To study aerosol-climate interactions on regional scales and in different atmospheric environments, covering major parts of India.
Location of field sites for ambient PM2.5 measurements
Sampling sites are located where it is possible to capture regionally representative aerosol, i.e., outside urban centres and away from local pollution sources but not limited to diesel, cook stove/wood smoke agricultural field burning, automobile, road dust, or construction dust emissions. Further, these sites will also not be located in places with unusual/non representative meteorology (such as in a valley) for a given region. Evidence gathered from the following steps were used in identifying and finalizing a site:
- Literature-review of emissions inventory/dispersion modelling results: Examine emissions inventory for major sources/contributors to fine PM mass at potential site, estimate their zone of influence and stay outside that zone.
- Trajectory-ensemble and wind-rose methods.
- Coefficient of Divergence (COD) and cross-correlation (r) analyses (using monthly average satellite derived fine PM):
Figure: COD and r2 plots for the site IISER-Bhopal to show regionally representativeness of the site
Field operations and sampling for carbonaceous aerosols
Speciation Air Sampler System (SASS) from Met One Instruments will be used for ambient aerosol sampling at all the PMF sites simultaneously. Along with the aerosol sampling meteorological parameters like ambient temperature, relative humidity, wind speed, wind direction and wet precipitation will be continuously monitored at the PMF sites. Continuous aerosol sampling for 2 years is scheduled at one day interval, total sampling time is 24hrs. Different filter matrix like Quartz, Teflon and Nylon filter papers will be used for PM2.5 sampling.