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91.
Kakatkar Rashmi Gnanaseelan C. Chowdary J. S. Parekh Anant Deepa J. S. 《Theoretical and Applied Climatology》2018,131(3-4):1235-1247
Theoretical and Applied Climatology - In this study, factors responsible for the deficit Indian Summer Monsoon (ISM) rainfall in 2014 and 2015 and the ability of Indian Institute of Tropical... 相似文献
92.
S. A. Kadam S. D. Gorantiwar S. N. Das A. K. Joshi 《Journal of the Indian Society of Remote Sensing》2017,45(2):297-305
Penman–Monteith method adapted to satellite data was used for the estimation of wheat crop evapotranspiration during the entire growth period using satellite data together with ground meteorological measurements. The IRS-1D/IRS-P6 LISS-III sensor data at 23.5 m spatial resolution for path 096 and row 059 covering the study area were used to derive, albedo, normalized difference vegetation index, leaf area index and crop height and then to estimate wheat crop evapotranspiration referred to as actual evapotranspiration (ETact). The ETact varied from 0.86 to 3.41 mm/day during the crop growth period. These values are on an average 16.40 % lower than wheat crop potential evapotranspiration (ETc) estimated as product of reference crop evapotranspiration estimated by Penman–Monteith method and lysimetric crop coefficient (Kc). The deviation of ETact from ETc is significant, when both the values were compared with t test for paired two sample means. Though the observations on ETact were taken from well maintained unstressed experimental plot of 120 × 120 m size, there was significant deviation. This deviation could be attributed to, the satellite images representing the actual crop evapotranspiration as function crop canopy biophysical parameters, condition of the crop stand, climatic and soil conditions and the microclimate variation over area of one hectare. However, Penman–Monteith method represents a flat rate of specific growth stage of the crop. 相似文献
93.
Anita Joshi 《Solar physics》1995,157(1-2):315-324
This paper presents the results of studies of the asymmetries (N-S and E-W) for different manifestations of solar activity events (sunspot groups, H flares and active prominences/filaments) during the maximum-phase (1989–1991) of solar cycle 22. During the period considered, the results obtained show the existence of a real N-S asymmetry, whereas the E-W asymmetry may exist only for H flares. There is no definite relationship between the asymmetries and the occurrence of events; however, around low activity sometimes we find enhanced asymmetry, and low asymmetry around high activity. Our study suggests a good agreement with similar studies made by others. 相似文献
94.
Sanjaya Gurung Bikas C. Bhattarai Rijan B. Kayasth Dorothea Stumm Sharad P. Joshi Pradeep K. Mool 《寒旱区科学》2016,8(4):311-318
Although Himalayan glaciers are of particular interest in terms of future water supplies, regional climate changes, and sea-level rises, little is known about them due to lack of reliable and consistent data. There is a need for monitoring these glaciers to bridge this knowledge gap and to provide field measurements necessary to calibrate and validate the results from different remote sensing operations. Therefore, glaciological observations have been carried out by the Cryosphere Monitoring Project(CMP) since September 2011 on Rikha Samba Glacier in Hidden valley, Mustang district in western Nepal in order to study its annual mass balance. This paper presents the first results of that study. There are 10 glaciers in Hidden Valley, named G1, G2, G3, up to G10. Of these, G5 is the Rikha Samba Glacier, which has the largest area(5.37 km2) in this valley and the highest and lowest altitudes(6,476 and 5,392 m a.s.l., respectively). The glacier mass balance discussed in this paper was calculated using the glaciological method and the equilibrium line altitude(ELA). The glacier showed a negative annual point mass balance along the longitudinal profile of its lower part from September 10, 2011 to October 3, 2012. Stake measurements from October 4, 2012 to September 30, 2013 indicated a negative areal average of annual mass balance-0.088±0.019 m w.e. for the whole glacier. Based on these observations, the ELA of the Rikha Samba Glacier is estimated at 5,800 m a.s.l. in 2013. This negative balance may be due to rising air temperatures in the region, which have been incrementally rising since 1980 accompanied by little or no significant increase in precipitation in that period. The negative mass balance confirms the general shrinking trend of the glacier. 相似文献
95.
96.
