The presentation shows how relative humidity affects other ecological parameters in meteorology. This also shows the relationship between and among the ecological parameters in meteorology
Humidity refers to the amount of water vapor in the air. It can be measured using instruments like a psychrometer, which uses the difference between dry and wet bulb thermometer readings. Relative humidity indicates the percentage of water vapor an air sample can hold compared to its maximum capacity. Other expressions of humidity include vapor pressure, absolute humidity, dewpoint, specific humidity, and mixing ratio. Proper measurement requires accounting for factors like temperature fluctuations, instrument errors, and air ventilation.
This document provides an overview of a village-level crop and weather analysis project conducted by students in an agricultural meteorology program. It introduces the group members and describes the objectives of their Rural Agricultural Work Experience (RAWE) program, which aims to give students hands-on experience analyzing rural institutions, farms, and the impacts of traditions on farming communities. The document then provides background on agrometeorology and its relevance to agriculture before describing the study village of Darjeepara and presenting findings on its water resources, hydrological map, cropping patterns, irrigation sources, and monthly farm operations. Water balances and phenological analyses are also given for specific crops grown by two farmers.
B.sc agri i paam unit 4 agricultural meteorologyRai University
Agricultural meteorology is the study of meteorology and climatology in relation to agriculture. It involves characterizing agricultural climates, planning crops for stable production, managing crops based on weather forecasts, monitoring crop health and growth, modeling crop-climate relationships, and researching how climate impacts crops. Weather refers to short-term atmospheric conditions while climate describes average weather patterns over many years. Important meteorological instruments used in agriculture include anemometers to measure wind speed, thermometers for temperature, psychrometers for humidity, barometers for pressure, hygrometers for relative humidity, rain gauges, and wind vanes. Weather forecasts of various timescales help farmers plan operations and protect crops and livestock.
This document discusses condensation and the formation of fog and clouds. It begins by defining condensation as the process where a gas transforms into a liquid due to changes in pressure and temperature. It then discusses the necessary and sufficient conditions for condensation to occur, including cooling air to below its dew point until saturated and the presence of condensation nuclei. The document proceeds to describe different types of fog like radiation fog, advection fog, and freezing fog that form through various cooling mechanisms. It also covers cloud condensation nuclei and the classification system used to identify different types of clouds.
This document discusses various climatological classification systems, focusing on Koppen's and Thornthwaite's classifications. Koppen's system classifies climates into 5 main groups (A through E) based on temperature and precipitation averages. Thornthwaite's system uses potential evapotranspiration and temperature effective indices to classify climates into humidity and temperature provinces. The document also briefly outlines Troll's classification system which differentiates tropical climates based on the number of humid months.
This document provides an introduction to agro-meteorology. It defines key terms like climatology, meteorology, agro-climatology, and agro-meteorology. Agro-meteorology examines the relationship between weather, climate, and agriculture. It seeks to understand how meteorological and hydrological conditions impact agriculture. The scope of agro-meteorology is to apply meteorological knowledge to improve crop production and develop sustainable agricultural systems.
The document discusses various tools used in weather forecasting, including meteorological stations, pilot balloons, radiosondes, weather radars, sodars, and satellites. Pilot balloons and radiosondes are used to collect temperature, humidity, and wind data at different altitudes. Weather radars like Doppler radars detect rain and wind patterns. Sodars measure wind speed above ground using sound wave scattering. Satellites like Kalpana-1 and INSAT provide visual images and infrared data on clouds, temperature, and moisture profiles to forecast weather.
Soil water movement
Soil water movement
Soil water movement
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Humidity refers to the amount of water vapor in the air. It can be measured using instruments like a psychrometer, which uses the difference between dry and wet bulb thermometer readings. Relative humidity indicates the percentage of water vapor an air sample can hold compared to its maximum capacity. Other expressions of humidity include vapor pressure, absolute humidity, dewpoint, specific humidity, and mixing ratio. Proper measurement requires accounting for factors like temperature fluctuations, instrument errors, and air ventilation.
This document provides an overview of a village-level crop and weather analysis project conducted by students in an agricultural meteorology program. It introduces the group members and describes the objectives of their Rural Agricultural Work Experience (RAWE) program, which aims to give students hands-on experience analyzing rural institutions, farms, and the impacts of traditions on farming communities. The document then provides background on agrometeorology and its relevance to agriculture before describing the study village of Darjeepara and presenting findings on its water resources, hydrological map, cropping patterns, irrigation sources, and monthly farm operations. Water balances and phenological analyses are also given for specific crops grown by two farmers.
B.sc agri i paam unit 4 agricultural meteorologyRai University
Agricultural meteorology is the study of meteorology and climatology in relation to agriculture. It involves characterizing agricultural climates, planning crops for stable production, managing crops based on weather forecasts, monitoring crop health and growth, modeling crop-climate relationships, and researching how climate impacts crops. Weather refers to short-term atmospheric conditions while climate describes average weather patterns over many years. Important meteorological instruments used in agriculture include anemometers to measure wind speed, thermometers for temperature, psychrometers for humidity, barometers for pressure, hygrometers for relative humidity, rain gauges, and wind vanes. Weather forecasts of various timescales help farmers plan operations and protect crops and livestock.
This document discusses condensation and the formation of fog and clouds. It begins by defining condensation as the process where a gas transforms into a liquid due to changes in pressure and temperature. It then discusses the necessary and sufficient conditions for condensation to occur, including cooling air to below its dew point until saturated and the presence of condensation nuclei. The document proceeds to describe different types of fog like radiation fog, advection fog, and freezing fog that form through various cooling mechanisms. It also covers cloud condensation nuclei and the classification system used to identify different types of clouds.
This document discusses various climatological classification systems, focusing on Koppen's and Thornthwaite's classifications. Koppen's system classifies climates into 5 main groups (A through E) based on temperature and precipitation averages. Thornthwaite's system uses potential evapotranspiration and temperature effective indices to classify climates into humidity and temperature provinces. The document also briefly outlines Troll's classification system which differentiates tropical climates based on the number of humid months.
