9,816 research outputs found

    Applying the Betts-Miller-Janjic scheme of convection in prediction of the Indian monsoon

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    The performance of the Betts-Miller-Janjic scheme of convection has been investigated for prediction of the Indian monsoons. For this purpose a limited area numerical weather prediction model with two schemes of convection, one with the Betts-Miller scheme and other with the Betts-Miller-Janjic scheme, is run for five cases of monsoon depression that made landfall over the Indian coast. The results from the two schemes are compared. Detailed analyses of mean sea level pressure, wind, and rainfall have shown that the Betts-Miller-Janjic scheme has considerably improved the rainfall prediction over the Indian landmass and improvement is also seen in the mean sea level pressure fields and cyclonic circulation associated with the depression at the 850-hPa level. The forecast results are further verified by computing the root-mean-square errors, and the difference in the skill scores between the two model runs are tested for their statistical significance. It is found that the Betts-Miller-Janjic scheme has a statistically significant effect on the model skill beyond 24 h, with maximum impact on mean sea level pressure and geopotential height. The performance of the Betts-Miller-Janjic scheme of convection has been investigated for prediction of the Indian monsoons. For this purpose a limited area numerical weather prediction model with two schemes of convection, one with the Betts-Miller scheme and other with the Betts-Miller-Janjic scheme, is run for five cases of monsoon depression that made landfall over the Indian coast. The results from the two schemes are compared. Detailed analyses of mean sea level pressure, wind, and rainfall have shown that the Betts-Miller-Janjic scheme has considerably improved the rainfall prediction over the indian landmass and improvement is also seen in the mean sea level pressure fields and cyclonic circulation associated with the depression at the 850-hPa level. The forecast results are further verified by computing the root-mean-square errors, and the difference in the skill scores between the two model runs are tested for their statistical significance. It is found that the Betts-Miller-Janjic scheme has a statistically significant effect on the model skill beyond 24 h, with maximum impact on mean sea level pressure and geopotential height

    Thermodynamic adjustment parameters in the Betts-Miller scheme of convection

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    The sensitivity of the prediction of a monsoon depression to the adjustment parameters in a Betts-Miller scheme of deep convection is examined and an optimum parameter set is identified for the monsoon depression. For this purpose, a number of experiments have been carried out with a limited area model by assigning different values to the adjustment parameters, namely, the saturation pressure departure, the stability weight, and the adjustment time period. When one parameter is varied, the other two are kept constant. Results indicate that the depression track is sensitive to all three adjustment parameters. The upper-tropospheric temperature is sensitive to the stability weight and the rainfall rates are sensitive to the saturation pressure departure values. The rainfall shows minor sensitivity to the stability weight and the adjustment time period. A set of adjustment parameters that produced the best forecasts is taken as the optimum parameter set for the monsoon depression

    Malignant Melanoma of Nose and Paranasal Sinuses: 2 Case Reports

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    Malignant melanoma is one of the rare and highly aggressive diseases of the sinonasal cavity. High index of suspicion is required for diagnosis as the patient usually presents with non specific signs and symptoms. In the natural course of the disease, higher rate of loco regional recurrences and distant metastasis are seen making the overall prognosis of disease very poor. In reviewing the various treatment modalities used in the past, surgical resection of the tumour with postoperative radiotherapy is preferred one. Advances in surgery, radiotherapy and chemotherapy don’t have any impact on improved survival, which remains poor in this disease. We report two cases of malignant melanoma, which were treated at our institute

    Primary Non-Hodgkin's Malignant Lymphoma of the Sinonasal Tract

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    Primary non-Hodgkin’s lymphomas (NHL) of the sinonasal tract are rather uncommon entities. Morphologically and radiographically, sinonasal lymphomas are difficult to distinguish from other malignant neoplasms or non- neoplastic processes. They have a variable presentation from fulminant destructive manifestations to chronic indolent type of disease and may mimic as carcinomas and invasive fungal infection respectively. We report a case of primary NHL involving sinonasal tract in elderly female, which was clinically and radiologically mimicking as sinonasal malignany and was proven as NHL on histological examination and confirmed by immunohistochemistry. A high index of suspicion, appropriate histopathological examination and immunohistochemistry is necessary to differentiate sinonasal lymphomas from other possibilities. Failure to do so may miss the diagnosis and delay appropriate treatmen

