008624   Jaswal A K;Koppar A L (NO, , India Meteorological Dep, Hivajinagar, Pune-411 005, Email: akjaswal@imdpune.gov.in) : Climatology and trends in near-surface wind speed over India during 1961-2008. Mausam 2013, 64(3), 417-36.

This study analyses near-surface wind speed changes in India during 1961 to 2008. Consisting of monthly wind speed data of 171 stations, the results show that most of the stations in India have experienced significant weakening of wind speed, both at monthly and annual timescales. All-India averaged annual mean wind speed has decreased from 9.7 kmph in 1961 to 5.0 kmph in 2008 resulting in a 49% decrease. All India averaged rate of decrease in annual mean wind speed is -0.88 kmph/decade. On monthly scale, the largest rate of decline is in June (-1.33 kmph/decade) and the smallest is in October (-0.60 kmph/decade). Spatially, large declines are found in western India, south peninsula and the coastal areas while central, southeast and northeast India have the lesser change in wind speed. Significant weakening of wind speed has occurred primarily in regions along Gujarat, Maharashtra, Tamil Nadu, north Karnataka, coastal Orissa and coastal West Bengal which also have higher annual mean wind speed. Annual mean wind speeds exceeding 15 kmph are observed only over Gujarat and south Tamil Nadu. Some parts of Rajasthan, west Madhya Pradesh, Maharashtra, north Karnataka and adjoining Andhra Pradesh and some pockets along west and east coasts experience wind speeds of 10-15 kmph. Stations having annual mean wind speed exceeding 10 kmph are rare in north India. The study evaluates climatology of winds and its long-term trends over various regions of India where wind power can be profitably utilised. The prominent regions are in Gujarat and adjoining Madhya Pradesh, south Rajasthan, north Maharashtra, north Karnataka, south Tamil Nadu, coastal Andhra Pradesh and along the west coast from Gujarat to Goa and along the east coast from Kolkata to Nagapatinam.

19 illus, 1 table, 22 ref

008623   Hazarika D;Thangaraj M;Sahu S K;Kathiresan K (Centre of Advanced Study in Marine Biology, Faculty of Marine Science, Annamalai Univ, Parangipettai-608 502, Email: coralholder@yahoo.com) : Genetic diversity in three populations of Avicennia marina along the eastcoast of India by RAPD markers. J envir Biol 2013, 14(3), 663-6.

Genetic diversity was analysed in three populations of the mangrove species, Avicennia marina by using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). Ten random decamer primers were used to score the diversity from three locations of eastcoast of India: Parangipettai (Tamil Nadu), Kakkinada (Andhra Pradesh) and Sundarbans (West Bengal). These primers produced 388 scorable DNA fragments, of which 252 (64.98%) were polymorphic, 182 (46.90%) were monomorphic, and 14 (3.61%) were unique. RAPD banding patterns displayed variations between and within the populations, while, there was no morphological variation.

1 illus, 3 tables, 19 ref

008622   Gore P G;Chavan A B (NO, , India Meteorological Dep, Pune-411 005, Email: gore_prabhavati@rediffmail.com) : Probabilities of wet spells over North Eastern India leading to flood condition. Mausam 2013, 64(3), 475-80.

Floods are caused by the inadequate capacity within the banks of rivers to contain the high flows brought down from the upper catchments due to heavy rainfall. The sub-divisions Assam and Meghalaya and Sub-Himalayan West Bengal from northeastern parts of India are prone to flood conditions in the southwest monsoon season. In the present study an attempt has been made to give the probabilities computed by first order Markov chain model with certain threshold value for 2 and 3 consecutive wet weeks for selected districts of the sub-divisions Assam and Meghalaya and Sub-Himalayan West Bengal. The critical periods identified for certain region when probabilities of wet spells exceed 80% may lead to give awareness and planning for heavy rainfall in those areas.

2 illus, 2 tables, 9 ref

008621   Ghaedi S;Movahedi S (NO, Payame Noor Univ, Islamic Republic of Iran, Email: sohrab.ghaedi@gmail.com) : Role of red sea trough on humidity source of east mediterranean cyclones. Mausam 2013, 64(3), 539-46.

Mediterranean cyclones, especially east cyclones of this sea, play a very important role in precipitation events of cold season in Iran. In the other hand formation of surface trough over the Red Sea makes possible the displacement of humidity from tropical area to extra-tropical area. To determine the role of Red Sea trough in supplying humidity sources of EM cyclones, surface data of geopotential height, specific humidity and Vertical and Horizontal component of wind in limited 5 through 65 degrees of north latitude and 0 through 80 degrees of east longitude were used. During the study 56 cyclones formed over the east of Mediterranean recognized which were simultaneous to the Red Sea troughs events. Convergence maps of moisture flux of 10 cases of simultaneous cyclones with Red sea trough which were strong, were drawn. Verification of convergence maps of moisture flux of selected cases show some required humidity for EM cyclones are initiated from Arabian Sea and then to some extent are reinforced over Persian Gulf and Gulf of Aden and then by passing over Red Sea eater to the south east of Mediterranean Sea. Actually Red Sea has not an important role in the humidity source of these cyclones and acts as a pass way for displacement of humidity of tropical area to extra-tropical area and injects the required humidity into the EM cyclones. To determine the regions and the amount of suction in the high levels, composite maps of ageostrophic divergence and jet streams of polar front were used.

11 illus, 1 table, 28 ref

008620   Gaonkar S B;Rao P C S;Kore P A;Joshi S P; Abhang P R;Singh U P (NO, , India Meteorological Dep, Pune, Email: sbgaonkar@gmail.com) : Analysis of sea level pressure and sea surface temperature anomalies in the month of may for th excess and deficit Indian summer monsoon rainfall. Mausam 2013, 64(3), 553-7.

