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AGROMETROLOGY - Coggle Diagram
AGROMETROLOGY
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2.Agricultural Meteorology: Focuses on the interactions between the atmosphere and various elements of agriculture, including crops, grasses, trees, animals, pests, and diseases.
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Temperature remains nearly constant up to 20 km, then begins to rise until reaching about 50 km.
The top of this layer, where the maximum temperature is attained, is called the stratopause.
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Located above the stratopause, extending up to around 80 km.
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Atmospheric composition transitions from molecular forms (O₂ and N₂) up to 200 km to atomic forms (O and N) above 200 km.
The term ionosphere is used to describe the layers with high electron density, typically between 100 to 300 km.
Here's a breakdown of the important concepts in Agricultural Meteorology related to radiation and energy:
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oVisible (Photosynthetically Active Radiation, PAR): 400 nm to 740 nm
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oPhotosynthetically Active Radiation (PAR): Contains 39.8% of the total energy, which is crucial for photosynthesis.
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cc is the speed of light,
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oAn ideal physical body that absorbs all radiation incident upon it and emits the maximum possible intensity of radiation at all wavelengths.
oEmissivity (EE): Ratio of emittance of a surface to that of a black body; for a black body, E=1E=1.
oAbsorptivity (aa): Ratio of the amount of radiant energy absorbed to the total energy incident upon a surface; for a black body, a=1a=1.
oFor a white body, emissivity and absorptivity are 0.
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oEarth is considered a "grey body," meaning its emissivity and absorptivity are less than 1 but not 0.
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oRatio of the radiant energy reflected from a surface to the total energy incident upon that surface.
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oThe flux density or intensity of the solar beam at the top of the atmosphere and at Earth's mean distance from the sun.
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oRanges from 4 to 80 µm, with a peak at 9.66 µm.
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Here’s a concise summary of the key points related to radiation, temperature, and atmospheric pressure in Agricultural Meteorology:
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oThe total of incoming and outgoing radiation over Earth’s surface is zero, meaning the Earth is in radiative balance.
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oPyradiometer: Measures longwave radiation, either in the upward or downward direction.
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oAmplitude of Daily Oscillation: Half of the difference between the maximum and minimum temperature of a day.
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Vertical Temperature Gradient (Lapse Rate): Change of temperature with vertical distance, typically 6.5°C/km up to the tropopause.
oCardinal Temperatures: Maximum, optimum, and minimum temperatures crucial for plant growth.
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oSpecific Heat: The amount of heat absorbed or released to raise or lower the temperature of a unit mass of material by 1°C.
oThermal Conductivity: The quantity of heat flowing through a unit cross-section of soil in response to a temperature gradient of 1°C per cm of depth.
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oSoil temperatures are generally higher in ridges and lower in furrows, but maximum temperature is often attained earlier in furrows than in ridges.
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oAtmospheric Pressure: Defined as the weight of the air column per unit area above the Earth’s surface, extending to the limit of the atmosphere.
Here’s a summary of the key concepts related to atmospheric pressure, wind, and related phenomena in Agricultural Meteorology:
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oA low-pressure belt along the equator (5°N to 5°S latitude) is known as the Intertropical Convergence Zone (ITCZ) or doldrums.
oTrade Winds: Inflowing winds towards ITCZ are called trade winds—Northeast trades in the Northern Hemisphere and Southeast trades in the Southern Hemisphere.
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oA high-pressure belt at 20° to 30° latitude, where dry air descends, known as "horse latitudes," is part of the Hadley Cell circulation.
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oWinds moving from the horse latitudes towards the polar regions get deflected, becoming South-Westerlies in the Northern Hemisphere, known as "prevailing westerlies" or "anti-trade winds." This circulation is part of the Ferrel Cell.
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oWinds in the polar regions, known as polar easterlies, circulate as part of the Polar Cell.
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oControlled by four factors: Pressure Gradient Force, Coriolis Force, Centrifugal Force, and Frictional Force.
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oCyclones: Also known as "Lows" or "Depressions," exhibit counterclockwise motion in the Northern Hemisphere and clockwise in the Southern Hemisphere.
oAnticyclones: Show opposite motion—clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
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Wind speed: 35-47 knots (Cyclonic Storm), 48-63 knots (Severe Cyclonic Storm), above 64 knots (Hurricane or Typhoon).
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Here’s a summary of the concepts related to wind measurement, humidity, and related processes in Agricultural Meteorology:
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Measurement Height: Wind speed and direction are typically measured at a height of 3 meters for agrometeorological purposes.
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Latent Heat of Vaporization: The energy required to evaporate 1 kg of water at 20°C is approximately 2.45 MJ.
Latent Heat of Fusion: When 1 kg of water freezes, it releases about 0.34 MJ of heat energy.
Latent Heat of Sublimation: The energy required for the direct transition of water from the solid to vapor phase (bypassing the liquid phase) is approximately 2.834 MJ/kg.
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oAbsolute Humidity: The ratio of the mass of water vapor to the total volume of moist air, expressed in kg/m³.
oSpecific Humidity: The ratio of the mass of water vapor to the total mass of air (including water vapor), expressed in kg/kg of moist air.
