Atmosphere Online Test Geography Lesson 4 Questions in English

Weather refers to the state of atmosphere at a particular place at any given time denoting the short term variations of atmosphere in terms of temperature, pressure, wind, moisture, cloudiness, precipitation and other elements. Weather is highly variable from time to time, day to day and place to place. Weather is not constant. It is always changing within hours or a day.

Climate is the average weather conditions of an area for a long period of time Climate is constant. It is a permanent condition of a place.

The World Meteorological Organization (WMO) has suggested data for a period of 30 consecutive years to be referred for calculating the climatic averages of various weather elements

The ancient Greeks called the tilt of latitude as ‘klima’, literally meaning ‘slope’ or ‘inclination

Then the earth was divided into seven latitudinal regions, called ‘klimata’. The word came into modern European languages as clime or ‘climate’, denoting the average weather condition.

Water vapour, aerosols and tiny solid particles occur in varying quantities as suspended material. These are responsible for weather phenomena as they have ability to absorb and release heat energy.

The atmosphere is composed of mixture of many gases, water vapour and other solid particles. The major components are nitrogen (78%), oxygen (21%) and other gases (1%). Argon, Carbon dioxide, Neon and the other gases found in the atmosphere

The atmosphere is divided into five distinct layers based on the temperature variations. They are, Troposphere, Stratosphere, Mesosphere, Ionosphere (Thermosphere) and Exosphere

Troposphere extends approximately to a height of 8 km from the poles and 18 km from the equator.

The height of the troposphere changes seasonally also. It increases during summer and decreases during winter.

All weather phenomena occur in this layer as it has dust particles and water vapor. This layer has clouds which produce precipitation on the earth

The Sun’s rays directly fall on the earth and then they are reflected back into the atmosphere. The temperature decreases in the troposphere with increase in altitude at the rate of 1degree C for 165 meter or 6.5 degree C for every 1000 meters of ascent. This is known as lapse rate of temperature

This is the densest layer as it contains 70 to 80 percent of gases. The outer boundary of the troposphere is called tropopause, which is about 1.5 kilometer thick.

Stratosphere is the second layer of the atmosphere found above the troposphere. It approximately extends up to a height of 50 km from the earth’s surface.

Temperature is constant up to a height of 20 km and increases gradually up to the stratopause where temperature is nearly -4 degree C.

The lower part of this layer is highly concentrated with ozone gas which is called as ‘ozonosphere’

Ozonosphere prevents the ultra-violet rays from the Sun to enter into the lower part of the atmosphere as the rays are highly harmful it causes skin cancer and other ill effects to living organisms. But the ozone layer safeguards the life on the earth.

The mesosphere is the third layer of the atmosphere found approximately up to a height of 85 km above the surface of the earth

The temperature decreases with increase of altitude due to the absence of ozone

Upper boundary of mesosphere is called mesopause where temperature reaches -90 degree C.

Luminous Noctilucent clouds form here due to the presence of cosmic dust.

Meteors falling from the space get burned in this layer. It is because when meteors hit the air, the air gets compressed and heated up causing meteors to burn out.

The ionosphere is the fourth layer of the atmosphere extending approximately up to a height of 400 km

It is due to the absorption of very short wave and high energy solar radiation by the atoms of hydrogen and oxygen gases

When light energy is transformed into heat energy, some gas molecules lose or gain electrons and become the charged particles called ions. The charged particles forming the lower part of the thermosphere as a zone, is called Ionosphere

The charged particles forming the lower part of the thermosphere as a zone, is called Ionosphere. These ionized particles create auroras at higher latitudes

Ionosphere can reflect radio waves back to the earth. This facilitates long distance wireless satellite communication.

The upper most layer of the atmosphere which extends into the outer space from above 400 km up to 1600km

These atoms can travel hundreds of kilometres without colliding with one another. Thus, the exosphere has no longer behaves like a gas

The gravitational pull is minimal in this layer. This layer gradually merges with the space.

Ozone is form of oxygen that combines three atoms into each molecule. This way the ozone layer protects all life on earth

It absorbs and filters the harmful ultraviolet B radiation coming from the sun. It causes health problems like asthma and other respiratory illness.

Snow covered ground during night, due to terrestrial radiation and higher albedo, most of the heat is lost to the atmosphere and the surface is cooled.