2 illus, 3 tables, 12 ref

008619   Dharwadkar A;Roy S K;Pradeep Kumar;Swain A K; Raghu Ram (Polar Studies Div, Geological Survey of India, NH 5P, NIT, Faridabad-121 001, Email: amit.dharwadkar@gsi.gov.in) : GPR profiling over lake untersee, central dronning maud land, East antarctica. Indian J Geosci 2013, 67(2), 153-8.

Ground Penetrating Radar (GPR) is a non-invasive, cost- and time-effective geophysical technique for subsurface investigations. The present communication reports an attempt to study the physical layering in the perennially-frozen Lake Untersee in central Dronning Maud Land in East Antarctica using GPR. The vertical as well as lateral variations in the frozen surface of the lake are delineated using the GPR profiles. The data was collected using SIR 20 GPR system with 400 MHz antenna in a single fold, fixed offset, free-run mode. The frozen upper surface of the lake shows high degree of lateral and vertical variations mainly reflecting variable compaction of different ice layers. The surface ice layer over Lake Untersee is found to vary from 1.5 m to 4.5 m in thickness. At least two to three interfaces have been deciphered up to a depth of 40 m of GPR profile which probably result due to stratification in the lake owing to contrasting physical and chemical properties.

5 illus, 4 ref

008618   Das P;Mondal S K;Dutta S (Applied Mathematics with Oceanology and Computer Programming Dep, Vidyasagar Univ, Midnapore-721 102, Email: pdas.math1986@gmail.com) : Asymptotic solution for 3D Lee waves across Assam-Burma hills. Mausam 2013, 64(3), 501-16.

Attempt has been made to obtain an asymptotic solution for the updraft/downdraft associated with Lee wave across the Assam-Burma hills (ABH) for an idealized basic flow, where, both stability and wind in the basic flow remain invariant with height. ABH has been approximated by two three dimensional elliptical barriers, separated by a valley of some finite distance. For simplicity, the basic flow has been assumed to have only one component normal to the major ridges of the barriers. For this purpose, perturbation technique has been applied to the governing equations. The perturbation vertical velocity (ω ) and streamline displacement (η) are expressed as double integrals, which have been attempted to approximate as an asymptotic expansion. The results obtained are found to be consistent and have been compared with the results obtained by earlier investigators.

4 illus, 34 ref

008617   Chan P W;Lee Y F (NO, , Hong Kong Observatory, Hong Kong, China, Email: pwchan@hko.gov.hk) : Application of brightness temperature data from a ground-based microwave radiometer to issue low-level windshear alert over Hong Kong international airport. Mausam 2013, 64(3), 457-66.

Use of the microwave radiometer in the alerting of low-level windshear at the Hong Kong International Airport has been discussed in Chan and Lee (2011). This paper extends the previous work by considering all the 14 channels of the microwave radiometer in use in Hong Kong and trying out other proxies of the fluctuations of the brightness temperature of the radiometer apart from variance, namely, auto-correlation of the time series. It turns out that the oxygen channels with frequencies in the region of 57 to 58 GHz perform the best in the capturing of the low-level windshear, probably because their effective ranges are close to the heights of the windshear reports (below 500 m, or 1600 feet) and there are temperature fluctuations associated with terrain-induced windshear, the main cause of low-level windshear in the spring time (the period under investigation in this study). By combining the radiometer-based windshear alerts with those from the Light Detection And Ranging (LIDAR) systems or the Windshear and Turbulence Warning System (WTWS), it is possible to achieve a hit rate of pilot windshear reports close to 95% and an alert duration less than 20% over the most used departure runway corridor in the spring time, which are comparable with the overall windshear alerting service at the Hong Kong airport. Among the two approaches, viz., (i) variance and (ii) auto correlation coefficient of the brightness temperatures, the variance of brightness temperature of the radiometer performs slightly better with a higher hit rate.

6 illus, 2 tables, 8 ref

008616   Bhattacharjee S;Nandy S;Mazumdar N;Sarma K P (NO, Geological Survey of India, Southern Region, Petrology Div, Bandlaguda, Hyderabad-500 068, Email: raju_gsi@rediffmail.com) : Late palaeozoic episode of granite magmatism from zimithang of higher Himalayas: implications for the evolution of higher Himalayan crystalline belt from Western Arunachal Pradesh, India. Indian J Geosci 2013, 67(2), 107-16.

Higher Himalayan Crystalline belt of western Arunachal Himalayas exposes two generations of granite: (a) Zimithang Granite and (b) tourmaline-bearing leucogranite. This paper presents petrological characteristics and EPMA dating of xenotime from Zimithang Granite. The Zimithang Granite is a grey to pink coloured porphyroclastic augen gneiss, foliated and partly undeformed monzo- to syeno-granitic in composition and crops out as a large batholith ernplaced in an extensional tectonic regime. Megascopically and petrographically the Zimithang Granite is divided into two variants: (a) grey type (b) leuco type. As per QAP plots these are senso stricto granites, the grey variant is syenogranite while the leuco variant is monzogranite. The Zimithang Granite overrides the Lumla Formation (an equivalent of Dirang Formation of Lesser Himalayas exposed in a window) of Lesser Himalayan sequence to the south along the Lumla-Zimithang road section at 35.5 km post from Lumla while Zimithang Granite marks an intrusive contact with Sela Group at 27°42'N: 91°48'E on way to PTSo from Zimithang. However, the northern contact is not exposed in India. EPMA xenotime dating of both the variants of Zimithang Granite gave 286 ±41 Ma indicating an episode of granite magmatism during early Permian which has hitherto not been reported.

