Weather and climate Book Back Questions 8th Social Science Lesson 10

8th Social Science Lesson 10

10] Weather and climate

Book Back Questions with Answer and Do You Know Box Content

Do You Know?

Earth’s atmosphere is a layer of gases surrounding the planet earth and retained by the earth’s gravity. It contains about 78% nitrogen, 21% oxygen, 0.97% argon, 0.03% carbon dioxide and 0.04% trace amounts of other gases and water vapour.

Scientific study of weather is called Meteorology and the scientific study of climate is called climatology.

The word Climate is derived from the ancient Greek word “Klimo” which means “Inclination”.

Distribution of weather elements are shown by means of Isolines on maps. Isolines are those which join the places of equal values. Isolines are given different names based on the weather element they represent.

Isotherm – Equal temperature.

Isocryme – Equal lowest mean temperature for a specified period

Isohel – Equal sunshine

Isollobar – Equal pressure tendency showing similar changes over a given time

Isobar – Equal atmospheric pressure

Isohyet – Equal amount of rainfall

Temperature varies both horizontally and vertically. Temperature decreases with increasing height is known as Lapse rate which is 6.5 degree Celsius per 1000 meters in troposphere.

Highest Temperature ever recorded: The highest temperature ever recorded on the earth is 56.7^oC (134^o F) . It was recorded on 10^th July 1913 at Greenland Ranch of Death Valley, California, USA.

Lowest Temperature ever recorded: The lowest temperature ever recorded on the earth is -89.2^oC (-128.6^oF; 184.0 K) . It was recorded on 21^st July, 1983 at Soviet Vostok Station in Antarctica.

Highest pressure ever recorded: The highest ever air pressure at sea level was recorded at Agata, Russia on 31^st December, 1968. The pressure was 1083.8mb

Lowest pressure ever recorded: The lowest pressure of 870mb was recorded at Typhoon Tip, near Guam, Mariana Island in Pacific Ocean on 12^th October, 1979.

Why do your ears pop in Ariplanes? As you go up in an airplane, the atmospheric pressure becomes lower than the pressure of the air inside your ears. Your ears pop because they are trying to equalize or match the pressure. The same thing happens when the plane is on the way down and your ears have to adjust to a higher atmospheric pressure.

With decreasing air pressure, the availability of oxygen to breath also decreases. At very high altitudes, atmospheric pressure and available oxygen get so low that people can become sick and even die. Mountain climbers use bottled oxygen when they ascend very high peaks. They also take time to get used to the altitude as the quick move from high pressure to low pressure can cause decompression sickness. Aircraft create artificial pressure in the cabin which makes the passengers remain comfortable while flying.

Brazil has a large area where the average wind speed is low. Gabon, Congo and DR Congo in Africa, Sumatra, Indonesia and Malaysia are the least windy places on earth.

Al-Balakhi, an Arab Geographer collected climatic data from the Arab travellers and prepared the First climatic Atlas of the world.

Choose the best answers:

1. Earth’s atmosphere contains about __________ percentage of nitrogen and oxygen.

(a) 78% and 21%

(b) 22% and 1%

(c) 21% and 0.97%

(d) 10% and 20%

2. ____________ is generally defined as the average conditions of the weather of a place or a region.

(a) Earth

(b) Atmosphere

(c) Climate

(d) Sun

3. The earth receives energy from ___________

(a) Current

(b) Electro Magnetic Radiation

(c) Waves

(d) Heat

4. Which one the following represents places with equal amount of rainfall?

(a) Isotherm

(b) Isohel

(c) Isobar

(d) Isohytes

5. ____________ is used to measure the humidity.

(a) Anemometer

(b) Barometer

(c) Hygrometer

(d) Thermometer

Fill in the blanks:

1. ____________ refers to the condition of atmosphere for a short period of time.

2. The scientific study of weather is called ______________

3. The highest temperature ever recorded on the earth is ___________

4. ____________ is a ratio between the actual amount of water vapour and the maximum amount of water vapour the air can hold.

5. _______________ and _____________ are measured by anemometer and wind vane respectively.

6. _______________ are imaginary lines which connect the same temperatures of different places.

Match the following:

1. Climate – Locating and Tracing storms

2. Isonif – Cyclone

3. Hygrometer – Equal snowfall

4. Radar – Long term changes

5. Low pressure – Humidity

State true or false. If false, correct the statement:

1. The atmosphere is a layer of gases surrounding the planet.

2. The scientific study of weather is called Climatology.

3. Isohel refers equal sunshine.

4. Humidity is calculated by Aneroid Barometer.

Answers:

Choose the best answers:

1. 78% and 21% 2. Climate 3. Electro-magnetic radiation 4. Iso-hytes 5. Hygrometer

Fill in the blanks:

1. Weather 2. Meteorology 3. 56.7⁰C 4. Relative Humidity 5. Wind speed and Wind direction 6. Isotherms

Match the following:

1.Climate- Long Term Changes

2.Isonif- – Equal Snowfall

3.Hygrometer- Humidity

4.Radar- Locating and Tracking Storms

5.Low Pressure- Cyclone

State true or false. If false, correct the statement:

1.True

2.False

Correct answer: The Scientific study of weather is called Meteorology

3.True

4.False

Correct answer: Air Pressure is calculated by Aneroid Barometer