Air Quality and SAFAR-India

By: Staff Reporter
SAFAR is an indigenous technological initiative by the MoES for India’s urban centres that combines the best of weather and air pollution research to generate air quality forecast leading to preventive action for better health. In its five years of existence, SAFAR has notched up successes that have earned plaudits not only from large section of society but also from the World Meteorological Organisation.
Magazine Articles Technology

Air pollution has become India’s biggest challenge in the 21st century, given its wide ranging impact on human health and agricultural production. Recent studies have shown that air pollution is the fourth major cause for death globally and by far the leading environmental risk factor for disease.

Causes of air pollution

There are several factors responsible for the deterioration of air quality in any particular region; dominant among which are emissions of hazardous pollutants from scattered sources in a region. In India, one of the main contributors to poor air quality is the burning of wood, dung and other biomass for cooking and heating purposes. This exposes millions of families to high levels of particulate matter in their own dwellings. Among other major sources of pollution are the combustion of fossil fuels in the transport and industrial sectors, and the burning of waste in urban areas. These emissions alter the composition of air in the atmosphere, resulting in an adverse impact on human health.

Air quality forecasts can assist the general public in coping with health problems caused by higher levels of air pollutants including particulate matter, ground level ozone, sulphur dioxide, nitrogen dioxide, and carbon monoxide. Location specific forecasts can help people to avoid high levels of exposure in their routine life and also assist decision makers in formulating mitigation policies. Early warning systems that can predict air quality 1 to 3 days in advance can thus be an effective tool to reduce the health and environmental costs associated with air pollution.

Apart from pollutants that result from human activities, there are other parameters, that affect human health and the environment. For example, high levels of UV radiation not only lead to an increase in skin disease and cataracts of the eye in humans but affect plants, aquatic organisms and other natural systems as well.

Government initiatives on air pollution

Under the plan scheme Metropolitan Air Quality and Weather Services, Ministry of Earth Sciences (MoES) has introduced a national initiative, System of Air Quality and Weather Forecasting and Research, known as ‘SAFAR’ for metropolitan cities of India to provide location specific information on air quality in near real time and its forecast for the first time in India. System developed by Indian Institute of Tropical Meteorology (IITM), Pune, along with ESSO partner institutions—India Meteorological Department (IMD) and National Centre for Medium Range Weather Forecasting (NCMRWF) and implemented in collaboration with local municipal corporations and educational institutions.

In a first of its kind in the country, SAFAR was successfully developed with indigenous capabilities in record time for the National Capital Region (NCR) Delhi and dedicated to its citizens as an operational system during the Commonwealth Games 2010.

The successful implementation of SAFAR in both operational and research mode was lauded by the Global Atmospheric Watch (GAW), and the Global Urban Research Meteorology and Environment (GURME) project of the World Meteorological Organisation (WMO), and recommended for replication in other developing countries. The successful implementation of SAFAR-Delhi led to the development of  SAFAR-Pune for the Pune Metropolitan Region (PMR) in 2013 and SAFAR-Mumbai for the Mumbai Metropolitan Region in 2015 with more advanced features.

SAFAR is a technological innovation which brings several different scientific components such as air quality, weather monitoring, and emission inventory development on one platform, to yield an end product that can better our understanding of the quality of air we breathe and serve as a decision support system for urban planning in India.

SAFAR observational network

A dense air quality and weather network has been established under SAFAR in each concerned city to cover different micro-environments that include the industrial, residential, downtown, and peri-urban areas. At each station, levels of particulate matter (PM10, PM2.5, PM1), 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) are monitored at about 3 m height above the ground along with weather parameters including temperature, rainfall, humidity, wind speed, wind direction, solar radiation and ultraviolet radiation flux. Calibrations of online analysers are noted at appropriate time intervals using inbuilt calibrators for some pollutants and with external calibration cylinders with multipoint calibration techniques for others (Fig. 1).


Development of emission inventory

Under SAFAR, a high resolution (1kmx1km) emission inventory has been developed by ESSO-IITM for NCR-Delhi, PMR-Pune and Mumbai by using a bottom up approach. The accuracy and reliability of emission inventory has been maintained by collecting unique region specific activity data through an extensive field survey. Country specific emission factors have been selected to estimate the total emissions of oxides of nitrogen (NOX); carbon monoxide (CO); black carbon (BC); organic carbon (OC); particulate matter <2.5 micron (PM2.5); particulate matter <10 micron (PM10); sulphur dioxide (SO2) and volatile organic compounds (VOCs) from the transport, industry, residential, and slum sectors. Particulate emissions from untouched sources, paved and unpaved roads, are also estimated. The spatial distribution of pollutants is studied by using geographical information system (GIS) based statistical models. These inventories are critical to the atmospheric chemistry transport models. Hence, these are meticulously accomplished in each of the SAFAR cities.

Development of air quality forecasting model

Air quality forecasting is a highly specialised area and requires huge computational powers. To forecast the air quality of various pollutants along with weather parameters, IITM uses four nested domains. All these four domains run interactively and feedback of meteorology to chemistry and vice-versa are accounted for. This requires several key inputs for accurate forecasting, such as—emission inventory of pollutants from various sources, weather parameters, topographical data, land use-land cover data, among others.

Converting data to information

The real time data generated through the system along with the forecast is then converted into information as air quality-now, air quality-tomorrow, weather-now, weather-tomorrow, UV index-skin advisory, AQI-health advisory and city pollution maps and disseminated to the public through various user friendly communication media such as SAFAR-Air (mobile app for Android and Iphone), SAFAR toll free numeber—1800 180 1717 and SAFAR-India web portal— Apart from these, 12-15 true colour LED boards have been installed in each SAFAR city at crowded locations. The major beneficiaries of this data are disaster management units, environment departments of urban local bodies, and the health, agricultural, aviation, and town planning sectors. They can also be used by policy makers to implement short term and long term mitigation strategies, besides creating awareness about air quality and its impact on human health.


To develop a robust air quality prediction system for metropolitan cities where sources of air pollution manifests all around is a big challenge. One needs a robust database of each and every air pollution source located in the city and its geographical distribution over the region for the utmost accuracy. This task can be achieved by developing high resolution emission inventories for various air pollutants under SAFAR.

Once the inventories are taken care of, the challenge lies in developing the forecasting model which could predict air quality with three days lead-time and with minimum uncertainty.

Apart from emissions, there are many other atmospheric processes which drives the concentration of local pollutants in the air, including long range and short range transport of air pollutants, extreme weather conditions and associated boundary layer processes, mechanism of secondary aerosol formation etc. For the same Atmospheric Chemistry Transport Model has been successfully set-up with two way nesting and interactive processes which takes care of the entire chemical and weather processes that governs air quality in a particular area.

Another major challenge is reporting facts about pollution levels to the public, decision makers and other stakeholders. It is very crucial to understand when to report 24, 1 and 8 hour average of different pollutants, and compare them with the National Ambient Air Quality Standards (NAAQS), as also select an appropriate monitoring site since readings should not get affected by any source of pollution in the city.


SAFAR is a unique project for India’s urban centres, which combines air quality monitoring and weather data to generate atmospheric forecasts days in advance for the general public. The SAFAR observational network is developed in such a way that it covers all important micro environments in the city. Quality control, quality assurance and regular calibration is especially attended to, for best results. Lauded for its achievements by the WMO, SAFAR holds great promise for urban planners, especially where public health is concerned.

Leave a Reply

Your email address will not be published. Required fields are marked *