5 illus, 4 tables, 18 ref

008615   Balaji Prasath B;Nandakumar R;Dinesh Kumar S; Ananth S;Shenbaga Devi A;Jayalakshmi T;Raju P;Thiyagarajan M; Santhanam P (Marine Science Dep, School of Marine Sciences, Bharathidasan Univ, Tiruchirapalli-620 024, Email: sanplankton@yahoo.co.in ) : Seasonal variations in physico-chemical characteristics of pond and ground water of Tiruchirappali, India. J envir Biol 2013, 14(3), 529-37.

Aim of this study was to assess the open pond and groundwater quality of Tiruchirapalli city of Tamil Nadu, India. The groundwater quality viz., pH, electrical conductivity, total hardness, calcium ion, magnesium ion, chloride, carbonate, bicarbonate, inorganic nitrate, nitrite, phosphate, ammonia and reactive silicate were analysed with respect to various seasons and recorded in the range of 7.1 to 8.1, 97.67 to 533.67 mhos cm^{-1, 7.07 to 186 mg I-1, 4.67 and 112.0 mg I-1, 2.40 to 92.80 mg I-1, 15.23 to 661.73 mg l-1, 60 to 480 mg I-1, 22.7 to 544.9 mg I-1, 15.33 to 68.00 mg I-1, 0.001 to 0.480 mg I-1, 0.01 to 0.42 mg I-1, 0.02 to 0.75 mg I-1 and 1.1 to 2.96 mg I-1 respectively. The present findings concluded that the quality of ground waters can be considered suitable for human consumption. But the pond water available in and around Tiruchirappalli city was not fit for human usage, agricultural or industrial purposes.}

1 illus, 7 tables, 29 ref

008614   Amudha B;Raj Y E A (NO, , Regional Meteorological Centre, Chennai-600 006, Email: amudha_aug@yahoo.com) : Operational weather forecasting using data from automatic weather stations and other modern observing systems - case study of tropical cyclone Jal 2010. Mausam 2013, 64(3), 437-56.

Hourly meteorological data available from hitherto unrepresented locations due to the installation of satellite-based Automatic Weather Stations (AWS) by India Meteorological Department are valuable. The potential utility of data from such AWS for operational weather forecasting is tremendous, particularly during adverse weather situations like that of a cyclonic storm. In this paper, a case study of the Tropical Cyclone (TC) Jal which formed during the period 4-8 November, 2010 over Bay of Bengal and crossed north of Chennai has been undertaken mainly by utilising data from AWS in the southern Indian peninsula. Utility of the data in assessment of the intensity of Jal has been explained. The landfall location of Jal near Sriharikota (SHR) around 1800 UTC of 7th November, 2010 could be pinpointed using wind and hourly pressure data correlated with inputs from other rnodern equipments like the High Wind Speed Recorder, products from Doppler Weather Radar (DWR) at Chennai and high resolution imageries from Kalpana-1 satellite. The pressure defect and maximum winds in the cyclone field have been computed by using a theoretically derived proportionality constant (K). An analysis on the effect of environmental flow, direction of movement and friction on the maximum winds observed in a land station has been made using the wind speed values recorded by AWS at Ennore Port located north of Chennai. The possible lower bound of wind speed of the cyclone while out at sea has been computed and verified that the operational declaration of the TC Jal as a cyclonic storm at 0600 UTC of 7th was correct.

18 illus, 2 tables, 25 ref

008613   Ahasan M N;Chowdhury M A M;Quadir D A (NO, SAARC Meteorological Research Centre (SMRC), Dhaka, Bangladesh, Email: nazmul_smrc@yahoo.com) : Simulation of a heavy rainfall event of 11 june 2007 over Chittagong, Bangladesh using MM5 model. Mausam 2013, 64(3), 405-16.

Study attempts to simulate a heavy rainfall event that occurred on 11 June 2007 over Chittagong, Bangladesh using the Fifth-Generation PSU/NCAR Mesoscale Model (MM5). This extraordinary rainfall event was localized over Chittagong region and recorded 425 mm of rainfall within a span of 24 hrs on that eventful day. The event resulted in large human and economic losses due to flash flood and land slide. The MM5 model was run on triple-nested domains at 45, 15, 5 km horizontal resolution using Anthes-Kuo (i.e., AK) cumulus parameterization scheme (CPS) with medium range forecast (MRF) planetary boundary layer (PBL) scheme. The results obtained through MM5 suggest that the highly localized heavy rain over Chittagong was the result of an interaction of the mesoscale severe convective processes with the large scale active monsoon system. The analysis shows that the convective cells formed over Chittagong were very intense but short-lived and required moisture have been supplied from the Bay of Bengal. A sensitivity test of cumulus parameterizations in MM5 model has also been conducted. The results show that the model simulated rainfall amount over Chittagong has been overestimated by AK CPS with MRF PBL formulation and underestimated by Grell, KF, BM and KF2 cumulus parameterization schemes compared to the observed TRMM rainfall and all CPS are underestimated as compared with BMD RNG. Finally, the Anthes-Kuo cumulus scheme with MRF PBL has been found to perform better in estimating rainfall over Bangladesh. The model performance was evaluated by examining the different predicted parameters like mean sea level pressure, upper and lower level circulations, wind shear, relative vorticity, convergence, moisture and rainfall. The results indicate that the MM5 model with the right combination of the nesting domain, horizontal resolution and cumulus parameterization schemes was able to simulate the heavy rainfall event, and associated synoptic features reasonably well, though there are some biases in the rainfall pattern.