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oRelative Humidity: The ratio of the amount of water vapor in the air to the total amount the air can hold at a given temperature, expressed as a percentage.
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Dew Point Temperature: The temperature at which air becomes saturated if cooled at constant pressure without the addition or removal of vapor.
oAt this temperature, the actual vapor pressure equals the saturation vapor pressure.
Vapor Pressure Deficit: The difference between saturation vapor pressure and actual vapor pressure.
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Hair Hygrometer: Measures humidity continuously using a bundle of human hair, which expands and contracts in response to changes in humidity.
Here’s a summary of the key concepts related to atmospheric moisture, clouds, and condensation:
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Saturation Vapor Pressure: The pressure exerted by the water vapor when the air is saturated. Above an ice surface, it is lower than above a supercooled liquid surface at the same temperature because the latent heat for the change from solid to vapor (sublimation, 2.834 MJ/kg) is greater than for the change from liquid to vapor (evaporation, 2.45 MJ/kg).
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Clouds: An assembly of tiny water droplets and/or ice particles suspended in the atmosphere above the Earth’s surface.
Dry Adiabatic Lapse Rate (DALR): The rate at which the temperature of unsaturated air cools as it rises, approximately 0.98°C per 100 meters.
Lifting Condensation Level (LCL): The altitude at which rising air cools to its dew point and condensation begins.
Saturated Adiabatic Lapse Rate (SALR): The rate at which the temperature of saturated air decreases with height, typically about 0.5°C per 100 meters. This rate is always less than DALR.
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Condensation Nuclei: Microscopic particles that provide surfaces for water vapor to condense into droplets.
oHygroscopic Nuclei: Particles like sulfur dioxide and nitric oxide that absorb water and facilitate condensation.
oNon-Hygroscopic Nuclei: Particles such as dust, sand, and volcanic ash that provide surfaces for condensation without absorbing water.
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Condensation Phenomena: Dew, fog, frost, and smog are results of condensation occurring near the ground.
oDew: Forms on clear, calm nights with sufficient moisture.
oFog: Occurs when visibility is reduced to less than 1 km due to the presence of tiny water droplets.
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Frost: Forms when the dew point temperature falls below the freezing point, leading to ice crystal formation instead of liquid dew.
These concepts are essential for understanding weather patterns, climate, and their effects on agriculture.
Here’s a detailed overview of smog, cloud formation, and cloud classification:
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Smog: A combination of fog and smoke, typically found in industrial areas. It’s a type of air pollution that reduces visibility and can have harmful health effects.
Condensation: For moist air to condense into clouds or precipitation, it must be cooled. This cooling can occur through:
oOrographic Effect: When air is forced to ascend over mountains, leading to cooling and condensation.
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oConvergence: When air masses collide, forcing air to rise and cool.
oConvection: When warm air rises due to surface heating, cools, and condenses into clouds.
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World Meteorological Organization (WMO) Cloud Atlas (1956): Describes 10 main cloud types, grouped into three families based on altitude.
High Clouds (6-18 km in Tropics, 5-12 km in Mid-latitudes, 3-8 km in Polar Regions):
Cirrus (Ci): Feather-like clouds composed of ice crystals, often showing brilliant colors at sunset and sunrise. They do not produce precipitation.
Cirro-cumulus (Cc): Thin, whitish layers without shadows, often arranged in groups, lines, or ripples, known as "mackerel sky."
Cirro-stratus (Cs): Whitish, transparent clouds covering the sky, giving a milky appearance.
Middle Clouds (2-8 km in Tropics, 2-7 km in Mid-latitudes, 2-4 km in Polar Regions):
Alto-cumulus (Ac): Clouds arranged in lines or waves, sometimes referred to as sheep clouds or wool pack clouds.
Alto-stratus (As): Uniform sheets of grey or bluish clouds, through which the sun or moon appears as a bright spot. These clouds can produce light drizzle or snow.
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Strato-cumulus (Sc): Low, lumpy clouds, often covering the sky in patches.
Stratus (St): Low, uniform layers of clouds resembling fog, typically found close to the ground.
Nimbo-stratus (Ns): Thick, dense clouds that produce continuous precipitation, often difficult to see due to their coverage and the precipitation they produce.
Cumulus (Cu): Thick, dense clouds with vertical development, resembling cauliflower. They typically form during the day over land and dissipate at night.
Cumulo-nimbus (Cb): Towering clouds with significant vertical development, often rising like mountains or towers. These clouds are associated with heavy rainfall, thunderstorms, lightning, and hail.
Here’s a detailed breakdown of the concepts related to precipitation, cloud seeding, and other weather phenomena:
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Cumulus/Cumulo-nimbus Rain: Reduces visibility to as low as 100 meters, often associated with heavy downpours, thunderstorms, and sometimes hail.
Cloud Seeding: A technique used for artificial rainmaking by introducing substances into clouds to encourage precipitation:
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Orographic Precipitation: Occurs on the windward side of mountains where moist air rises, cools, and precipitates. Beyond a certain height, the rainfall decreases, known as the inversion of rainfall.