Nitrogen oxide released by emitted by supersonic aircrafts can also destroy the ozone molecules to break down. Ozone-depleting substances are present throughout the stratospheric ozone layer because they are transported great distances by atmospheric air motions.

The severe depletion of the Antarctic ozone layer known as the “ozone hole” occurs because of the special atmospheric and chemical conditions that exist there and nowhere else on the globe.

The very low winter temperatures in the Antarctic stratosphere cause polar stratospheric clouds (PSCs) to form.

Special reactions that occur on PSCs, combined with the relative isolation of polar stratospheric air, allow chlorine and bromine reactions to produce the ozone hole in Antarctic

Special reactions that occur on PSCs, combined with the relative isolation of polar stratospheric air, allow chlorine and bromine reactions to produce the ozone hole in Antarctic, springtime.

Satellite images of the earth over last decades observed that the atmospheric ozone layer is getting thinner. On October 2, 2015, the ozone hole was recorded to its maximum size of 28.2 million sq.km over Antarctica.

On October 2, 2015, the ozone hole was recorded to its maximum size of 28.2 million sq.km over Antarctica. The size of the ozone hole is larger than the size of continent of North America

To protect the ozone layer for our future generation, avoid using products which are emitting pollutants such as aerosol sprays, blowing agents for foams and packing materials, as solvents and as refrigerants.

The Dobson Unit (DU) is the unit of measurement for total ozone.

The surface of the earth is heated by the sun’s rays in the form of short wave radiation

The surface of the earth is heated by the sun’s rays in the form of short wave radiation. The heat received by the earth is called ‘Solar Radiation’ or ‘Insolation’. Heating of atmosphere is an indirect process

Terrestrial radiation supplies more heat energy to the atmosphere due to its long wave length.

The heat energy reflected, absorbed and radiated back into the space equals the energy received by the earth. Incoming radiation and the outgoing radiation pass through the atmosphere. The earth maintains its optimum temperature.

Of the remaining 65% of heat, 14% are absorbed by the atmosphere and 51% are absorbed by the earth’s surface (34% of direct solar radiation and 17% from scattered radiation). 51% received by the earth are radiated back to the space directly as terrestrial radiation

In total, 17% are radiated to space directly and 48% are absorbed by the atmosphere (14% from insolation and 34% from terrestrial radiation) are radiated back to space gradually

Distribution of temperature varies both horizontally and vertically. Horizontal Distribution of Temperature, Vertical Distribution of Temperature

On maps, the horizontal distribution of temperature is commonly shown by isotherms. Isotherms are line connecting points that have an equal temperature at mean sea level.

The angle formed by the solar radiation to the ground is called ‘angle of incidence’. The solar radiation passes vertically along the equator

The angle of incidence decreases from equator towards the poles. The area heated by the solar radiation increases towards the poles and therefore, temperature decreases from the equator to the poles.

Land is heated and cooled at a faster rate due the conduction process whereas water is heated and cooled at slower rate due to convection process

Water takes 2.5 times of heat energy to heat a unit area compared to land. Thus, the land will have higher temperature than the water in summer and vice versa during the winter. So more land mass in northern hemisphere (15.2 degree C) leads to higher average temperature than the southern hemisphere (13.3 degree C).

Warm ocean currents carry warm water from the tropical region towards the poles and increase the temperature along the coast. Cold ocean currents carry cold water from Polar Regions and decrease the temperature along the coasts.

Warm winds like trade wind and westerly, that carry higher heat energy, increase the temperature while cold polar easterlies carry lower heat energy from polar region reduces the temperature.

The cloudy sky obstructs the solar radiation from the sun to earth and reduces the temperature.

The more reflection from the snow surface leads to low temperature accumulation. But the dense forest, which reflects less heat energy and absorbs more heat energy, leads to higher temperature.

If a wind or air mass blows towards the mountain, it influences the distribution of temperature on either side of the mountain.

Polar easterlies and blizzards are obstructed by Himalayas in Asia and Alps in Europe respectively. This leads to lower temperature in the northern slopes and higher temperature in the southern slopes of the respective mountains

The condition at which the temperature increases with altitude is called as ‘inversion of temperature’. In this condition, warm air lie over cold air.

During Long winter nights the bottom layer of the atmosphere in contact with the ground is cooled and the upper layer remains relatively warm.

