Geography

IAS Parliament 7 years

Analyse the vital importance of monsoon prediction for India. Discuss the geographical and technological challenges for India in making accurate monsoon prediction.

KEY POINTS

Importance of Monsoon prediction

· It is key for farmers to determine when to carry out the sowing.

· Faulty predictions of intra-seasonal variation or forecasting a change in global weather can affect agricultural outputs.

· Predicting the length of the monsoon is relevant for planning hydro power generation.

· They are also important for the government to take policy decisions.

· The outcomes of prediction errors have ripple effects on stock markets.

Challenges

Geographical challenges

· India falls in the tropical region so the changes in the weather conditions are more frequent than anywhere else in the world.

· The parameters also frequently change, thereby having an effect on the forecast.

· Rising temperatures responsible for changes in the monsoon’s behaviour, like increased intensity of rainfall in short durations is hard to predict.

· Effects of large number of external factors like ElNino, Tropical Easterly Jet are hard to be precise about.

Technological challenges

· IMD is using a dynamical model along with a statistical model.

· Statistical Model – A statistical model is based on parameters that are assumed to influence the monsoon.

· For example, increased Himalayan snow cover was seen to be associated with a strong monsoon, and El Nino was seen to influence the monsoon negatively.

· Dynamical Model – A dynamical model simulates in the computer the actual conditions in the atmosphere that lead up to a monsoon season.

· Developing and using them involves –

a) Understanding the physics of the monsoon well.

b) Developing mathematical equations that determine the behaviour of the atmosphere and the sea during the monsoon.

c) Measuring the initial conditions accurately over land and the sea.

d) Making a computer calculate how these initial conditions evolve based on the equations.

· In practice this is a hard task, and no dynamic model has been accurately able to predict all aspects of monsoon season accurately.

· Because, it is difficult to understand the physics well, data are hard to get, and simulating the evolution of a coupled ocean-atmosphere model is hard for the most powerful computers in the world so far.

· Lack of block-wise data on prediction creates distress, because rainfall varies so much even within the district.

· Lack of software professionals – India has more computing power and better models to work with. There is a lack of competent software professionals and scientists working with the IMD.