Multi-model ensemble-based probabilistic prediction of tropical cyclogenesis using TIGGE model forecasts     

Neeru Jaiswal  C. M. Kishtawal  Swati Bhomia  P. K. Pal 《Meteorology and Atmospheric Physics》2016,128(5):601-611

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Cloud — Aerosol interaction during lightning activity over land and ocean: Precipitation pattern assessment   总被引：1，自引：0，他引：1  

Jayanti Pal  Sutapa Chaudhuri  Arumita Roy Chowdhury  Tanuka Bandyopadhyay 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(3):251-261

The present study attempts to identify the land - ocean contrast in cloud - aerosol relation during lightning and non-lightning days and its effect on subsequent precipitation pattern. The thermal hypothesis in view of Convective Available Potential Energy (CAPE) behind the land - ocean contrast is observed to be insignificant in the present study region. The result shows that the lightning activities are significantly and positively correlated with aerosols over both land and ocean in case of low aerosol loading whereas for high aerosol loading the correlation is significant but, only over land. The study attempts to comprehend the mechanism through which the aerosol and lightning interact using the concept of aerosol indirect effect that includes the study of cloud effective radius, cloud fraction and precipitation rate. The result shows that the increase in lightning activity over ocean might have been caused due to the first aerosol indirect effect, while over land the aerosol indirect effect might have been suppressed due to lightning. Thus, depending on the region and relation between cloud parameters it is observed that the precipitation rate decreases (increases) over ocean during lightning (non-lightning) days. On the other hand during non-lightning days, the precipitation rate decreases over land.  相似文献   

Radiation damage-controlled localization of alteration haloes in albite: implications for alteration types and patterns vis-à-vis mineralization and element mobilization     

D. C. Pal  T. Chaudhuri 《Mineralogy and Petrology》2016,110(6):823-843

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Soil characterization in and around a proposed waste disposal facility at Nuclear Fuel Complex,Hyderabad, India     

Amrit Pal Singh  Manish Chopra  Faby Sunny  A. Vinod Kumar  R. B. Oza  D. S. Suryanarayana 《Environmental Earth Sciences》2016,75(6):540

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Impact of fly ash on channel morphology and ambient water quality of Chandrabhaga River of Eastern India   总被引：1，自引：0，他引：1  

Swades Pal  Susanta Mahato  Samrat Sarkar 《Environmental Earth Sciences》2016,75(18):1268

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Deformation behavior of migmatites: insights from microstructural analysis of a garnet–sillimanite–mullite–quartz–feldspar-bearing anatectic migmatite at Rampura–Agucha,Aravalli–Delhi Fold Belt,NW India     

Prakash  Abhishek  Piazolo  Sandra  Saha  Lopamudra  Bhattacharya  Abhijit  Pal  Durgesh Kumar  Sarkar  Saheli 《International Journal of Earth Sciences》2018,107(6):2265-2292

International Journal of Earth Sciences - In the present study we investigate the microstructural development in mullite, quartz and garnet in an anatectic migmatite hosted within a Grenvillian-age...  相似文献   

Singular spectrum analysis,harmonic regression and El-Nino effect on total ozone (1979–1993) over India and surrounding regions     

Chandramadhab Pal 《Journal of Earth System Science》2018,127(5):74

The Total Ozone Mapping Spectrometer (TOMS) is a satellite instrument that records Total Column Ozone (TCO) concentration (in DB) of the atmosphere in the form of different overpass files. We have selected 23 sites over India (15), Pakistan (4), Bangladesh (1) and adjoining China (3) to investigate the TCO scenario over this region. About 114,000 historical records (1979M1–1992M12) from 23 overpass files were processed to generate 23 monthly mean time series (TS) of TCO. Statistical analysis followed by singular spectrum analysis (SSA), harmonic regression (HR) and spatial interpolation have been used to accomplish the investigation. Four dominant signals; quasi-biennial signal (QBI, \(\hbox {T} = 30.12\) months), quasi-annual signal (QAN, \(\hbox {T} = 19.69\) months), annual signal (ANN, \(\hbox {T} = 12\) months) and semi-annual signal (SAN, \(\hbox {T} = 6\) months) were discerned to explain the variability. Direct latitudinal effect on the TCO distribution was observed. The variance was limited between 80.53 and 90.13%; ANN contributes 65.93–93.22% followed by SAN 0.58–5.69%, QAN 0.33–5.48%, and QBI 0.06–5.94%. Peak values of the oscillations are estimated from phasor diagrams: QBI, March to May in the mid-latitude; QAN, April, and May; ANN, February to April; SAN, March to May. Incisive pictures of the average distribution and variability of four sinusoids were investigated from contour plots. Two ozone valley were discerned from Spatial interpolation; one over Deccan Plateau in low and other over Tibetan Plateau in high latitude. 179 outliers from \(23 \times 168\) observations have been identified after harmonic regression. The appearance of the outliers is highly consistent with extreme phases of multivariate ENSO Index and Dipole Mode Index.  相似文献   