During inversion of temperature dry air near the surface absorbs less terrestrial radiation and allows them to escape into space

During inversion of temperature the higher amount of terrestrial radiation reaches the higher altitude which leads to lower temperature at low level due to clear sky.

The subsidence of cold mountain wind at the early morning leads to the displacement of warm air from the valley to higher altitude. This type of inversion is called as ‘valley inversion’.

Albedo is the amount of solar radiation reflected from the surface. The variation is based on the nature of the earth’s surface. Snow has higher albedo compared to forest.

The earth has been divided into three heat zones according the amount of insolation received. These are the Torrid Zone, the Temperate zone and the Frigid Zone.

The heat energy reflected, absorbed and radiated back into the space equals the energy received by the earth. Incoming radiation and the outgoing radiation pass through the atmosphere. The earth maintains its optimum temperature.

Warm winds like trade wind and westerly, that carry higher heat energy, increase the temperature while cold polar easterlies carry lower heat energy from polar region reduces the temperature.

The clear sky during the day allows more solar radiation to reach the earth’s surface and increases the temperature. Meanwhile clear sky at night allows more terrestrial radiation to escape

The temperature decreases with increasing altitude from the surface of the earth. The vertical decrease in temperature of troposphere is called as ‘Normal Lapse Rate’ or ‘vertical temperature gradient’ at which the temperature reduces at the rate of 6.5 degree C per 1000 meter of ascent

The conditions for inversion of temperature are -- Long winter night, Cloudless sky, Dry air near the surface, Snow covered ground, Formation of fronts, Mountain wind

It is the hottest zone

The zone lying between the Tropic of cancer and Tropic of Capricorn is called Torrid zone’. The sun’s rays are vertical throughout the year and it receives maximum insolation. Thus, this is the hottest zone.

The temperate zone lies between the Tropic of Cancer and Arctic Circle in the northern hemisphere and the Tropic of Capricorn and Antarctic Circle in the southern hemisphere

This region never experiences overhead sun light but experiences longer days and shorter nights during summer and vice versa during winter. This region experiences moderate temperature and is therefore called as ‘Temperate zone’.

This region always receives more oblique rays of the sun and so the temperature is very low. It is the coldest zone. This region experiences 24 hours of day and night during peak summer and winter respectively.

Torrid Zone (23 ½ degree N to 23 ½ degree S), Temperate Zone (23 ½ degree N to 66 ½ degree N and 23 ½ degree S to 66 ½ degree S), Polar Zone (Frigid Zone – 66 ½ degree N to 90 degree N and 66 ½ degree S to 90 degree S)

Annual Temperature is the average annual temperature of a region for a year. Mean Annual Temperature is the average of 3 0years of annual temperature of the region.

The longer wavelengths are absorbed by greenhouse gases in the atmosphere, increases the temperature of atmosphere. The energy for the earth is from the sun

Annual Range of Temperature is the difference between highest and lowest temperature of a place in a year. Diurnal range of Temperature is the difference between highest temperature and lowest temperature of a place in a day

This region never experiences overhead sun light but experiences longer days and shorter nights during summer and vice versa during winter. This region experiences moderate temperature and is therefore called as ‘Temperate zone’.

Global warming is observed in a century scale. The temperature increase over the years has been due to the greenhouse gas concentration such as carbon dioxide, water vapor, methane and ozone.

An urban heat island is an urban area or metropolitan area that is significantly warmer than its surrounding rural area due to high concentration of high rise concrete buildings, metal roads, sparse vegetation cover and less exposure of soil. These factors cause urban regions to become warmer than their rural surroundings, forming an “island” of higher temperatures

Planting trees and other vegetation, provides shade and cooling effect through evapotranspiration and it lowers the surface and air temperature.

Atmospheric pressure is defined as the force per unit area exerted against a surface by the weight of the air molecules above the earth surface. The atmospheric pressure is not distributed uniformly over the earth

The amount of pressure increases or decreases, according to the amount of molecule that exerts the force on the surface.

When temperature of the air increases, the air expands and reduces the number of molecules over the unit area. It leads to reduction in pressure. Similarly, when the temperature falls, the air contracts and the pressure increase. Therefore, the temperature and atmospheric pressure are inversely related.

