Climatology MCQ Questions and Answers

Statement 1 is correct. Land comprises only 19.1% of Southern Hemisphere, In Northern Hemisphere, the majority of area is composed of land masses. Less landmass in Southern Hemisphere results in lesser frictional drag in motion of westerlies, thus resulting in stronger and persistent Westerlies.

Statement 2 is incorrect. Coriolis force is equal in both the hemispheres at their respective latitudes. The magnitude of the Coriolis force depends on the speed of the object and its latitude. ‘The Coriolis force is zero at the equator and increases toward the poles.

La Nina events represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific. It is indicated by sea-surface temperature decrease by more than 0.90 for at least five successive three-month seasons.

Statement 1 is incorrect. La Nina is characterised by unusually cold ocean temperatures in the Equatorial Pacific compared to El Nino, which is characterized by unusually warm ocean temperatures in the Equatorial Pacific.

Statement 2 is incorrect. La Nina is favourable to Indian monsoon whereas, El Nino has adverse effect on south- west monsoon. La Nina leads to heavy floods in Australia. Heavy floods often lead to waterlogging resulting in poor agricultural output. There are increased temperatures in Western Pacific, Indian Ocean and off the Somalian coast. In the western Pacific, La Nina increases the potential for landfall in those areas most vulnerable to their effects, and especially into continental Asia and China.

Mangroves area groupo trees an shrubs at live in the coastal intertidal zone.

Mangrove forests can be recognized by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water. The roots also slow the movement of tidal waters, causing sediments to settle out of the water and build up the muddy bottom.

The sturdy root system of mangrove trees helps form a natural barrier against disasters such as tsunamis and floods. Even under such extreme circumstances, mangroves’ dense root and branch networks could help dissipate tsunamis, reducing their devastation.

The stratosphere is found above the tropopause and extends up to a height of 50 km. One important feature of the stratosphere is that it contains the ozone layer.

Statement 1 is correct. The stratosphere is very dry and air there contains little water vapor and there is almost complete absence of clouds and thunderstorms. Less water vapour and absence of clouds means less drag which helps maintain fuel efficiency.

Statement 2 is correct. Unlike the troposphere, there is almost complete absence of vertical winds or thunderstorms in the lower stratosphere.

Monsoon refers to the seasonal change in the direction of the prevailing winds of a region. Monsoons cause wet and dry seasons throughout much of the tropics. Monsoons are most often associated with the Indian Ocean. Monsoons always blow from cold to warm regions. The summer monsoon and the winter monsoon determine the climate for most of India and Southeast Asia.

Option c is correct. A monsoon is a seasonal reversal in wind patterns over a region. The seasonal wind shift is usually accompanied by a dramatic change in precipitation. ‘The phenomenon is best developed over the Indian subcontinent.

During winter, there is a high-pressure area north of the Himalayas. Cold dry winds blow from this region to the low-pressure areas over the oceans to the south. In summer, a low-pressure area develops over interior Asia, as well as, over north-western India. Thus, wind in India blows from the northeast during cooler months and reverses direction to blow from the southwest during the warmest months of the year.

Statement 1 is correct. ‘The atmosphere is generally heated from the terrestrial radiation emitted by the Earth’s surface as gases in the atmosphere do not absorb the incoming solar radiation. Therefore, temperature is maximum near the surface of the Earth.

Statement 2 is incorrect. As the air rises upwards it cools down, as result of this its water holding capacity decreases.

Statement 3 is correct. Due to decreased atmospheric pressure the density of air decreases as we go upward due to low pressure and hence, less heat can be absorbed. Also, as the warm air rises it cools down adiabatically.

The tropical savanna climate has alternating dry and wet seasons. The wet summer season lasts 6 to 8 months and during these days, there is plenty of rainfall. Winter lasts for 4 to 6 months and there might be no rains in winter this results in frequent forest fires.

Option a is incorrect. Rainfall throughout the year is a characteristic of Equatorial region.

Option b is incorrect. “The Mediterranean region falls under the influence of wet westerlies during winter season and receive rainfall in winters only.

Option c is incorrect. Tropical Savannah region experience dry conditions for a longer duration than wet conditions. Extremely short dry season is a characteristic of regions experiencing Tropical Monsoon climate.

