A new method to derive middle atmospheric temperature profiles using a combination of Rayleigh lidar and O₂ airglow temperatures measurements

The vertical temperature profiles in a typical Rayleigh lidar system depends on the backscatter photon counts and the CIRA-86 model inputs. For the first time, we show that, by making simultaneous measurements of Rayleigh lidar and upper mesospheric O2 temperatures, the lidar capability can be enhanced to obtain mesospheric temperature profile up to about 95 km altitudes. The obtained results are compared with instantaneous space-borne SABER measurements for a validation

Improved time series prediction with a new method for selection of model parameters

A new method for model selection in prediction of time series is proposed. Apart from the conventional criterion of minimizing RMS error, the method also minimizes the error on the distribution of singularities, evaluated through the local Holder estimates and its probability density spectrum. Predictions of two simulated and one real time series have been done using kernel principal component regression (KPCR) and model parameters of KPCR have been selected employing the proposed as well as the conventional method. Results obtained demonstrate that the proposed method takes into account the sharp changes in a time series and improves the generalization capability of the KPCR model for better prediction of the unseen test data

Observations on the trawl-fisheries of the Bombay and Saurashtra waters, 1949-50 to 1954-55

A historical account of trawling experiments made in Indian waters before the Second World War is given by Chidambaram (1953). Of these, the Bombay waters were covered by S. T. Premier in the year 1900, S. T. William Carrick in 1921-22 and S. T. Madras in 1923. The results of working of S. T. William Carrick are available in the excellent report of Hefford (1949) while those of S. T. Premier and S. T. Madras have not been published. The outcome of these initial trials was not encouraging and it was felt that trawling might not prove economically successful in the areas worked. A reliable picture was, however, obtained of the different species of fishes occurring in these waters during different seasons of a single year

Future Indian earth observation systems

Indian Earth Observation (EO) capability has increased manifold since the launch of Bhasakra-I in 1979 to Cartosat-Z in 2007. Improvements are not only in spatial, spectral. temporal and radiometric resolutions but also in their coverage and value added products. It has also entered into the arena of passive and active microwave remote sensing. stereo viewing and viewing from the geo-synchronous platform at moderately high resolution. Observations specific to oceans and atmosphere are getting further emphasis. Demand for a constellation of satellites for monitoring disaster situations is strongly made. In this context, India has made extensive plans for continuity and enhancement in EO capability. not only towards its OWn national needs. but also as a contributing participant towards Global Earth Observation System of Systems (GEOSS). Major emphasis of the future plan has been to consolidate theme-specific satellites. in order to fill the gaps in observation including those for disaster monitoring and mitigation, and also to develop synergy with international missions for complementing and supplementing Indian missions. The future Indian EO systems include those for land applications-Resourcesat witli wide swath LlSS- Ill, high resolution Cartosat (0.3 m) and Imaging Radar (RISAT: C-band, multi- polarization). It also proposes to develop space based hyper-spectral sensor and atmospheric corrector. The future ocean application sensors include improved Ocean Color Monitor, Ku band scatterometer and a thermal IR sensor. The two major satellites dedicated for atmospheric observations are INSAT-3D with 6 channel imager and 19 channel sounder. and the ISRO-CNES joint venture Megha Tropiques with three sensors viz. MADRAS, SAPHIRE and ScaRab. Satellite for Argos and Ka band radio altimeter (SA RA I,). a joint ISRO-CNES mission is also underway. L-band polarimetric radiometer. hyper spectral sounder. rain radar, millimeter wave sounder, high resolution imager from geo-synchronous platform are some of the sensors being considered for future missions

Latitude gradient in aerosol properties across the Inter Tropical Convergence Zone: results from the joint Indo-US study onboard Sagar Kanya