The relationship analysis between altitude and atmospheric pressure is very peculiar. The upper atmosphere is thin and less dense. The pressure at sea level is highest and keeps decreasing rapidly with increasing altitude because of the progressive reduction of the mass above the point where it is measured

The temperature and atmospheric pressure are inversely related.

The rotation of the earth affects the moving objects on the earth surface. Free moving objects, affected by the rotation of the earth, do not follow a straight line

A car travelling down a straight road at 95 km/hr in northern hemisphere would drift to the right of the path if the friction between surface and tyre is absent.

A car travelling down a straight road at 95 km/hr in northern hemisphere would drift to the right of the path if the friction between surface and tyre is absent. This is the reason why racket launching stations are located on the east coastal areas. Example: Sriharihota, French Guyana

Cool air is dense and heavy. As a consequence it sinks vertically. It results in additional weight and pressure which cause a high pressure area to occur on the ground.

When the air gets heated it expands, becomes light and rises vertically. As air rises, the pressure it exerts on the earth surface is reduced, causing a low pressure area

The atmospheric pressure belts envelope on the surface of the earth. They are equatorial low pressure belt, subtropical high pressure belts, sub polar low pressure belts and polar high pressure belts

Wind direction is identified by an instrument called Wind Vane and wind speed is measured by Anemometer.

Wind is the horizontal movement of air molecules from areas of high pressure to areas of low pressure to maintain the atmospheric equilibrium. The wind always moves perpendicular to isobars

If the earth did not rotate, the winds would blow in a straight path. Then the rotation of the earth results in Coriolis Effect and it deflects the direction of the wind

From the equator to the poles, each hemisphere has four pressure belts and totally there are seven belts on the globe. The pressure belts lead to formation of primary wind system

This region is a belt of calm and referred to as the ‘Doldrums’

The winds blow from the subtropical high pressure belt towards the equatorial low pressure belt. Due to Coriolis Effect these winds are deflected to the right in the northern hemisphere and to the left in the southern hemisphere.

As winds are named after the direction from which they originate they are called as the North East and South east trade winds. As the winds favored trading ships in equatorial low pressure belt they are called as ‘Trade winds’.

It is said that to avoid the slowing down of ship due to high pressure in the subtropical high pressure belts the horses were thrown into the sea. So this belt is called as ‘Horse latitude’.

The subtropical high pressure belt is between 25 degree to 35 degree N and S Air begins to cool when it reaches higher altitude over equatorial region and flows towards the poles. This wind collides with the wind coming from the polar region at higher altitude and subsides down over subtropical latitudes. This leads to formation of high pressure belt along the subtropical region

The sinking air bifurcated in to two branches towards the equator and poles, they are called as trade winds and westerly respectively. Westerlies flow towards the pole from sub tropics and turn towards right and left in northern hemisphere and southern hemisphere respectively.

The warm westerly wind from subtropical region moves towards the pole and collide with the cold polar easterly wind from polar high pressure region and raises up to form sub polar low pressure belt.

The constant low temperature at the poles due to inclined solar radiation and reduced insolation leads to the formation of polar high pressure belt on both poles.

The high pressure on the surface always coincide with the low pressure at higher altitude while the low pressure on the surface always coincide with higher pressure on the higher altitude. High pressure always has divergence of air masses from the center but low pressure has convergence of air.

Ocean is dominant in the southern hemisphere between the latitudes 40º and 60ºS. Hence the westerlies are so powerful and persistent that the sailors used such expressions as “Roaring Forties”, “Furious Fifties” and “Screeching Sixties” for these high velocity winds in the latitudes of 40º, 50º and 60º respectively

There are two important bases on which the pressure belts are formed, they are temperature and dynamism

The Equatorial low pressure belt and the Polar high pressure belts are formed due to high and low temperature. So, they are called as thermally formed pressure belts

The Subtropical high pressure belts and the Sub polar low pressure belts are formed due to movement and collision of wind system. So, they are called dynamically formed pressure belts

The cell formed by westerly wind along with subtropical high and sub polar low pressure belt is called as Ferrell cell

The pressure belts and primary wind systems are dynamic in character, because they shift 5 degree north and 5 degree south from their position along with the apparent movement of the sun

Monsoon and cyclones are considered as secondary wind system

The word monsoon is derived from Arabic word mausim which means season. Monsoon are seasonal winds which reverse their direction due to unequal heating and cooling of the land and water.

