLOUDS ARE CLASSIFIED ACCORDING TO
FORM, SHAPE AND GENERAL APPEARANCE.
VARIOUS TYPES OF CLOUDS ARE SEEN AT
DIFFERENT HEIGHTS
60. PRECIPITATION
ALL FORMS OF LIQUID OR SOLID FORMS OF
WATER FALLING FROM THE CLOUD AND
REACHING EARTH SRUFACE
FORMS OF PRECIPITATION
RAINFALL - Important Form – Primary source of soil
moisture
DRIZZLING
SNOW
HAIL
SLEET
61. MEASUREMENT OF RAINFALL
RAIN GAUGE
Measured in mm or cm
TWO TYPES OF RAINGAUGE
STANDARD RAINGAUGE
AUTOMATIC RAINGAUGE
62. RAIN AND ITS AFFECT ON
CROPS
CROPS DEPENDS ON RAIN FOR MOSITURE
SUPPLIES IRRIGATIONWATER TO RIVERS,
TANKS AND WELLS
DEFFICIENT RAIN LIMITS CROP GROWTH
HEAVY RAIN IS BAD FOR CROPS –
INDUCES WATER STAGNATION
CUT OFF AERATION
CAUSES SOIL EROSION
63. EFFECTIVE RAINFALL
THE QUANTITY OF RAIN FALL RECEIVED IN A
PARTICULAR OCCASION WHCH IS USEFUL
FOR CROP PRODUCTION AT THE SITE
WHERE IT FALLS IS CALLED EFFECTIVE
RAIN FALL
70. RADAR
RAdio Detection And Ranging
Is an object detection system that uses
electromagnetic waves specifically radio waves
to identify the range altitude, direction or speed of
objects
Meteorologists use radar to monitor precipitation .
It has become he primary tool for short term
weather forecasting and to watch for severe
weather such as thunderstorms ,tornadoes
,winter storms, precipitation types
73. Radiosonde
Small box like instrument that is carried into the
upper atmosphere by balloon .
As it travels upward it transmits meteorological
measurements to ground station
It measure temp, humidity and air pressure
Radiosondes are attached to a helium filled
neoprene balloons that are designed to burst
when they reach a specified altitude
So need not be returned to earth to retrieve the
data
It can be operated up to around 30,000 feet
77. AUTOMATIC WEATHER STATION (AWS)
An Automatic weather station (AWS) is an
automated type of traditional weather station.
It enable measurements from remote areas or
save human labour.
It may be in real -time via a local link to a
computer system or via telecommunications or
satellite systems.
GSM mobile phone technology has also been
known to be used. (Global System for Mobile
Communications)
An alternative is the storage of the information in
local data storage such as flash memory for
78. Most automatic weather stations have
1. Thermometer for measuring temperature
2.Anemometer for measuring wind speed
3. Hygrometer for measuring humidity
4. Barometer for measuring pressure
5.rain gauge for measuring rainfall
6. ceilometers for measuring cloud height
AUTOMATIC WEATHER STATION (AWS)
79. MONSOON
INDIA RECEIVES RAIN DUE TO MONSOON
MONSOON IS A SEASONAL WIND REGIME
DUE TO THE SEASON WIND SHIFT
OCCURRING IN LAND AND SEA
BASED ON THE ORIGIN OF MONSOON WINDS
TWO MONSOON OCCURS IN INDIA
SOUTH WEST MONSOON
NORTH EAST MONSOON
80. MONSOON IN KERALA
BOTH THE MONSOONS ARE IMPORTANT FOR
KERALA
SOUTH WEST MONSOON – KALAVARSHAM
/EDAVAPATHY
MAY – JUNE to AUGUST - SEPTEMBER
60% OF THE TOTAL RAINFALL
NORTH EAST MONSOON – THULAVARSHAM
SEPTEMBER – OCTOBER to NOVEMBER – DECEMBER
30% OF THE TOTAL RAINFALL
SUMMER SHOWERS
10% OF THE TOTAL RAINFALL
81.
82.