This document provides an introduction to agro-meteorology. It defines key terms like climatology, meteorology, agro-climatology, and agro-meteorology. Agro-meteorology examines the relationship between weather, climate, and agriculture. It seeks to understand how meteorological and hydrological conditions impact agriculture. The scope of agro-meteorology is to apply meteorological knowledge to improve crop production and develop sustainable agricultural systems.
The document discusses various tools used in weather forecasting, including meteorological stations, pilot balloons, radiosondes, weather radars, sodars, and satellites. Pilot balloons and radiosondes are used to collect temperature, humidity, and wind data at different altitudes. Weather radars like Doppler radars detect rain and wind patterns. Sodars measure wind speed above ground using sound wave scattering. Satellites like Kalpana-1 and INSAT provide visual images and infrared data on clouds, temperature, and moisture profiles to forecast weather.
Soil water movement
Soil water movement
Soil water movement
Soil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movementSoil water movement
Water vapor is the most important gas in the atmosphere and is the source of all condensation and precipitation. The water cycle begins with evaporation and includes condensation, precipitation, and water running off or sinking into the ground. Clouds are classified based on their height and form, with cirrus, cumulus and stratus being the main cloud types located in the high, middle and low levels of the atmosphere respectively. For precipitation to form, cloud droplets must grow substantially through processes like collision-coalescence in warm clouds and the Bergeron process in cold clouds. The type of precipitation reaching the surface depends on the temperature profile in the lower atmosphere.
Cyclones involve a closed circulation around a low pressure center, spinning counterclockwise in the Northern Hemisphere. They bring strong winds inward and cause extensive damage from heavy rain. Cyclones are known by different names depending on location, such as hurricanes in the Atlantic and typhoons in the Western Pacific. Anticyclones circulate clockwise around a high pressure center, pushing winds outward and typically bringing fine weather. Key differences between cyclones and anticyclones are the direction of circulation and associated weather patterns.
This document discusses evapotranspiration, which is the total amount of water lost as vapor from soil, plant surfaces, and water bodies. It defines evaporation as movement of water to the air from sources like soil and water bodies, while transpiration is movement of water within plants and subsequent loss of water vapor through leaf stomata. The document outlines different types of evapotranspiration and factors that affect the process, like plant/crop characteristics, soil properties, and geographical factors. It also describes methods to determine evapotranspiration rates, including indirect methods like water balance and energy balance approaches, and direct methods like using lysimeters to measure actual evapotranspiration.
Humidity refers to the amount of water vapor in the air. There are three main types of humidity: absolute, relative, and specific. Absolute humidity is a direct measure of the mass of water in a given volume of air. Relative humidity compares the actual water content of the air to the maximum amount the air can hold at a given temperature. Specific humidity measures the ratio of water vapor to total air mass. Relative humidity is affected by temperature and the amount of water in the air. High humidity can impact climate, plants, animals, human comfort, and more. The most humid areas tend to be near the equator and coastal regions.
This document discusses cloud formation and types of clouds. It presents that clouds are formed through convection as warmer air rises and cools, causing water vapor to condense into liquid droplets or ice crystals. Clouds are classified into high, middle, and low-level clouds based on their height and composition. Factors like surface heating, topography, fronts, convergence, and turbulence can influence cloud formation. Clouds impact the environment by regulating temperature through reflection and absorption of heat and enabling precipitation through the water cycle.
Wind affects crop production in both beneficial and harmful ways. At low velocities below 10 km/hr, wind can help crops through processes like transpiration and photosynthesis. However, above this threshold wind can damage crops through mechanical impacts like lodging, fruit shedding, and uprooting. Management strategies to reduce wind stress include windbreaks, ridges, maintaining crop residues, and cultivar selection. Properly installed windbreaks can decrease wind speed and increase humidity and soil/air temperatures to boost yields by 6-44%.
1. Soil aeration is the exchange of gases like oxygen and carbon dioxide between the soil pores and atmosphere. It ensures sufficient oxygen for plant roots and microbes while preventing excess carbon dioxide build up.
2. Gaseous exchange occurs through both mass flow and diffusion. Mass flow is driven by pressure gradients while diffusion occurs down partial pressure gradients between the soil pores and atmosphere.
3. Factors like soil texture, structure, moisture and organic matter influence the gas composition and aeration status of soils by affecting the pore space available for gas exchange. Well-aerated soils support better plant growth.
Atmospheric pressure is caused by the weight of the air above pressing down. It is measured in millibars using a barometer. There are mercury and aneroid barometers. Pressure varies due to altitude, temperature, and water vapor content. Higher altitudes, warmer temperatures, and more moisture all result in lower air pressure. The earth's rotation also affects pressure, creating semi-permanent high and low pressure belts globally.
Crop Microclimate Modification to Address Climate ChangeUditDebangshi
Climate-related agricultural vulnerabilities, as
well as their implications for food security and
farm livelihoods, have been extensively
documented. Extreme weather events such as
floods, droughts, heat and cold waves,
hailstorms, strong winds, cyclones, and other
weather events have increased the exposures of
agriculture to climate risk. These processes are
hampered by a lack of appropriate climatic
elements, resulting in an unfavourable drop in
crop productivity. Increased frequency and
intensity of droughts and floods, as well as
erratic precipitation patterns are predicted to
increase year-to-year yield variability in crop
production. Microclimate, which refers to the
climatic elements in the immediate vicinity of
the plants, is critical because it regulates and
affects the physiological reactions of the plants
as well as the energy exchange activities
between the plant and its surroundings.
Implementation of such microclimatic
modifications in crop production are required to
manage extreme weather risks and boost crop
output in order to increase food security and
agricultural sustainability in this changing
climate. The goal of this paper is to improve
crop production and land productivity by
modifying microclimate as a manifestation of
the efficiency and effectiveness of growth factor
utilisation.
This document provides information about types of wind and wind mechanisms. It discusses three types of wind: permanent winds like trade winds and westerlies; seasonal winds that change direction with the seasons, like monsoons; and local winds that influence small areas, such as land and sea breezes. It also describes the mechanisms that drive wind circulation globally in three cells - the Hadley cell near the equator, the Ferrell cell in the mid-latitudes, and the polar cell near the poles. Air flows from high to low pressure in each cell, transporting heat around the world.
deals with temperature, density, pressure, winds and humidity parameters of the atmosphere; Prssure gradient force, coriolis force, gravity force and friction force and winds and currents, ; pressure lows and highs, atmospheric circulation, winds.
