AGRI Grovestudies
Weather and Climate
Weather Weather refers to the state of the atmosphere at a particular place and time, with respect to variables such as temperature, precipitation, humidity, wind speed and direction, and atmospheric pressure. It is the day-to-day variation in atmospheric conditions that are observed and measured, such as sunny or cloudy skies, rain or snow, and hot or cold temperatures.
Climate
Climate refers to the long-term average weather conditions of a region, typically over a period of 30 years or more. Unlike weather, which can change rapidly over short periods of time, climate reflects the overall patterns and trends in temperature, precipitation, wind, and other atmospheric variables over a longer time period.
Components of Climate -
Climate is a complex system that is influenced by a variety of factors. The main components of climate are:
Atmosphere: The atmosphere is the layer of gases that surrounds the Earth. It plays a crucial role in regulating the Earth's climate by absorbing and reflecting solar radiation and by trapping heat.
Hydrosphere: The hydrosphere includes all of the water on Earth, including oceans, lakes, rivers, and groundwater. It plays a critical role in regulating the Earth's temperature and climate through the circulation of heat and water.
Cryosphere: The cryosphere includes all of the frozen water on Earth, including glaciers, ice caps, and sea ice. It plays a key role in regulating the Earth's climate by reflecting solar radiation and by storing large amounts of water.
Land surface: The land surface includes all of the Earth's land areas, including forests, grasslands, deserts, and urban areas. It plays an important role in regulating the Earth's climate by absorbing and reflecting solar radiation and by exchanging heat and water with the atmosphere.
Biosphere: The biosphere includes all living organisms on Earth, including plants, animals, and microorganisms. It plays a critical role in regulating the Earth's climate by absorbing and releasing carbon dioxide and other greenhouse gases, as well as by exchanging heat and water with the atmosphere.
Components/variable / Elements of Weather -
The main components of weather are:
Temperature: Temperature is a measure of the heat energy in the atmosphere. It is influenced by factors such as the amount of solar radiation, the time of day, and the season.
Humidity: Humidity refers to the amount of moisture in the air. It is influenced by factors such as temperature, wind, and precipitation.
Precipitation: Precipitation refers to any form of water that falls from the atmosphere, such as rain, snow, sleet, or hail. It is influenced by factors such as temperature, humidity, and atmospheric pressure.
Wind: Wind is the movement of air in the atmosphere. It is influenced by factors such as differences in atmospheric pressure, temperature, and the rotation of the Earth.
Pressure: Atmospheric pressure is the force exerted by the weight of the atmosphere on the Earth's surface. It is influenced by factors such as temperature, humidity, and wind.
Cloud cover: Cloud cover refers to the amount of clouds in the sky. It is influenced by factors such as temperature, humidity, and atmospheric pressure.
Earth's Atmosphere
The Earth's atmosphere is a layer of gases that surrounds the planet and provides a range of important services to life on Earth. It is composed primarily of nitrogen (78%), oxygen (21%), and small amounts of other gases, including carbon dioxide, water vapor, and trace amounts of other gases.
Composition of Earth Atmosphere
The Earth's atmosphere is composed primarily of nitrogen (78.08%) and oxygen (20.95%). The remaining 0.97% is made up of trace gases, including argon (0.93%), carbon dioxide (0.04%), neon, helium, methane, krypton, hydrogen, and ozone.
Carbon dioxide is a particularly important gas in the atmosphere as it plays a key role in regulating the Earth's temperature and climate through the greenhouse effect. Human activities, such as burning fossil fuels and deforestation, are increasing the concentration of carbon dioxide in the atmosphere, leading to global warming and climate change.
Water vapor is another important gas in the atmosphere, as it plays a key role in the formation of clouds and precipitation. While the concentration of water vapor in the atmosphere varies widely depending on location and weather conditions, it is generally present in the atmosphere in concentrations of around 1% to 4%.
Particulate matter , the atmosphere also contains small solid and liquid particles, such as dust, pollen, and sea salt, known as aerosols. These particles can have a range of effects on the climate, including reflecting or absorbing solar radiation and influencing cloud formation.
Structure of Earth's Atmosphere
The Earth's atmosphere can be divided into several layers, each with its own unique characteristics. These layers are defined based on changes in temperature and other atmospheric properties with increasing altitude. The layers of the Earth's atmosphere, starting from the surface and moving upward, are:
Troposphere: The troposphere is the lowest layer of the atmosphere, extending from the Earth's surface to an altitude of around 8-15 kilometers. This is where most of the Earth's weather occurs, and it is characterized by decreasing temperature with increasing altitude.
Stratosphere: The stratosphere extends from the top of the troposphere to an altitude of around 50 kilometers. It is characterized by increasing temperature with increasing altitude, due to the presence of the ozone layer, which absorbs ultraviolet radiation from the Sun.
Mesosphere: The mesosphere extends from the top of the stratosphere to an altitude of around 80 kilometers. This layer is characterized by decreasing temperature with increasing altitude, and it is the coldest layer of the atmosphere.
Thermosphere: The thermosphere extends from the top of the mesosphere to an altitude of around 600 kilometers. This layer is characterized by increasing temperature with increasing altitude, due to the absorption of high-energy solar radiation by atoms and molecules in the atmosphere.
Exosphere: The exosphere is the outermost layer of the atmosphere, extending from the top of the thermosphere to the edge of space. This layer is characterized by very low density, and it merges gradually into the vacuum of space.
Solar Radiation
Solar radiation refers to the energy that is emitted by the sun in the form of electromagnetic waves. This energy travels through space and reaches the Earth's atmosphere, where it can be absorbed or reflected by various materials.
Solar radiation is important for many natural processes on Earth, including photosynthesis, weather patterns, and climate. It is also the source of energy for many renewable energy technologies, such as solar panels and solar thermal systems. However, excessive exposure to solar radiation can also be harmful to human health, causing skin damage and an increased risk of skin cancer.
Radiation Law -
The direct transfer from heat from the sun to the earth throughly the space and atmophere indicates the radiation and heat from one place to another occurs in the from of Electro magnetic wave in the same manner and with in the same manner and with the same speed of light the wavelength of electromagnetic radiation given .
λ = c/v
Where λ = Wavelength (The shortest distance between consecutive crests in the wave trance)
C = Velocity of light (3x1010 cm sec-1
) V = Frequency means number of vibrations of cycles
per second y the equation.
Plank’s law -. E= h v
Where h= Plank‘s constant (6.62x10-34 J sec), V= Frequency
Kirchoff’s law - a (λ) = e (λ)
Stefan-Boltzmann’s law - E = σ T4
Wein’s Displacement laws -. λmax = 2897 T-1 μ = 2897/T μ
Albedo
It is the percentage of reflected radiation to the incident radiation. (Varies with colour
and composition of the earth‘s surface, season, angle of the sun rays). Value is Highest in winter
and at sunrise and sunset.
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