Weather and climate
Aug 17, 2015
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- 1. WEATHER AND CLIMATE CHAPTER 2
- 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
- 3. IMPORTANT GASES OF ATMOSPHERE 78% 21% 0.94% 0.033%
- 4. LAYERS OF ATMOSPHERE
- 5. METEOROLOGY THE SCIENCE OF ATMOSPHERE WHEN IT IS RELATED TO CROPS AGRICULTURAL METEOROLOGY
- 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
- 9. METEOROLOGICAL OBSERVATORY AN AREA WHICH HOUSES METEOROLOGICAL EQUIPMENTS
- 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
- 12. ISOTHERMS
- 13. Soil thermometer
- 14. 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
- 15. BAROMETER Atmospheric pressure is expressed In millimeters. Standard atmospheric pressure is 76mm of Hg at 273 K
- 16. 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
- 17. 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
- 18. MEASURING WIND WIND VELOCITY IS MEASURED BY EQUIPMENT CALLED CUP ANEMOMETER WIND DIRECTION IS MEASURED BY USING WIND VANE
- 19. ANEMOMETERS FOR MEASURING THE VELOCITY OF WIND UNIT KM/HOUR TWO TYPES ARE THERE ROBINSONS 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
- 20. ROBINSONS CUP ANEMOMETER
- 21. 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
- 22. WIND VANE
- 23. WIND DIRECTIONS N S EW SW SE NE NW
- 24. 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
- 25. ABSOULUTE HUMIDITY IT IS THE MASS OF WATER VAPOUR PER UNIT VOLUME OF AIR IN THE ATMOSPHERE
- 26. 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
- 27. MEASUREMENT OF HUMIDITY MEASURED BY HYGROMETER
- 28. 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
- 29. 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
- 30. 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
- 31. 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
- 32. 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
- 33. MEASURING DURATION OF SUNLIGHT USING SUNSHINE RECORDER
- 34. 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
- 35. How sunshine recorder records
- 36. USED IN SUNSHINE RECORDER
- 37. 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
- 38. PAN EVAPORIMETER
- 39. 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
- 40. 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
- 41. VARIOUS TYPES OF CLOUDS ARE SEEN AT DIFFERENT HEIGHTS
- 42. 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
- 43. MEASUREMENT OF RAINFALL RAIN GAUGE Measured in mm or cm TWO TYPES OF RAINGAUGE STANDARD RAINGAUGE AUTOMATIC RAINGAUGE
- 44. 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
- 45. 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
- 46. AUTOMATIC RAIN GAUGE
- 47. RADAR
- 48. 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
- 49. Weather balloon
- 50. Radiosonde
- 51. 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
- 52. AUTOMATIC WEATHER STATION (AWS)
- 53. 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
- 54. 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)
- 55. 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
- 56. 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
- 57. 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
- 58. 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)
- 59. AGRICULTURAL SEASONS OF WAYANAD NANJA JUNE to DECEMBER PUNJA DECEMBER to MAY
- 60. 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
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- 65. 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
- 66. TYPES OF WEATHER FORECAST
- 67. 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
- 68. 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
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