Use of agro meterological instruments in agricultureDIVYA KESHARWANI
This document provides an overview of various agro-meteorological instruments and their uses in agriculture. It discusses instruments for measuring temperature (thermometers), wind speed and direction (anemometers, wind vanes), humidity (psychrometers), rainfall (rain gauges), evaporation (evaporimeters), sunshine (sunshine recorders), cloud cover, and atmospheric pressure (barometers). The key uses of these instruments include planning irrigation, controlling crop losses, understanding crop environment relationships, and improving plant health and yields.
Vivek Yadav's presentation discusses agrometeorological instruments used for protected crop cultivation. It introduces meteorology and explains how measuring weather parameters like temperature, humidity, solar radiation, and rainfall can help farmers plan cropping patterns, reduce losses, and manage pests and diseases. The presentation describes common instruments for measuring these parameters, including sunshine recorders, quantum sensors, pyranometers, thermometers, barometers, hygrometers, and rain gauges. It provides photos and explanations of how each instrument works.
This document provides information about meteorology presented by Suliman Khan, M. Mehran, and Sajjad Khan. It defines meteorology as the study of the earth's atmosphere and discusses the importance of meteorology in areas like navigation, aviation, agriculture, and more. It also describes key components of the atmosphere like its composition, humidity, dew point, and how the atmosphere protects biological life on Earth.
This presentation covers direct and indirect methods of moisture measurement with clear descriptions of installation, principle, interpretation of readings, advantages and disadvantages of each method.
Horizontal Distribution & Differences of Temperature discusses how several factors influence the horizontal and latitudinal distribution of temperatures around the Earth. Some of the key factors discussed include:
1. Latitudinal variations in solar radiation, which causes temperatures to decrease with increasing latitude away from the equator.
2. The mosaic of land and ocean surfaces, which disrupts the strict latitudinal zonation of temperatures. Proximity to oceans moderates temperatures.
3. Altitude, with temperatures decreasing about 6.5°C for every 1000m increase in elevation due to thinner air.
4. Cloud cover, which influences the difference between day and night temperatures through absorption and reflection of radiation.
Evaporation, transpiration and evapotranspirationStudent
1) Evaporation, transpiration, and evapotranspiration are key processes in the hydrological cycle. Evaporation is the process by which liquid water changes to a gas, transpiration is the process by which plants release water vapor into the air, and evapotranspiration accounts for both soil evaporation and plant transpiration.
2) There are several methods for measuring evapotranspiration rates, including lysimeters, water balance methods, eddy covariance, and remote sensing techniques using satellites.
3) Potential evapotranspiration refers to the theoretical maximum amount of water that could be evaporated or transpired, while actual or effective evapotranspiration depends on available water supply from the soil and
Role of Agrometeteorology Advisory Services In AgricultureNaveen Bind
This document discusses the role of agrometeorological advisory services in agriculture. It begins with an introduction to agrometeorological advisory services provided by the India Meteorological Department to enhance crop production and food security. Advisory services are provided at the district level through agrometeorological field units. The document then discusses the objectives, importance, information needs, dissemination, tools and products used in advisory services. It provides examples of the economic and on-farm impacts of advisory services and concludes that such services play a vital role in risk mitigation for agriculture.
The document discusses absolute and relative humidity. Absolute humidity is a direct measure of the amount of water vapor in the air. Relative humidity is the amount of water vapor relative to the air's temperature, since warm air can hold more water vapor than cold air. For the same amount of water vapor, cooler air will have a higher relative humidity and warmer air will have a lower relative humidity.
The document defines several terms related to humidity: humidity is the amount of water vapor in the air; relative humidity compares the actual vapor to the maximum possible at a given temperature; specific humidity measures the actual quantity of water vapor in a parcel of air. It also describes how relative humidity changes with temperature, gaining or losing water vapor, and defines dew point temperature as the temperature at which air reaches saturation.
Water vapor is the most important gas in the atmosphere and is the source of all condensation and precipitation. The water cycle begins with evaporation and includes condensation, precipitation, and water running off or sinking into the ground. Clouds are classified based on their height and form, with cirrus, cumulus and stratus being the main cloud types located in the high, middle and low levels of the atmosphere respectively. For precipitation to form, cloud droplets must grow substantially through processes like collision-coalescence in warm clouds and the Bergeron process in cold clouds. The type of precipitation reaching the surface depends on the temperature profile in the lower atmosphere.
Cyclones involve a closed circulation around a low pressure center, spinning counterclockwise in the Northern Hemisphere. They bring strong winds inward and cause extensive damage from heavy rain. Cyclones are known by different names depending on location, such as hurricanes in the Atlantic and typhoons in the Western Pacific. Anticyclones circulate clockwise around a high pressure center, pushing winds outward and typically bringing fine weather. Key differences between cyclones and anticyclones are the direction of circulation and associated weather patterns.
This document discusses evapotranspiration, which is the total amount of water lost as vapor from soil, plant surfaces, and water bodies. It defines evaporation as movement of water to the air from sources like soil and water bodies, while transpiration is movement of water within plants and subsequent loss of water vapor through leaf stomata. The document outlines different types of evapotranspiration and factors that affect the process, like plant/crop characteristics, soil properties, and geographical factors. It also describes methods to determine evapotranspiration rates, including indirect methods like water balance and energy balance approaches, and direct methods like using lysimeters to measure actual evapotranspiration.
Humidity refers to the amount of water vapor in the air. There are three main types of humidity: absolute, relative, and specific. Absolute humidity is a direct measure of the mass of water in a given volume of air. Relative humidity compares the actual water content of the air to the maximum amount the air can hold at a given temperature. Specific humidity measures the ratio of water vapor to total air mass. Relative humidity is affected by temperature and the amount of water in the air. High humidity can impact climate, plants, animals, human comfort, and more. The most humid areas tend to be near the equator and coastal regions.