As part of the Indian Ocean Experiment (INDOEX) Intensive Field Phase (IFP), a cruise by ORV Sagar Kanya was conducted in the Arabian Sea and the Indian Ocean from 20 January to 12 March 1999. Measurements on aerosol properties such as optical depth, mass concentration, size distribution, scattering and absorption coefficients were measured using instruments such as sun-photometer, quartz crystal microbalance, nephelometer and particle-soot absorption photometer. One of the important findings is the large north-south asymmetry in the aerosol characteristics. Aerosol optical depth values were very high, exceeding 0.4, close to the west coast of India and the Arabian Sea, which is greater than by a factor of 4 or more, compared to the values south of the ITCZ. The wavelength exponent α, is found to be in the range of 1.3 to 1.7 in the high optical depth region and is in the range of 0.5 to 0.7 over the pristine region. Aerosol mass concentration data show that the nucleation mode aerosols (radius < 0.1 µm) are systematically higher over the Arabian Sea, with values ranging from 20 to 50 µg/m3. Correlating the aerosol mass with the scattering coefficient, we get a scattering to mass concentration ratio of 2.27 m2/g, for the Arabian Sea region, which is in between the values reported by other workers, 3.3 m2/g for the continent and 1.67 m2/g for the marine regions, elsewhere in the world. The single scattering albedo, ω derived from the scattering and absorption data, is around 0.9 for aerosols found over the Arabian Sea, while near the coastal regions the values are as low as 0.8. Low ω and high optical depth found in the coastal region and Arabian Sea indicate large absorption by aerosols. The results undoubtedly show a large spatial difference in aerosol characteristics between north and south of the ITCZ which could lead to a large asymmetry in aerosol radiative forcing between the two regions

Influence of Polymer Restraint on Ballistic Performanceof Alumina Ceramic Tiles

An experimental study has been carried out to evaluate the influence of confinement ofalumina ceramic tiles through polymer restraint, on its ballistic performance. Tiles of 99.5 per centpurity alumina were subjected to ballistic impact against 7.62 mm armour piercing projectiles atvelocities of about 820 m/s. The tiles of size 75 mm x 75 mm x 7 mm were confined on both facesby effectively bonding varying numbers of layers of polymer fabrics. These were then bondedto a 10 mm thick fibre glass laminate as a backing using epoxy resin. High performance polyethyleneand aramid polymer fabrics were used in the current set of experiments for restraining the tiles.Comparative effects of confinement on energy absorption of tiles with varied number of layersof fabrics were evaluated. It was observed that by providing effective confinement to the tile,energy absorption could be doubled with increase in areal density by about 13 per cent.Photographs of the damage and the effects of restraint on improvement in energy absorptionof ceramic tiles are presented and discussed

Extension service for prawn farming

The technology of prawn culture in India is still traditional and extensive called trapping-cum-holding in brackish water ponds, but adoption of Improved extensive prawn culture technology Is claimed to be picking up fast In several places notably In West Bengal, Kerala, Andhra Pradesh and Orissa. The production from such culture practices is estimated at 15000-17000 tons/year, accounting for about 5% of the total prawn production In India the technology of scientific prawn culture is now available. Though steps are being taken to motivate, and encourage the fish farmers to take up prawn culture on scientific lines to increase their Income, lack of an appropriate extension network Is felt to be a major handicap In the field. This paper attempts to review the various extension services available for taking up prawn culture by the fish farmers. Identifies the pitfalls and proposes a working fisheries extension programme for prawn culture In Indi

Economic analysis of prawn culture in Andhra Pradesh - Some preliminary findings

Inadaquate supply of quality seed is one of the chief constraints that impedes the quick development of ptawn culture. Estuaries still remain the largest source of prawn seed supply. They are likely to remain so atleast for sometime in offing before the hatchery production of seeds is undertaken commercially and massively. The Marine Products Export development Authority assists the prawn farmers in setting up prawn seed banks by providing technical assistance on prawn culture, undertaking site selection and farm surveys, preparing project reports for submitting to the banks to get financial assistance, releasing subsidy to the tune of 16% on the capital cost of the project and providing continued technical assistance throughout the culture period. Already some prawn farmers have started establishing such prawn seed banks and supplying prawn seed commercially. This paper presents and discusses results of case studies on the economic feasibility of setting up prawn seed banks by fish farmers/prawn farmers

Status of brackishwater prawn farming in Andhra Pradesh

Andhra Pradesh is estimated to have 762.51 ha of brackishwater area under prawn culture- Prawn culture In brackishwater ponds as well as in paddy fields converted into prawn ponds is picking up fast In the coastal districts of Andhra Pradesh, especially in East Godavari, Krishna and Guntur districts. There are more than 200 ha of brackishwater areas suitable for prawn culture in West Godavari district alone. IVIore and more are being brought under prawn farming in this district. Seml-lntensive culture technology is employed by the fish farmers. The average yield Is estimated at 450 kg/ha/crop. This paper presents and discusses the status of prawn culture in Andhra Pradesh, identifies the constraints and suggests strategies for bringing the abundantly available brackishwater areas under scientific prawn culture to Increase the yield from these ponds