Variations in the length of daytime and night time from season to season are due to revolution on Earth on tilted axis. Day and night are the consequence of the earth’s rotation on its axis. But the axis is tilted 23.5 degrees. Due to this reason, during the earth’s revolution around the sun, polar regions spend long periods pointed towards the sun in the summers and long periods pointed away from the sun during winters. The same is true for other regions, thus causing variations in length of day and night.

‘The annual range of temperature is defined as the difference between the hottest and coldest months at a place, taking monthly mean temperatures in each case. It is given approximately by the difference between the average of the January maximum and minimum temperatures, and the corresponding average for July.

Statement 1 is correct. The continents get heated faster and get cooled faster in comparison to the Oceans. The annual range oftemperature is high in the interior ofthe continent because places located in the interior of the continent are far away from the moderating influence of the sea.

Statements 2 is incorrect. Altitude affects the daily range of temperature and annual mean temperature but has negligible impact on annual range oftemperature. Latitude affects the annual range of temperature. The annual range of temperature increases with increasing latitude.

Statement 3 is incorrect. Wind is generally stronger near the coasts compared to interior areas of continents.

Statement 4 is incorrect. Rainfall in the interiors of the Continents is generally low as compared to Coasts. It is because the rain bearing winds from seas and oceans tend to loss most of the moisture till they reach the interiors. The continents get heated faster and get cooled faster in comparison to the Oceans. The annual range of temperature is high in the interior of the continent because places located in the interior of the continent are far away from the moderating influence of the sea.

Statement 1 is correct. Equatorial forests are found within 5 degrees north and south of the equator. Primary tropical rainforest is vertically divided into at least five layers: the overstory, the canopy, the understory, the shrub layer, and the forest floor. The canopy is the dense ceiling of closely spaced trees and their branches. It is the primary layer of the forest and resembles a roof of the forest.

Statement 2 is correct. Tropical rainforests support the greatest diversity of living organisms on Earth. Although they cover less than 2 percent of Earth’s surface, rainforests house more than 50 percent of all plants and animals found on land. The primary reason behind this abundance of diversity is the high amount of sunlight this region receives.

Statement 3 is correct. An important characteristic of the canopy system is the presence of plants known as epiphytes, that grow on canopy trees. Epiphytes are not parasitic because they draw no nutrients away from the host, but climb the host tree to access direct sunlight.

Central Asian Steppe are dry, grassy plain. Steppes are located in the heart of the continents, meant they have little maritime influence. Their climate is thus continental with extremes of temperature. With recorded temperatures as high as 45 oc in summer and in winter falls to —55 oc. Trees are very scarce in the steppes, because of the scanty rainfall (25-50 cm annually).

The lands do not allow people to settle permanently and the thinly scattered population live in small nomadic groups, herding cattle, goats, horses, camels, and sheep. These grasslands were dominate by nomadic and semi- nomadic peoples like the kirghiz.

‘Thunder is caused by the rapid expansion of the air surrounding the path of a lightning bolt. It is caused by intense convection on moist hot days. A thunderstorm is a well-grown cumulonimbus cloud producing thunder and lightning.

Many small bits of ice or water droplets(frozen raindrops) bump into each other as they move around in the air. All of those collisions create an electric charge. After a while, the whole cloud fills up with electrical charges.

The positive charges or protons form at the top of the cloud and the negative charges or electrons form at the bottom of the cloud. Since opposites attract, that causes a positive charge to build up on the ground beneath the cloud.

The grounds electrical charge concentrates around anything that sticks up, such as mountains, people, or single trees. Once the negative charge at the bottom of the cloud gets large enough, a flow of negative charge called a stepped leader rushes toward the Earth. ‘The positive charges at the ground are attracted to the stepped leader, so positive charge flows upward from the ground. When the stepped leader and the positive charge meet, a strong electric current carries positive charge up into the cloud. This electric current is known as the return stroke. We see it as the bright flash of a lightning bolt.

The South Atlantic and South-Eastern Pacific are as void of cyclonic activity largely due to the ITCZ having a tendency to stay near or north of the equator. For a tropical cyclone to occur in South Atlantic and South-Eastern Pacific regions, a broad convergence zone is needed to reach about 5 degrees of latitude away from the equator in order for the Coriolis Force to have sufficient intensity to organize a full-fledged tropical cyclone, and the Atlantic ITCZ almost never shifts that far south.