This document discusses cloud formation and types of clouds. It presents that clouds are formed through convection as warmer air rises and cools, causing water vapor to condense into liquid droplets or ice crystals. Clouds are classified into high, middle, and low-level clouds based on their height and composition. Factors like surface heating, topography, fronts, convergence, and turbulence can influence cloud formation. Clouds impact the environment by regulating temperature through reflection and absorption of heat and enabling precipitation through the water cycle.
Wind affects crop production in both beneficial and harmful ways. At low velocities below 10 km/hr, wind can help crops through processes like transpiration and photosynthesis. However, above this threshold wind can damage crops through mechanical impacts like lodging, fruit shedding, and uprooting. Management strategies to reduce wind stress include windbreaks, ridges, maintaining crop residues, and cultivar selection. Properly installed windbreaks can decrease wind speed and increase humidity and soil/air temperatures to boost yields by 6-44%.
1. Soil aeration is the exchange of gases like oxygen and carbon dioxide between the soil pores and atmosphere. It ensures sufficient oxygen for plant roots and microbes while preventing excess carbon dioxide build up.
2. Gaseous exchange occurs through both mass flow and diffusion. Mass flow is driven by pressure gradients while diffusion occurs down partial pressure gradients between the soil pores and atmosphere.
3. Factors like soil texture, structure, moisture and organic matter influence the gas composition and aeration status of soils by affecting the pore space available for gas exchange. Well-aerated soils support better plant growth.
Atmospheric pressure is caused by the weight of the air above pressing down. It is measured in millibars using a barometer. There are mercury and aneroid barometers. Pressure varies due to altitude, temperature, and water vapor content. Higher altitudes, warmer temperatures, and more moisture all result in lower air pressure. The earth's rotation also affects pressure, creating semi-permanent high and low pressure belts globally.
Crop Microclimate Modification to Address Climate ChangeUditDebangshi
Climate-related agricultural vulnerabilities, as
well as their implications for food security and
farm livelihoods, have been extensively
documented. Extreme weather events such as
floods, droughts, heat and cold waves,
hailstorms, strong winds, cyclones, and other
weather events have increased the exposures of
agriculture to climate risk. These processes are
hampered by a lack of appropriate climatic
elements, resulting in an unfavourable drop in
crop productivity. Increased frequency and
intensity of droughts and floods, as well as
erratic precipitation patterns are predicted to
increase year-to-year yield variability in crop
production. Microclimate, which refers to the
climatic elements in the immediate vicinity of
the plants, is critical because it regulates and
affects the physiological reactions of the plants
as well as the energy exchange activities
between the plant and its surroundings.
Implementation of such microclimatic
modifications in crop production are required to
manage extreme weather risks and boost crop
output in order to increase food security and
agricultural sustainability in this changing
climate. The goal of this paper is to improve
crop production and land productivity by
modifying microclimate as a manifestation of
the efficiency and effectiveness of growth factor
utilisation.
This document provides information about types of wind and wind mechanisms. It discusses three types of wind: permanent winds like trade winds and westerlies; seasonal winds that change direction with the seasons, like monsoons; and local winds that influence small areas, such as land and sea breezes. It also describes the mechanisms that drive wind circulation globally in three cells - the Hadley cell near the equator, the Ferrell cell in the mid-latitudes, and the polar cell near the poles. Air flows from high to low pressure in each cell, transporting heat around the world.
deals with temperature, density, pressure, winds and humidity parameters of the atmosphere; Prssure gradient force, coriolis force, gravity force and friction force and winds and currents, ; pressure lows and highs, atmospheric circulation, winds.
Use of agro meterological instruments in agricultureDIVYA KESHARWANI
This document provides an overview of various agro-meteorological instruments and their uses in agriculture. It discusses instruments for measuring temperature (thermometers), wind speed and direction (anemometers, wind vanes), humidity (psychrometers), rainfall (rain gauges), evaporation (evaporimeters), sunshine (sunshine recorders), cloud cover, and atmospheric pressure (barometers). The key uses of these instruments include planning irrigation, controlling crop losses, understanding crop environment relationships, and improving plant health and yields.
Vivek Yadav's presentation discusses agrometeorological instruments used for protected crop cultivation. It introduces meteorology and explains how measuring weather parameters like temperature, humidity, solar radiation, and rainfall can help farmers plan cropping patterns, reduce losses, and manage pests and diseases. The presentation describes common instruments for measuring these parameters, including sunshine recorders, quantum sensors, pyranometers, thermometers, barometers, hygrometers, and rain gauges. It provides photos and explanations of how each instrument works.
This document provides information about meteorology presented by Suliman Khan, M. Mehran, and Sajjad Khan. It defines meteorology as the study of the earth's atmosphere and discusses the importance of meteorology in areas like navigation, aviation, agriculture, and more. It also describes key components of the atmosphere like its composition, humidity, dew point, and how the atmosphere protects biological life on Earth.
This presentation covers direct and indirect methods of moisture measurement with clear descriptions of installation, principle, interpretation of readings, advantages and disadvantages of each method.
Horizontal Distribution & Differences of Temperature discusses how several factors influence the horizontal and latitudinal distribution of temperatures around the Earth. Some of the key factors discussed include:
1. Latitudinal variations in solar radiation, which causes temperatures to decrease with increasing latitude away from the equator.
2. The mosaic of land and ocean surfaces, which disrupts the strict latitudinal zonation of temperatures. Proximity to oceans moderates temperatures.
3. Altitude, with temperatures decreasing about 6.5°C for every 1000m increase in elevation due to thinner air.
4. Cloud cover, which influences the difference between day and night temperatures through absorption and reflection of radiation.
Evaporation, transpiration and evapotranspirationStudent
1) Evaporation, transpiration, and evapotranspiration are key processes in the hydrological cycle. Evaporation is the process by which liquid water changes to a gas, transpiration is the process by which plants release water vapor into the air, and evapotranspiration accounts for both soil evaporation and plant transpiration.
2) There are several methods for measuring evapotranspiration rates, including lysimeters, water balance methods, eddy covariance, and remote sensing techniques using satellites.
