- Discuss the concept of air mass, its types and explain its role in macro-climatic changes. [200 words]
- An air mass is a distinctive, homogeneous, body of air in terms of temperature, humidity and lapse rate, having little horizontal variation in temperature and moisture.
- When the air remains over a homogeneous area for a sufficiently longer time, it acquires the characteristics of the area. For example, air mass formed over Canada will be very cold and dry.
The sub division of these groups is made according to the source regions, as following:
- Based on moisture contents: Continental or Maritime
- Based on Temperature: Tropical or Polar or Arctic
Five types of air mass:
- continental Arctic (cA)
- continental Polar (cP)
- continental Tropical (cT)
- maritime Polar (mP)
- maritime Tropical (mT)
Role in Macro-climatic Changes:
- The properties of vertical distribution of temperature and moisture content of an air mass influence the accompanying weather.
- The air masses carry atmospheric moisture from oceans to continents and cause precipitation over landmasses. For example, maritime-tropical air sourced over warm waters of the Atlantic Ocean, Caribbean Sea and Gulf of Mexico, primarily between 10 and 30 degrees north of latitude, is the main contributor of precipitation for much of North America east of Rocky Mountains.
- They transport latent heat, thus removing the latitudinal heat balance.
- The mixing of air masses achieved along the alternating warm and cold fronts of a mid-latitude cyclone is part of the process by which the heat of the lower latitudes is transferred poleward and the weather associated with these disturbances is determined by characteristics of the air masses involved.
- Among the following States, which one has the most suitable climatic conditions for the cultivation of a large variety of orchids with minimum cost of production, and can develop an export oriented industry in this field? [CSE(PRE)-2011]
a. Andhra Pradesh
b. Arunachal Pradesh
c. Madhya Pradesh
d. Uttar Pradesh
DAILY CURRENT AFFAIRS
- Which of the following statement(s) is/are true about the objectives of the National Digital Communications Policy-2018:
- Providing accessibility of broadband to all and creation of four million additional jobs in the Digital Communications sector.
- Enhancing the contribution of Digital Communication sector to India’s GDP.
- Ensuring Digital Sovereignty.
b. 2 & 3 only
c. 1 & 3 only
d. All of the above
- Which of the following statement(s) is/are true about the Defence Acquisitions Council?
- It is chaired by the Home Minister of India.
- It gives ‘in principle’ acceptance of necessity to each Capital acquisition project for defence procurement and categorises the acquisition projects under the categories of ‘Buy’, ‘Buy & Make’ and ‘Make’.
a. 1 only
b. 2 only
c. None of the above
d. All of the above