There are two equatorial current flowing from east to west – the North EC and South EC. In between the two, there flows a equatorial counter current in the opposite direction, i.e from west to east. Most of the water from North EC and South EC travels polewards, however some of the water gets deflected towards equators leading to piling up of waters in the area near Brazil, due to convergence of the two equatorial currents give rise to the equatorial counter current.

Statement 1 is incorrect. ‘Ihe Westerlies are prevailing winds from the west toward the east in the middle latitudes between 300N and 600N, and 300S and 600 S. They originate from the high-pressure areas in the horse latitudes and tend towards the poles and steer extra tropical cyclones in this general manner.

Statement 2 is correct. Western disturbances which originate over the Mediterranean Sea are steered towards North western India by the Westerly Jet Stream causing winter rains.

A tropical rainforest climate or equatorial climate is a tropical climate usually found within 10 to 15 degrees latitude of the equator. They experience high mean annual temperatures and small temperature ranges. Annual rainfall is high, amounting to more than 2000 mm that falls throughout the year, there is almost absence of any seasonal variation. A tropical rainforest climate is typically hot, very humid, and wet. Due to high temperature and high humidity, and convergence of trade winds which uplift the air, there is rainfall throughout the year.

Dew is small drops of water that form on the ground and other surfaces outdoors during the night.

Option b is correct. Dewdrops are formed when the moisture is deposited in the form of water droplets on cooler surfaces ofsolid objects such as stones, grass blades and plant leaves. The ideal conditions for its formation are clear sky, calm air, high relative humidity, and cold and long nights. When the sky is clear and the trees and plants are cooler at nights, there is more evaporation of water and hence more dew formation. For the formation of dew, it is necessary that the dew point is above the freezing point. ‘The air containing moisture to its full capacity at a given temperature is said to be saturated. The temperature at which saturation occurs in a given sample of air is known as dew point. Dew forms when the temperature becomes equal to the dewpoint. This often happens first at ground level for two reasons. First, longwave emission causes the earth’s surface to cool at night. Condensation requires the temperature to decrease to the dewpoint. Second, the soil is often the moisture source for the dew. Warm and moist soils will help with the formation of dew as the soil cools overnight. Cloudy skies reflect back the Earth’s radiation and that prevents earth’s surface to cool at night.

Statement 1 is incorrect. Jet Streams occur in both the hemisphere. Jet streams are high altitude westerly wind system blows at a height of 6 to 14 km, with very high speed up to 450 km/hr in wavy form in both hemispheres. At most times in the Northern and Southern Hemispheres, there are two jet streams: a subtropical jet stream centered at about 30 degrees latitude and a polar-front jet stream whose position varies with the boundary between polar and temperate air.

Statement 2 is correct. Only tropical cyclones have eye. The eye is a region of mostly calm weather at the centre of tropical cyclones. A mature tropical cyclone is characterised by the strong spirally circulating wind around the centre, called the eye. The diameter of the circulating system can vary between 150 and 250 km.

Statement 3 is incorrect. ‘The eye experiences the higher temperature and lower pressure as compared to the surroundings. The eye is a region of calm with subsiding air. Around the eye is the eye wall, where there is a strong spiralling ascent of air to greater height reaching the tropopause. ‘Ihe wind reaches maximum velocity in this region, reaching as high as 250 km per hour. Torrential rain occurs here.

Whether a given cloud will heat or cool the surface depends on several factors, including the cloud’s altitude, its size, and the make-up of the particles that form the cloud.

Statement 1 is incorrect: Low, thick clouds primarily reflect solar radiation and cool the surface of the Earth.

Statement 2 is incorrect: High, thin clouds primarily transmit incoming solar radiation; at the same time, they trap some of the outgoing infrared radiation emitted by the Earth and radiate it back downward, thereby warming the surface of the Earth.

Statement 1 is correct. ‘The moraine creates topographic depression in which the melt water is generally accumulated leading to formation of glacial lake. Such moraine-dammed lakes appear to be the most common type of glacial lakes. When this lake is watertight, melt waters will accumulate in the basin until seepage or overflow limits the lake level. The impoundment of the melt may sometimes be unstable, leading to sudden release of large quantities of stored water. A moraine is any accumulation of unconsolidated debris (regolith and rock) that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice sheet.