3) Potential evapotranspiration refers to the theoretical maximum amount of water that could be evaporated or transpired, while actual or effective evapotranspiration depends on available water supply from the soil and
Role of Agrometeteorology Advisory Services In AgricultureNaveen Bind
This document discusses the role of agrometeorological advisory services in agriculture. It begins with an introduction to agrometeorological advisory services provided by the India Meteorological Department to enhance crop production and food security. Advisory services are provided at the district level through agrometeorological field units. The document then discusses the objectives, importance, information needs, dissemination, tools and products used in advisory services. It provides examples of the economic and on-farm impacts of advisory services and concludes that such services play a vital role in risk mitigation for agriculture.
The document discusses absolute and relative humidity. Absolute humidity is a direct measure of the amount of water vapor in the air. Relative humidity is the amount of water vapor relative to the air's temperature, since warm air can hold more water vapor than cold air. For the same amount of water vapor, cooler air will have a higher relative humidity and warmer air will have a lower relative humidity.
The document defines several terms related to humidity: humidity is the amount of water vapor in the air; relative humidity compares the actual vapor to the maximum possible at a given temperature; specific humidity measures the actual quantity of water vapor in a parcel of air. It also describes how relative humidity changes with temperature, gaining or losing water vapor, and defines dew point temperature as the temperature at which air reaches saturation.
This document discusses various aspects of water in the atmosphere and how it relates to meteorology. It covers the water cycle and how water changes state between solid, liquid, and gas through processes like melting, evaporation, condensation, and sublimation. It also defines key humidity terms like relative humidity, saturation, and dew point. Relative humidity depends on both the air temperature and its water vapor content compared to the maximum it can hold at a given temperature.
This document defines several key terms related to humidity:
- Humidity refers to the amount of water vapor in a gas. It can be expressed in terms of absolute humidity, relative humidity, and dewpoint.
- Absolute humidity is the actual amount of water vapor per liter of gas, measured in mg/L. Relative humidity expresses the amount of water vapor as a percentage of the maximum the gas can hold at a given temperature. Dewpoint is the temperature at which the gas reaches 100% relative humidity.
- The maximum amount of water vapor a gas can hold depends on temperature - the warmer the gas, the more water vapor it can hold before reaching saturation.
This document discusses key components of weather including temperature, humidity, and air pressure. It explains that temperature is a measure of how warm or cold the air is and affects humidity levels. Humidity refers to the amount of water vapor in the air, with low humidity feeling dry and high humidity feeling damp. Air pressure is the weight of the atmosphere pressing down, and is impacted by temperature and humidity with changes in pressure often accompanying weather changes.
This document discusses relative humidity and temperature and their effects on collections. It begins by explaining that relative humidity is the amount of water vapor in the air compared to the total amount the air can hold at a given temperature. Changes in relative humidity and temperature can damage collections, especially fluctuations. Extremes can still stabilize collections if they adjust, but changes are more harmful. The document provides tips for minimizing damage by understanding and controlling humidity and temperature levels.
This document discusses water and moisture in the atmosphere. It covers the global distribution of water, properties of water including its phases and heat properties. It also discusses concepts of humidity including relative humidity and specific humidity. Atmospheric stability is influenced by environmental and adiabatic lapse rates. Clouds and fog form when rising air parcels become saturated.
This document discusses temperature and humidity. It begins by defining temperature and explaining different methods of temperature measurement, including mercury thermometers, resistance thermometers, and thermistors. It then discusses measuring body temperature, factors that influence body temperature, and methods of heat transfer from the body. The document also covers thermoregulation, causes of hyperthermia, temperature changes during surgery, effects of hypothermia, and methods for preventing hypothermia, including through the use of humidity.
The document discusses the differences between climate and weather, as well as global warming and climate change. Climate is the average weather over a long period of time and is influenced by slow changes in factors like the ocean, land, and sun's energy output. Weather can change rapidly from day to day. Global warming refers to a long-term increase in Earth's average temperature due to greenhouse gases, while climate change involves long-term changes in temperature, precipitation, and other factors. The document then outlines how human activities like burning fossil fuels and deforestation have dramatically altered the climate by increasing greenhouse gases in the atmosphere. This is expected to cause the global temperature to increase by 1.4-5.8 degrees Celsius by 2100 with
AARC Clinical Practice Guideline
Humidification during Mechanical Ventilation
HMV 1.0 PROCEDURE:
The addition of heat and moisture to inspired gases delivered to the patient during mechanical ventilatory support via an artificial airway
HMV 2.0 DESCRIPTION/DEFINITION:
When the upper airway is bypassed, humidification during mechanical ventilation is necessary to prevent hypothermia, inspissation of airway secretions, destruction of airway epithelium, and atelectasis.(1-7) This may be accomplished using either a heated humidifier or a heat and moisture exchanger (HME). (HMEs are also known as hygroscopic condenser humidifiers, or artificial noses). The chosen device should provide a minimum of 30 mg H2O/L of delivered gas at 30°C.(8,29) Heated humidifiers operate actively to increase the heat and water vapor content of inspired gas.(11-14) HMEs operate passively by storing heat and moisture from the patient's exhaled gas and releasing it to the inhaled gas.(I5-25)
The document describes the design, fabrication, and performance evaluation of a waste heat driven desiccant dehumidifier. It contains silica gel as the absorbent material. The dehumidifier operates in absorption and regeneration cycles. In absorption, moist air passes through the silica gel beds which absorb moisture. In regeneration, hot air is passed through to release the absorbed moisture and regenerate the silica gel. Experimental results show the dehumidifier can reduce humidity by 5-10 grams of moisture per kilogram of dry air over approximately 10 minutes of absorption before leveling off. The start-up period for regeneration is around 12 minutes to fully dry the silica gel.
The document discusses the water cycle and different states of water in the atmosphere. It describes key water and atmospheric concepts like relative humidity, dew point, clouds, precipitation, and different types of clouds and precipitation. The main topics covered are the water cycle, states of water as ice, liquid, and vapor in the atmosphere, how temperature and humidity are related, what causes clouds and precipitation to form, and different classifications of clouds and precipitation.