10 illus, 3 tables, 26 ref

008612    (NO, , Meteorological Office, Pune-411 005) : Cyclones and depressions over the North Indian Ocean during 2012. Mausam 2013, 64(3), 397-404.

1 illus, 3 tables

007474   Zhu C;Hao W (State Key Laboratory of Hydrology - Water Resources and Hydraulic Engi, Nanjin Hydraulic Research Institute, Nanjing, 210029, China) : Modelling of grey differential model of river water pollution and its application. Nat Envir Pollut Technol 2013, 12(4), 637-40.

Based on the grey theory, grey characters of river environment system were analyzed. The velocity and dispersion coefficient and attenuation in river were considered as uncertainty parameters and expressed as grey parameters. A grey differential equation of contaminant diffusion in river was built. And the equation has special structure. The truncation error of finite differential method in solving the model was corrected. According to the model, distribution values of pollutant concentration under sudden pollutant discharge can be obtained directly, which can provide abundant and useful water quality information for the plan and control of water pollution. It is shown that the calculated results obtained from the grey model are reliable and reasonable.

3 illus, 9 ref

007473   Zhao L;Lin J;Wang X (School of Economics, Zhejiang Gongshang Univ, Hangzhou, 310018, China) : Potential water resources crisis based on STIRPAT model: a case from Zhejiang in China. Nat Envir Pollut Technol 2013, 12(4), 631-6.

Zhejiang province in China is confronting with pressing problems for how to rationally develop and sustainably use water resources. Due to the large population base, water resource per capita in Zhejiang is not plentiful, although it is a place abundant in water. As in the 2011, water resource per capita in Zhejiang province is 1,362 m^{3. In view of this, Zhejiang province should be regarded as an area of moderate water shortage. The paper introduces the STIRPAT model to describe and further explore linkages between water consumption and population as well as other socio-economic factors to select out major ones affecting water resources consumption for 11 prefecture-level cities in Zhejiang province. Based on the empirical results, paper tries to propose suggestions for long-term water management in Zhejiang province.}

14 ref

007472   Yue-jian W;Jing D;Yang L;Zhi-hui L (School of Resources and Environment Science, Xinjiang Univ, Urumqi 830054, China) : Research on a new physical based hydrological model applied in Ebinur lake basin in China. Nat Envir Pollut Technol 2014, 13(1), 39-40.

Physical based hydrologic model based on grid-scale for water resources management (WYJ) was applied into the Ebinur Lake basin in Xinjiang Province, China. Several physical parameters were considered in this model and calculated based on the physical properties by combination with GIS tools. We have considered the warm-up period in order to reduce the error accoused by the uncertainty produced from the physical model. After the calibration and validation of the model, the results showed that the model was able to simulating the basin hydrological processes with high efficiency especially in ground surface. The N-S efficiency coefficient was once exceeded 0.85 in simulation periods and R^{2 can also reach 0.92. We can draw a conclusion that this physical model can be applied into the Ebinur Lake basin and can provided for decision making for the government.}

4 illus, 14 ref

007471   Lingyun H;Xianyong M;Jing D;Yuejian W;Yongge C;Xiangling T (College of Science Geography Dep, Shihezi Univ, Shihezi, 832000, China) : Ecological characteristics and change analysis of Xin jiang Junggar basin based on the NDVI. Nat Envir Pollut Technol 2014, 13(1), 192-6.

SPOTVGT NDVI data of 1998 to 2008 were selected to analyse the ecological pattern and variation characteristics of Junggar basin in China. Conclusions are as follows: The overall ecological pattern of the basin is that, an apparent and continuous oasis belt was formed in the north, a small oasis area was distributed in the northern basin, and the ecological condition in the centre of the basin is poor but stable. The most flourishing period of the natural vegetation in the basin is in August, while in the central part of the basin, it lasts from late May to early June; vegetation also apparently appears flourishing during this period with subsequent downfall of ephemeral plants. While the ephemeral plants are distributed in the whole basin except the artificial farmland, flourished in the oasis edge, rare in the central part of the basin, but a slightly prosperous area was formed in the middle of the basin (North of Hutubi). The biomass in the basin has increased within basin in recent years mainly due to the agricultural expansion. The development activities of human mainly affect the edge of the oasis with the range of 50 km, and the greatest impact area is near the edge of the oasis with 5-10 km.

5 illus, 16 ref

006526   Vishnoi B N (India Meteorological Dep, Weather Radar Station, Jaisalmer-345 001, Email: bn.vishnoi@imd.gov.in) : Sector wise echoes study and climatology around Jaisalmer. Mausam 2014, 65(1), 93-8.

Capability of Weather Radar to see through the thunder clouds and rain has made it a unique observation tool for remotely surveying the atmosphere. Pulsed radar technique has been applied with remarkable success to map the rain field of various duration and intensities along with movement of storms in real time within the effective detection range of radar. It is a very good tool for forecaster to provide better warning for impending storms and heavy rainfall over the area under radar surveillance and thereby losses due to storm can be minimized while their benefits can be continued like water resource management. In the present work attention has been focused on conducting a comprehensive study of frequencies of occurrence of echoes around Jaisalmer up to 200 km from radar site and the surrounding of it has divided into four equal sectors, i.e., sector-1 (NW, 270°-360°), sector-2 (NE, 0°-90°), sector-3 (SE, 90°-180°) and sector-4 (SW, 180°-270°). Total number of echoes under the study was 28918 for the period from 19th April, 1993 to 31st December, 2010. Total number of echoes analyzed in Sector-1, were 5441(18.8%), in sector-2, number of echoes analyzed were 9554(33.0%), in sector-3, number of echoes analyzed were 9479 (32.8%) and in sector-4, number of echoes analyzed were 4444(15.4%). Radar echoes to be classified month-wise and the lowest number of average echoes observed in the month of December was 0.4%, in the month of November 0.5%, in October and March 1.6% and in the month of January and February 2.0%. The highest number of annual average echoes observed in the month of July was 30.1% followed by August 24.6%, June 17.2%, May 8.3%, April 6.3% and September 5.8%. Height wise echoes analyzed and the highest number of echoes found for 3 km in all the four sectors were 29.0% and the lowest were for 16 km as 0.2%.

