Detection of snow melt and freezing in Himalaya using OSCAT data

Journal of Earth System Science - A study of the snow cover melt and freeze using Ku band Oceansat scatterometer (OSCAT) HH polarised backscatter coefficient ( $\sigma ^{\mathrm {0}}_{\text {HH}}$...     

On the evolution of the ‘f’ family in the restricted three-body problem

Poincaré surface of section technique is used to study the evolution of a family ‘f’ of simply symmetric retrograde periodic orbits around the smaller primary in the framework of restricted three-body problem for a number of systems, actual and hypothetical, with mass ratio varying from 10⁻⁷ to 0.015. It is found that as the mass ratio decreases the region of phase space containing the two separatrices shrinks in size and moves closer to the smaller primary. Also the corresponding value of Jacobi constant tends towards 3.     

Analysis of thermo-hydrologic-mechanical impact of repository for high-level radioactive waste in clay host formation: an Indian reference disposal system

In our study, a coupled hydrologic-mechanical analysis is done of the excavation damaged zone, before the emplacement of nuclear waste. This is followed by a coupled thermal-hydrologic-mechanical analysis to evaluate the impact of nuclear waste repository in porous water containing rock mass. This analysis has been under taken in accordance with the Indian reference disposal system. The paper considers the changes in pore pressure and stresses due to excavation of disposal holes. A critical study of rock mass permeability, porosity, thermally induced stresses, strains, and temperature distribution after the emplacement of nuclear spent fuels in disposal holes has also been done. Coupling to the mechanical constitutive equations is done via ??effective?? normal strain rates.     

Analysis of marine aerosol optical depth retrieved from IRS-P4 OCM sensor and comparison with the aerosol derived from SeaWiFS and MODIS sensor

Aerosol optical depth is regularly derived from SeaWiFS and MODIS sensor and used by the scientific community in various climatic studies. In the present study an attempt has been made to retrieve the aerosol optical depth using the IRS-P4 OCM sensor data and a comparison has been carried out using few representative datasets. The results show that the IRS-P4 OCM retrieved aerosol optical depth is in good agreement with the aerosols retrieved from SeaWiFS as well as MODIS. The RMSE are found to be ±0.0522 between OCM and SeaWIFS and ±0.0638 between OCM and MODIS respectively. However, IRS-P4 OCM sensor retrieved aerosol optical depth is closer to SeaWiFS (correlation = 0.88, slope = 0.96 and intercept = ?0.013) compared to MODIS (correlation = 0.75, slope = 0.91 and intercept = 0.0198). The mean percentage difference indicates that OCM retrieved AOD is +12% higher compared to SeaWiFS and +8% higher compared to MODIS. The mean absolute percentage between OCM derived AOD and SeaWiFS is found to be less (16%) compared to OCM and MODIS (20%).     

Aircraft measurements of aerosol black carbon from a coastal location in the north-east part of peninsular India during ICARB

During the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) over India, high-resolution airborne measurements of the altitude profiles of the mass concentrations (M_B) of aerosol black carbon (BC) were made off Bhubaneswar (BBR, 85.82°E, 20.25°N), over northwest Bay of Bengal, in the altitude region upto 3 km. Such high-resolution measurements of altitude profiles of aerosols are done for the first time over India. The profiles showed a near-steady vertical distribution of MB modulated with two small peaks, one at 800m and the other at ～2000m. High resolution GPS (Global Positioning System) sonde (Vaisala) measurements around the same region onboard the research vessel Sagar Kanya (around the same time of the aircraft sortie) revealed two convectively well mixed layers, one from ground to ～700m with an inversion at the top and the other extends from 1200m to ～2000m with a second inversion at ～2200m and a convectively stable region in the altitude range 700–1200m. The observed peaks in the M_B profile are found to be associated with these temperature inversions. In addition, long-range transport from the Indo-Gangetic Plain (IGP) and deserts lying further to the west also influence the vertical profile of BC. Latitudinal variation of MB showed a remarkable land ocean contrast at the 500m altitude (within the well mixed region) with remarkably lower values over oceans, suggesting the impact of strong sources over the mainland. However, above the ABL (at 1500m), the latitudinal variations were quite weak, and this appears to be resulting from the impact of long-range transport. Comparison of the altitude profiles of M_B over BoB off BBR with those obtained during the earlier occasion over the inland stations of Hyderabad and Kanpur showed similarities above ～500m, with M_B remaining around a steady value of ～1 μg m^?3. However, large differences are seen within the ABL. Even though the observed M_B values are not unusually high, their near constancy in the vertical column will have important implications to radiative forcing.     