This document discusses different types of winds and cyclones. It describes planetary winds like trade winds and polar winds, and seasonal winds like monsoons. It also outlines local winds such as land and sea breezes. The document discusses cyclones as low pressure depressions with strong winds and storms. It provides different names for cyclones in various ocean basins. Conditions favorable for cyclone formation include warm sea surfaces and a pre-existing low pressure area. Cyclones form with an eye at the center surrounded by rising air and clouds. Tropical cyclones occur in tropical regions while temperate cyclones are caused in middle latitudes.
The atmosphere is composed primarily of nitrogen and oxygen. It also contains water vapor, ozone, and particulates. Atmospheric pressure decreases with increasing altitude and is measured with a barometer. The layers of the atmosphere include the troposphere closest to Earth where weather occurs, the stratosphere containing most ozone, the mesosphere being the coldest, and the thermosphere where temperatures increase with altitude. Solar radiation enters the atmosphere and is scattered, reflected, absorbed, and contributes to the greenhouse effect, while heat is transferred through conduction and convection.
Presentation to AAAEA Technical conferencehbaroudi
This document summarizes case studies of wet weather flow issues from combined and separate sewer systems. It discusses common causes of combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs), such as infiltration of groundwater. Examples are provided of systems in Detroit, Southeast Oakland County, and Center Line that experience CSOs/SSOs and the corrective actions taken, including storage basins, separation of storm and sanitary sewers, rehabilitation, and flow monitoring. Regulatory requirements and approaches to address overflows are also summarized.
CONSTRUCTION OF DEHUMIDIFIER - ANALYSIS REPORTSajal Tiwari
A dehumidifier is a bit like a vacuum cleaner: it sucks in air from your room at one end, takes the moisture out of it, and then blows it back out into the room again. The moisture drips through into a collection tank that you have to empty, from time to time. Dehumidifiers work in one of two ways—by refrigeration (cooling air to remove moisture using similar technology to a refrigerator) or by absorption/adsorption (where moisture is absorbed into or adsorbed onto a drying material and then removed). The refrigeration method is far more appealing since its functioning can be controlled far more easily and effectively, thereafter it can be used as an Air conditioner if needed. In this project, we are aiming to develop a dehumidifier that is conducive to the local weather and is cheap and effective simultaneously.
This short document lists several common adjectives including good, bad, boring, funny, interesting, and exciting. It appears to be providing examples of different types of adjectives that can be used to describe things without much additional context. The document is simply listing different adjectives with no other details provided.
The field concerned with the study of health and disease in the defined community or group.
Its goal is to identify the health problems and needs of people (community diagnosis) and to plan, implement and evaluate the effectiveness of health care system.
Humidity refers to the amount of water vapor in the air. There are three main types of humidity: absolute humidity measures the actual mass of water in a given volume of air, relative humidity compares the actual water content to the maximum amount the air can hold, and specific humidity is the ratio of water vapor mass to total air mass. Relative humidity is the most common measurement and can be measured using a psychrometer. Factors like temperature, altitude, and vegetation affect relative humidity levels in different areas. High humidity has impacts on global climate by trapping heat and influencing evaporation and precipitation, and also affects industries, agriculture, and human comfort levels.
Humidity refers to the amount of water vapor in the air. There are three main types of humidity: absolute, relative, and specific. Absolute humidity is a direct measure of the mass of water in a given volume of air. Relative humidity compares the actual water content of the air to the maximum amount the air can hold at a given temperature. Specific humidity measures the ratio of water vapor to total air mass. Relative humidity is affected by temperature and the amount of water in the air. High humidity can impact climate, plants, animals, human comfort, and more. The most humid areas tend to be near the equator and coastal regions.
Air conditioning is the process of simultaneously controlling temperature, humidity, cleanliness, and air motion to provide thermal comfort and proper environment for industrial processes. It can be categorized based on its function as either comfort air conditioning for spaces occupied by humans and animals or industrial air conditioning for manufacturing facilities. Air conditioning systems are also classified based on their equipment arrangement as central station, unitary station, or combined systems. Maintaining proper temperature and humidity is important for textile manufacturing since physical properties of fibers are affected by moisture content.
Moisture exists in the atmosphere in gaseous, liquid, and solid forms. Water vapor is the gaseous form and is an important greenhouse gas. Clouds consist of liquid water or ice crystals, while rain, snow, and hail are liquid or solid precipitation. Evaporation from oceans and transpiration from plants are major sources of atmospheric moisture. Relative humidity measures the amount of water vapor in the air compared to the maximum it can hold at a given temperature.
Weather is affected by temperature, humidity, air pressure, and wind. These factors are interrelated. A change in one can impact the others. Temperature and air pressure have an inverse relationship - higher temperatures mean lower air pressures as the air expands. Higher temperatures also mean higher humidity as warm air holds more water vapor. Relative humidity decreases with increasing temperature. Wind blows from high to low pressure as air moves to equalize differences. Global wind patterns are caused by uneven heating and pressure differences.
Pschometry and psychometric properties.pptxbaghbana bajoi
what is Psychrometric?
Psychrometry is a branch of science in which we study the thermodynamics of air and moisture with primary objective of developing human comfort.
=> Saturated air. Saturated air is a saturated mixture of air and water vapor mixture, where the vapor is at the saturation temperature and pressure.
FOR EXAMPLE :
when we feel thirsty,we need water to quench the thirsty, similarly air also feel thirsty and it need water to quench it thirsty or air has affinity to absorb the water
When temperature is high, so causes the air feel more thirsty.
=> Saturated air;
Saturated air is that air which holds water vapour at its maximum concentration at a particular temperature and pressure.
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Humidity refers to the amount of water vapor in the air. It is measured by relative humidity and dew point temperature. Condensation occurs when warm, moist air rises and cools, causing water vapor to condense into liquid water droplets. The main types of precipitation are rain, snow, sleet, hail, and drizzle, which occur via different meteorological processes like convection, orographic lifting, and frontal lifting. Thunderstorms occur when upward motion within clouds causes water droplets to collide and become electrified.