2 illus, 2 tables, 8 ref

006525   Vanaja S J;Mudgal B V;Thampi S B (Centre for Water Resources, Anna Univ, Chennai, Email: josephine.vanaja@yahoo.com) : Rainfall-runoff modeling using doppler weather radar data for adyar watershed, India. Mausam 2014, 65(1), 49-56.

Precipitation is a significant input for hydrologic models; so, it needs to be quantified precisely. The measurement with rain gauges gives the rainfall at a particular location, whereas the radar obtains instantaneous snapshots of electromagnetic backscatter from rain volumes that are then converted into rainfall via algorithms. It has been proved that the radar measurement of areal rainfall can outperform rain gauge network measurements, especially in remote areas where rain gauges are sparse, and remotely sensed satellite rainfall data are too inaccurate. The research focuses on a technique to improve rainfall-runoff modeling based on radar derived rainfall data for Adyar watershed, Chennai, India. A hydrologic model called 'Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS)' is used for simulating rainfall-runoff processes. CARTOSAT 30 m DEM is used for watershed delineation using HEC-GeoHMS. The Adyar watershed is within 100 km radius circle from the Doppler Weather Radar station, hence it has been chosen as the study area. The cyclonic storm Jal event from 4-8 November, 2010 period is selected for the study. The data for this period are collected from the Statistical Department, and the Cyclone Detection Radar Centre, Chennai, India. The results show that the runoff is over predicted using calibrated Doppler radar data in comparison with the point rainfall from rain gauge stations.

7 illus, 1 table, 14 ref

006524   Valdiya K S (NO, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore-560 064, Email: valdiya@jncasr.ac.in) : River Sarasvati. Curr Sci 2013, 104(8), 996-7.

illus, table, ref

006523   Uddin M M;Zafar M;Chowdhury S R (Institute of Marine Sciences and Fisheries, University of Chittagong, , Chittagong 4331, Bangladesh, Email: mmu_ims76@yahoo.com) : Water, salt and nutrient flux through the lower Meghna River estuary, Bangladesh. Indian J Geomar Sci 2014, 43(2), 280-3.

Water, nutrient and Salt transport through the lower Meghna River-estuary, a combined flow of the Ganges and Brahmaputra and many other rivers and creeks, were studied. Material (salt, water and nutrients) fluxes covering an area of about 532 km2 were calculated. Present study consists a single layer simple box model to study the budget of the materials in the lower reaches of the river estuary. Hatiya Channel, the system produces net amount of DIP and DIN in almost all the seasons i.e. source of nutrients, and the production of nutrients were higher during monsoon. Residual water volume and mixing volume were high during monsoon. A quick exchange of residual water takes place during monsoon.

3 illus, 3 tables, 11 ref

006522   Thangaraj M;Saranya S;Divya S;Ramanadevi V; Subburaj J (Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai-608 502, Email: coralholder@yahoo.com) : Molecular phylogenetic status of some marine Cymothoid isopods in Southeast coast of India. Indian J Geomar Sci 2014, 43(2), 271-6.

In this study, 16S rRNA and COI genes of four Indian isopod species and nine other species (retrieved from NCBI) of the three parasitic habits were examined to present a different hypothesis on the evolutionary history of the family. Present study infers that there is no relationship among the habitat-specific species. Phylogenetic tree support the monophyly of the family and the specialized mouth parts bearing species (endoparasites) are not necessarily derived from the scale attaching ones (ectoparasites). The use of more molecular markers can greatly improve the taxonomic revisions of the Cymothoidae and the present work could be a valuable first step towards this task.

2 illus, 3 tables, 22 ref

006521   Sunitha Devi S;Dutta S;Prasad K (NO, India Meteorological Dep, Pune, Email: sunithas.devi@gmail.com) : Energetics of super cyclone 'GONU' and very severe cyclonic storm 'SIDR'. Mausam 2014, 65(1), 37-48.