Human control of climate change

The use of analogies and repeated feedback might help people learn about the dynamics of climate change. In this paper, we study the influence of repeated feedback on the control of a carbon-dioxide (CO₂) concentration to a goal level in a Dynamic Climate Change Simulator (DCCS) using the “bathtub” analogy. DCCS is a simplification of the complex climate system into its essential elements: CO₂ concentration (stock); man-made CO₂ emissions (inflow); and natural CO₂ removal or absorption in the atmosphere (outflow). In a laboratory experiment involving DCCS, we manipulated feedback delays in two ways: the frequency of emission decisions and the rate of CO₂ absorption from the atmosphere (climate dynamics). Our results revealed that participants’ ability to control the CO₂ concentration generally remained poor even in conditions where they were allowed to revise their emission decisions frequently (i.e., every 2?years) and where the climate dynamics were rapid (i.e., 1.6% of CO₂ concentration was removed every year). Participants’ control of the concentration only improved with repeated feedback in conditions of lesser feedback delay. Moreover, the delay due to climate dynamics had a greater effect on participants’ control than the delay due to emission decisions frequency. We provide future research directions and highlight the potential of using simulations like DCCS to help people learn about dynamics of Earth’s climate.     

Spatial patterns of crime among Indian cities

An analysis of inter-city patterns of crime in India was undertaken. Using data for fourteen different types of crime and for 99 cities, standard correlation techniques were used to analyze the inter-relationships between different types of crime and the spatial distribution of these types. Factor analysis was applied to regionalize crime groups. An attempt is made to explain the crime patterns which emerge from the analysis, and the concentration of crime in the north-central region of India.     

On the abnormally high natural remanent magnetization of certain lavas

Summary The rock specimens found to have natural remanent magnetization of abnormally high intensity, have been generally from hill sides or tops, or from ridges high up from the local surroundings. A field of several hundred oersteds has been found sufficient to produce in some of the artificially demagnetized specimens an isothermal magnetization of the same order as the abnormal natural ones, and this magnetization has shown a similar degree of stability as the natural one. Variations in the direction and magnitude of the natural magnetic vector have been found over a distance of a few centimetres. Laboratory tests indicate a normal chemical composition for the specimens. The lightning discharge seems to be the plausible cause of abnormally high magnetization of rocks, which is generally isothermal and might have originated in the recent past, but the magnetization is sometimes complicated probably by the thermal effect of the discharge.     

Novelist Sarat Chandra's perception of his Bengali home region: a literary geographic study

Sarat Chandra, a Bengali novelist of the first half of the 20th century, has described the landscape of his southern Bengal Region and has interacted through his characters a deep psychological response appropriate to the region and time. His work forms an excellent resource base to reconstruct the region of his time and establish phenomenological relationship through the feelings expressed by the characters of his novels. Sarat Chandra's Home Region is a stream-filled area with people's activity directed to agriculture, though Calcutta was already established as a center of westernization and modernization. Feudal exploitation, Zamindars' tyrrany, degenerative caste-division, child marriage, prohibition of widow's right to remarry, decaying extended family and losing person-to-person relationship of the traditional Bengal were some of the characteristics of the regional cultural geography. The cities, particularly Calcutta, had started to show signs of modernization: industries, equal rights to women, widow re-marriage and elitist ideas. Bramho Samaj was pioneering the social modernization. In summation, the Home Region, being a transitional stage of decaying feudalism and incipient industrialization, was engaged in a struggle between the old and the new, decadent traditional and modern, rural and urban, caste rigidity and liberal social customs, religious fanaticism and rationalism. Sarat Chandra's work, particularly, provides an inroad to understand the cultural aspects of his Home Region.