The document discusses hydrological losses and factors affecting evaporation. It defines different types of hydrological losses including interception, depression storage, evaporation, transpiration, and infiltration. It then discusses various meteorological parameters that influence the evaporation process such as temperature, humidity, wind, radiation, and atmospheric pressure. Temperature affects evaporation rate but not always proportionally. Humidity and vapor pressure influence the vapor pressure deficit which governs evaporation rate. Wind helps carry away moisture and accelerates evaporation up to a critical speed. The nature of the evaporating surface like soil moisture levels also impacts evaporation rate.
The document discusses atmospheric humidity and related concepts. It defines humidity as the amount of water vapor in the air, and notes that humidity varies due to evaporation and condensation. Instruments like psychrometers are used to measure humidity by determining the difference between wet and dry bulb temperatures. The document also examines vapor pressure, dew point, relative humidity, and other terms, and how humidity levels fluctuate over time due to factors like temperature changes and the seasons.
Relative humidity is defined as the ratio of the partial pressure of water vapor in an air-water mixture to the equilibrium vapor pressure of water at a given temperature. It can be measured using various devices, including resistive, capacitive, crystal, thermal, gravimetric, and optical hygrometers. Resistive hygrometers measure changes in the electrical resistance of moisture-absorbing materials as humidity varies. Capacitive hygrometers detect changes in capacitance of a polymer film. Crystal hygrometers measure changes in mass of a hygroscopic crystal as it absorbs water from the air.
Weather refers to the conditions of the atmosphere at a specific time and place, including air temperature, wind, humidity, and pressure. Air temperature is measured by a thermometer and refers to the average motion of air molecules. Wind results from differences in air pressure and is measured by a wind vane or anemometer. Humidity is the amount of water vapor in the air and is measured as a percentage using a psychrometer. Atmospheric pressure is measured using a barometer and low pressure is associated with stormy weather while high pressure brings fair weather.
Absolute humidity measures the amount of water vapor in the air regardless of temperature, while relative humidity measures water vapor relative to the air's temperature. Warm air can hold more moisture than cold air. Maintaining an indoor relative humidity of 40-60% is optimal for health and comfort, as too much or too little humidity can cause issues. A Zehnder Enthalpy Exchanger recovers both thermal and humidity energy from extracted stale air and transfers it to incoming fresh air, helping maintain comfortable moisture levels in the home.
The document discusses various components of weather including:
1. Uneven heating of the Earth's atmosphere by the sun causes air movements and reactions that produce the wide variety of weather conditions.
2. Key weather variables such as temperature, air pressure, moisture, wind speed and direction are measured using instruments like thermometers, barometers, and anemometers.
3. Moisture in the atmosphere exists as water vapor, liquid droplets, or ice crystals, and the amount of moisture the air can hold depends on temperature. Changes in temperature and moisture can lead to precipitation.
This document provides information about an air conditioning course, including its title, credit hours, course code, teaching methods, attendance requirements, evaluation methods, and topics covered in the course. The course covers topics like principles of air conditioning, refrigeration equipment and refrigerants, psychrometric charts, air distribution systems, humidity measurement and control, ventilation, and illumination. References for the course are also provided.
1. Humidity refers to the amount of water vapor present in the air. Relative humidity is the percentage of water vapor in the air relative to the maximum amount that could be held at a given temperature.
2. A hygrometer is an instrument used to measure humidity. Common types include hair hygrometers, which use the hygroscopic property of human hair to expand and contract based on humidity levels.
3. Hair hygrometers work by arranging human hairs in parallel beams under tension. When humidity increases, the hairs absorb moisture and expand, moving an attached pointer along a calibrated scale to indicate the relative humidity percentage. They are inexpensive but slow-responding.
Meteorological factors such as wind speed, temperature, and humidity influence the dispersion of air pollutants from their sources. Calm air with low wind allows pollutants to accumulate near their source, while strong winds disperse pollutants over larger areas, lowering their concentration. Temperature inversions trap pollutants near the ground. Rain can help remove pollutants from the air but can also lead to acid rain. Turbulence and stability of the atmosphere determine how pollutant plumes behave and spread. Different plume types occur under varying meteorological conditions and impact pollutant concentrations near the ground.
The document discusses atmospheric stability and its relationship to moisture and weather. It defines stable, unstable, and conditionally unstable atmospheres based on environmental lapse rates. Stability impacts cloud formation and precipitation - unstable air leads to tall clouds and heavy rain while stable air suppresses vertical air movement and yields light precipitation. Daily changes in temperature and moisture content can increase or decrease atmospheric stability.
This document provides an overview of concepts related to heating, ventilation, and air conditioning (HVAC) design. It begins with definitions of key terms like thermal load and psychrometry. It then discusses outdoor and indoor design conditions, principles of cooling load, and components of heating and cooling load. Specific topics covered include psychrometric processes, properties of air like temperature and humidity, and factors that affect human comfort like air movement and clothing. Methods of heat transfer and concepts like thermal conductivity and U-values are also summarized. Finally, it briefly outlines principles of air cooling and different types of air conditioners.
Presentation on Evaporation, its process and factors affecting evaporation.pptxSohailAkhtar20pwciv5
Sohail Akhtar is presenting on the topic of evaporation. The presentation will cover what evaporation is, the factors that affect evaporation, and methods to measure evaporation. Evaporation is when a liquid turns to a gas, such as water evaporating into water vapor. It is influenced by temperature, surface area, humidity, and wind speed. Evaporation can be measured directly using lysimeters, pans, or indirectly through the water budget, aerodynamic, or energy budget methods.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...Travis Hills MN
By harnessing the power of High Flux Vacuum Membrane Distillation, Travis Hills from MN envisions a future where clean and safe drinking water is accessible to all, regardless of geographical location or economic status.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
2. Outline
I
• Introduction
II
• Measurement Used to Determine Atmospheric Humidity
III
• Effect of Humidity
IV
• Instruments Used to Measure Humidity
V
• Relationship of Humidity to other Meteorological
Parameters
VI
• Humidity on Land and Oceans
3. Introduction
Atmospheric humidity is a measurable quantity of the moisture content found in the Earth’s
atmosphere.
Humidity is the amount of water vapour in the atmosphere. The main sources of water vapour
in the lower atmosphere are evaporation and transpiration.
