Contrasting Signals of Glacier Changes in Zanskar Valley,Jammu & Kashmir,India Using Remote Sensing and GIS   总被引：1，自引：0，他引：1  

Swagata Ghosh  A. C. Pandey  M. S. Nathawat  I. M. Bahuguna  Ajai 《Journal of the Indian Society of Remote Sensing》2014,42(4):817-827

The study of advancement and recession of the glaciers in the Himalayas is essential due to their contrasting response towards climatic change. In the present study, Survey of India (SOI) topographical maps of 1962, IRS: LISS-III image of 2001 and LANDSAT-5: TM (Thematic Mapper) image of 2009 were used to analyze the glacier fluctuations in a part of Zanskar valley. The analysis carried out on 212 glaciers indicated decrease of 57 km² (8 %) of glacier area over many glacier which was partly compensated with area increase by 42 km² (6 %) in other glaciers, resulting an overall glacier area decrease by only 15 km² (2 %) from 1962–2001. Due to glacier fragmentation the number of glaciers increased from 212 in 1962 to 238 by 2001. Although majority of glaciers (88 %) exhibited retreat (up to 13 my^?1), minor advancement (<15 my^?1) also took place in few glaciers during this period. Advancement took place mainly in larger glaciers (2–5 km² and >5 km²) located over wider altitudinal range (700 m–1,000 m) whereas smaller glaciers (<2 km²) with narrow altitudinal range (100 m–500 m) exhibited retreat. The supraglacial debris analysis indicated that percentage of debris cover over glaciers ranges from 1.43 % to 18.15 %. Smaller glaciers (<2 km²) were debris free in comparison to the larger glaciers (>5 km²). During 2001–2009 majority of the glaciers were apparently stable in terms of their area and snout position indicating less impact of climate forcing in parts of Zanskar valley as compared to other parts of the Himalaya.  相似文献   

The luminosity, colour and morphology dependence of galaxy filaments in the Sloan Digital Sky Survey Data Release Four     

Biswajit Pandey  Somnath Bharadwaj 《Monthly notices of the Royal Astronomical Society》2006,372(2):827-838

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Full Resolution Images From The Mauritius Radio Telescope     

V.N. Pandey  N. Udaya Shankar  Radhakrishna Somanah 《Astrophysics and Space Science》2002,282(1):29-41

The first set of full resolution images have been made using the Mauritius Radio Telescope (MRT) for the Right Ascension range 18:00 to 19:00 hours and the declination range -70^° to -10^°.This is a part of the southern sky survey at 151.5 MHz being carried out using the MRT. To minimise the effect of bandwidth decorrelation, the images are made from the visibilities recorded with four different delay settings. This paper discusses three key issues of data analysis for the survey: Selection of good data for the survey, detection and removal of interference in the images and, preliminary analysis of these images. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Stellar contents of two young open clusters: NGC 663 and 654     

A. K. Pandey  K. Upadhyay  K. Ogura  Ram Sagar  V. Mohan  H. Mito  H. C. Bhatt  B. C. Bhatt 《Monthly notices of the Royal Astronomical Society》2005,358(4):1290-1308

UBVRI CCD photometry in a wide field around two young open clusters, NGC 663 and 654, has been carried out. Hα and polarimetric observations for the cluster NGC 654 have also been obtained. We use the photometric data to construct colour–colour and colour–magnitude diagrams, from which we can investigate the reddening, age, mass and evolutionary states of the stellar contents of the these clusters. The reddening across the cluster regions is found to be variable. There is evidence for anomalous reddening law in both clusters; however, more infrared and polarimetric data are needed to conclude about the reddening law. Both clusters are situated at about a distance of 2.4 kpc. Star formation in both clusters is found to be a continuous process. In the case of NGC 663, star formation seems to have taken place sequentially, in the sense that formation of low-mass stars precedes the formation of most massive stars. Whereas, in the case of NGC 654, formation of low-mass stars did not cease after the formation of most massive stars in the cluster.  相似文献   

Climate change and adaptation: an integrated framework linking social and physical aspects in poorly-gauged regions     

Sujata Manandhar  Vishnu Prasad Pandey  Futaba Kazama 《Climatic change》2013,120(4):727-739