Observations of mid-troposhheric circulation from water vapour radiances of polar orbiting satellites     

M S Narayanan  P K Pal  P C Joshi  M Mali  Baby Simon 《Journal of Earth System Science》1989,98(3):247-254

Water vapour tracers can provide useful information on winds at ≈ 500mb by observing the 6·7μ radiances. This fills the data gap in the cloud motion winds provided by conventional meteorological geostationary satellites. There is no geostationary satellite at present over the Indian Ocean with 6·7μ imaging capability to provide mid-tropospheric winds. The potentials of 6·7μ radiances, available from polar orbiting satellites, for mid-tropospheric circulation features have been examined in this study. Tiros-N satellite data of May 1979 and ECMWF level-IIIb wind data were analysed to relate the radiances with the streamlines. We find that the radiances of 6·7μ from orbiting satellites agree well with the wind field.  相似文献   

Spatial Distribution of the Biotic Community in the Thermal Gradients of the Two Hot Springs     

B. B. Jana  D. N. Pal  H. L. Sarkar 《洁净——土壤、空气、水》1982,10(1):101-108

The runoff channels of two hot springs are investigated at seven and six stations with water temperatures of 64 … 34 or 44 … 35 °C, respectively. The temperatures are constant in the annual variation. With decreasing temperature, the pH-values and alkalinity decrease, whereas the hydrogen carbonate content and the orthophosphate concentration increase. In the range above 60 °C the mat consists of cyanophyceae and bacteria, and, unexpectedly, already from 60 °C also diatoms occur as dominant forms, below 40 °C the mat consisting of green algae and diatoms. With rotatoria, crustaceae and insects, herbivorous species occur only below 40 °C, fish species are regularly found below 38 °C.  相似文献   

Experimental superensemble forecasts of tropical cyclones over the Bay of Bengal   总被引：2，自引：1，他引：2  

T. S. V. Vijaya Kumar  J. Sanjay  B. K. Basu  A. K. Mitra  D. V. Bhaskar Rao  O. P. Sharma  P. K. Pal  T. N. Krishnamurti 《Natural Hazards》2007,41(3):471-485

This study entails the implementation of an experimental real time forecast capability for tropical cyclones over the Bay of Bengal basin of North Indian Ocean. This work is being built on the experience gained from a number of recent studies using the concept of superensemble developed at the Florida State University (FSU). Real time hurricane forecasts are one of the major components of superensemble modeling at FSU. The superensemble approach of training followed by real time forecasts produces the best forecasts for tracks and intensity (up to 5 days) of Atlantic hurricanes and Pacific typhoons. Improvements in track forecasts of about 25–35% compared to current operational forecast models has been noted over the Atlantic Ocean basin. The intensity forecasts for hurricanes are only marginally better than the best models. In this paper, we address tropical cyclone forecasts over the Bay of Bengal for the years 1996–2000. The main result from this study is that the position and intensity errors for tropical cyclone forecasts over the Bay of Bengal from the multimodel superensemble are generally less than those of all of the participating models during 1- to 3-day forecasts. Some of the major tropical cyclones, such as the November 1996 Andhra Pradesh cyclone and October 1999 Orissa super cyclone were well handled by this superensemble approach. A conclusion from this study is that the proposed approach may be a viable way to construct improved forecasts of Bay of Bengal tropical cyclone positions and intensity.  相似文献