F.Y.B.Sc. | Sem II | GG-201-202
PHYSICAL GEOGRAPHY
GG – 201 : ATMOSPHERE
GG – 202 : HDRYOSPHERE

The atmosphere is of immense importance for the existence of the living organisms of the earth. The atmosphere safeguards the lives of living beings against the effect of harmful rays of the sun. Its gaseous elements like carbon dioxide rear the vegetation and oxygen safeguards the living creatures. The human activities on the surface of the earth helps to bring changes in the structure of the atmosphere, particularly large scale deforestation, industrial smoke, and burning of coal, mineral oil and the natural gas polluting the atmosphere. For the interest of the living beings of the earth, we should refrain ourselves from contaminating the atmosphere. So, we should have an idea about the structure of the atmosphere and how it works.
According to the theory of hot origin of the earth in the beginning, the earth was a hot gaseous mass and the gases associated with the earth were also hot. Hence, they easily escaped from the earth and lost into the atmosphere. Thereafter, cooling and solidification of hot magma and formation of solid earth crust released several gases namely water vapour, carbon dioxide, hydrogen, methane, ammonia etc. through the process of degassing.
The Earth system comprises four spheres viz. the lithosphere (solid rocky part of Earth), atmosphere (air surrounding Earth), Hydrosphere (water part of Earth), and biosphere (living things). Thus, hydrosphere is one of the four spheres of Earth system. The water is present in all three phases: solid, liquid and gas. It is distributed among the ocean, glaciers and ice caps, groundwater, surface water and water in the atmosphere in the form of water vapor and clouds. The study of hydrosphere is utmost important for many purposes.
The primary importance of the hydrosphere is that it contains water, which sustains a variety of life forms and plays an important role in regulating the atmosphere and surrounding ecosystems. The water is not only important for living organisms but also for several natural processes.The oceanic salinity not only affects the marine organisms and plant community but it also affects the physical properties of the oceans such as temperature, density, pressure, waves and currents etc.various aspects of oceanic body is elaborately explained in this book.
It is our pleasure to present this book Introduction to lithosphere to the student of F.Y.B.Sc and teachers from different universities especially for KBC, North Maharashtra University, Jalgaon. The teachers will find lot of deficiencies in this book which are made according to new syllabus.