Statement 2 is correct. The high temporal and high spatial remote sensing imagery from satellites supported by field surveys will allow decision makers to better assess the possible risk of future outbursts in this region.

Statement 3 is correct. Through extensive research, CDAC has deployed India’s first GLOF Early Warning System in Sikkim to predict GLOFs, which will help the Government authorities in case of an impending GLOF event.

The High temperature recorded in Death Valley (california) is a result of ‘Heat dome’. Heat dome is the phenomenon in which high pressure circulation in the atmosphere acts like a dome or cap which traps hot ocean air at the surface and favours the formation of a heat wave. Heat dome happens when strong, high- pressure atmospheric conditions combine with influences from La Niha, creating vast areas of sweltering heat that gets trapped under the high-pressure “dome.”

‘The Fujiwhara effect is a phenomenon that occurs when two nearby cyclonic vortices move around each other. When cyclones are in proximity of one another, they start rotating about a point between the two systems due to their cyclonic wind circulations.

If one cyclone (hurricane) is a lot stronger than the other, the smaller one will orbit it and eventually crash into it. If both are comparable in size than the two vortices will be attracted to each other, and eventually spiral into the center point and merge, or merely spin each other around for a while before shooting off on their paths.

Often the effect is additive with the two cyclones (hurricanes) come together, and we usually end up with one massive cyclone instead of two smaller ones.

Option a is incorrect. Heat waves occur when actual maximum temperature is 2450C.

Option b is incorrect. Heat waves is a period ofabnormally high temperatures that occurs during the summer season. In India, heat waves typically occur between March and June, and in some rare cases even extend till July.

Option c is correct. Severe heat waves occur when temperature departure from normal is greater than 6.40C.

Option d is incorrect. To declare a heat wave, the set criteria should be met at least in 2 stations in a Meteorological subdivision for at least two consecutive days and it will be declared on the second day.

El Nino Modoki is associated with strong anomalous warming in the central tropical Pacific and cooling the eastern and western tropical Pacific. During El Nino modoki event, warming is observed more in the central part with cooling on its both sides that is in the eastern and western Pacific Ocean.

Statement 1 is correct. Under conditions of temperature inversion, when the falling snow reaches the layer of warm air, it melts, then it hits the layer of cold air just above Earth’s surface and refreezes. This results into creation of tiny ice pellets called as sleet.

Statement 2 is correct. Hailstones are clumps of layered ice that form in updraughts (rising air) within thunderstorms. Hailstones form when an upward current of air generated by thunderstorms lift water droplets high in the troposphere. When the raindrops freeze in the upper atmosphere and fall down then they are again lifted by the upward air currents of the thunderstorm. This continues till the pellets become too heavy to be lifted by the air currents and fall to the ground as hailstones.

Statement 3 is correct. Due to repeated upliftment of frozen pellets by the upward air current of the air, the hailstones are made of many layers of ice which increases their size. Hence, hailstones are larger pellets than the pellets that make up sleet.

Statement 1 is correct. In the interior parts of the continents large landmass is available to get heated, resulting into hot air on a huge scale, which helps in the convectional rainfall.

Statement 2 is incorrect. High temperature and intense heating are needed for the air to get heated and ultimately rise, which condenses in the upper atmosphere. Therefore, such rain is common in the summer or during the hotter part of the day.

Statement 1 is incorrect. Haze (not fog) is formed due to unequal refraction of light in air of different densities in the lower atmosphere. Fog occurs when water condenses on dust and other particles like smoke.

Statement 2 is correct. Dense fogs are more likely to occur in the high and middle latitudes rather than tropics.

Statement 3 is correct. Fog only occurs in the lower strata of atmosphere as a sort of dense ‘ground cloud’.

Statement 1 is correct. Positive IOD brings good monsoon rainfall in India and Indian Ocean and poor rainfall in eastern parts of Indian Ocean.

Statement 2 is Incorrect. Strong El Nino events contribute to weaker monsoons and even droughts in India.

Statement 3 is Incorrect.La Nina means Little Girl in Spanish. La Nina has the opposite effect of EI Nino. During La Nina events, trade winds are even stronger than usual, pushing more warm water toward Asia. Off the west coast of the Americas, upwelling increases, bringing cold, nutrient-rich water to the surface.

