12-14 September, 2011, Lucknow - Earth Science India
12-14 September, 2011, Lucknow - Earth Science India
12-14 September, 2011, Lucknow - Earth Science India
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National Conference on <strong>Science</strong> of Climate Change and <strong>Earth</strong>’s Sustainability: Issues and Challenges ‘A Scientist-People Partnership’<br />
<strong>12</strong>-<strong>14</strong> <strong>September</strong>, <strong>2011</strong>, <strong>Lucknow</strong><br />
was controlled by westerly air flow under cold and dry conditions. Climatic<br />
amelioration, the post LGM warming seem to have taken place ca. 17.5 and <strong>12</strong>.5 ka BP,<br />
can be suggested to document strong chemical weathering, strong hydrodynamics and<br />
organic enrichment in the lake under the raised precipitation conditions. A weak<br />
monsoon between ca. <strong>12</strong>.5 and 11.3 ka BP is inferred by the presence of low Kaolinite,<br />
Illite, LOI, SiO 2 and high Muscovite, K, Ti, Fe, MgO, TiO 2 , Na 2 O and positive δ 13 C.<br />
The lake level started to rise from about ca. 11.3 ka BP onward due to intensified<br />
glacier melt and the onset of summer monsoon moisture supply. Summer monsoon<br />
influence weakened after ca. 10.8 to 7.2 ka BP and fostered a return to dry conditions<br />
with the increasing influence of westerly disturbances. The period between ca. 7.2 and<br />
5.8 Ka BP is interpreted as strengthening of monsoon, chemical weathering,<br />
accumulation of fine grained material and eutrophic conditions and may suggest high<br />
precipitation regime. The lake shrank gradually after ca. 5.8 ka BP towards its lowest<br />
stand at about ca. 4.2 ka BP, as an abrupt decrease in monsoon precipitation. Our results<br />
indicate that the orbitally driven regional climate variability is well reflected in the<br />
Yunam basin by hydrological cycles. Extensive summer monsoon moisture seems to<br />
have influenced the area only during the early Holocene.<br />
The soft sediment deformation structures from four prominent horizons within the<br />
profile, approximately ca. 25.3-24.8 ka BP, ca. 20.8-19.5 ka BP, ca. 18.0-17.5 Ka BP,<br />
and ca. <strong>12</strong>.5-<strong>12</strong>.0 ka BP in age are incorporated. These dates constrain the<br />
palaeoseismic activity during Quaternary as manifestations of the ongoing tectonic<br />
processes.<br />
SIMULATION RESULTS FROM A MATHEMATICAL<br />
OCEAN MODEL<br />
Anshu Prakash Mishra 1,2 , S. Rai 1 and A.C. Pandey 1<br />
1 Department of Atmopsheric and Ocean Studies, University of Allahabad, Allahabad<br />
2 Central Water Commission, Sewa Bhawan, R.K.Puram, New Delhi.<br />
email: anshu_786@rediffmail.com<br />
A z-coordinate numerical ocean model with free surface rigid lid approximation<br />
has been implemented for global domain and driven at surface by NCEP/NCAR wind<br />
stress climatologies and executed for 25 years. Several results of interest were studied<br />
mainly for the Southern <strong>India</strong>n Ocean region spanning from 60°S-10°N, 30°E-<strong>12</strong>0°E<br />
including Antarctic Circumpolar Current (ACC) region (40°S to 60°S). The fidelity of<br />
the model is examined for sub-surface horizontal circulation, sub-surface vertical<br />
velocity (overturning circulation), transport phenomenon, heat fluxes including<br />
statistical estimation for Sea Surface Temperature (SST). Statistical estimation of SST<br />
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