Krishna Mohan,K S; Dr.Mohanakumar,K(Cochin University Of Science And Technology, February , 2013)
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Abstract:
Tropical cyclones genesis, movement and intensification are highly dependent
on its environment both oceanic and atmospheric. This thesis has made a detailed
study on the environmental factors related to tropical cyclones of North Indian
Ocean basin. This ocean basin has produced only 6% of the global tropical
cyclones annually but it has caused maximum loss of human life associated with
the strong winds, heavy rain and particularly storm surges that accompany severe
cyclones as they strike the heavily populated coastal areas.
Atmospheric factors studied in the thesis are the moisture content of the
atmosphere, instability of the atmosphere that produces thunderstorms which
are the main source of energy for the tropical cyclone, vertical wind shear to
which cyclones are highly sensitive and the Sub-Tropical westerly Jetsteram and
its Asian high speed center. The oceanic parameters studied are sea surface
temperature and heat storage in the top layer of the ocean. A major portion of the
thesis has dealt with the three temporal variabilities of tropical cyclone frequency
namely intra-seasonal (mainly the influence of Madden Julian Oscillation), inter-
annual (the relation with El Nino Southern Oscillation) and decadal variabilities.
Regarding decadal variability, a prominent four decade oscillation in the frequency
of both tropical cyclones and monsoon depressions unique to the Indian Ocean
basin has been brought out.
The thesis consists of 9 chapters.
Description:
Department of Atmospheric Sciences, Cochin University of Science
and Technology,
Satyanarayana Murty, A; Dr.Sharma,G S(Cochin University of Science and Technology, March , 1984)
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Abstract:
It became so usual for the east coast of India to face at least IO to 15 cyclones every year, out of which 3 to 4 may reach the deep depression stage. As a result the east coast of India experiences frequent heavy damages of varying intensities due to storm surges and it is also not unusual to experience a calamitous deluge once in a decade or so. Loss of life and damages can be minimized only if the magnitude of the surge could be predicted at least a day in advance. Therefore, an attempt to study the storm surges generated by the cyclones that strike the
east coast of India and. suggest a method of predicting them through nomogram is made
Description:
School of Marine Science,Cochin University of Science and Technology
Mrudula, G; Dr.Mohan Kumar, K(Department of Atmospheric Sciences, May , 2005)
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Abstract:
In the present thesis, an attempt has been made to study the characteristics of troposphere and lower stratosphere during the passage of tropical cyclones from a tropical station in India using MST radar. MST radar is an excellent tool for studying various features of the atmosphere from ground to mesospheric heights, as it can be operated continuously with good time and altitude resolution. The major objectives are to identify the multiple layers of reflectivity observed in the atmosphere during cyclones, to study the troposphere characteristics during these cyclones and its dependence on cyclone position and intensity, to detect the waves present in the atmosphere, to study the transport of momentum fluxes and to understand stratosphere. The winds in the troposphere and lower stratosphere are greatly affected by the passage of cyclones; the presence of high reflectivity layers below the tropopause suggests the passage of severe weather systems etc. are some of the major findings of the study. The study can be extended further to understand the circulation and dynamics of the atmosphere associated with the passage of tropical cyclones. The gravity wave generation and its characteristics during the passage of storms is another important aspect to be studied in detail.