Atmospheric water vapour accounts for only about 1/1000th of the total amount of water in
the global hydrological cycle.
The total volume of water in the atmosphere is about 1.3 x 1013 m3 , the overwhelming
majority of which is the vapor phase (Air Resources Laboratory, 2008)
Oceans contain about 1.35 x 1018 m3 of water (Air Resources Laboratory, 2008)
Atmospheric water vapour is one of the most important factors in determining Earth’s
weather and climate, because of its role as greenhouse gas and because of the large amounts
of energy involved as water changes between the gaseous (vapor) phase and liquid and solid
phases
5. Absolute humidity (g of vapour/m3 of air)– expresses the vapour
content of the air using the mass of water vapour contained in a given
volume of air. Absolute humidity changes when the volume changes,
even though the mass of water vapour has not changed.
Specific humidity ( g of vapour/kg. of air)– measures the water vapour
content of the air using mass of water for a given mass of air. Specific
humidity doesn’t change as the air parcel expands or is compressed.
Vapour Pressure – measures the water vapour content of the air using
partial pressure of the water vapour in the air.
Measurements
6. Measurements
Mixing Ratio (g of water vapour/kg. of dry air) -
refers the ratio of the mass of water vapour to the
mass of dry air in the sample. It is not affected by
changes in pressure and temperature.
Saturation mixing ratio - refers to the mass of water
vapour that can held in a kilogram of dry air at
saturation. Saturation can be generally defined as the
condition of liquid water or the deposition of ice at a
given temperature and pressure.
Relative humidity – the most commonly used to
measure humidity. It is the amount of water in the air
relative to the saturation amount the air can hold at a
given temperature multiplied by 100.
Temperature
Degrees
Celsius
Vapor (g) per
Kilogram of Dry
Air
50 88.12
40 49.81
30 27.69
20 14.85
10 7.76
0 3.84
7. Fig. 1 Illustration on how relative humidity changes
in a parcel of air with an increase in air temperature
Note:
The more water
vapour in the air, the
higher the relative
humidity is at a given
temperature.
Air with a relative
humidity of 50%
contains half of water
vapour it could hold
at a particular
temperature.
Measurements
8. Factors
Change the amount of water vapour available –
Example: Lake – relative humidity can be increased by evaporation
from the surface of the lake.
Water vapour Humidity
Change the temperature of the air -
Example: No water vapour is added.
Air temperature Relative humidity
9. Note:
Relative humidity varies considerably, tending to be the highest close to
dawn when the air temperature is at its lowest, and decreasing as the
air temperature rises. The decrease in the relative humidity towards
midday tends to be the largest in summer. In areas with high humidity
levels, the transmission of solar radiation is reduced because of
atmospheric absorption and scattering. High humidity reduces
evaporation of water and sweat. Consequently, high humidity
accompanied by high ambient temperature causes a lot of discomfort.
(http://mnre.gov.in)
10.
11. Effects of Humidity
Transpiration of water vapour through leaf stomata depends on the gradient of
moisture between the leaf interior (which is saturated) and the overlying air, as
well as the availability of moisture in the soil. The lower the atmospheric humidity,
the greater the transpiration rate. The transpiration rate is determined by a balance
between the amount of energy available to convert water from the liquid to vapour
phase and the moisture gradient.
Transpiration rates also depend on the resistance to water movement between the
leaf and the air.
Atmospheric humidity affects the organisms by modifying its water content. Some
forms are hygroscopic and absorb water from moist air. Different studies showed
that specific organisms gains or lose weight depending on the humidity’s in a
certain environment.
Animals
Plants
12. Humans
Humans too are very sensitive to humidity because our skin relies on the air to
get rid of moisture.
So if the air is at 100% relative humidity, sweat will not evaporate into the air. As
a result, we feel much hotter than the actual temperature when the relative
humidity is high. If the relative humidity is low, we can feel much cooler than the
actual temperature because our sweat evaporates easily, cooling us off.
For example, if the air temperature is 75 degrees Fahrenheit (24 degrees Celsius)
and the relative humidity is zero percent, the air temperature feels like 69
degrees Fahrenheit (21 C) to our bodies. If the air temperature is 75 degrees
Fahrenheit (24 C) and the relative humidity is 100 percent, we feel like it's 80
degrees (27 C) out. People tend to feel most comfortable at a relative humidity of
about 45 percent (www.science.howstuffworks.com). High humidity causes
health problems such as sunstroke and heatstroke.
14. Sling psychrometer- often used to determine
relative humidity. Consists of thermometers
(wet bulb and dry bulb).
The difference between the dry and wet bulb
reading will give with the aid of psychometric
table, the dew point temperature and the
relative humidity. Performed near saturation
but under read at lower humidities
Hygrothermograph – records both relative
humidity and temperature on graph paper in
the same manner as the thermograph and
barograph do.
15. Hair hygrometers – it works on the fact that hair changes its length when
humidity varies. This device usually consists of a number of human or horse hairs
connected to the mechanical lever system. When humidity increases the length of
the hair becomes longer. This device is less accurate than the psychrometer.
Satellites – on a global scale, humidity is being measured using remotely placed
satellites. These satellites are able to detect the concentration of water in the
troposphere at altitudes between 4 and 12 kilometers. Satellites that can measure
water vapour have sensors that are sensitive to infrared radiation.
16. Relationship of humidity to
other Meteorological
ParametersWeather Parameters Relationship Remarks
Air pressure Inversely proportional More humidity in the air, the lighter the air
pressure and When less humidity is in the air,
there is more air pressure. (Givoni, 1976).
Air temperature Directly related to
solar radiation
Higher the temperature, the higher is the
amount of energy in the air.
(Bharat and Sheeba, 2011)
Precipitation Directly proportional As precipitation increases, humidity also
increases.
Temperature Inversely proportional Temperature changes; relative humidity also
changes but in opposite direction.
Soil temperature Indirect and minimal Air temperature was the factor that influenced
most the soil temperature.
(Salamene et. al. 2010)
Wind Less affected Air pressure differences between different
locations will cause air pressure differences
which in turn produce air movement (wind)