S. N. Tripathi

Estimation of aerosol optical properties and radiative effects in the Ganga basin, northern India, during the wintertime

[1] An aerosol model has been developed using mass size distributions of various chemical components measured at Kanpur (an urban location in the Ganga basin, GB, in northern India) and applied to estimate the radiative effects of the aerosols over the entire GB during the winter season. The number size distribution of various species was derived from the measured mass concentration, and the optical properties were calculated using Mie theory. The maximum anthropogenic contribution to the total extinction was estimated to be � 83%. The relative contributions of various species to the aerosol optical depth (AOD) at 0.5 mm are in the following order: (NH4)2SO4 (nss-SO4, 30%), nitrate (NO3 , 24%), salt (mainly NaCl and KCl, 18%), dust (17%) and black carbon (BC, 11%). Relative contribution of nss-SO4 ,N O3 and salt to the calculated AOD decreases with wavelength, and that of dust increases with wavelength, whereas BC contribution is spectrally insensitive. The extinction coefficient strongly depends on the RH, as the scattering by fine mode fraction, which contributes 88% to the total extinction, is enhanced at high ambient RH. The spectral variation of absorption coefficient indicates that the most likely source of BC in this region is fossil fuel. The spectral variation of single scattering albedo (SSA) in the coarse mode fraction suggests mixing of BC and dust particles. During the observational period, the mean shortwave (SW) clear sky top of the atmosphere (TOA) and surface forcing over Kanpur are estimated to be � 13 ± 3 and � 43 ± 8 W m � 2 , respectively. The corresponding longwave forcings are 3.6 ± 0.7 and 2.9 ± 0.6 W m � 2 , respectively. Mean AOD at 0.55 mm over the GB as derived from MODIS data is 0.36 ± 0.14. Extending our model over the entire GB, the net mean TOA and surface forcing become � 6.4 and � 30.2 W m � 2 (with overall � 15% uncertainty). This results in high atmospheric absorption (+23.8 W m � 2 ), translating into a heating rate of 0.67 K day � 1 . The SW surface to TOA forcing ratio (� 3.7) over the GB is 23% higher than the corresponding value for Indian Ocean. The aerosols reduce the incoming solar radiation reaching the surface by � 19%, which has significant effect on the regional climate.

Predictions of the electrical conductivity and charging of the aerosols in Titan's nighttime atmosphere

The electrical conductivity and electrical charge on the aerosols in atmosphere of Titan are computed for altitudes between 0 and 400 km. Ionization of methane and nitrogen due to galactic cosmic rays (GCR) is important at night where these ions are converted to ion clusters such as CH + CH4 ,C 7H + ,C 4H + ,a nd H 4C7N + . The ubiquitous aerosols observed also play an important role in determining the charge distribution in the atmosphere. Because polycyclic aromatic hydrocarbons (PAHs) are expected in Titan’s atmosphere and have been observed in the laboratory and found to be electrophilic, we consider the formation of negative ions. During the night, the very smallest molecular complexes accept free electrons to form negative ions. This results in a large reduction of the electron abundance both in the region between 150 and 350 km over that predicted when such aerosols are not considered. During the day time, ionization by photoemission from aerosols irradiated by solar ultraviolet (UV) radiation overwhelms the GCR-produced ionization. The presence of hydrocarbon and nitrile minor constituents substantially reduces the UV flux in the wavelength band from the cutoff of CH4 at 155 to 200 nm. These aerosols have such a low ionization potential that the bulk of the solar radiation at longer wavelengths is energetic enough to produce a photoionization rate sufficient to create an ionosphere even without galactic cosmic ray (GCR) bombardment. At altitudes below 60 km, the electron and positive ion abundances are influenced by the three-body recombination of ions and electrons. The addition of this reaction significantly reduces the predicted electron abundance over that previously predicted. Our calculations for the dayside show that the peaks of the charge distributions move to larger values as the altitude increases. This variation is the result of the increased UV flux present at the highest altitudes. Clearly, the situation is quite different than that for the night where the peak of the distribution for a particular size is nearly constant with altitude when negative ions are not present. The presence of very small aerosol particles (embryos) may cause the peak of the distribution to decrease from about 8 negative charges to as little as one negative charge or even zero charge. This dependence on altitude will require models of the aerosol formation to change their algorithms to better represent the effect of charged aerosols as a function of altitude. In particular, the charge state will be much higher than previously predicted and it will not be constant with altitude during the day time. Charging of aerosol particles, whether on the dayside or nightside, has a major influence on both the electron abundance and electrical conductivity. The predicted conductivities are within the measurement range of the HASI PWA instrument over most but not all, of the altitude range sampled.