This paper discusses the energetics aspects of two tropical cyclones formed over the north Indian Ocean during 2007, viz., the Super Cyclonic Storm (GONU) and the Very Severe Cyclonic Storm (SIDR). From the analysis of various energetics terms such as the Eddy Available Potential Energy (A_E), Zonal Available Potential Energy (A_z), Zonal Kinetic Energy (K_z), Eddy Kinetic Energy (K_E) and their generation and inter-conversions i.e., G(A_E), G(A_z), C(A_E KE), C(A_z, KZ), C(K_z, KE) and C(A_z, A_E) have been computed on day to day basis during the periods of their intensifications over the domain 5° N to 25° N, 55° E to 75° E in respect of 'GONU' and 5° N to 25° N, 77° E to 97° E for 'SIDR'. Besides the above, the area averaged value of σ (Sigma), the vertically averaged Moist Static Energy (MSE), has also been computed on each day. Day-to-day evolution of these parameters is mapped and described. Some of the distinguishing features in the energetic of these two intense vortices which formed in entirely different climatological settings have been brought out. It is noticed that in the case of 'GONU', though both barotropic and baroclinic energy conversions have taken place during the life cycle, the intensification phase is characterized by an enhancement in AE, K_E and vertically integrated Moist Static Energy. Enhancement in A_E can be attributed to the generation of A_E, which may again be attributed to the asymmetric latent heat of condensation associated with the asymmetric rainfall in the cyclone field. Enhancement in KE may be attributed to the enhancement in both barotropic and baroclinic conversion into K_E. Though most of these observations made for 'GONU' are found to be attributable to 'SIDR' as well, the intensification of 'SIDR' appears to have more similarity to that of a typical growing mid-latitude baroclinic wave. In this case, the enhancement in A_E, could also be attributed to positive C(A_z,A_E), which is mainly due to interaction with mid-latitude baroclinic westerly wave. The energetics analysis also indicates that GONU had helped in the enhancement of seasonal mean meridional circulation where as the SIDR had inhibited the enhancement of seasonal mean meridional circulation.

5 illus, 15 ref

006520   Su L;L Y;Zheng J;Guo J;Xu Y;Chen G (The Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, anzhou, 730000 Gansu, PR China, Email: longsu@lzb.ac.cn) : Thermolytic dynamics and prediction of natural gas generation from marine source rocks in the deepwater area of Qiongdongnan Basin, China. Indian J Geomar Sci 2014, 43(2), 149-62.

Present study is to quantify individual natural gas generation in the deepwater area of the Qiongdongnan Basin based on the basin modeling from the shallow-water, and to evaluate kinetic parameters and geological extrapolations using an optimization procedure.Kinetic model presented reproduces the detailed features of shale pyrolysis and coal processing. The idea of blending these two approaches is not new, but until now the most sophisticated attempts reproduced only the gross features of kerogen cracking. It will help to forecast preferable prospect area, and to accelerate the prospecting of natural gas in the deepwater area of the Qiongdongnan Basin.

7 illus, 4 tables, 39 ref

006519   Sonal D;Lakhmapurkar J;Gavali D (NO, , Gujarat Ecology Society, 3rd Floor, Synergy House, Subhanpura, Vadodara, Gujarat, Email: sdeshkar.101@gmail.com) : Temporal variation in the nutrient fluxes in Narmada estuary. Indian J Geomar Sci 2014, 43(2), 284-8.

Present study consists the temporal changes in the fluxes of the macronutrients in Narmada estuary between the years 2005 and 2010. Temperature, salinity, nitrogen and phosphates were studied. One way ANOVA test was performed and the results suggest difference over the period of time in the parameters like temperature, salinity, nitrates, phosphates and total Phosphates at different level of significance. There is noted increase in certain nutrients over the period of time. The study infers that the effluent flow, sewage drainage, catchment runoff and the tides are having great influence on the macronutrient fluxes.

2 illus, 1 table, 33 ref

006518   Sharma N K;Tiwari A K (NO, , ) : Vegetation analysis in Kumaun Himalaya using remote sensing. Res Rev : J Space Sci Technol 2014, 3(1), 9-16.

Vegetation and land use of Kumaun Himalaya was analyzed using remote sensing data. A total of 15 vegetation and land use classes were mapped, of which, eight vegetation types and seven land use categories were identified. Utilizing the knowledge of altitude bound distribution of vegetation digital elevation model (DEM) was used for the post- classification refinements. Forest spreads over 52% of total geographical area, while 48% of the total geographical area is covered with non-forest types including scrub, grassland, plantation, agriculture, water body and snow. Temperate and subalpine broadleaf forest dominated the forest class followed by pine forest. Information generated in present study will provide input to planners for laud use planning and natural resources management.

006517   Sharma G K;Chaudhary J L (NO, I.G. Krishi Vishwavidyalaya, Kumhrawand, Jagdalpur-494 005, Email: girijesh_sharma@yahoo.com) : Time trends in temperature of Bastar plateau agro-climatic zone of Chhattisgarh. Mausam 2014, 65(1), 29-36.

Trend analysis of data has been made for understanding likely temperature changes. This study was at Shaheed Gundadhoor College of Agriculture and Research Station, Jagdalpur (Chattisgarh) under NICRA project by analysing 32 years (1980-2011) daily weather data of Jagdalpur station for Bastar region (Chattisgarh) through weather cock software developed by CRIDA, Hyderabad. The analysis showed that number of days recorded under different ranges of maximum temperature is not in increasing pattern in this region. However, number of days recorded under different ranges of winter seasonal minimum temperature values are in significantly increasing pattern showing cooling trend. Number of days with minimum temperature ≤ 10 °C is found increasing in the months of December and January and statistically significant at 1 per cent level. Number of days with ≤ 7 °C showed cooling trend in the months of December, January and February. Analysis of maximum temperature crossing certain threshold values ≥ 40 °C, ≥ 41 °C, ≥ 42 °C, ≥ 43 °C done lead to conclusion that trends shown by linear equations are all non-significant, indicating that number of such days are not on the increase. However, as an exception, maximum temperature crossed value of 40 °C in March 1996; in May 2003, there were 23 days which crossed 40 °C and June 2003 was comparatively warmer with 12 days crossing 40 °C, out of which 6 days crossed 41 °C.

8 illus, 3 tables, 4 ref

006516   Sharma B B;Golani P R (Geological Survey opf India, , Jhalana Dungri, Jaipur-302 004, Email: bbsharma.gsi@gmail.com) : Magnesite in the Palaeoproterozoic metasedimentary carbonate sequence of Aravalli Supergroup in Gujarat, Western India. Curr Sci 2013, 104(8), 1013-15.

