Miscellaneous Study Materials 19 Nov 2019

Rainfall


Rainfall
The amount of moisture in air is commonly recorded as relative humidity; which is the percentage of the total water vapour air can hold at a particular air temperature. The presence of warm, moist and unstable air and sufficient amount of the hygroscopic nuclei is a prerequisite condition for rainfall. The warm and moist air after being lifted upwards becomes saturated and clouds are formed after condensation of water vapour around the hygroscopic nuclei such as dust particles. Download Attachment

Introduction of Cyclones


Cyclone is a system of low atmospheric pressure in which the barometric gradient is steep. Cyclones represent circular fluid motion rotating in the same direction as the Earth. This means that the inward spiralling winds in a cyclone rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale cyclonic circulations are centred on areas of low atmospheric pressure. The cyclones can be tropical cyclones or temperate cyclones (extra-tropical cyclones). Download Attachment

Ocean bottom Relief


 On a large scale, the landscapes of can be divided into three orders of relief called Megarelief. The Megareliefs include the largest landscapes by scale, from enormous ocean basins and continents down to local hills, spurs, cliffs, valleys, gorges and river terraces. Download Attachment