Convective Precipitation: Caused by intense surface heating, leading to the rise of moist air and resulting in strong winds, thunderstorms, heavy rainfall, lightning, and sometimes hail.
Cyclonic/Frontal Precipitation: Occurs when two air masses of different temperatures meet, common in tropical regions:
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Fog: A type of stratus cloud lying close to the earth’s surface with water droplets of 10-50 micrometers.
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Hail: Precipitation composed of irregular ice pieces, typically 5-50 mm in diameter.
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Glaze: Freezing rain that forms a clear ice layer, common in temperate climates during winter.
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Sleet: Rain mixed with ice, occurring when snow melts as it falls.
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Geo-stationary Satellites: Use infrared sensors to provide continuous day and night images of cloud cover.
Rainfall: The most common form of precipitation, where water droplets larger than 0.5 mm fall to the earth’s surface.
oDroplet Evaporation: A droplet with a 0.1 mm radius evaporates after falling 150 meters at 5°C and 90% relative humidity, while a 1.0 mm droplet could fall up to 42 km before evaporating.
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Tamil Nadu: Receives only 20-40% of its rainfall from the southwest monsoon, with most rainfall occurring during the northeast monsoon.
Jammu and Kashmir: Receives 35-40% of its rainfall from the southwest monsoon, but the majority of rainfall occurs from western disturbances between November and April.
Here's a summary and explanation of the points related to weather forecasting, evapotranspiration, and plant growth:
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Western Disturbance: Defined as a low-pressure system or a trough of low pressure at the surface, or a cyclonic circulation in the upper atmosphere. These disturbances can bring significant weather changes, including rainfall, particularly in the Indian subcontinent during winter.
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IMD's Monsoon Prediction: The India Meteorological Department (IMD) uses 16 regional and global land-ocean-atmosphere parameters for predicting the Indian monsoon.
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Evapotranspiration (ET): The total water lost through transpiration by vegetation plus evaporation from the soil, expressed in millimeters (mm).
Potential Evapotranspiration (PET): Represents the maximum amount of water that can be lost through evaporation from wet soil and transpiration from short-cut grass, assuming unlimited water supply. It reflects the atmospheric demand for water on a given day.
Reference Crop Evapotranspiration: The rate of evapotranspiration from a standardized grass cover, 8-15 cm tall, completely shading the ground and not limited by water supply. It is expressed in mm/day.
Consumptive Use of Water: The total volume of water used by plants for transpiration, evaporation from the soil, and metabolic processes, expressed in mm/day.
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ET Calculation: According to Doorenbos and Pruitt, the formula for evapotranspiration is: ET=Kc×PETET=Kc×PET where KcKc is the crop coefficient, PET is potential evapotranspiration, and ET is actual evapotranspiration. Alternatively, ET/PET=KcET/PET=Kc
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Day Neutral Plants: Plants that do not require a specific day length for flowering and can grow regardless of light conditions. Examples include tomato, cotton, sweet potato, and pineapple.
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5.The phenomenon where the Earth’s atmosphere traps heat, leading to a warming of the surface, is known as:
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12.Which wind belt is found near the equator and is characterized by calm, light winds?
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13.The amount of water vapor in the air compared to what the air can hold at that temperature is called:
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4.The dry, warm wind that descends the leeward side of a mountain is called:
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6.What is the term for the temperature at which air becomes saturated with moisture and condensation begins?
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9.Which phenomenon is associated with a sudden cooling of the Pacific Ocean, opposite to El Niño?
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11.Which weather condition is characterized by high pressure at the center and generally clear skies?
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14.What term describes a localized, violent windstorm characterized by a rotating column of air?
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15.Which climatic phenomenon is responsible for the reversal of wind patterns over the Indian subcontinent?
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4.Which type of precipitation occurs when rain falls through a layer of freezing air near the ground?
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6.What is the name of the wind system that blows from the northeast in the Northern Hemisphere during winter?
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14.Which type of fog forms when warm, moist air passes over a cooler surface?
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7.Which type of climate is characterized by hot, dry summers and mild, wet winters?
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10.Which type of precipitation occurs when the air temperature is below freezing from the cloud base to the ground?
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7.Which meteorological phenomenon is characterized by strong winds and heavy rainfall, usually forming over warm ocean waters?
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8.In the context of weather patterns, what does the term "La Niña" refer to?
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13.Which type of frost occurs due to radiation cooling on clear, calm nights?
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ob) Dry, hot summers and mild, wet winters
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14.b) Dry, hot summers and mild, wet winters
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10.What is the primary factor responsible for the formation of the Intertropical Convergence Zone (ITCZ)?
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oa) Hot, dry summers and cool, wet winters
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oc) Cold, snowy winters and warm summers
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4.Which phenomenon is characterized by the periodic warming of sea surface temperatures in the central and eastern Pacific Ocean?
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oc) A sudden, intense rainfall event
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3.a) Hot, dry summers and cool, wet winters
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2.What phenomenon causes an increase in sea surface temperatures in the central and eastern Pacific Ocean?
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4.Which type of cloud is known for covering the sky like a blanket, leading to overcast conditions?
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