The seasonal prediction of the Indian summer monsoon rainfall (ISMR) is very important for our country, especially for planning strategies towards management of agricultural production and water resources. The seasonal prediction of the monsoon by dynamical models is based on the fact that the slowly varying boundary conditions like sea surface temperature (SST), soil moisture, snow cover, etc. exert significant influence on atmospheric development on seasonal time-scales in the tropics. Although the seasonal mean monsoon seems to be potentially predictable, atmospheric GCM simulations have not shown enough skill in capturing the inter-annual variations in the monsoon rainfall. Considerable research on predictability of the monsoon has established that the Indian Summer Monsoon has a limited potential predictability. It has also been recognized that ocean-atmosphere coupling is crucial in determining the potential predictability of the monsoon. Therefore, a coupled ocean-atmosphere climate model will be required for predicting the monsoon.

Indian summer monsoon season has periods of active (above normal rainfall) and break (below normal rainfall) epochs. Frequent or prolonged breaks lead to drought conditions. The long breaks in critical growth periods of agricultural crops lead to substantially reduced yield. Poor rice production in India during 1972, 1979 and 1987 appear to be due to such long breaks. Prediction of monsoon active and break spells, two to three weeks in advance, therefore assumes great importance for agricultural planning (sowing, harvesting etc) and water management. So there is a need for development of techniques based on statistical and dynamical methods for the forecasting of active break periods in ensuing monsoon season in the extended range time scale. Prediction of monsoon intra-seasonal oscillation is a major research program at the international and national domain.

a) Objectives:

1. To develop and improve a System for Seasonal Prediction of Monsoon.
2. To develop and improve a System for Extended Range Prediction of Active/Break Spells.
3. To carry out basic research on variability and predictability of the tropical climate system required for improving forecast.

b) Participating Institutions:

Indian Institute of Tropical Meteorology, Pune

c) Implementation Plan:

This is a continuing scheme. Following major activities would be continued to meet the objectives:

1. To develop an Indian model based on CFS coupled model and improve the skill of the seasonal forecast by the model to useful range.
2. To improve  prediction skill for both summer (SW) and winter (NE) monsoon over Indian region by improving the parameterization schemes of the model and replacing different modules in the system, wherever required. Once the model is suitably established at IITM, it can be gradually transferred to IMD (for operational forecast of Indian monsoon) after training some IMD scientists for its use.
3. To develop Multi-Model Ensemble (MME) system for improving the skill of monsoon prediction.
4. To develop new empirical techniques in addition to improvement in the existing empirical models for improving the prediction skills of active and break phases of monsoon. To evaluate, validate and improve the forecast skills of Coupled Climate Forecast System (CFS) for extended range forecast, etc.  and to disseminate forecast in real time using both empirical and dynamical models. Thus, continuance of the programme is well justified.
5. To set up the pollution monitoring stations and forecasting system within the regional model domain to provide accurate validation of the regional chemical model.
6. Physical mechanism responsible for Indian monsoon variability on each time scale will be will be built up.
7. The existing tree-ring data network will be enhanced by developing tree-ring chronologies from different parts of the country as well as from other South and Southeast Asian countries.
8. A mobile laboratory facility equipped with all the observational equipments to observe development of clouds and aerosols under different background meterological conditions will be developed.
9. The existing free-fall tube is proposed to be renovated and some new facilities to be added to produce and suspend sub-millimeter drops for the study of the interaction between microphysical and electrical properties of thunderstorm.
10. The importance of global electrical changes will be assessed in providing a physical mechanism for amplifying the small changes associated with atmospheric and climate effects.
11. A 3D lightning mapping array will be designed and fabricated to reconstruct the lightning channel and study the charge distribution of thunderstorm.
12. Role of land surface processes on boundary layer evolution will be studied.
13. A regional chemical transport model zoomed in for the Indian region will be used for interpretation.
14. Monitoring tropospheric vertical distribution and seasonal variability in Black carbon and air pollutants over India with special reference to Indo-Gangetic plane.
15. Study the long-term changes (anthropogenic and natural variabilities) in ozone and other climate forcing parameters in the middle atmosphere using 3-D general circulation model. Also to study the impact of GHG forcing on the middle atmospheric climate and navigation system.
16. To upgrade the existing High Performance Computer system of the IITM with storage and necessary infrastructure.

d) Deliverables:

1. Improved prediction skill of seasonal mean monsoon at 3 months lead time
2. Improved prediction skill of active/break cycles of summer monsoon at 20 days lead time
3. An Indian dynamical model based on NCEP coupled model, namely the CFS model.
4. Unravel the physical processes responsible for ‘internal’ IAV of monsoon.
5. Build a reliable high-resolution proxy climatic data base in India, particularly for the past few centuries.
6. Understand the coupling processes that exist between physicochemical, radiative, dynamical and biological phenomena in the Earth’s environment and provide valuable input information for modeling, sensitivity and simulation studies of weather/climate, hydrological cycle and environmental pollution. These studies have special significance over the tropics, where the convective and dynamical processes associated with high-altitude thunderstorms greatly affect the vertical distributions of aerosols and gases.
7. Prediction of thunderstorm formation and its severity by establishing an Automatic Weather Station network around Pune. Design and fabricate a 3D lightning mapping array to reconstruct lightning channel and to study charge distribution of thunderstorm.
8. Monitoring tropospheric vertical distribution and seasonal variability in Black carbon and air pollutants over India with special reference to Indo-Gangetic plane and mountain regions to understand the radiative forcing from the chemical constituents using aircraft with high response time technology development for aircraft. This will also help in validation of chemical climate radiative forcing model (CCRM) and facilitate the calculation of radiative forcing over Indian region.

e) Budget Requirement : 200 crores

(Rs. In crores)