April, 2008

April, 2008   ||  Volume 12 No.2


Preliminary Rock and Palaeomagnetic Results from the
(Neoproterozoic) Bhima Basin, India

M.R.Goutham, S.K.Patil1, M.S.Seena1 and E.T.Anoop1

Centre of Exploration Geophysics, Osmania University, Hyderabad - 500 007
1Dr. K.S. Krishnan Geomagnetic Research Laboratory, Jhunsi, Allahabad -221 505
E.mail: gouthammr@rediffmail.com

APalaeomagnetic and rock magnetic results of the samples from Lower Bhima Group are reported here. Magnetic cleaning by different techniques give an impression that these rocks are remagnetized. IRM studies indicate that the magnetic carrier in the lower and upper Sedam Subgroup of Bhima Group is hematite and magnetite respectively. Possibly this is also an indication of remagnetization of Bhima Group of rocks by Deccan lava flows.


Day-to-day variation of geomagnetic H field and equatorial ring current
M.E.James, R.G.Rastogi1 and H.Chandra1
Physics Department, Gujarat University, Ahmedabad, India
1Physical Research Laboratory, Ahmedabad, India
E-mail : hchandra@prl.res.in

TThe paper describes the day-to-day fluctuations of the horizontal component of the geomagnetic field along Indo-Russian chain of stations during midday and midnight hours in relations to the corresponding variations of Dst index. The correlation between DH and Dst index is around 0.8 for all latitudes. The slope of the regression line is about 1.0 during daytime but during the nighttime hours the slope is only around 0.5. This suggests that the nighttime tail currents have almost equal contribution towards fluctuations of DH as due to the disturbance ring current. The equatorial electrojet current, designated by DH(TRD) - DH(ABG) has no correlation with Dst index because any variation of Dst are removed from DH at both stations and electrojet currents represents only the ionospheric current component.

Studies on hydrologic extremities over India – Monsoon Period

B.Sivaram and A.A.L.N.Sarma1
Eritrea Institute of Technology, Asmara, Eritrea, East Africa.
1Dept. of Meteorology and Oceanography, Andhra University, Visakhapatnam - 530 003.
E.mail: sivaramboppe@yahoo.co.in, aalnsarma_met@rediffmail.com

In the present investigation, an attempt has been made to study and understand some of the aspects of hydrologic extremities in terms of prevalence of varied degrees of drought, humidness and climate shifts of All India on a weekly basis, through the revised water balance model during the monsoon period from 1951 to 1998. Weekly aridity, humidness and climate shifts of the south west monsoon period are studied for All India and compared to march of Southern Oscillation Index and Sea Surface temperature of Nino 3 region during the period 1981 to 1991, 1992 to 1998.

Development of an agroclimatic model for the estimation of rice yield
A.A.L.N.Sarma, TV.Lakshmi Kumar and K.Koteswararao
Dept of Meteorology & Oceanography, Andhra University,

Visakhapatnam – 530 003
E.mail :aalnsarma_met@rediffmail.com,

lkumarap@gmail.com & koti_viz@yahoo.com

It deserves an utmost importance to look out for an agroclimatic model for the expected quantum of the rice production especially in Andhra Pradesh in advance in the present era of increasing food demand. Growing degree day or heat unit theories of the crops and Integrated Normalized Difference Vegetation Index along with the rainfall are made use of in obtaining in relation with the crop yield of rice. The atmospheric and oceanic indices such as Southern Oscillation Index and Sea Surface Temperature of Nino 3 region are also incorporated in developing the multi-regression model for the estimation of rice yield.