M. V. Popov A. S. Andrianov N. Bartel C. Gwinn B. C. Joshi D. Jauncey N. S. Kardashev A. G. Rudnitskii T. V. Smirnova V. A. Soglasnov E. N. Fadeev V. I. Shishov 《Astronomy Reports》2016,60(9):792-806
The RadioAstron ground–space interferometer has been used to measure the angular sizes of the scattering disks of the three distant pulsars B1641–45, B1749–28, and B1933+16. The observations were carried out with the participation of the Westerbork Synthesis Radio Telescope; two 32-m telescopes at Torun, Poland and Svetloe, Russia (the latter being one antenna of the KVAZAR network); the Saint Croix VLBA antenna; the Arecibo radio telescope; the Parkes, Narrabri (ATCA), Mopra, Hobart, and Ceduna Australian radio telescopes; and the Hartebeesthoek radio telescope in South Africa. The full widths at half maximum of the scattering disks were 27 mas at 1668 MHz for B1641–45, 0.5 mas at 1668 MHz for B1749–28, and 12.3 at 316 MHz and 0.84 mas at 1668 MHz for B1933+16. The characteristic time scales for scatter-broadening of the pulses on inhomogeneities in the interstellar plasma τsc were also measured for these pulsars using various methods. Joint knowledge of the size of the scattering disk and the scatter-broadening time scale enables estimation of the distance to the effective scattering screen d. For B1641–45, d = 3.0 kpc for a distance to the pulsar D = 4.9 kpc, and for B1749–28, d = 0.95 kpc for D = 1.3 kpc. Observations of B1933+16 were carried out simultaneously at 316 and 1668 MHz. The positions of the screen derived using the measurements at the two frequencies agree: d 1 = 2.6 and d 2 = 2.7 kpc, for a distance to the pulsar of 3.7 kpc. Two screens were detected for this pulsar from an analysis of parabolic arcs in the secondary dynamic spectrum at 1668 MHz, at 1.3 and 3.1 kpc. The scattering screens for two of the pulsars are identified with real physical objects located along the lines of sight toward the pulsars: G339.1–04 (B1641–45) and G0.55–0.85 (B1749–28). 相似文献
97.
A. O. Varghese V. B. Sawarkar Y. L. P. Rao A. K. Joshi 《Journal of the Indian Society of Remote Sensing》2016,44(1):49-57
Ardeotis nigriceps, commonly known as Great Indian Bustard (GIB), is a Critically Endangered, Evolutionary Distinct and Globally Threatened (EDGE) and endemic species to the Indian subcontinent. GIB is under tremendous threat in its last strongholds and sliding inextricably towards extinction. The GIB sanctuary in Maharashtra (India) is one of the last refuges of the bird constituting an area of 8496 km2 spread over in seven talukas of Solapur and Ahemednagar districts. Major portion of the sanctuary (94.3 %) consists of privately owned lands under a variety of economic vocations and large number of villages and townships. In view of the legal restrictions relating to Protected Area under the Wildlife (Protection) Act of India 1972, the inhabitants of villages and townships faced a very difficult situation regarding use of their lands, development of properties and deriving benefits from planned local and regional development. This created conflict between local people and the forest department over the use of land, which necessitated the rationalization of the sanctuary. The objective of the present study was to map the suitable habitat of GIB in GIB Wildlife Sanctuary as an input for the realignment of the GIB Sanctuary by identifying areas that are important for the GIB. Main parameters considered for the habitat suitability assessments are, habit and habitat of GIB, slope, minimum patch size and disturbance sources. Based on the criteria derived for the ecological and biological requirements of GIB, binary deductive habitat suitability modeling has been done using remote sensing and GIS and prioritized the potential habitats of GIB. The net area of important suitable habitat of GIB in GIB sanctuary is 2304.99 km2 out of 8496.44 km2. The output of the present study has been used as an input by the committee (set by Honorable Supreme court of India) on rationalization of the GIB Sanctuary and the sanctuary has been rationalized with an area of 1222 km2. 相似文献
98.
Sitiraju Srinivasa Rao Dinesh Kumar Sahadevan Milind R. Wadodkar M/ S. S. Nagaraju Sudipta Chattaraj William Joseph Prasanth Rajankar Titu Sengupta M. V. Venugopalan Subrata N. Das Asok Kumar Joshi Jaswanth Raj Sharma Eadara Amminedu 《Journal of the Indian Society of Remote Sensing》2016,44(2):277-285
99.
Ten spectrograms of T Vul at a dispersion of 8.47 Å mm–1 have been used for an analysis of the parameters of stellar atmosphere during its pulsation cycle. A differential curve of growth method relative to the Sun has been used to evaluate atmospheric parameters. The range in exc is from 0.88 to 1.00. Mean abundances for twenty elements have been estimated relative to [N
Fe]. A deficiency by a factor of 2.4 has been found ins-process elements with respect to those formed by thee-process. 相似文献
100.
Suksun Horpibulsuk Martin D. Liu Deepa S. Liyanapathirana Jirayut Suebsuk 《Computers and Geotechnics》2010,37(1-2):1-9
In this paper, the mechanical properties of cemented clay are studied. The theoretical framework of the Structured Cam Clay (SCC) model is extended to describe the behaviour of cemented clay. The SCC model is modified to take into account special features of the behaviour of cemented clay. The widely used mean effective stress parameter is modified to include the influence of cementation on the strength and the plastic deformation of cemented clay. A new destructuring function is also suggested to represent the removal of the cementation structure, especially in the formation of the final failure state for artificially strongly cemented clay. The revised model is then employed to simulate and predict the behaviour of cemented clay with various degrees of cementation and confining stresses. The main features of the complicated behaviour of cemented clay can be reasonably represented well by the theoretical framework of the SCC model. Finally, the influence of cementation on the model parameters is discussed, and empirical equations are proposed to determine some of the key model parameters for engineering practice. 相似文献