The land absorbs more heat energy during summer, which leads to formation of low pressure over the continent. The ocean will have relatively lower temperature than the continent leading to formation of high pressure system over ocean

The wind blows from sea to land during summer. The land radiates more heat energy to space during winter leading to the formation of high pressure above the continent. But the ocean will have relatively higher temperature than the continent leading to formation of low pressure system over ocean. So, wind blows from land to sea during the winter season.

The wind blows from sea to land during summer wind blows from land to sea during the winter season. This mechanism has an important effect on rainfall received over the region

There are three distinct characteristics related to monsoon wind system which differentiates it from other wind systems. They are; (1) Minimum 160 degree reversal of wind direction between seasons. (2) They affect a large part of the continents and oceans. (3)The formation of low and high pressure systems over land and water and their interchange between the seasons.

If any wind system has all the above mentioned characters of monsoon in one season but absence of at least one in the other season then is called as ‘Pseudo monsoon’. The other names are ‘Monsoon tendency’ or ‘false monsoon’.

Monsoon system is classified into two groups based on the location. They are; a. Asian Monsoon b. South Asian Monsoon.

The presence of high temperature with low pressure in the lake Baikal region leading to flow of wind from Pacific Ocean to interior part of Asia during summer

Meanwhile, in winter the low temperature and high pressure in the Lake Baikal region and high temperature and low pressure in the Aleutian Island region leading to flow of wind from Central Asia to Pacific Ocean is known as ‘Winter Monsoon of Asia’

During Winter Monsoon of Asia as the wind system flows off shore, the rainfall does not occur in the continent of Asia except western coast of Japan.

South Asian Monsoon includes the countries in the southern part of Himalayas, that is India, Pakistan, Bangladesh, Sri Lanka, Maldives, Nepal and Bhutan

South Asian monsoon system has been classified into two groups based on the direction of origin of wind namely south west monsoon and north east monsoon

During summer in south west monsoon the Indian peninsula is heated more than the sea around it. Intense low pressure is formed in the region of Peshawar of Pakistan.

The Indian Ocean has higher pressure due to relatively low temperature. So the wind blows from Indian Ocean towards South Asia as Southeast Winds. The wind turns towards right due to Coriolis Effect and blows as south west winds which bring heavy rains. This is known as south west monsoon in Indian Subcontinent.

The south west monsoon wind system bifurcates into two branches as Arabian Sea branch and Bay of Bengal branch.

The orographic effect by the Western Ghats results in heavy rainfall in the windward side and low rainfall in the leeward side. So the west coast of India receives high rainfall when compared to the eastern side of the Western Ghats

Kerala is the first state to receive rainfall from the south west monsoon in India. Then, the wind gradually moves towards the north of the western coast and leads to gradual development of the monsoon in parts of Karnataka, Goa, Maharashtra, Gujarat and Rajasthan

Kerala is the first state to receive rainfall from the south west monsoon in India, which occurs during first week of June. Then, the wind gradually moves towards the north of the western coast and leads to gradual development of the monsoon in parts of Karnataka, Goa, Maharashtra, Gujarat and Rajasthan. The wind further advances towards foot hill of the Himalayas and creates orographic rainfall in the Himalayan states, Punjab and Haryana. The other part of the Arabian Sea branch moves towards the east and results in onset of monsoon in Uttar Pradesh and Bihar. Here, it unites with the Bay of Bengal branch and leads to heavy rainfall and flood.

Bay of Bengal branch flows from south west which results in orographic rainfall in Sri Lanka and reaches Andaman and Nicobar Islands and results in orographic rainfall

Indira point in the Great Nicobar is the first place which receives rainfall during south west monsoon in India during middle of May.

The wind flows parallel to the east coast of India and Eastern Ghats. So Coromandel Coast of India doesn’t get enough rainfall during south west monsoon.

The wind strikes Arakanyoma Mountain in Myanmar and results in heavy rainfall in western coast of Myanmar. The wind funnels towards north eastern part of India after deflected by the Arakanyoma Mountain in Myanmar. This wind strikes Meghalaya plateau which leads to heavy rainfall in Bangladesh and north eastern part of India

Mawsynram, the wettest place (highest annual rainfall) in the world, is located in the windward side of Meghalaya plateau.

