MONSOON FORECAST MODEL
No Comments
MONSOON FORECAST MODEL
Subject : Environment
Context : The India Meteorological Department (IMD) may introduce new monsoon models this year to better forecast changes in rainfall.
Concept :
Dynamical Model:
- It is also called the Monsoon Mission Coupled Forecast System. It relies on the supercomputers, mathematically simulating the physics of the ocean and the atmosphere.
- This model is better at forecasting the state of the weather a week or two in advance and is not yet considered reliable by meteorologists in forecasting the monsoon.
Statistical Model:
- Traditional statistical model equates relationships of physical parameters, such as for instance sea surface temperatures, snowfall, the temperature of landmass etc, with the actual observed rainfall in the past.
- For example , it takes into consideration the global weather models pointing to negligible chances of El Nino, a warming of the central equatorial Pacific which is associated with the drying up of monsoon rain. The IMD relies on this model.
- In any given year, there is a 33% chance of a normal monsoon that’s why there is high confidence that the monsoon in 2020 would be normal.
Proposed Models
- The three models under consideration are:
- 12 global circulation models (dynamical) whose outputs would be combined into a single one.
- Model that gauges rainfall based on the sea surface temperature in the tropics .
- Statistical model based on climate variables observed during the pre-monsoon.
- All of them are ‘ensembles’ meaning smaller models are combined to arrive at an average value.