2 illus, 1 table, 11 ref

006515   Shaji C;Kar S K;Vishal T (Centre for Oceans, Rivers, Atmosphere and Land Sciences (CORAL)Indian Institute of Technology, Kharagpur-721 302) : Storm surge studies in the North Indian Ocean. Indian J Geomar Sci 2014, 43(2), 125-47.

Warm tropical North Indian Ocean (NIO), like the warm tropical North Atlantic and South and Northeast Pacificoceans, is a breeding ground for tropical cyclones. Tropical cyclones occur, quite often with severe intensity, in the tropical NIO during pre-monsoon and post-monsoon seasons, and are accompanied by very strong winds, torrential rains and storm surges. A storm surge is a meteorologically forced long wave motion, which can generate sustained elevations of the sea surface above the levels caused by the normal astronomical tides. Although storm surges result from the combined action of extreme wind stress and, to a lesser extent, reduced atmospheric pressure on shallow coastal shelf seas, the precise impact of the surge at any particular location is sensitive to certain meteorological,topographic and hydrological parameters, which include i) intensity and path of the cyclone and its spatial and temporal scales, ii) width and slope of the continental shelf, iii) geometry of local coastal and shelf features (bays, headlands, inlets, barrier islands, offshore islands and reefs), and iv) interactions of surge, astronomical tides, wind waves, river discharge and precipitation. The havoc caused by storm surges is found to be extremely severe in many countries situated around the NIO rim. Hence, real time monitoring and prediction of storm surges is of great importance in these regions. Various storm surge studies so far have taken place in the NIO region, particularly those in the Bay of Bengal and Arabian Sea, are dealt with in this article. After providing the details of the equations governing storm surges, an up-to-date review is attempted. Eventually, the authors' views on what future directions could be taken in order to improve numerical storm surge modeling and predictions in the NIO region are mentioned.

^iia20 illus, 6 tables, 55 ref

006514   Shah A A (Applied Geology Dep, Curtin University, 98009 Miri, Sarawak, Malaysia, Email: afroz/shah@curtin.edu.my ) : Two great historical earthquake ruptures revealed in Nepal. Curr Sci 2013, 104(8), 994.

13 ref

006513   Saxena A;Prasad V;Singh I B (NO, Birbal Sahni Institute of Palaeobotany, 53, University Road, Lucknow-226 007, Email: indrabir@yahoo.com) : Holocene palaeoclimate reconstruction from the phytoliths of the lake-fill sequence of Ganga Plain. Curr Sci 2013, 104(8), 1054-62.

A 2.8 m thick Holocene sediment succession of Lahuradewa lake, located on the interfluve surface of Ghaghara-Ami rivers, close to the Lahuradewa archaeological site, is studied for phytolith assemblage to reconstruct the palaeoclimate variability during the Holocene. The phytolith morphotypes of grasses (Poaceae) have been used as proxy environmental indicators. Phytolith morphotypes belonging to sub-family Panicoidae indicate warm and humid climate; Chloridoidae indicate warm and dry climate and Festucoidae indicate cool and moist climate. Lake profile in general shows dominance of Panicoidae morphotypes over others, though atcertain intervals they show fluctuating trend. Well-defined parameter of phytolith index (Iph) is used to infer dry phases in the succession. On the basis of Iph, five wet phases alternating with four dry phases have been identified during the past 10,600 cal yrs BP. The four dry phases are: (1) 10,300-9,200 cal yrs BP, (2) 5300-4100 cal yrs BP, (3) 1650-1200 cal yrs BP and (4) 950-700 cal yrs BP, out of which the 5300-4100 cal yrs BP dry phase was the most prominent.

6 illus, 49 ref

006512   Sawaisarje G K;Khare P;Shirke C Y;Deepakumar S;Narkhede N M (NO, , India Meteorological Dep, Shivajinagar, Pune-411 005, Email: gksawaisarje@gmail.com) : Winter fog over Indian subcontinent : climatological perspectives. Mausam 2014, 65(1), 19-28.

Fog is localized phenomenon where horizontal visibility is reduced to less than 1000 m due to suspension of very small water droplets in the air. In fact Fog is cloud at surface level. This phenomenon matters to us in our daily activities due to its effect on life, public health, road safety, and economic prosperity. Its knowledge is essential to meet critical societal needs. In India, radiation and advection fog are most common which occur mostly over north India in winter. This study presents results of spatial variability of average number of days having visibility less than 1000 m at 0300 UTC during winter season over Indian subcontinent (0° N-35° N and 60° E-100° E) using synoptic hour daily surface data. Analysis of Fog events based on half hourly METAR observations for winter months (December 2010-February 2011) at selected ICAO stations of India is also presented. The monthly spatial variability of average number of days with fog having visibility less than 1000 m indicates presence of fog over Indo-Gangetic plains on an average of 7 to 10 days during December and more than 8 days during January. South Gangetic West Bengal is susceptible to fog during February. Seasonal variation of fog shows that there is prominence of fog over Indo-Gangetic plains on an average of more than 6.5 days. Significant incidences of foggy days occur over South Interior Karnataka and Coastal Karnataka has incidence of foggy days on an average of 6.5 days. North India is susceptible to dense fog on average of 2.5 days during the season while Gangetic West Bengal, West Rajasthan and adjoining parts of east Rajasthan and East Uttar Pradesh have occurrence of fog on an average of 3.5 days. Thick fog occurs on an average of 3 days over northern India during the winter season. Analysis of time series of air temperature, dew point temperature, dew point depression, visibility, zonal and meridional components of wind and its magnitude at selected ICAO stations indicate that visibility reduces to below 1000 m while light winds are southeasterly at Ahmedabad, northerly to northwesterly at Amritsar, northerly to northeasterly at New Delhi, westerly to southwesterly at Kolkata, Guwahati and dew point depression is below 3 °C during such conditions. Long period 1971-2010 analysis of visibility conditions less than 1000 m over Indian subcontinent shows Indo-Gangetic plains region to have average wind speed to be 0.6 m/s, air temperature in the range 9 °C to 15 °C during December-February at 0300 UTC. Long period 1971-2010 analysis of relative humidity shows Indo-Genetic plains region to have relative humidity in the range 72% to 84% at 0300 UTC during December-February.

