What are the three modes of meteorological observation used globally ?

 The three modes of observation are :

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.