rural india, poor air quality. goverment of india, SAFAR Pune

Predicting Poor Air Quality Events

By: Gufran Beig and Neha Parkhi
Air pollution is a growing problem in India. Factories, power plants, automobiles and dust, smoke from bush fires and volcanic eruptions are responsible for pollution. The deterioration of air quality thus results into a corresponding increase in health problems, eventually inducing the monitoring of air quality and its prediction as a prime necessity in day-to-day life.

Timely air quality information, even 24 hours in advance can assist those coping with health problems that are aggravated by ground-level ozone, sulphur dioxide, nitrogen dioxide, carbon monoxide, particulate matter and other pollutants. Air quality advisories or alerts issued when pre-determined pollutant threshold exceeds should result in actions to reduce pollution levels and encourage people to avoid polluted areas thereby alleviating adverse effects on health. Briefly, in response to the air quality advisories people can try to take actions against the increased pollution themselves like use public transportation and pool together, stagger work hours or even stay indoors and industry and regulatory agencies may decide on temporary shutdown of polluting factories, thermal power plants, etc. Similarly the traffic controlling authorities can reroute the flow of traffic to avoid hot spot areas.

Apart from these air pollutants resulting from human activities, there are other parameters which affect human health and harm the environment as well. For example, the pollen season that is reasonably well-known to people who are allergic. The presence of pollen, its density and trajectory, as well as the possibility of being removed from the atmosphere by brief showers, all depend on the weather advisories. Also, the amount of UV radiation which not only leads to increase in skin diseases and eye cataracts in humans but also
affect plants, aquatic organisms and other natural systems depend on the weather conditions. These radiations also play an important role in modulating the level of air pollutants.

The ‘System of Air Quality and Weather Forecasting and Research’ known as SAFAR system, first of this kind in the country, is successfully developed with indigenous capabilities in record time for National Capital Region of Delhi and dedicated to citizens as an operational system during Commonwealth Games (CWG) 2010. The early warning system for air quality and weather developed under the project proved as a useful machinery to reduce the first hand impact of deteriorated air quality on human health during CWG-2010. The successful implementation of SAFAR in both operational and research mode is recognised by the global scientific communities and Global Atmospheric Watch (GAW). Global Urban Research Meteorology and Environment (GURME) project of United Nation’s World Meteorological Organization appreciated it and also recommended its replication in other metropolises, which is likely to set an example for developing countries. Recently on 1st May 2013, the SAFAR system was dedicated to citizens of Pune Metropolitan Region, named ‘SAFAR-Pune’ with more advanced features and value added products.

Under the scheme “Metropolitan Advisories for Cities for Sports, Tourism (Metropolitan Air Quality and Weather Services), Ministry of Earth Sciences (MoES), Govt. of India, has introduced SAFAR for greater metropolitan cities of India to provide location specific air quality information and forecast for the first time in India. The SAFAR system is developed by Indian Institute of Tropical Meteorology (IITM), Pune, along with Earth System Science Organisation (ESSO) partner institutions namely India Meteorological Department (IMD) and National Centre for Medium Range Weather Forecasting (NCMRWF).

Fig 1: A view of Air Quality Monitoring Station (AQMS) and Automatic Weather Station (AWS) at Pune.
Fig 1: A view of Air Quality Monitoring Station (AQMS) and Automatic Weather Station (AWS) at Pune.

System components

Observational network: Under the project dense observational network of air quality monitoring stations (AQMS) and automatic weather stations (AWS) (Fig 1) has been established (50 x 50 km domain of metropolitan region) by selecting representative sites of different micro-environments including industrial, residential, background/cleaner, urban complex, agricultural zones etc.

Air quality indicators monitored at about 3 m from the ground includes particulate matter (PM10, PM2.5), black carbon (BC), ozone (O3), carbon monoxide (CO), carbon dioxide (CO2), oxides of nitrogen (NO, NO2, NOx), volatile organic compounds (VOC’s) and mercury (Hg). In addition to this temperature, rainfall, humidity, wind speed, wind direction, and solar radiation are monitored along with ultraviolet radiation flux in terms of erythemal UV dose using AWS and UV-E radiometer. Calibrations of the online analysers are performed at appropriate time intervals using in-built calibrators for some pollutants or with external calibration cylinders with multipoint calibration techniques for other elements.

