Comparison of Kalpana-1 atmospheric motion vectors with other observations     

S. K. Deb  Inderpreet Kaur  C. M. Kishtawal  P. K. Pal 《Theoretical and Applied Climatology》2014,115(3-4):693-702

The operational derivation of atmospheric motion vectors (AMVs) using infrared (10.5–12.5 μm) and water vapor (6.3–7.1 μm) channels of successive geostationary satellite images started in the 1980s. Subsequently, AMVs have become an important component for operational numerical weather prediction throughout the globe for the last decade or so. In India, at the Space Applications Centre, Indian Space Research Organisation, the operational derivation of AMVs (infrared winds and water vapor winds) from the Indian geostationary satellite Kalpana-1 has been initiated a few years back. Recently, an L-band radar lower atmosphere wind profiler (LAWP) has been installed at the National Atmospheric Research Laboratory, Gadanki located at (13.58°N, 79.28°E) for continuous high-resolution wind measurements in the lower atmosphere. In this study, a comparison of Kalpana-1 AMVs with wind measurements from LAWP and radiosonde has been carried out for a period of one and a half years. The performances of Kalpana-1 AMVs are also assessed by a separate comparison of Meteosat-7 AMVs, derived at the European Organisation for the Exploitation of Meteorological Satellites, with wind measurements from LAWP and radiosonde. Both sets of comparison show that AMVs from Kalpana-1 and Meteosat-7 are comparable over the Indian Ocean region.  相似文献   

Height Assignment Improvement in Kalpana-1 Atmospheric Motion Vectors   总被引：1，自引：0，他引：1  

S. K. Deb  Steve Wanzong  C. S. Velden  Inderpreet Kaur  C. M. Kishtawal  P. K. Pal  W. P. Menzel 《Journal of the Indian Society of Remote Sensing》2014,42(4):679-687

The real-time operational use of atmospheric motion vectors (AMVs) at numerical weather prediction (NWP) centers in India are being adversely affected due to inaccurate height assignment of cloud tracers, especially in thin semi-transparent clouds. In India, the operational derivation of AMVs from the Indian geostationary satellite Kalpana-1 began few years ago. A statistical empirical method (SEM) of height assignment, based on a genetic algorithm, is currently used to estimate the height of the retrieved vectors from Kalpana-1. This method has many limitations. In this paper, attempts have been made to implement the widely used and well tested height assignment methods such as the infrared window (WIN) technique, the H₂O intercept, and the cloud base method in the Kalpana-1 AMV retrieval algorithm. The new height assignment algorithm significantly improves the statistics of the retrieved winds when compared to radiosondes, especially in high and mid levels winds.  相似文献   

Radon as seismic precursor: new data with well water of Jalpaiguri,India     

Dipak Ghosh  Argha Deb  Swarup Ranjan Sahoo  Subrata Haldar  Rosalima Sengupta 《Natural Hazards》2011,58(3):877-889

This paper reports the measurement of radon concentration in well water at the site of Jalpaiguri (26°32′N, 88°46′E) near the active fault zone of West Bengal, India. Radon concentration has been measured in well water with the help of solid-state nuclear track detectors (SSNTD). The study indicates a positive correlation between radon anomaly and earthquake. The data of radon content in well water have been compared with that in soil gas at the same site.  相似文献   

Dissipative gravitational collapse of an (an)isotropic star     

Shyam Das  Ranjan Sharma  Bikash Chandra Paul  Rumi Deb 《Astrophysics and Space Science》2016,361(3):99

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Proterozoic Rifting in the Pranhita-Godavari Valley: Implication on India-Antarctica Linkage     

Asru K. Chaudhuri  Gautam K. Deb 《Gondwana Research》2001,4(4):592-593

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Susceptibility assessment of shallow landslides on Oahu, Hawaii, under extreme-rainfall events   总被引：1，自引：0，他引：1  