Statement 1 is incorrect. Trade winds between latitudes 35-40 degrees North and South of the equator, brings plentiful rainfall to the eastern coast of the continents and goes on decreasing towards the west.

Statement 2 is incorrect. Westerlies between 45-65 degrees North and South of the equator, the rainfall is first received on the western margins of continents and it goes on decreasing towards the east.

Statement 1 is incorrect. ‘The rate of change of pressure in regard to distance is the pressure gradient. The vertical pressure gradient force is much larger than that Of the horizontal pressure gradient force.

Statement 2 is correct. ‘Ihe difference between vertical and horizontal pressure gradient force is balanced by the gravitational force. Hence, we do not experience strong upward winds.

Option 1 is correct. The surrounding atmosphere exerts buoyant force on low-pressure cells and hence the air within a low pressure cell rises. On the other hand, the air within a high-pressure cell sinks as it is denser than the surrounding atmosphere. Rising air is associated with convergence and unstable weather (cyclonic conditions) whereas the sinking (subsiding) air is associated with divergence and stable conditions (anticyclonic conditions).

Option 2 is correct. Frictional Force affects the speed of the wind. It is greatest at the surface and its influence generally extends up to an elevation of 1 – 3 km. Over the sea surface the friction is minimal.

Option 3 is correct. Coriolis Force deflects the wind to the right direction in the northern hemisphere and to the left in the southern hemisphere.

Option 4 is correct. Centripetal acceleration creates a force directed at right angles to the wind movement and inwards towards the centres of rotation. ‘This force produces a circular pattern of flow (vortex) around centres of high and low pressure.

Statement 1 is correct. When isobars are straight, and when there is no friction, the pressure gradient force is balanced by the Coriolis force, and the resultant wind blows parallel to the isobar (deflection of the wind is maximum). Elhis wind is known as the geostrophic wind.

Statement 2 is correct. The Jet Stream is a geostrophic wind blowing horizontally through the upper layers of the troposphere, generally from west to east, at an altitude of 20,000 – 50,000 feet.

Statement 1 is incorrect. Relative humidity could be defined as the percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature.

Statement 2 is correct. “The ability of the air to hold water vapour depends on temperature along with other factors. With the change of air temperature, the capacity to retain moisture increases or decreases and the relative humidity is also affected. Relative humidity increases with the decrease in temperature of the water vapour content and vice versa.

Statement 3 is correct. Relative humidity is greater over the oceans and least over the continents. It is due to amount of availability of water vapor over the oceans is greater than over the land.

Statement 1 is correct. Earth’s axis makes an angle Of h with the plane of its orbit round the sun which influences the amount of insolation received at different latitudes. Thus, rotation of earth on its axis plays a major role in controlling insolation.

Statement 2 is correct: The angle of inclination of the rays depends on the latitude of a place. The higher the latitude the less is the angle they make with the surface of the earth resulting in slant sun rays. Vertical ray covers less area which means the energy remains concentrated in a small area. Due to inclination slant rays has to pass through greater depth Of the atmosphere resulting in more absorption, scattering and diffusion.

Statement 3 is correct: Length Of the day has a direct relation with the amount of insolation. For instance the amount of insolation received in winter by middle and higher latitudes is less than what is received in summer. It is directly linked to the length of the day which is shorter in winter in high and mid latitudes.

Statement 4 is correct: The atmosphere is largely transparent to short wave solar radiation. The incoming solar radiation passes through the atmosphere before striking the earth’s surface. If the atmosphere is not transparent then the light will get scattered in the atmosphere and back into space.

Option a is correct: Terrestrial radiation is the amount of energy which is radiated out by the earth’s surface. It is also called as effective radiation as it helps in heating the lower portion of the atmosphere.

Option b is correct: In the terrestrial heat budget of the earth total amount of energy received is 51% of the total insolation. Out of this 23% of the energy is lost in the form of terrestrial radiations.

Option c is correct: Greenhouse gases trap the outgoing terrestrial radiation which results in generating heat in the atmosphere in the night in absence of the sun. This is called as greenhouse effect, where the energy from the terrestrial radiations acts as a warm blanket for the earth.

Option d is incorrect: Terrestrial radiations are long wave radiations which are reflected back to earth by greenhouse gases. This reflection is only possible because of long wave nature of terrestrial radiation otherwise it would have simply crossed through them just like the incoming short wave radiations.