Suneela,S S; Dr.Viswanadham,D V; Dr.Ram Mohan,H S(Cochin University of Science And Technology, January , 1989)
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Abstract:
The deteriorating air quality especially in urban
environments is a cause of serious concern. In spite of being
an effective sink, the atmosphere also has its own
limitations in effectively dispersing the pollutants being
dumped into it continuously by various sources, mainly
industries. Many a time, it is not the higher emissions that
cause alarming level of pollutants but the unfavourable
atmospheric conditions under which the atmosphere is not able
to disperse them effectively, leading to accumulation of
pollutants near the ground. Hence, it is imperative to have
an estimate of the atmospheric potential for dispersal of
the substances emitted into it. This requires a knowledge of
mixing height, ventilation coefficient, wind and stability of
the region under study. Mere estimation of such pollution
potential is not adequate, unless the probable distribution
of concentration of pollutants is known. This can be
obtained by means of mathematical models. The pollution
potential coupled with the distribution of concentration
provides a good basis for initiating steps to mitigate air
pollution in any developing urban area. In this thesis, a
fast developing industrial city, namely, Trivandrum is chosen
for estimating the pollution potential and determining the
spatial distribution of sulphur dioxide concentration. Each
of the parameters required for pollution potential is
discussed in detail separately. The thesis is divided into
nine chapters.
Description:
School of Marine Sciences, Cochin University of Science and Technology
Nandakumar, A; Dr.Murthy, A V S(Cochin University of Science and Technology, November , 1983)
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Abstract:
The objective of the present study is to elucidate the hydrological conditions of the shelf waters along the southern half or the west coast of India and their relation to the sooplankton bionase and pelagic fish resources. Data from six hydrography-plankton sections worked during the 1972-75 period of cape camerin. Quilon. cochin. Kasaragod. Karwar and kotnagiri formed the basis of the present study.Stations were fixed along the transects 10 nautical miles apart. Starting with the first station at around 15 metre depth and were usually occupied 5 to 8 times in an year at an interval of about 6 weeks. Data relating to oil sardines and macherel fisheries were availed from published information relating to the period mainly of the Central Marine fisheries Research Institute. The range of different parameters namely temperature. salinity. density and dissolved oxygen at different depths and their sloping features against the coast are discussed. Three seasons. namely south-west monsoon (summer monsoon). north-east monsoon (winter monsoon) and hot weather season are designated and data of the core months of each of these seasons considered in the study.
Abish, B; Dr.Mohan Kumar, K(Cochin University of Science and Technology, April , 2011)
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Abstract:
This doctoral thesis addresses the growing concern about the significant changes in the climatic and weather patterns due to the aerosol loading that have taken place in the Indo Gangetic Plain(IGP)which includes most of the Northern Indian region. The study region comprises of major industrial cities in India (New Delhi, Kanpur, Allahabad, Jamshedpur and Kolkata). Northern and central parts of India are one of the most thickly populated areas in the world and have the most intensely farmed areas. Rapid increase in population and urbanization has resulted in an abrupt increase in aerosol concentrations in recent years. The IGP has a major source of coal; therefore most of the industries including numerous thermal power plants that run on coal are located around this region. They inject copious amount of aerosols into the atmosphere. Moreover, the transport of dust aerosols from arid locations is prevalent during the dry months which increase the aerosol loading in theatmosphere. The topography of the place is also ideal for the congregation of aerosols. It is bounded by the Himalayas in the north, Thar Desert in the west, the Vindhyan range in the south and Brahmaputra ridge in the east. During the non‐monsoon months (October to May) the weather in the location is dry with very little rainfall. Surface winds are weak during most of the time in this dry season. The aerosols that reach the location by means of long distance transport and from regional sources get accumulated under these favourable conditions.
The increase in aerosol concentration due to the complex combination of aerosol transport and anthropogenic factors mixed with the contribution from the natural sources alters the optical properties and the life time of clouds in the region. The associated perturbations in radiative balance have a significant impact on the meteorological parameters and this in turn determines the precipitation forming process. Therefore, any change in weather which disturbs the normal hydrological pattern is alarming in the socio‐economic point of view. Hence, the main focus of this work is to determine the variation in transport and distribution of aerosols in the region and to understand the interaction of these aerosols with meteorological parameters and cloud properties.
