The Indian Space Research Organisation’s (ISRO) weather satellites INSAT-3D and 3DR have onboard imager payloads which are currently being utilised to monitor Aerosol Optical Depth (AOD). AOD serves as an indicator of particles and smoke from biomass burning which affects visibility and leads to the increase of PM2.5 and PM10 concentration in the atmosphere.
Understanding the Aerosol Optical Depth (AOD)
The measurement of the extinction of the solar beam by dust and haze in the atmosphere is known as Aerosol Optical Depth (AOD). The aerosol particles, including dust, smoke, and pollution, within our atmosphere can obstruct sunlight. They do this by either absorbing or scattering light. In essence, AOD informs us about how much direct sunlight is prevented from reaching the earth’s surface due to these aerosol particles.
Impact on Indo-Gangetic Plain
Research has revealed that there is a higher concentration of AOD and PM2.5 and PM10 particles over the Indo-Gangetic Plain, specifically covering parts of Delhi, Uttar Pradesh, and Bihar during the months of October and November. These high concentrations of pollutants are primarily sourced from regions of Punjab and Haryana during stubble burning events.
Trends in Stubble Burning
There has been a noted increase in fire occurrences by 4% over the regions of Punjab and Haryana during the October-November period between the years 2003 and 2017.
| Year | Percentage Increase in Fire Occurrences |
|---|---|
| 2003 | 0% |
| 2017 | 4% |
ISRO’s Role: Satellite Data and Stubble Burning
Since 2015, ISRO has been employing satellite data to monitor stubble burning. Additionally, it utilises this data to generate maps of the stubble burned area during the Kharif season.
The INSAT-3D & 3DR Satellites: Weather Updates in India
India receives weather updates every 15 minutes via the INSAT-3D & 3DR weather satellites. The INSAT 3DR was launched in 2016 as a sequel to INSAT-3D, which took flight in 2013.
