Atmosphere — Part 2 MCQs with Explanations

The continuous circulation of water among the hydrosphere, atmosphere and Lithosphere is known as hydrologic cycle. The water, or hydrologic, cycle describes the pilgrimage of water as water molecules make their way from the Earth’s surface to the atmosphere and back again, in some cases to below the surface. This gigantic system, powered by energy from the Sun, is a continuous exchange of moisture between the oceans, the atmosphere, and the land.

The layer of atmosphere composed of ionic gaseous molecules helping in propagation of radio waves is Ionosphere. It is the 2nd layer from the top. It ranges from 60km. to 1000km. It also protects Earth from meteorites.

As we go upwards altitude wise, the density of gases gets reduced. They seldomly occur till the altitude of 300km.

Dew points indicate the amount of moisture in the air. The higher the dew points, the higher the moisture content of the air at a given temperature. Dew point is a temperature at which a given sample of air becomes saturated.

The stratosphere is said to be ideal for flying jet aircraft. This is because this layer is rich in ozone which reduces fuel consumption, the temperature is constant and ideal for aircraft engine efficiency, this layer is out of the firing range of anti-aircraft guns and of the absence of clouds and other weather phenomena.

Doldrums are Equatorial zone with low pressure. As this region lies along the equator, it receives highest amount of insolation. Due to intense heating, air gets warmed up and rises over the equatorial region (convection). Whenever there is vertically upward movement of air, the region at the surface will be at low pressure. Thus the belt along the equator is called equatorial low pressure belt.

The following places that are favourably influenced by the Trade winds are West Indies, Brazil, Mexico and Madagascar.

In the northern hemisphere, the wind blowing from the Horse latitudes to the Doldrums is called Trade wind. Trade wind blow out from the Subtropical High Pressure belts. In the northern hemisphere, they blow towards the equatorial low and called North East Trade Winds. In the Southern hemisphere they blow towards the equatorial low and become the South East Trade winds.

The dense mass of small water drops on smoke particles in the lower layers of the atmosphere is Smog. Smog is a kind of air pollution, originally named for the mixture of smoke and fog in the air. Classic smog results from large amounts of coal burning in an area and is caused by a mixture of smoke and sulfur dioxide.

Argon is the chemically inactive gas present in the atmosphere.

As Ionosphere is one of the upper most layers, the solar and cosmic radiations heat it up rapidly, the gaseous material available here is in ionic state. Hence temperature increases rapidly.

Solar energy heats the earth’s surface. But the energy does not stay bound up in the earth’s environment forever. Instead, as the earth warms, it emits thermal radiation. This thermal radiation, which is largely in the form of long-wave infrared rays, eventually finds its way out into space, leaving the earth and allowing it to cool. However, not all of the infrared rays pass into space. Some of the infrared rays are absorbed by greenhouse gases and warm the atmosphere. So the amount of greenhouse gases in the atmosphere is directly related to the temperature of the atmosphere.

Temperature generally decreases towards the poles because progressively lesser solar energy per unit area falls on the earth's surface as we move to polar regions. Longer the path of the sun’s rays, greater is the amount of reflection and absorption of heat by the atmosphere. As a result, the intensity of insolation is less.

Troposphere varies in its thickness between equator and poles. Near the equator, the troposphere is thicker than at the poles, since the spinning of the Earth tends to shift air towards the equator. The thickness of the troposphere also varies with season. Stratosphere does not experience Normal Lapse Rate. There it generally gets colder as you go higher due to the expansion of gases as the pressure decreases. Technically, the stratosphere has a negative 'lapse rate' (temperature increases with height), while the lower atmosphere's lapse rate is positive.

Excess carbon in the atmosphere warms the planet. when carbon dioxide concentrations rise, air temperatures go up, and more water vapor evaporates into the atmosphere which then amplifies greenhouse heating.

Only tropical cyclones that form over the Atlantic Ocean or eastern Pacific Ocean are called "hurricanes." Tropical cyclones are like giant engines that use warm, moist air as fuel. That is why they form only over warm ocean waters near the equator. The warm, moist air over the ocean rises upward from near the surface.

Orographic precipitation or Rain produced when moist air is lifted as it moves over a mountain range. As the air rises and cools, orographic clouds form and serve as the source of the precipitation, most of which falls upwind of the mountain ridge. Some also falls a short distance downwind of the ridge and is sometimes called spillover. On the lee side of the mountain range, rainfall is usually low, and the area is said to be in a Rain Shadow.