Water Quality Monitoring of Sur Sarovar (Keetham) Lake, Agra (Uttar Pradesh)

Water quality information in aquatic ecosystem is crucial in setting up guideline for resource management. The biota in the surface water is governed entirely by various environmental conditions that determine the selection of species as the physiological performance of the individual organisms. This study explores the water quality status and pollution sources in Sur Sarovar (Keetham) Lake, Agra (Uttar Pradesh), water quality parameters analyze of five sampling zone was done from water samples collected monthly from September 2014 to July 2015. The primary production of organic matter, in the form of phytoplankton and macrophytes is more intense in Sur Sarovar (Keetham) Lake. In contrast to the chemical quality of water bodies, which can be measured by suitable analytical methods, biological quality is a combination of both qualitative and quantitative characterization. The present piece of research work is initiated on pollution status at Sur Sarovar (Keetham) Lake by interference and increase in the population of phytoplankton and microbe. We were selected keys physico chemical parameters for analysis like, temperature 19.50 to 38.00 °C, pH 7.39±0.04 to 8.21±0.06, dissolve oxygen 5.90 ± 0.55 mg/L to 6.48 ± 0.87 mg/L, alkalinity 93.73 ± 5.09 mg/L to 124.27 ± 5.05 mg/L, hardness 119.33 ± 9.06 mg/L to 138.93 ± 8.07 mg/L, ammonia 0.52± 0.03 mg/L to 0.64 ± 0.032 mg/L, nitrate 0.71 ± 0.02 mg/L to 1.79 ± 0.02 mg/L, nitrite 0.21 ± 0.01 to 0.47 ± 0.02 mg/L, phosphate 0.22 ± 0.03 mg/L to 0.36 ± 0.05 mg/L and heavy metal concentration like Zn 0.023 ± 0.00 mg/L to 0.27 ± 0.00 mg/ L, Cr 0.022 ± 0.00 to 0.036 ± 0.00 mg/L , Cd 0.002 ± 0.00 mg/L to 0.010 ± 0.00 mg/L, Pb 0.013 ± 0.00 mg/L to 0.033 ± 0.00 mg/L, Hg 0.015 ± 0.00 to 0.02 ± 0.00 mg/L in the water were undertaken.

Impact of Transgenic Fishes on Aquatic Ecosystem and Biodiversity of Freshwater Teleost

Critics showed objections on the genetic engineering process on the some points whish were both ethical and ecological. This happened because it was sure that these genetic engineering processes must have been causing the gene flow and raise alarm against intellectual property rights. Problems also evolved on using GMOs in the form of food because fishes are being used as a nutritive food worldwide. So it raised a question in the mind of critics that it can cause many forms of lethal allergies to the consumers as the GM fishes were labelled. These issues caused a check over the trade of these GM fishes internationally. Thus due to all these prominent issues FDA has a power to restrict these GM fishes as 1) food 2) conditions in which they are used 3) a check after the approval. Public is confident if the above written three points have positive outcome. So these three points are the backbone for the approval of GM as food for public. So the potential research benefits of genetically modified fish will be fruitful only if these transgenic fish are kept separate from genetic pool of the wild species. There is possibility of transmission of the transgenes to the wild fishes which can make these transgenes a permanent resident of an environmental ecosystem.