Monsoon wind - resource pack

Northeast- northwest monsoon

Explain why Delhi receives very light rainfall in Fig. 4.                                                  [4]

-        Delhi receives light rainfall due to northeast monsoon (October – February)

-        an area of high pressure forms overs Indian sub-continent and Central Asia while an area of low pressure forms over Australia

-        due to differences in pressure between the northern and southern hemispheres, air moves from Central Asia down towards Indian sub-continent

-        resulting in drier and colder winds that bring with it light rainfall as they blow across cold land to Delhi

Southwest-southeast monsoon

With reference to Fig. 6, explain how Mangalore, India is affected by Southwest monsoon.  [4]                                                                                              

·        Max 3 marks awarded only if student never make reference to Mangalore, India.

·        Between June and September, when it is summer in the northern hemisphere.  Air over Central Asia heats up, expands and rises, forming a region of low pressure over the area. 

·        During the same period, the southern hemisphere is experiencing winter.  The low temperature causes the air to be cold and dense, exerting a greater force on the earth’s surface.  This results in an area of high pressure over Australia.

·        Due to the difference in pressure between Central Asia and Australia, air from Australia moves to the Indian sub-continent and Central Asia as the southeast monsoon winds.  As the winds cross the Equator, the Coriolis effect deflects the winds to the right. 

·        These winds become the southwest monsoon winds and warm up as they head for Central Asia.  The warm air picks up moisture as it travels over the Indian Ocean and brings heavy rain to the Mangalore, India.