Ionosphere is the top layer of the atmosphere. Radio waves are deflected in the ionosphere of the atmosphere.

Tropical cyclones, including hurricanes and typhoons, can develop and mature anywhere within the tropical zone. The tropical zone encompasses the region between the Tropic of Cancer and the Tropic of Capricorn, which includes warm ocean waters in tropical and subtropical regions around the globe. These cyclones form over warm ocean waters, where the sea surface temperatures are typically above 26.5°C (80°F), providing the necessary energy for their development. The warm and moist air near the ocean's surface rises and creates a spinning motion due to the Earth's rotation, leading to the formation of these cyclonic systems. As they move across the warm waters, tropical cyclones can intensify and become powerful storms. Therefore, they can develop and mature anywhere within the tropical zone.

The monsoon has well-developed cycle in South and South East Asia. The monsoon through axis experiences considerable day to day variation in its position, which has a vital bearing on the monsoon rainfall distribution in the region.

Westerlies in southern hemisphere are stronger and persistent than in northern hemisphere because southern hemisphere has less landmass as compared to northern hemisphere.

A layer in the Earth's atmosphere called Ionosphere facilitates radio communication.

Temperate lows are Sub-polar low pressure belts. The Coriolis effect from earth's rotation sets the resulting winds into Hadley cells, which produces low pressure at the equator and sub polar areas, high pressure at mid latitudes, and low sub-polar pressures, as well as trade winds, doldrums, and jet streams.

The plane of contact of the troposphere and stratosphere is known as tropopause. The tropopause is the boundary region between the troposphere and the stratosphere.

The ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 to 30 kilometres (12 to 19 mi) above earth, though the thickness varies seasonally and geographically.

In the northern hemisphere, south-facing slopes are warmest because the sun stays mostly in the southern half of the sky.

Ozone is the layer in Stratosphere with in atmosphere. It shields Earth from harmful UV rays of Sun. But, due to pollution and continuous exposure to green house gases a hole has developed in Ozone above Antarctica near South pole.

The general characteristics associated with tropical cyclones are that they are confined to a particular period of the year (mainly summer) and normally move from east to west.

In the northern hemisphere, isotherms bend sharply equator-ward over the continents during winter. Large landmasses in the Northern hemisphere cause isotherms to bend toward the equator in winter and poles in summer as they change their temperature much more than the water.

Either of the two belts over the oceans at about 30° to 35° N and S latitudes is known as Horse Latitude. Horse latitude, either of two subtropical atmospheric high-pressure belts that encircle Earth around latitudes 30°– 35° N and 30°– 35° S and that generate light winds and clear skies. Because they contain dry subsiding air, they produce arid climates in the areas below them.

Warm dry winds blowing down the east slopes of rockies is known as chinook. They are a type of warm, dry wind that occur on the downward slope of a mountain when warm air has lost its moisture.

It is the branch of science which is concerned with the processes of atmosphere e.g. forecasting weather. Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting.

Tropical cyclones have circular isobars. A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. Tropical cyclones originate entirely within the tropical air mass. Tropical cyclones are like giant engines that use warm, moist air as fuel. That is why they form only over warm ocean waters near the equator. The warm, moist air over the ocean rises upward from near the surface. Tropical cyclones are more destructive than the western disturbances. Tropical cyclones out at sea cause large waves, heavy rain, flood and high winds, disrupting international shipping and, at times, causing shipwrecks.

Extremely cold northeasterly or easterly winds blowing in eastern Russia and central Siberia are called buran.

The albedo of Cirrus cloud is the highest. Cirrus are thin, wispy clouds that appear at high altitude and consist of ice crystals.

Land masses are heated and cooled much faster than water bodies. Land gets heated by conduction, Water has higher specific heat and Water gets heated by convection.

The correct sequence of the zonal pressure belts are Equatorial low, Subtropical high, Subpolar low and Polar high.

The cold and dense air blowing down the mountain slope during the night is known as Katabatic wind. Katabatic wind, also called downslope wind, or gravity wind, wind that blows down a slope because of gravity. It occurs at night, when the highlands radiate heat and are cooled.

The layer of the atmosphere that reflects radio waves is the ionosphere. That is because there are gas particles in the ionosphere that are ionized, or that carry an electrical charge. The ionosphere is a layer which includes the thermosphere and part of the mesoshere and exosphere.

The atmosphere of Venus is made up almost completely of carbon dioxide. It also includes small doses of nitrogen and clouds of sulfuric acid.