Temporal analysis of particulate matter load over Delhi for the period of 2014-2015
Student name: Ms Ketki Rai
Guide: Dr Kamna Sachdeva
Year of completion: 2016
Host Organisation: Indian Meteorological Department (IMD), New Delhi
Supervisor (Host Organisation): Dr S. K. Peshin
Abstract: Hourly mean mass concentrations of PM10 and PM2.5 particles were measured at
IMD, Lodhi Road in Delhi (less traffic site) from 1January 2014 to 31 December 2015.Indepth
air quality analysis was undertaken for both years by analyzing hourly, daily and seasonal
averages of PM concentrations. Average PM10 concentrations of 2015 were also correlated
with meteorological variables temperature (accuracy ± 1 degree Celsius), relative humidity
(RH) (accuracy ± 3%), wind speed (accuracy ± 2%) and wind direction (accuracy ± 2
degrees).The annual average for PM10 in 2014 comes out to be 212.6 microgram/m3 and
108.6 for PM2.5 respectively while the average concentration values of PM10 and PM2.5 for
2015 are recorded lower at 185 microgram/m3 and 80.7 microgram/m3 respectively.The air
quality in 2015, especially in terms of PM2.5 has significantly improved compared to the
previous year. PM concentrations during Diwali were found to be much lesser in 2015 as
compared to 2014.Hourly variation analysis revealed overall bimodal trend with peaks in late
morning to noon and midnight corresponding to high traffic hours and mixing depths.
Correlation analysis of meteorological effects with PM concentrations showed strong
correlations being observed with similar results for post monsoon and winter while mostly
showing opposite results for monsoon season.Seasonal PM concentrations averages were least
for monsoon months, which can be attributed to downwash effect of rain and maritime
(Southern)winds blowing during monsoon. High PM concentrations were found for post
monsoon and winter seasons. This can be attributed to low temperature, calmer winds and
continental (Northern) winds. Thus various meteorological parameters are seen to have an
impact on PM concentrations with clear inter-seasonal variability being observed.
Keywords: Particulate Matter 10&2.5, Air Quality, Meteorological parameters,
Seasonal Variation,Annual Variation