The wind flows parallel to the east coast of India and Eastern Ghats. So Coromandel Coast of India doesn’t get enough rainfall during south west monsoon. The wind strikes Arakanyoma Mountain in Myanmar and results in heavy rainfall in western coast of Myanmar. The wind funnels towards north eastern part of India after deflected by the Arakanyoma Mountain in Myanmar. This wind strikes Meghalaya plateau which leads to heavy rainfall in Bangladesh and north eastern part of India. The wind further advances towards the Himalayas where it creates heavy rainfall in the southern slopes. This leads to flood in River Brahmaputra

During south west monsoon the Bay of Bengal branch of wind further advances towards the Himalayas where it creates heavy rainfall in the southern slopes. The wind gradually moves towards the west and results in onset of monsoon in Bhutan, Sikkim, West Bengal, Nepal and Bihar. It joins with Arabian Sea branch in Bihar and results in heavy rainfall and flood

The south west monsoon gradually withdraws from south Asian continent due to apparent movement of the Sun towards the southern hemisphere. This is called as ‘Withdrawal of South West Monsoon’.

During winter the Indian Subcontinent becomes colder than the Indian Ocean. As a result the wind blows from Northeast to South West direction

During winter the Indian Subcontinent becomes colder than the Indian Ocean. As a result the wind blows from Northeast to South West direction. This is dry wind system and it does not produce rainfall in the coastal region of south Asia except the Coromandel Coast of India and Sri Lanka. This is known as North East Monsoon or Retreating Monsoon in South Asia.

During the El Nino year the temperature of the ocean water increases. This weakens the high pressure over Indian Ocean thereby reduces the strength of south west monsoon over south Asia. However during winter, it induces the low pressure over the ocean resulting in severe depressions and cyclones. Agriculture in India mostly depends on the rainfall brought by the monsoons.

The tertiary winds are formed due to pressure gradients which may develop on a local scale because of differences in the heating and cooling of the earth’s surface

During daytime, land heats up much faster than water. The air over the land warms and expands leading to form low pressure. At the same time, the air over the ocean becomes cool because of water’s slower rate of heating and results in formation of high pressure. Air begins to blow from high pressure over ocean to the low pressure over the land. This is called as ‘Sea breeze’

Fishermen go for fishing at early morning along the land breeze and return to the shore in the evening with the sea breeze.

During night time, the wind blows from land to sea and it is called as Land breeze

A valley breeze develops during the day as the sun heats the land surface and air at the valley bottom and sides. As the air gets heated it becomes less dense and begins to blow gently up the valley sides. This is called as valley

The valley wind process reverses at night leading to blow of wind from mountain top to valley bottom referred to as ‘mountain wind

Mountain and valley wind systems influence the weather pattern of the mountain top and valley bottom. Mountain top can be seen clearly at early morning and valley bottom at evening

Mountain top will be covered with clouds at evening due to rising of valley wind system and valley bottom would be covered by clouds at early morning due to arrival of mountain wind system. These clouds are sometimes called as ‘fog’ which is used for cultivation in the dry regions like Yemen.

Local wind systems influence the weather pattern where ever they blow

Bora is north easterly from Eastern Europe to north eastern Italy. Mistral is cold northerly from central France and the Alps to Mediterranean.

Khamsin is south easterly from North Africa to the eastern Mediterranean. Loo is hot and dry wind which blows over plains of India and Pakistan.

Nor’ wester is a wind that bring rain to west coast, and the warm dry winds to the east coast of New Zealand’s Southern Island, caused by mass prevailing winds being uplifted over the Southern Alps, often accompanied by the distinctive arched cloud pattern

Karaburan is a ‘Black storm’ a spring and summer katabatic wind of central Asia

Khamsin is South easterly from North Africa to the eastern Mediterranean. Loo is Hot and dry wind which blows over plains of India and Pakistan. Bora is North easterly from Eastern Europe to north eastern Italy

Nor’easter is a strong winds from north east in the eastern United States, especially New England

Simoom is a strong, dry, desert wind that blows in the Sahara, Israel, Jordan, Syria, and the desert of Arabia.

Sirocco is a southerly from North Africa to southern Europe. Zonda wind blows on the eastern slope of Andes in Argentina