Facultyhttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/4242024-02-07T20:39:09Z2024-02-07T20:39:09ZImplementation of a Neural Network Classifier for Noise Sources in the OceanMohan Kumar, KSupriya, M HSaseendran Pillai, P Rhttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/46822014-08-22T20:30:13Z2009-01-01T00:00:00ZImplementation of a Neural Network Classifier for Noise Sources in the Ocean
Mohan Kumar, K; Supriya, M H; Saseendran Pillai, P R
The paper investigates the feasibility of implementing an intelligent
classifier for noise sources in the ocean, with the help of artificial neural networks,
using higher order spectral features. Non-linear interactions between the component
frequencies of the noise data can give rise to certain phase relations called Quadratic
Phase Coupling (QPC), which cannot be characterized by power spectral analysis.
However, bispectral analysis, which is a higher order estimation technique, can
reveal the presence of such phase couplings and provide a measure to quantify such
couplings. A feed forward neural network has been trained and validated with higher
order spectral features
PROCEEDINGS OF SYMPOL 2009
2009-01-01T00:00:00ZLocal Hadley circulation over the Asian monsoon region associated with the Tropospheric Biennial OscillationMohan Kumar, KPillai, P Ahttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/46812014-08-22T20:30:12Z2007-07-09T00:00:00ZLocal Hadley circulation over the Asian monsoon region associated with the Tropospheric Biennial Oscillation
Mohan Kumar, K; Pillai, P A
The Tropospheric Biennial Oscillation (TBO), a major interannual
variation phenomenon in the Indo-Pacific region,
is the result of strong ocean-atmosphere coupling over the
Asian-Australian monsoon area. Along with other meteorological
and oceanographic parameters, the tropical circulation
also exhibits interannual oscillations. Even though the
TBO is the result of strong air–sea interaction, the circulation
cells during TBO years are, as yet, not well understood. In
the present study, an attempt has been made to understand
the interannual variability of the mean meridional circulation
and local monsoon circulation over south Asia in connection
with the TBO. The stream function computed from the zonal
mean meridional wind component of NCEP=NCAR reanalysis
data for the years 1950–2003 is used to represent the
meanmeridional circulation. Mean meridional mass transport
in the topics reverses from a weak monsoon to a strong monsoon
in the presence of ENSO, but in normal TBO yearsmean
transport remains weak across the Northern Hemisphere.
The meridional temperature gradient, which drives the mean
meridional circulation, also shows no reversal during the
normal TBO cycle. The local Hadley circulation over the
monsoon area follows the TBO cycle with anomalous ascent
(descent) in strong (weak) monsoon years. During normal
TBO years, the Equatorial region and Indian monsoon areas
exhibit opposite local Hadley circulation anomalies
Theor. Appl. Climatol. 91, 171–179 (2008)
2007-07-09T00:00:00ZMeteorological aspects of mud bank formation along south west coast of IndiaBabu,C AAsha, Philip SHareeshkumar, P Vhttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/38052014-09-11T06:23:07Z2013-08-15T00:00:00ZMeteorological aspects of mud bank formation along south west coast of India
Babu,C A; Asha, Philip S; Hareeshkumar, P V
The study mainly intends to investigate the meteorological aspects associated with the formation of mud
banks along southwest coast of India. During the formation of mud bank, the prominent monsoon
organized convection is located in the equatorial region and relatively low clouding over Indian
mainland. The wind core of the low level jet stream passes through the monsoon organized convection.
When the monsoon organized convection is in the equatorial region, the low level wind over the
southwest coast of India is parallel to the coastline and toward south. This wind along the coast gives rise
to Ekman mass transport away from the coastline and subsequently formation of mud bank, if the high
wind stress persists continuously for three or more days. As a result of the increased alongshore wind
stress, the coastal upwelling increases. An increase in chlorophyll-a concentration and total chlorophyll
can also be seen associated with mudbank formation
www.elsevier.com/locate/csr
2013-08-15T00:00:00ZRole of sea-surface wind and transport on enhanced aerosol optical depth observed over the Arabian SeaBabu,C AShivaprasad, Phttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/38042014-07-09T05:48:20Z2012-02-17T00:00:00ZRole of sea-surface wind and transport on enhanced aerosol optical depth observed over the Arabian Sea
Babu,C A; Shivaprasad, P
The objective of this study is to understand the reasons for the enhancement in
aerosol optical depth (AOD) over the Arabian Sea observed during June, July and
August. During these months, high values of AOD are found over the sea beyond
10◦ N and adjacent regions. The Arabian Sea is bounded by the lands of Asia
and Africa on its three sides. So the region is influenced by transported aerosols
from the surroundings as well as aerosols of local origin (marine aerosols). During
the summer monsoon season in India, strong surface winds with velocities around
15 m s−1 are experienced over most parts of the Arabian Sea. These winds are capable
of increasing sea spray activity, thereby enhancing the production of marine
aerosols. The strong winds increase the contribution of marine aerosols over the
region to about 60% of the total aerosol content. The main components of marine
aerosols include sea salt and sulphate particles. The remaining part of the aerosol
particles comes from the western and northern land masses around the sea, of
which the main component is transported dust particles. This transport is observed
at higher altitudes starting from 600 m. At low levels, the transport occurs mainly
from the Indian Ocean and the Arabian Sea itself, indicating the predominance
of marine aerosols at these levels. The major portion of the total aerosol loading
was contributed by coarse-mode particles during the period of study. But in the
winter season, the concentration of coarse-mode aerosols is found to be less. From
the analysis, it is concluded that the increase in marine aerosols and dust particles
transported from nearby deserts results in an increase in aerosol content over the
Arabian Sea during June, July and August.
International Journal of Remote Sensing
Vol. 33, No. 16, 20 August 2012, 5105–5118
2012-02-17T00:00:00Z