Chiranjivi Jayaram, Ch V; Dr. Balchand, A N(Cochin University of Science & Technology, May , 2011)
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Abstract:
In this thesis, a variety of available satellite data products have been made use of
to bring out a synergistic analysis on the upwelling phenomenon in SEAS. Basic
concepts of remote sensing, upwelling and linked oceanography topics have been
dealt in this work .Auxiliary data products utilized in this study are described
in chapter 2. The climatological monthly variability of the upwelling signatures
are detailed under chapter 3. Chapter 4 presents the forcing factors that trigger
the upwelling process in SEAS. Chapter 5 describes the oceanic response to the
forcing factors with respect to the SST cooling and CHLA blooms. Chapter 6
presents the heat budget of the region and the variability of heat budget terms
with respect to upwelling. Chapter 7 describes the inter-annual variability of
upwelling intensity in SEAS and the influence of climatic events on upwelling.
Thara, K J; Dr. Sajeev, R(Cochin University of Science & Technology, July , 2011)
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Abstract:
The thesis attempts to study the changes in oceanographic parameters associated with extreme climatic events,the influence of oceanographic as well as meteorological parameters on fishes.The characteristics of major pelagic fishes of southwest coast of India(Oil sardine and Indian mackerel) have been described here.A description on study area and period of study is also described .The impact of extreme climatic events on the oceanographic variability of Eastern Arabian Sea.The extreme climatic event,the Indian Ocean Dipole associated with EI Nino Southern Oscillation is taken into consideration.The variability in oil sardine and mackerel landings of southwest coast of India during the study period.The trend analysis of the landings has been done and also a prediction model is applied for the landings.The influence of environmental parameters on oil sardine as well as mackerel fishery has been explained .With regression analysis ,the significant relation between environmental parameters and fish landings are also been recognized.The prediction of landings is done with these environmental parameters.
Description:
Dept.of Physical Oceanography,Cochin University of Science and Technology
Suryakumari, S; Dr. Muraleedharan Nair, S(Cochin University of Science and Technology, August , 2009)
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Abstract:
The present study which is the first of its kind in this region is an
attempt to generate adequate information on the relative abundances, the
seasonal and spatial variations as well as on the source and fate of organic
compounds found associated with the dissolved, particulate and
sedimentary compartments of Chalakudy river system. The study aimed at
investigating variations, the relative proportion of dissolved, particulate and
sedimentary fractions of these materials as well as the pollution extent so as
to be able to comment on the present condition of this river-estuarine
system. This thesis focuses attention on the role of biogeoorganics in modifying the ecological and environmental condition of the dissolved,
particuIate and sediment compartments with their minute variability
subjected to various physical, chemical and biogeochemical processes. A
scheme of study encompassing all these objectives provides the frame work
for the present investigation.
Description:
Department of Chemical
Oceanography,Cochin University of Science
and Technology
Madhu,N V; Gopalakrishnan,T C(Cochin University of Science and Technology, September , 2004)
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Abstract:
The thesis describes the importance of Indian EEZ, definition and the various factors affecting primary production, general account of phytoplankton and its importance in marine ecosystem etc. In review of literature, general oceanography of Arabian Sea and Bay of Bengal and hydrography of eastern Arabian Sea and western Bay of Bengal. It deals with the distribution patterns of primary production, chlorophyll a, phytoplankton composition and particulate organic carbon in the eastern Arabian Sea and western Bay of Bengal during different seasons. Factors that affect primary productivity are irradiance, temperature, stability of the surface waters, nutrients and zooplankton grazing. The differential biological response of eastern Arabian Sea and western Bay of Bengal to monsoonal regimes. A precise estimation on the primary production of the entire EEZ of India on a regional basis and on a seasonal scale would be the only way to achieve any kind of predictive assessment on the fish stock and their sustainable yield. This study mainly envisages the qualitative and quantitative aspects on the magnitude of phytoplankton standing crop and production of organic carbon and their relationship to environmental characteristics during summer monsoon, Inter monsoon and winter monsoon periods in the east and west coasts of the Indian EEZ.This study revealed that the seasonality exerts a great impact on the biological production in the eastern Arabian Sea and western Bay of Bengal. High biological production may be the reason why most of the fish landings are Concentrated in the west coast of India than east coast. The present data on Phytoplankton production rate and the species composition will provide a meaningful ground for evaluations of exploitable renewable resources of the IndianEEZ
