PM10 Source Identification Using the Trajectory Based Potential Source Apportionment (trapsa) Toolkit at Kochi, India

A recently developed open source tool kit named the Trajectory based Potential Source Apportionment (TraPSA) was used to identify the sources of respirable particulates at Kochi, India. Using 24-h average particulate matter data from samples collected at five regulatory monitoring stations over the five-year period from January 2011 to October 2016, local and regional scale analyses were made. Concentration field analysis was performed using back trajectories generated by Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model with inputs from atmospheric reanalysis data. Conditional bivariate probability function analyses were made using local meteorology data to identify the influence of local sources. Most of the stations indicated the contribution from local traffic activities during low wind conditions and from a nearby industrial area especially during high speed winds. Back trajectory analysis identified potential source areas in Kerala as well as in nearby state of Tamil Nadu as contributing to the air quality at Kochi. Arabian sea on the western side was also observed to be a potential source area for Kochi. The study demonstrated the utility of TrapSA as a tool for deriving information about the potential source areas affecting particulate matter mass concentrations.