IMD has evolved from focusing on weather forecasting to becoming a key player in climate research, disaster management and air quality monitoring
The completion of 150 years of establishment of the India Meteorological Department (IMD) is a matter of great pride for every Indian. The India Meteorological Department (IMD), established in 1875, has played a pioneering role in meteorological and atmospheric studies in India. Initially focused on weather forecasting and seismology, the Department gradually expanded its scope to include climate research, disaster management, and environmental monitoring. IMD was perhaps the first institution in India to start systematic long-term measurement of solar radiation, precipitation chemistry, ozone, and aerosol optical and physical properties.
Recognising the importance of atmospheric composition, IMD became an active partner in global atmospheric environment monitoring and research programs and contributed significantly towards ozone hole, air quality, precipitation chemistry, climate change, solar dimming and brightening research. The Earth’s climate system has demonstrably changed since the pre-industrial era. IMD has a key responsibility in understanding the science of climate change and variability as well as adaptation and mitigation strategies. It plays a prominent role in facilitating a broader use of climate information, products and services. IMD has been mandated to operate the national meteorological observing systems; develop and maintain data archives; undertake climate monitoring; and carry out climate diagnostics, climate analysis and climate assessment.
All this reliable and authentic data and information collected over 150 years has provided a proper assessment of climate change in India and has also helped in developing policy formulation for adaptation and mitigation measures. The air quality forecast and assessment system helps CAQM and other pollution control authorities in the country to make decisions for air quality management including the implementation of GRAP.
The problem associated with air pollution is very complex as many factors contribute to changes in concentrations of the main pollutants. The major factors are anthropogenic emissions, urbanisation, specific topography, emissions sources, environmental factors and meteorology. The advances in computational resources allowed the use of advanced deterministic chemical transport models, leading to more accurate air quality forecasts, replacing the previous empirical and statistical approach which has some limitations.
The scientists at India Meteorological Department and Indian Institute of Tropical Meteorology (IITM), Pune, Ministry of Earth Science jointly developed the advanced Air Quality Early Warning System (AQEWS). The advanced modelling framework consists of a high-resolution fully coupled state-of-the-science Weather Research and Forecasting model coupled with chemistry (commonly known as WRF-Chem), and ingest data from satellites on aerosol optical depth, surface data from air quality monitoring stations across India and high-resolution emissions from various anthropogenic and natural sources including dust and stubble burning, to create more accurate initial conditions using state-of-the-art data assimilation techniques, to improve forecasts.
The chemical data assimilation is further integrated with dynamical downscaling at a 400-meter resolution to provide a very high spatial resolution air quality forecast for the Delhi region. The prediction part of the system consists of two modelling frameworks, one is based on the NCAR atmospheric chemistry transport model (WRF-Chem) and the second one is based on the Finnish Meteorological Institute model SILAM (System for Integrated modelling of Atmospheric composition). The models take into account the latest land use land cover (LULC) change information over Delhi, background aerosols and pollutants, long-range transport of dust from dust storms and particulate matter from stubble burning. The predictions are now available up to 72 hours lead time at 400 meter resolution and 10 days in advance at 10 km resolution for the Delhi region. The advanced warning system provides (a) an air quality forecast at 400 meters for the Delhi/ NCR region, (b) an air quality forecast on primary and secondary stress of Delhi/NCR at 400 meters resolution, (c) an air quality forecast at 10 km resolution for entire South Asian region, (d) real-time observations of air quality over Delhi/NCR region, (e) details about natural aerosols like dust (from dust storms) and particulate matter using different satellite datasets, (f) Near real-time fire information over India, (g) forecast of the contribution of non-local fire emissions. Consistent efforts are required to further improve the model performance.
The field of environmental meteorology has witnessed transformative innovations, with cutting-edge technologies enabling precise, real-time insights into atmospheric dynamics and air quality.
The accuracy of air quality forecasts is essential for mitigating the health impacts and economic costs of air pollution. IMD and associated institutions are continuously striving for improvement in environment monitoring and air quality prediction.
IMD’s historical contributions have not only improved the scientific understanding of India’s unique atmospheric conditions but have also played a critical role in global efforts to combat air pollution and climate change.
Many compliments to the meteorological community for their hard work in making IMD a global leader in the field of weather and climate.
(The author is Chairperson of the Commission for Air Quality Management in NCR and Adjoining Areas; Views are personal)
