Authors:
Hiba Haq; Saifuddin Jilani Pages: 1 - 7 Abstract: In this paper we investigated the terrestrial seasonal correlation between total column ozone (TCO) and solar variables, viz. mass of coronal mass ejections (CMEs) and sunspot number (SSN) over three major cities Karachi (24.870 o N & 67.030 o E, , Lahore (31.550 o N & 74.330 o E, and Quetta (30.1798 o N & 66.975 o E, 1721 m) of Pakistan. The analysis has been carried out for the 23rd and 24th solar cycles. The non-stationary characteristics of solar data variables and the impact of climate fluctuations (QBO and ENSO) on TCO have been removed by applying the empirical mode decomposition (EMD) technique. A polynomial model has been developed between CMEs mass with TCO and SSN with TCO for all three stations during all seasons. The goodness of the model has been checked on basis of the chai square (χ2) test, coefficient of determination (R2), sum square error (SSE), and root mean square error (RMSE). The correlation coefficient has been calculated between the studied variables. This study reveals that TCO over all three stations is negatively correlated with CMEs mass and SSN during all seasons. The maximum value of the correlation coefficient between CMEs mass and TCO is observed for the Lahore station during the winter season. Whereas, the maximum value of the correlation coefficient between SSN and TCO is observed for Lahore and Quetta during the spring season. The weakest correlation between CMEs mass with TCO and SSN with TCO is observed for Karachi station during the summer season. The negative correlation between TCO-CMEs mass and TCO-SSN indicates that TCO decreases with increasing the CMEs mass and SSN. PubDate: 2023-01-12 DOI: 10.12691/aees-11-1-1 Issue No:Vol. 11, No. 1 (2023)
Authors:
Letha P Cheriyan; Harish R, R. Steffy Pages: 8 - 14 Abstract: Pristine natural freshwater resources being severely contaminated by microbiological pollutants is still a big issue in many parts of the world. In the present study, water samples taken from the upstream, midstream, and downstream reaches of the Meenachil River were analysed for the presence of microbial pollution indicators such as faecal coliforms (FC), faecal streptococci (FS), and Eschericia coli. The E. coli isolates were subjected to antimicrobial susceptibility tests and the multiple antibiotic resistance (MAR) indexes were calculated so as to delineate the potential risk posed by infections to humans and animals using the river for routine potable and recreational purposes. E. coli was consistently isolated from all the samples collected from the different zones of the river. Other faecal coliforms such as Klebsiella oxytoca, Citrobacter koseri, Enterobacter, Proteus vulgaricus, and Shigella boydii were also identified. Higher FC/FS ratios were noticed for the midstream and the downstream sites indicating the contamination from high-risk sources such as human and anthropogenic domestic wastes. The MAR index values of E. coli isolates ranged from 0.33 upstream, 0.416 for midstream and 0.583 for the downstream reaches. Given that E. coli is an ideal indicator of faecal pollution, their existence and extended survival of multiple antibiotic resistance natural freshwater pose a potential risk for the consumers. Rapid urbanization and resultant waste drainage in the downstream stretches of the river might have accelerated the deterioration of the water quality up to a certain extent. Furthermore, the riverine system as it flows downstream loses its self-purification capacity due to the loss of natural water drifts. This may be attributed to the periodic shutdown of the salinity barrier, Thanneermukkam Bund in the confluence zone of the river which results in a temporary stagnation of the running waters in the lower stretches. PubDate: 2023-01-30 DOI: 10.12691/aees-11-1-2 Issue No:Vol. 11, No. 1 (2023)
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