Various frameworks related to climate change and adaptations that have been developed to date have notable benefits as well as significant limitations. It is not always practical to implement advanced climate change frameworks in situations with limited data availability. Social aspects, such as people’s experience and perception, are often under-prioritized. Therefore, this study introduces an integrated framework linking social and physical aspects of climate change to assess its impacts on water resources and to evaluate differing adaptation options in poorly gauged basins. A case study of the Kali Gandaki River Basin (KGRB) in western Nepal is presented to demonstrate the applicability of this framework. Results of the study show that people of the mountainous Mustang district in the KGRB have perceived climate change or climate variability, its impacts on water resources, as well as other water-related issues and potential adaptations or responses. Furthermore, evaluation of people’s perception using available physical data confirms the increase in temperature and average annual discharge in the Kali Gandaki River as well as poor water use, as a major problem at all levels in the basin. Despite increasing water availability, a concurrent increase in water use is difficult due to topographic constraints on irrigation development. However, the impacts of climate change are particularly severe in Mustang, owing to the fact that a large proportion of the population depends on a climate-sensitive livelihood like agriculture. Therefore, various adaptation options are identified in the agricultural sector, and one relevant option is further evaluated. The framework developed in this study has the potential to be further applied to other poorly gauged basins.  相似文献   

Photometric and polarimetric studies of three W UMa-type binaries: FZ Ori,V407 Peg and LP UMa     

Vinod Prasad  J. C. Pandey  M. K. Patel  D. C. Srivastava 《Astrophysics and Space Science》2014,353(2):575-594

We present analyses of new optical photometric observations of three W UMa-type contact binaries FZ Ori, V407 Peg and LP UMa. Results from the first polarimetric observations of the FZ Ori and V407 Peg are also presented. The periods of FZ Ori, V407 Peg and LP UMa are derived to be 0.399986, 0.636884 and 0.309898 d, respectively. The O?C analyses indicate that the orbital periods of FZ Ori and LP UMa have increased with the rate of 2.28×10^?8 and 1.25×10^?6 d?yr^?1, respectively and which is explained by transfer of mass between the components. In addition to the secularly increasing rate of orbital period, it was found that the period of FZ Ori has varied in sinusoidal way with oscillation period of ～30.1 yr. The period of oscillations are most likely to be explained by the light-time effect due to the presence of a tertiary companion. Small asymmetries have been seen around the primary and secondary maxima of light curves of all three systems, which is probably due to the presence of cool/hot spots on the components. The light curves of all three systems are analysed by using Wilson-Devinney code (WD) and the fundamental parameters of these systems have been derived. The present analyses show that FZ Ori is a W-subtype, and V407 Peg and LP UMa are A-subtype of the W UMa-type contact binary systems. The polarimetric observations in B, V, R and I bands, yield average values of polarization to be 0.26±0.03, 0.22±0.02, 0.22±0.03 and 0.22±0.05 per cent for FZ Ori and 0.21±0.02, 0.29±0.03, 0.31±0.01 and 0.31±0.04 per cent for V407 Peg, respectively.  相似文献   

The R Coronae Borealis stars: carbon abundances from forbidden carbon lines     

Gajendra Pandey  David L. Lambert  N. Kameswara Rao  Bengt Gustafsson  Nils Ryde  David Yong 《Monthly notices of the Royal Astronomical Society》2004,353(1):143-152

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Self-similar model of magnetohydrodynamic radiative shock waves with increasing density     

S. N. Ojha  D. S. Pandey 《Astrophysics and Space Science》1988,148(1):143-148

The magnetohydrodynamic model of shock waves has been discussed in an atmosphere with gravitation and radiation. The disturbance is headed by a strong shock of increasing density. The medium ahead of the shock is assumed to be inhomogeneous and at rest. Variation of magnetic field radiation flux, and other flow variables are given in tabular form.  相似文献   

On penetrative instabilities     

S. K. Pandey 《Astrophysics and Space Science》1980,71(2):499-506

The investigation of instabilities in a penetrative atmosphere discussed in our earlier paper (Pandeyet al., 1979) is extended to include thermal dissipation in a more realistic approximation. It is shown that the convective modes are not very sensitive to the presence of an overlying stable layer. The overstabilization of gravity modes is, however, found to occur under very stringent conditions, while the acoustic overstability is enhanced by the presence of an overlying stable layer.  相似文献   

Self-similar magnetogasdynamic cylindrical shock waves,I     

J. B. Singh  S. K. Pandey 《Astrophysics and Space Science》1988,146(1):71-78

Similarity solutions describing the flow of a perfect gas behind a cylindrical shock wave with transverse magnetic field are investigated in an inhomogeneous medium. The total energy of the shock wave is assumed to be constant. A comparative study has been made between the results with and without magnetic field.  相似文献