List of Forthcoming Papers

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List of Forthcoming Papers     

Experimental superensemble forecasts of tropical cyclones over the Bay of Bengal

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.     

Numerical Simulation of Andhra Severe Cyclone (2003): Model Sensitivity to the Boundary Layer and Convection Parameterization

The Andhra severe cyclonic storm (2003) is simulated to study its evolution, structure, intensity and movement using the Penn State/NCAR non-hydrostatic mesoscale atmospheric model MM5. The model is used with three interactive nested domains at 81, 27 and 9 km resolutions covering the Bay of Bengal and adjoining Indian Peninsula. The performance of the Planetary Boundary Layer (PBL) and convective parameterization on the simulated features of the cyclone is studied by conducting sensitivity experiments. Results indicate that while the boundary layer processes play a significant role in determining both the intensity and movement, the convective processes especially control the movement of the model storm. The Mellor-Yamada scheme is found to yield the most intensive cyclone. While the combination of Mellor-Yamada (MY) PBL and Kain-Fritsch 2 (KF2) convection schemes gives the most intensive storm, the MRF PBL with KF2 convection scheme produces the best simulation in terms of intensity and track. Results of the simulation with the combination of MRF scheme for PBL and KF2 for convection show the evolution and major features of a mature tropical storm. The model has very nearly simulated the intensity of the storm though slightly overpredicted. Simulated core vertical temperature structure, winds at different heights, vertical winds in and around the core, vorticity and divergence fields at the lower and upper levels—all support the characteristics of a mature storm. The model storm has moved towards the west of the observed track during the development phase although the location of the storm in the initial and final phases agreed with the observations. The simulated rainfall distribution associated with the storm agreed reasonably with observations.     

福建省矿山开采引发的地质灾害及防治建议

福建省矿产资源较丰富，各种规模矿山14000多座，为我省经济建设发挥了重要作用，由于粗放型开采，也引发了矿山地质灾害，造成多起伤亡事故和严重经济损失，同时引发社会安定问题。为此提出防治建议。     

滇西上芒岗金矿床地质地球化学特征

上芒岗金矿由下部原生卡林型和上部 红色粘土型金矿体所组成，赋矿地层为侏罗系勐戛组砂泥质岩、白云质灰岩和二叠系沙子坡组泥硅质灰岩、白云岩。北东向上芒岗断裂构造与不整合面和岩溶的复合控制了矿床和矿体。围岩蚀变以硅化（似碧玉岩化）、黄铁矿化、碳酸盐化和粘土化为主，并具有水平与垂向分带性。地球化学研究表明，蚀变与矿化岩石的稀土含量与未蚀变泥质灰岩基本一致，成矿溶液为富CI^－型和富SO4^2-型，爆裂温度为183－378℃，δ^34S=6.471‰-21.965‰，δ^18O=9.3‰-11.6‰，δD=-70‰--77‰，^206Pb/^204Pb=19.551-20.05,^207Pb/^204Pb=15.690-16.240,^208Pb/^204Pb=38.710=40.137。红色粘土型矿石的红土化作用只达到粘土阶段。     

Occurrence of heavy rainfall around the confluence line in monsoon disturbances and its importance in causing floods

It is well known that heavy rainfall occurs in the southwestern sector of the monsoon depressions due to strong convergence in that sector. By examining the rainfall distribution associated with the monsoon disturbances (lows and depressions) in one of the central Indian river basins, ‘Godavari’, the author found that when the disturbance-centre is away from the basin, heavy rainfall may also occur in the basin area close to the confluence line and cause severe floods in the river. The confluence line is the zone of convergence between the northeasterlies to the west of the disturbance centre and the monsoon westerlies. This study further reveals the importance of the position and movement of the confluence line with respect to the basin, on which the intensity and the raising period of the resulting flood depend.     

Seasonal and solar cycle association of zonal drifts of ionospheric plasma irregularities in the Indian equatorial region

Long series of simultaneous VHF scintillation observations at two stations situated in near magnetic east-west direction in the vicinity of the dip equator in the Indian region have been employed to investigate the night-time ionospheric plasma zonal drifts. The drifts are found to be predominantly easterly. On comparing the magnitudes of the drifts with those results derived earlier by HF fading technique, monitoring signals from two satellites at a station and spaced receiver experiment, their associations with the season and the degree of solar activity are discussed. On a broader scale, the annual mean sunspot number is shown to have a direct control on the derived drift, the positive relationship even on day to day basis with the solar flux is established. However, the relationship, as understood by the slope of the best fit line, in the Indian region (0.27) is found to be weaker when compared with the similar slope (0.45) in the American sector. There appears to be no geomagnetic activity control on the estimated drifts.     

Parabolic density function in sedimentary basin modelling

For modelling sedimentary basins of large thickness from their gravity anomalies, the concept of parabolic density function which explains the variation of true density contrast of the sediments with depth in such basins is introduced inBott's (1960) procedure. The analytical expression the gravity anomaly of a two-dimensional vertical prism with parabolic density contrast needed to estimate the gravity effect of the basin in modelling procedure is derived in a closed form. Two profiles of gravity anomalies, one across San Jacinto Graben, California and the other across Tucson basin, Arizona where the density of sediments is found to vary with depth are interpreted.     

Miscellaneous information 1989 (Addendum)

Miscellaneous information 1989 (Addendum)