Vayudoot Aviation

1. Monsoons are seasonal winds which

develop due to the high pressure over continents in winter and the subsequent low pressure which develops over the same areas in summer

blow only in the southeast Asia region

are from the southeasterly direction over the Indian sub continent in summer

are never in combination with trade winds

2. Near the equator upper winds tend to be

at speeds greater than 60 kt.

westerly.

easterly

calm.

3. The areas of greatest rainfall are

in the equatorial regions.

in the polar regions.

in central North America in summer due to the large convective cloud formations.

those where there is much polar front depression activity.

4. Northern hemisphere summers tend to be

colder than the southern hemisphere due to the smaller amount of solar radiation.

colder than the southern hemisphere because of the large land masses.

warmer than the southern hemisphere and the winters are colder

warmer than the southern hemisphere and winters are warmer too.

5. The warm temperature climatic zone is

approximately 35° - 40° of latitude and provides a wet summer season and a dry cold winter

approximately 20° - 35° of latitude and covers the high pressure desert regions of the world.

approximately 35° - 40° of latitude and is under the influence of polar front depressions throughout the year

approximately 35° - 40° of latitude and provides a warm dry summer with a cool wet winter

6. The Polar Front is

near the poles.

the region where warm sector depressions develop.

only apparent over the Atlantic ocean.

the boundary surface between polar continental and tropical continental air

7. Jet streams

have a speed in excess of 80 kt.

only occur in the troposphere.

are caused by a large difference in mean temperature in the horizontal.

are located above the tropopause.

8. Dust storms and haze are most common

with the Haboobs in winter

in unstable air with low pressure

in association with the sub tropical anticyclones over land

in temperate latitudes

9. The average temperature around the equatorial regions

is always above +40° C

is higher over the sea areas

has a very high range of temperatures throughout the year

varies on average from winter to summer by only some 5° C

10. The heat equator is

a line over the land joining places where the winter temperatures are highest.

coincident with the equatorial trough and ITCZ

a line over the land joining places where the summer temperatures are highest.

another name for the geographic equator

11. The upper winds tend to be westerly outside the tropics because

jet streams are usually westerly.

the rotation of the earth is west to east

surface winds are nearly always westerly.

the thermal winds are westerly on average.

12. The large change in the direction of trade winds is caused by

local pressure differences.

the change in geostrophic force when crossing the geographic equator.

an excess of air at height in association with the Hadley cells.

the cyclostrophic force in the equatorial regions.

13. The ITCZ is

the boundary between polar air and equatorial air.

the region between the two trade wind systems centred on the heat equator

a region of calm winds and layer type clouds with much haze.

the boundary region between the two monsoons.

14. Statistical pressure values tend to be

on average parallel to the lines of latitude in the southern hemisphere and much more variable in the northern hemisphere

much lower in winter in the northern hemisphere than in the southern hemisphere

on average parallel to the lines of latitude

higher over the oceans in winter

15. The Hadley cell is the name given to

the centre portion of a jet stream.

a cell formed by lifted air over the heat equator descending to the sub tropical highs

an initial bubble of air which is lifted by convection.

the CU cells which continue to form a CB.

16. The most notorious advection fogs occur

over Europe with high pressure to the north

over central North America in autumn and winter

over the sea in the region of Newfoundland and the Kamchatka peninsula

over southwest UK

17. Tropical Revolving Storms are

easily predictable.

can travel at speeds of 100 kt.

a summer weather feature.

can be very active well inland.

18. Trade winds in the southern hemisphere are

in opposition to the monsoons

southeasterly

usually from the northeast

southeast at first becoming southwest

19. The Savannah climatic zone is

approximately 10° - 20° of latitude and provides a wet winter season and a dry hot summer.

approximately 10°- 20° of latitude and provides dry trade wind conditions in winter and a wet summer season.

approximately 10° - 30° of latitude and has a period of long rains in spring and autumn, but is never dry.

approximately 20° - 30° of latitude and provides very dry desert conditions throughout the year.

20. Trade winds

only blow in the winter months.

blow towards the sub tropical anticyclones

are caused by lifting over the heat equator and the subsequent air movements from the sub tropical anticyclones

blow from the equatorial low pressure systems throughout the year.

21. Jet stream main locations are

in the warm air some 400 nm ahead of a warm front and some 200 nm behind a cold front and near the sub tropical highs.

in the warm air some 400 nm ahead of a warm or cold front and near the subtropical highs

only in association with the polar front.

in association with the polar front and with mountain waves.

22. The effect of mountain barriers on temperature is exemplified by the following

European temperatures are low in winter because there is no barrier to prevent cold Atlantic air crossing the area.

the Ural mountains of West Russia prevent most of the cold Siberian air reaching Europe in summer

the Rocky mountains of North America prevent cold Pacific air reaching inland, so summer temperatures to the east of the mountains are high

the Himalayas prevent warm dry air from Russia reaching India and Pakistan

23. The outflow from the Siberian High

is evident throughout the year.

is northwesterly over Japan, northeasterly over southeast Asia and easterly over Europe.

is the source of Polar Maritime air.

is northwesterly over Japan, northerly and northeasterly over China and northerly over the whole of India

24. The most numerous and frequent thunderstorms occur

in association with tropical revolving storms

over the east Indies area (Java) due to the intense surface heating.

in regions affected by cold fronts.

in association with the ITCZ over north Africa

25. The Tropopause is

normally the upper limit of weather.

the upper limit for jet streams and mountain waves.

more or less constant for any latitude.

is a boundary layer between the troposphere and the stratosphere.

Question Bank

Questions for GLOBAL CLIMATOLOGY