Description:
Department of Atmospheric Sciences,
Cochin University of Science and Technology
Philip,Mathew; Dr.Ravindranatha Menon,N(Cochin University of Science and Technology, August , 1990)
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Abstract:
The present scientific investigation of the effects of copper, mercury and cadmium has focussed on their effects on two commercially important marine bivalve species, Perna indica (brown mussel) and Donax incarnatus (wedge clam), conspicuous representatives of the tropical intertidal areas. The investigation centred around delineating the cause and effects of heavy metal stress, individually and in combination on these species under laboratory conditions. A clear understanding of the cause and effect can be had only if laboratory experiments are conducted employing sub-lethal concentrations of the above toxicants. Therefore, during the course of the investigation, sub-lethal concentrations of copper, mercury and cadmium were employed to assess the concentration dependent effects on survival, ventilation rate, O:N ratio and tissues. The results obtained are compared with the already available information and partitioned in sections to make a meaningful presentation.The thesis is presented in five chapters comprising INTRODUCTION, ACUTE TOXICITY, VENTILATION RATE, OXYGEN : NITROGEN RATIO and HISTOPATHOLOGY. Each chapter has been divided into various sections such as INTRODUCTION, REVIEW OF LITERATURE, MATERIAL AND METHODS, RESULTS and DISCUSSION
Description:
Head, Division of Marine Biology, Microbiology and
Biochemistry, School of Marine Sciences, Cochin University
of Science and Technology
Resmi, E A; Dr.Mohanakumar,K(Cochin University Of Science And Technology, September , 2012)
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Abstract:
The stratospheric warming events are categorized into major and minor
warming depending on the temperature increase in the polar stratosphere.
The warming is called a ‘major’, when the polar temperature increases
poleward from 60 degree latitude and followed by a reversal in the zonal
wind at 10 hPa (~32 Km). Usually major warming events are associated
with the displacement of polar vortex from high to mid latitudes or the
splitting of vortices in to two. The warming is called a "Minor", when the
polar temperature increases more than 25 degree in a period of a week or
less, at any stratospheric level with less intensified easterly wind anomalies. The stratospheric warmings generated during the transition
period of winter to spring are called final warmings. The warming events
observed in the early winter period (November to early December) over
Canadian region are called Canadian warmings. There is strong
interaction between stratosphere and troposphere during SSW period over
high and low latitudes regions.
The thesis consists of 7 chapters
Description:
Department of Atmospheric Sciences, Cochin
University of Science and Technology
Rosily, A V; Dr.Chandramohanakumar, N(Cochin University of Science & Technology, December , 2002)
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Abstract:
Sulphur is a non conservative major element and is the most active species in the redox processes in nature, especially in aquatic environment . The varying oxidative states from-2 to +6 make it possible to enter into many of the biogeochemical processes. Thus the history, present and future of the chemical composition and behaviour of the natural aquatic systems and sediments have footprints of the sulphur chemistry.Mangroves are considered to be the most productive, fishery supportive ecosystem operating in the intertidal regions. The interlinking of the mangroves with the sulphur chemistry is attempted here.
Description:
Department of Chemical Oceanography, Cochin University of Science and Technology
Krishna Kumar,P A; Chandramohanakumar, N(Cochin University of Science and Technology, October , 1999)
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Abstract:
This study focuses on the fractionation and quantification of chlorophenols, the most important and potential pollutant in this category, the distribution and seasonal dynamics of MBAS, phenols and clorophenols and development of a model to describe the chemical reactivity of the estuary are utilizing the dynamics of boron. The CES is highly influenced by various anthropogenic activities like discharge of agricultural, industrial and urban wastes operation of shipyard, oil and other transporting activities, fishing, dredging etc. Seasonal values of MBAS showed high values in the surface water during monsoon compared to premonsoon and postmonsoon. In the Cochin estuary o-chlorophenol and p-chlorophenol showed low values in the surface water compared to bottom water in the northern part of the estuary and higher values in the surface water in the southern part
Akula Raghunadha, Rao; Basil, Mathew(Naval Physical & Oceanographic Laboratory,Defence Research and Development Organisation, 2008)
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Abstract:
In the present study the availability of satellite altimeter sea level data with good spatial and temporal resolution is explored to describe and understand circulation of the tropical Indian Ocean. The derived geostrophic circulations showed large variability in all scales. The seasonal cycle described using monthly climatology generated using 12 years SSH data from 1993 to 2004 revealed several new aspects of tropical Indian Ocean circulation. The interannual variability presented in this study using monthly means of SSH data for 12 years have shown large year-to-year variability. The EOF analysis has shown the influence of several periodic signals in the annual and interannual scales where the relative strengths of the signals also varied from year to year. Since one of the reasons for this kind of variability in circulation is the presence of planetary waves. This study discussed the influence of such waves on circulation by presenting two cases one in the Arabian Sea and other in the Bay of Bengal.