83. AGRICULTURAL SEASONS IN INDIA
KHARIF – JULY – OCTOBER
CROP GROWN : RICE, JOWER, BAJRA, MAIZE,
GROUNDNUT, COTTON
RABI – OCTOBER – MARCH
CROPS GROWN : WHEAT,BARLEY, OATS,
JOWER
ZAID – MARCH – JULY
SUMMER CROPS
VEGETABLES
84. AGRICULTURAL SEASONS OF KERALA
VIRIPPU – APRIL – MAY to SEPT – OCT(1ST
SEASON)
MUNDAKAN – SEPT – OCT to DEC – JAN(2ND
SEASON)
PUNJA – DEC – JAN to MARCH – APRIL(3RD
SEASON)
86. NJATTUVELA
365 DAYS OF A YEAR IS DIVIDED INTO GROUPS
OF 14 DAYS CALLED NJATTUVELA
EACH GROUP OF 14DAYS BEARING THE NAME
OF A STAR
THERE ARE 27 NJATTUVELAS
ASWATHY NJATTUVELA to REVATHY
NJATTUVELA
NJATTUVELA MEANS - “NJAYARINTE NILA” –
POSITION OF SUN
FIRST NJATTUVELA - ASWATHY NJATTUVELA –
BEGINS ON MEDAM 1 – VISHU – APRIL 14 OR 15
IN THIRUVATHIRA NJATTUVELA RAIN WILL
COME WITHOUT BREAK – SUITABLE FOR
88. ഞാറ്റുവേലയ ും കൃഷിയ ും
കേരളീയർ ഞാറ്റുകേലക്കാത്ത് ോർഷിേ ചക്േം
രൂപക്െടുത്തിയിട്ടുണ്ട്. കേരളീയക്ര
സംബന്ധിചച്ചിടകത്താളം ക്യാതിശാസ്തക്തത്തിലും
ോലാേസ്ഥാശാസ്തക്തത്തിലും പരിചയത്തിലും ഊന്നി
ഒരു ക്ോലലം ലഭ്യമാേുന്ന മഴയുക്ട േിതരണക്ത്ത
ഏറ്റേും ശാസ്തക്തീയമായി നിർണ്ണയിച്ചതിന്ക്െ
ക്പതയക്ഷ ഉദാഹരണമാണ് ഞാറ്റുകേല സങ്കല്പം.
ഞാറ്റുകേലയിക്ല മഴയുക്ട ക്പകതയേതേൾ
പഴയക്ചാലലുേളിൽ നിന്ന് േയക്തമാകാേുന്നതാണ്.
അശവതി, ഭ്രണി ഞാറ്റുകേലേളിൽ ഇടയ്ക്കിടക് മഴ
ക്പയ്ും. രണ്ടു രാശിേളിലായി ലഭ്ികുന്ന
ോർത്തിേ ഞാറ്റുകേലയിൽ ക്പാതുക്േ മഴ
ഉണ്ടാോെിലല. എങ്കിലും ോർത്തിേ ോലിൽ
ോകകാൽ നനഞ്ഞാൽ മുകാലിൽ മുകും എന്ന
ക്ചാലലിൽ നിന്ന് കമടം രാശിയിൽ േരുന്ന
ോർത്തിേ ഞാറ്റുകേലയുക്ട 1/4 രാശിയിൽ ക്ചെിയ
മഴ ക്പയ്ക്താൽ തക്ന്ന മിഥുനം രാശിയിൽ േരുന്ന
3/4 രാശിയിൽ നലല മഴ ലഭ്ികുക്മന്ന േിേരം
ലഭ്ികുന്നു. മേയീരയം ഞാറ്റുകേലയിലും മഴ
മതിമെിയും എന്നും തിരുോതിര ഞാറ്റുകേലയിൽ
89. തിരുോതിര ഞാറ്റുകേലയുക്ട തുടകത്തിൽ
ക്തളിഞ്ഞ ോലാേസ്ഥയാക്ണങ്കിൽ
ഞാറ്റുകേലകൊകിനു നലല
മഴലഭ്ികുക്മന്നുമുള്ള "തിരുോതിരക്
ആദയം ക്തളിഞ്ഞാൽ കപാകിനു മഴ" എന്ന
ക്ചാലലും ക്പസക്തമാണ്. പുണർതത്തിൽ
പുേഞ്ഞ മഴയാണ്. ആയിലയം
ഞാറ്റുകേലയിൽ നലലമഴലഭ്ികുക്മന്നും
അത് അത്തമാേുകപാകഴകും
ശക്തമാേുക്മന്നും പഴയ ക്ചാലലുേളിൽ
നിന്ന് മനസ്സിലാകാം. തിരുോതിര
ഞാറ്റുകേല ഏറ്റേും കേമൻ എന്നാണ്
േർഷേർ േരുതുന്നത്. ഏത് ക്ചടി നട്ടാലും
എളുെം േളരും. പ്ലാേിന്ക്െയും
മാേിന്കെയും േപ് േക്ര
ക്പാടിച്ചുേരുമക്ക്ത. ഈ ഞാറ്റുകേലക്
91. WEATHER FORECASTING
DAILY WEATHER FORECAST INVOLVES
WORKS OF THOUSAND METEOROLOGISTS
THOUSANDS OF MACHINES
MODERN COMPUTERS – SATELLITES
FORECASTERS USE THE OBSERVATIONS
FROM GROUND AND SPACE, ALONG WITH
FORMULAS AND RULES BASED ON WHAT
HAS HAPPENED IN THE PAST, FOR MAKING
DAILY WEATHER FORECAST
93. WHY DO FORECASTS GO WRONG SOMETIMES….
DIFFERENT EQUATIONS PRODUCE
DIFFERENT RESULTS
SO METEROROGLISTS MUST USE
DIFFERENT METHODS ALONG WITH
COMPUTER FORECASTING
USING THESE METHODS FORECASTERS
COMEUP WITH THEIR “BEST GUESS” – HOW
THE WEATHER WILL BE OVER NEXT FEW DAYS
94. “CLIMATE IS WHAT WE EXPECT, WEATHER IS WHAT WE GET”-
MARK TWAIN
“INDIAN AGRICULTURE IS A GAMBLE WITH MONSOON”
GVHSS,MANANTHAVADY PREPARED ON 29/07/2015
