• Gufran Beig

Articles written in Journal of Earth System Science

• PM$_{2.5}$, PM$_{10}$ and surface ozone over Lumbini Protected Zone, Nepal, during monsoon season of 2012

Physical characterisation of PM$_{2.5}$, PM$_{10}$ and surface ozone measured during the period from 17 July to 21 August 2012 at four strategic locations in and around the Lumbini Protected Zone, Nepal, is done to assess air quality of the region and understand qualitatively source mechanisms of these pollutants. The measurement locations are Panditarama Lumbini International Vipassana Meditation Centre, Parsahawa, Bhairahawa and Tilaurakot, representing monastic, industrial, urban and control areas, respectively. The overall average concentration of PM$_{2.5}$ at these locations is $\sim$19 $\pm$ 12, 35 $\pm$ 13, 35 $\pm$ 11 and 25 $\pm$ 6 $\mu$g/m$^{3}$ and of PM$_{10}$ is $\sim$25 $\pm$ 11, 103 $\pm$ 41, 58 $\pm$ 15 and 32 $\pm$ 7 $\mu$g/m$^{3}$, respectively. PM$_{2.5}$ never crosses the safe limit of the National Ambient Air Quality Standards of Nepal (NNAAQS) in the monastic and control areas but either crosses the NNAAQS occasionally or remains in its vicinity at the other two locations. The PM$_{10}$ concentration frequently exceeds the safe limit in the industrial area but not in the other remaining areas. The analysis indicates the dominance of the impact of local sources and boundary layer thickness on the atmospheric loadings of the particulate matter. The daily average mixing ratio of surface ozone remains normally low at all the four observational sites although the mixing ratio of ozone at Panditarama Lumbini International Vipassana Meditation Centre is much lower than the NNAAQS but higher than that observed at Tilaurakot.

• The impact of crop residue burning (CRB) on the diurnal and seasonal variability of the ozone and PM levels at a semi-urban site in the north-western Indo-Gangetic plain

Ozone and particulate matter (PM), PM$_{10}$ and PM$_{2.5}$, were monitored along with meteorological parameters at a semi-urban location, Patiala, in the north-western Indo-Gangetic plain from December 2013 to November 2014. The annual mean concentration levels of PM$_{10}$, PM$_{2.5}$ and ozone were recorded as 178 $\mu$g m$^{-3}$, 88 $\mu$g m$^{-3}$ and 39 ppb, which also exceeded the national standards on a 24-h average basis, by 77.3% (335 days), 53.2% (338 days) and 20 days, respectively. High levels of PM (PM$_{10}$ and PM$_{2.5}$) were observed in winter (58–381 and 42–270 $\mu$g m$^{-3}$) and in the post-monsoon (71–320 and 39–320 $\mu$g m$^{-3}$) season and a rise in the level of ozone was observed in summer (22–72 ppb) and in the post-monsoon season (23–73 ppb), respectively. The rate of ozone production was the highest during the post-harvest fire period (3.94 ppb O$_{3}$/h in May and 4.23 ppb O$_{3}$/h in November). A Pearson correlation study showed the strong dependency of PM and ozone on meteorological variables. Relative humidity has the highest ranking for ozone and PM$_{10}$, while wind speed has the lowest rank for ozone, PM$_{10}$ and PM$_{2.5}$ in the order of factors affecting the level of pollutants. The generalised linear model and the neural network model (for ozone) and the random forest model (for PM) outperformed on the basis of performance indices and further cross-validation was done.

• # Journal of Earth System Science

Volume 130, 2021
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019