Sanjit K. Deb  Aly I. El-Kadi   《Geomorphology》2009,108(3-4):219-233

The deterministic Stability INdex MAPping (SINMAP) model, which integrates a mechanistic infinite-slope stability model and a hydrological model, was applied to assess susceptibility of slopes in 32 shallow-landslide-prone watersheds of the eastern to southern areas of Oahu, Hawaii, USA. Input to the model includes a 10-m Digital Elevation Model (DEM), an inventory of storm-induced landslides that occurred from 1949 to 2006, and listings of soil-strength and hydrological parameters including transmissivity and steady-state recharge. The study area of ca. 384 km² was divided into four calibration regions with different geotechnical and hydrological characteristics. All parameter values were separately calibrated using observed landslides as references. The study used a quasi-dynamic scenario of soil wetness resulting from extreme daily rainfall events with a return period of 50 years. The return period was based on almost-90-year-long (1919–2007) daily rainfall records from 26 raingauge stations in the study area. Output of the SINMAP model includes slope-stability-index-distribution maps, slope-versus-specific-catchment-area charts, and statistical summaries for each region.The SINMAP model assessed susceptibility at the locations of all 226 observed shallow landslides and classified these susceptible areas as unstable. About 55% of the study area was predicted as highly unstable, highlighting a critical island problem. The SINMAP predictions were compared to an existing debris-flow-hazard map. Areas classified as unstable in the current study were classified as low-to-moderate and moderate-to-high debris-flow hazard risks by the prior mapping. The slope-stability maps provided by this study will aid in explaining the causes of known landslides, making emergency decisions, and, ultimately mitigating future landslide risks. The maps may be further improved by incorporating heterogeneous and anisotropic soil properties and spatial and temporal variation of rainfalls as well as by improving the accuracy of the DEM and the locations of shallow landslide initiation.  相似文献   

A Report on the International Field Workshop on Gold Metallogeny in India     

Mihir Deb  V. Balaram 《Journal of the Geological Society of India》2009,74(1):141-141

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Hydrogeochemical evaluation and statistical analysis of groundwater of Sylhet,north-eastern Bangladesh     

Ahmed  Nasir  Bodrud-Doza  Md.  Islam  S. M. Didar-Ul  Choudhry  Manzoor Ahmad  Muhib  Md. Iftakharul  Zahid  Anwar  Hossain  Shahadat  Moniruzzaman  Md.  Deb  Nipa  Bhuiyan  Md. Abdul Quaiyum 《中国地球化学学报》2019,38(3):440-455

Acta Geochimica - To investigate the hydrogeochemical characteristics of groundwater 23 shallow, 30 intermediate and 38 deep wells samples were collected from Sylhet district of Bangladesh, and...  相似文献   

Wave force on vertically submerged circular thin plate in shallow water     

Pradip Deb Roy  Sukamal Ghosh   《Ocean Engineering》2006,33(14-15):1935-1953

The paper presented is a solution of shallow water wave force, using small amplitude linear wave theory on two-dimensional vertically submerged circular thin plates under three different configurations: (1) a surface-piercing circular thin plate, (2) a submerged circular thin plate, and (3) a bottom-standing circular thin plate. Finally Morison's equation is used for the determination of wave force which is based on the linear wave theory. The plate is submerged in water near the shore on uniformly sloping bottom. The solution method is confined in a finite domain, which contains both the region of different depth of water and the plate. Laplace's equation and boundary value problems are solved in a finite domain, by the method of separation of variables and the small amplitude linear wave theory. The variation of horizontal force by single particle, total horizontal force and moment with respect to the wave amplitude are obtained at different depth of water and at different wave period. It is observed that the force and moment are converging with the increase of wave period and the gradients of force and moment with respect to the wave amplitude are extremely high for lower wave period.  相似文献   

Non-similarity solutions for explosion waves in stellar interiors     

G. Deb Ray 《Astrophysics and Space Science》1995,232(2):209-216

Non-similarity solutions in closed-forms, for propagation of explosion (instantaneous or non-instantaneous) waves in stellar models, in which the density falls off inversely as a power of distance, has been obtained in this paper. The power index lies in the interval 1 < < 3. The similarity solutions for = 2 5, valid only for an instantaneous explosion, follows as a particular one. Unlike the case of similarity solutions, the total energy of the wave as well as the strength of the shock varies with time. Besides, the solutions are applicable for arbitrary values of time.The results are extensions of my previous work (1969).  相似文献