Development of Emission Inventory: Emission of various air pollutants as a consequence of burning of fossil fuel and bio-fuel in our day to day life for industrial activity, transportation, cooking, power generation, agricultural production, waste disposal and so on is important phenomenon which alters the normal composition of air. In any urban settlement these are the most potential air pollution sources but their contribution and intensity varies with geographical and socio-economical factors. To identify the major air pollution sources in the region and their region specific spatial distribution, scientific approach has to be adopted. Emissions inventory is the most effective scientific tool and most critical input to the 3-D atmospheric chemistry transport models along with meteorological input to forecast the air quality; the quality of forecast depending on the accuracy of emission inventories. It thus helps to implement effective air quality management programme and formulate environmental policy.

Under the project SAFAR a high resolution (1 x 1 km) emission inventory has been developed by ESSO-IITM for NCR-Delhi and for PMR-Pune by using bottom-up approach. Development of emission inventory is a complex process and require huge amount of activity data and knowledge of fundamental scientific processes. The accuracy and reliability of emission inventory has been maintained by collecting unique region specific activity data during the extensive field survey for several months involving more than 200 students of various educational organisations and proper country specific emission factors has been selected to estimate the total emissions from transport, industries, residential and slum sector. The particulate emissions from untouched source, paved and unpaved roads, are also estimated. The spatial distribution of pollutants has been studied by using GIS based statistical model.

Development of Air Quality and Weather Forecasting Model: The air quality forecasting is a highly specialised area and requires huge computational power. Atmospheric chemistry transport model is used for air quality forecasting. To forecast the air quality of various pollutants along with weather parameters, IITM uses four nested domain starting from near global to the local city level. The inner domain has a resolution of 1.67 x 1.67 km. All these 4 domains run interactively and feedback of meteorology to chemistry and vice-versa has been accounted. This model requires several key inputs for accurate forecasting. Major among them are—emission inventory of pollutants from various sources, weather parameters, topographical data, land use/cover data, initial and lateral boundary conditions, etc. The initial and lateral boundary conditions for the outermost domain in meteorological model has been taken either from NCEP reanalysis or from internally generated CFS of NCMRWF whereas for the chemical forecast model, it has been taken from Monitoring Atmospheric Composition and Climate (MACC), a project under MoU between IITM and EU project partners.

Fig 2: Air Quality Index
Fig 2: Air Quality Index


Under the project, measurements of air quality indicators and weather parameters have been made round the clock and the data is recorded and stored at every five minutes interval for quality checks and scientific analysis. This near real time online raw data is then converted in the public friendly format like Air Quality Index (AQI) or UV-Index at SAFAR-control room after quality control and check by an expert scientific team. AQI is a rating used for reporting the quality of air we breathe and the associated health effects (Fig 2). The UV Index is a measure of the amount of skin damaging UV radiation expected to reach the earth’s surface at the time when the sun is highest in the sky (around midday).



The SAFAR system provides information on current and 1-2 days advance forecast for air quality and weather, harmful radiation and emission scenario over the city area in a very simple and user friendly format. The systems location-specific products include air quality-now, air quality-tomorrow, weather-now, weather-tomorrow, UV Index –skin advisory, AQI-health advisory and city pollution maps. To disseminate the information to maximum stakeholders user friendly platforms have been developed where one can access our products easily including dynamic professional web portal (, digital display board system, integrated voice response service (toll free no +91 1800 1801 717), etc. The information is updated at each hour and public may subscribe to the alert network through the website to receive direct e-mail or SMS alerts for extreme weather conditions or air pollution events. All these facilities are available in English, Hindi and regional languages.



The near real time online raw data measured at various AQMS and AWS is transferred to AQMS server located in SAFAR Control Room at IITM, Pune, through the GPRS network. The raw data is then converted to AQI or UV-Index, etc. File transfer processor (FTP) master control server receives current data each hour from AQMS server through wired connectivity whereas the air quality and weather forecasting data for the next day is received from the high performance computation facility of IITM and IMD. The FTP master control server has the responsibility to channelise the data to the web server of SAFAR-Pune and IVRS from where it is fed into the communication network.

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