    Impact of modified physics in limited area model forecasts

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    A number of physical factors have been introduced to improve limited area model forecasts. The factors include land surface fluxes, shallow convection and radiation. The model including these additional physical factors (modified physics) is run for five cases of monsoon depression which made landfall over the Indian coast, and the results are compared with those of the control run. The forecasts are verified by computing the root mean square and mean errors. The differences in these skill scores between the two model runs are tested for their statistical significance. It is found that the modified physics has a statistically significant effect on the model skill with the maximum impact on the mean sea level pressure and the temperature. Detailed analyses of mean sea level pressure, wind, rainfall and temperature further confirm that the modified physics has maximum impact on mean sea level pressure and temperature and marginal impact on wind and rainfall. Furthermore, analyses of some model parameters related to physics at a grid point for one case of depression were done. The results show that the inclusion of the land surface physics, shallow convection and radiative processes have produced a better precipitation forecast over the grid point

    Application of semi-implicit scheme of integration to barotropic prediction

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    Application of a semi-implicit version of primitive equation barotropic model to predict monsoon depressions is proposed. Forecasts upto 48 hr have been quite satisfactory. The results are compared with those obtained from an explicit version of primitive equation barotropic model developed earlier. The flow patterns from these two versions are similar with few exceptions in isolated pockets, however, the forecast movement obtained from the semi-implicit version is comparable or slightly superior to those obtained from the explicit version. The computational time in semi-implicit and explicit schemes is approximately in the ratio of 1:2

    Aggressive Fibromatosis in Neck.

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    Aggressive fibromatosis (AF) is a locally aggressive infiltrative low-grade benign tumor that accounts for approximately less than 3% of all soft tissue tumors. In the head and neck region this tumor tends to be more aggressive and associated with significant morbidity. Aggressive surgery is a viable management option and may be successfully used as a single modality treatment, or in combination with radiotherapy. We report a rare case of AF in a 38 year old female, who presented with a painless mass over the left supraclavicular fossa, extending inferiorly into the thoracic inlet, which was excised successfully in toto with the help of cardiothoracic vascular surgeon (CTVS)

    Selection criteria for drought tolerance in spring wheat (Triticum aestivum L.)

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    Weathered basalt application for management of Vertisols: A traditional knowledge of groundnut (Arachis hypogaea) growers of Gujarat, India

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    793-799Gujarat tops with 27.87% of total groundnut production. The basaltic shrink-swell soils are generally evaluated as unsuitable for groundnut production in Saurtashtra region of Gujarat. They have untapped source of traditional knowledge for managing heavy shrink-swell soils of basaltic terrain. Groundnut growers of the region are applying weathered basalt (WB, Vēraḍēḍa bēsālṭanuṁ in Gujarati) in pure form which is naturally available or sometimes treated by mixing the farmyard manures (FYM) or groundnut husk, and/or fortified with nitrogenous and phosphatic fertilizers. A study was planned to find out the reason for higher production of groundnut with the application of WB before sowing the seed. For this study the farmers were divided in to 05 groups on the basis of forms and combinations of WB application in groundnut fields. The participatory approaches and personal interviews were combined to collect the data from 25 farmers of each group. After interviewing the farmers, we came to know that this practice is being followed since 40 years. The study revealed that the practice significantly reduces the contracting and expanding phenomenon in black Vertisols and improve physico-chemical properties of soils like hydraulic characteristics (infiltration, permeability, percolation and drainage), aeration, bulk density, porosity, thermal conductivity and also improve availability of secondary (Ca, Mg & S) and micronutrients (Fe, Mn, Zn & Cu). The present study forms the basis for upgrading the traditional management packages for sustainable groundnut production in black soil region of India

    On some aspects of initialization and forecasts in the Indian monsoon region.

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    Application of a dynamic initialization scheme for balancing initial wind and pressure fields for a one-level primitive equation model in the Indian region has been investigated. For this purpose, the model equations are integrated forward and backward around the initial time following the Euler backward time-difference scheme without restoration of any variable. For comparison, the initial wind-pressure balance has also been constructed from the observed horizontal motion field by a hierarchy of models of increasing complexity, using the geostrophic relation, the linear balance equation and the nonlinear balance equation. Furthermore, the 48 h forecasts are prepared using the balanced initial data derived from the static nonlinear balance equation and the dynamic initialization scheme. The forecast results from both initialization schemes are compared and discussed. The results obtained from the dynamic initialization scheme are found to be either slightly superior or comparable to those based on the static initialization scheme
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