Sponsor Area
In India the meterological observatories are normally classified into five categories. Observations are taken in these observatories transmit the data to the central observatory at Pune twice a day for forecasting.
Weather maps and charts are useful to us. They provide the primary tools for weather forecasting. They help in locating and identifying different air masses, pressure systems etc. They are useful to pilots and defence personnels like farmers and fishermen.
Describe the various weather symbols used in weather maps.
Weather elements are shown on the weather maps with the help of some symbols.
These are internationally recognized and are called weather symbols. Different weather phenomena can be identified with the help of these symbols.
1. Pressure: Isobars are used to show the atmospheric pressure of a place.
2. Temperature: Isotherms are used to show the temperature of a place.
3. Winds: Wind velocity and direction is shown by arrows. The system was devised by Admiral Beaufort in 1806 and is known as Beaufort Scale.
4. Clouds: Circles used to show the nature and amount of cloudiness.
5. Rainfall : Certain symbols and letters are used to show rainfall and other atmospheric phenomena.
1. Surface observations : These observations are distributed all over the country and take observations according to globally coordinated time and spacing.
2. Upper air observation : There is a lage number of observatories located around the globe which release balloon-borne instruments for sensing different elements like temperature, humidity, wind and pressure in the upper atmosphere.
3. Space-based platform : In recent decades a powerful new tool has become available to the meteorologists in the form of artificial satellites to make comprehensive and large scale observation of different elements at the ground level and as also in upper layers of the atmosphere.
(1) Continuous record of the atomospheric pressure, (2) Direction of the wind. (3) The velocity of wind. (4) Humidity in the air. () Maximum and minimum temperature for given period, (6) The amount of rainfall.
Sponsor Area
B.
The Indian Meteorological Department1. Thermometer used for measuring temperature.
2. Maximum and Minimum Thermometer is used for recording the highest and lowest temperatures occuring during a given period.
3. Wet and Dry Bulb Thermometer used for recording the humidity in the air.
4. Barometer used for measuring atmosphere pressure.
5. Rain Gauge used for measuring the amount of rain.
6. Wind Vane used for knowing the direction of wind. It also tells us the speed of the wind.
7. Anemometer used for measuring the wind velocity.
Study the figures given below and answer the following questions.
(1) Which seasons are shown in these maps?
(2) What is the value of the highest isobar in 6.9 and through which part of the country does it pass?
(3) What are the values of the highest and lowest isobars in fig? and where are they located?
(4) What are the patterns of temperature distribution in both maps?
(5) In which parts do you see the highest and lowest mean temperature in Fig?
(6) What relationship do you see between the distribution of temperature and pressure in both maps?
(1) The map 6.9 shows winter season and 6.10 shows the summer.
(2) 1020 and it passes through north western part of the country
(3) The highest value isobar is 1010 and it is located in south western part of the country (in Arabian sea). The lowest value isobar is 997 and it is located in western part of the country.
(4) Horizontal.
(5) The highest mean temperature is seen in southern part of the country. The lowest mean temperature in northern part of the country.
(6) The relationship between distribution of temperature and pressure is that where the temperature is high, the pressure is low and where the temperature is low, the pressure is high.
Sponsor Area
Sponsor Area