Sabin, T P; Dr. Babu, C A(Cochin University of Science and Technology, June , 2011)
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Abstract:
The SST convection relation over tropical ocean and its impact on the South Asian monsoon
is the first part of this thesis. Understanding the complicated relation between SST
and convection is important for better prediction of the variability of the Indian monsoon
in subseasonal, seasonal, interannual, and longer time scales. Improved global
data sets from satellite scatterometer observations of SST, precipitation and refined reanalysis
of global wind fields have made it possible to do a comprehensive study of
the SST convection relation. Interaction of the monsoon and Indian ocean has been
discussed. A coupled feedback process between SST and the Active-Break cycle of the
Asian summer monsoon is a central theme of the thesis. The relation between SST and
convection is very important in the field of numerical modeling of tropical rainfall. It is
well known that models generally do very well simulating rainfall in areas of tropical
convergence zones but are found unable to do satisfactory simulation in the monsoon
areas. Thus in this study we critically examined the different mechanisms of generation
of deep convection over these two distinct regions.The study reported in chapter 3 has shown that SST - convection relation over the
warm pool regions of Indian and west Pacific oceans (monsoon areas) is in such a way
that convection increases with SST in the SST range 26-29 C and for SST higher than
29-30 C convection decreases with increase of SST (it is called Waliser type). It is found that convection is induced in areas with SST gradients in the warm pool areas of
Indian and west Pacific oceans. Once deep convection is initiated in the south of the
warmest region of warm pool, the deep tropospheric heating by the latent heat released
in the convective clouds produces strong low level wind fields (Low level Jet - LLJ)
on the equatorward side of the warm pool and both the convection and wind are found
to grow through a positive feedback process. Thus SST through its gradient acts only
as an initiator of convection. The central region of the warm pool has very small SST
gradients and large values of convection are associated with the cyclonic vorticity of the
LLJ in the atmospheric boundary layer. The conditionally unstable atmosphere in the
tropics is favorable for the production of deep convective clouds.
Description:
Department
of Atmospheric Sciences, Cochin University of Science and Technology
Janat Augustine, K; Dr.Chandramohanakumar, N(Cochin University of Science & Technology, September , 2002)
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Abstract:
Humic substances are complex polymeric structures.No other polymers with such a wide range of properties are so widely distributed in nature.But still their moleculer structures are unknown. A structural knowledge is essential in determining their reactivity with metals.In the present work structural elucidation of humic acids from three different mangrove ecosystems of Cochin area is done with the available data from functional group analysis and various spectroscopic methods.13C NMR spectra of the solid samples with CPMAS,IR and SEM are very promising in revealing the complex structures of these polymeric substances.Sorptional studies on the sediment and humic acid of mangrove ecosystem reveals that the major portion of the organic matter is not extractable with Sodium hydroxide and humic acid only a small portion of the total organic matter. Humic acid is a good complexing agent and scavenger. Due to the nonextractable nature of the organic matter present with the sediment left after alkali extraction it is a better scavenger.
Description:
Department of Chemical Oceanography,Cochin University of Science and Technology
Nimmi,R Nair; Basil,Mathew; Mohankumar,K(Naval Physical and Oceanographic Laboratory, January , 2004)
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Abstract:
The objective of the present study is to understand the spatial and temporal variability of sea surface temperature(SST), precipitable water, zonal and meridional components of wind stress over the tropical Indian Ocean to understand the different scales of variability of these features of Indian Ocean. Empirical Orthogonal Function (EOF) and wavelet analysis techniques are utilized to understand the standing oscillations and multi scale oscillations respectively. The study has been carried out over Indian Ocean and South Indian Ocean. For the present study, NCEP/NCAR(National Center for Environmental Prediction National Center for Atmospheric Research) reanalyzed daily fields of sea surface temperature, zonal and meridional surface wind components and precipitable water amount during 1960-1998 are used. The principle of EOF analysis and
the methodology used for the analysis of spatial and temporal variance modes.