9 illus, 25 ref

006511   Satishkumar B;Muralikrishnan S;Narendran J; Raghu Venkataraman V;Dadhwal V K (National Remote Sensing Centre, Indian Space Research Organisation, , Hyderabad-500 037, Email: muralikrishnan_s@nrsc.gov.in) : Bias-corrected GOCE geoid for the generation of high-resolution digital terrain model. Curr Sci 2013, 104(7), 940-3.

This study aims at deriving a geoid over India using the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite, evaluate its accuracy and application potential. The main objective is to convert satellite-derived ellipsoid height to orthometric height using geoid derived from GOCE and convert an ellipsoid digital terrain model (DTM) to orthometric DTM for hydrology, flood undulation and coastal management. The study was carried out over two areas, viz. Kosi river basin, Bihar and Mahanadi river basin, Odisha. The results indicate that over a total of 148 benchmarks, the GOCE geoid has a bias of 1.5 m with reference to the ground geoid. The study also demonstrated that using benchmark data, it is feasible to derive a geoid from GOCE with 10-15 cm accuracy that would meet most of the user requirements.

3 illus, 1 table, 11 ref

006510   Santosh M (School of Earth Science and Resources, China University of Geosciences, 29 Xueyuan Road, Beijing 100083, China, Email: msantosh.gr@gmail.com) : Evolution of continents, cratons and supercontinents: building the habitable Earth. Curr Sci 2013, 104(7), 871-79.

Modern concepts of plate tectonics provide new insights into the processes of construction and destruction of continents, cratons and supercontinents. Starting from the magma ocean stage at around 4.6 Ga, and evolving through a water-covered oceanic realm in the early Archean with island arcs floating on a double-layered convecting mantle, the dynamic planet Earth commenced the building of continents and cratons. These were then episodically assembled into large supercontinents and broken apart. Plate tectonics cleaned up the early toxic oceans, built mountain chains and exposed these through sea-level drop in the Neoproterozoic, enabling weathering and transport of nutrients for evolving life. Drastic environmental changes influenced by both galactic and terrestrial processes in the late Neoproterozoic finally set the stage of making the Earth a habitable planet for modern life.

9 illus, 47 ref

006509   Rusu E;Diaconu S (Applied Mechanics Dep, University Dunarea de Jos of Galati, Romania, Email: sorin.diaconuu@ugal.ro) : Costal impact of a wave dragon based energy farm operating on the near shore of the Black Sea. Indian J Geomar Sci 2014, 43(2), 163-75.

An analysis of the wave climate based on historical data is first carried out. High resolution simulations with the SWAN spectr almodel were performed considering the most relevant environmental conditions that could be expected in the area targeted. In order to evaluate the impact of the wave energy farm, wave model simulations were carried out considering three different situations. These are without any wave energy converter, with one converter and with four converters operating in the nearshore. Impact in the geographical and in the spectral spaces was evaluated for various representative patterns. Moreover, in order to estimate the influence of the wave farm on the shoreline dynamics, the nearshore circulation was also assessed using the 1D Surf model. Results show that the presence of such a wave farm has a strong influence on the wave conditions immediately down wave but this influence is in general highly attenuated at the level of the coastline.

11 illus, 4 tables, 25 ref

006508   Rout J;Ojha A;Tripathy M;Pattnaik A K;Rajesh G;Samal R N (NO, , ) : Morphological dynamics of Chilika lake inlet-Odisha. Res Rev : J Space Sci Technol 2014, 3(2), 8-14.

Due to erosion and/or sedimentation of Chilika Lake Inlet Dynamics could be studied by using the Satellite images. Satellite imagery has an important rate in studying the dynamics of the inlet. The current study was carried out to investigate spatio-temporal inlet dynamics due to erosion and/or sedimentation by using Remote Sensing and GIS Technique, The study period is between the year 2008 and 2014 of. Chilika Lake because in this period Lake inlet extremely dynamic and unstable. During these 6 years the inlet has migrated 1.5 km towards. North direction and also three new natural inlet open and one has also merge with old inlet.

006507   Rout J;Ojha A;Srichandan S;Tripathy M;Bhatt K S;Samal R N;Pattnaik A K;Rajesh G (NO, , ) : Monitoring aquatic vegetation distribution in chilika lagoon with g-tech. Res Rev : J Space Sci Technol 2014, 3(1), 17-25.

Chilika Lagoon with a water spread area varies from 1,144 km 2 of in the monsoon season to 780 km2 in the winter dry season (National Wetland Atlas, Orissa) of a large wetlands eco-system. The lagoon had been facing with different problems, like shifting of the mouth, decrease in salinity level, shrinkage of water spread area due to sedimentation, increasing the fresh water weeds etc. To monitor the aquatic vegetation distribution from the year 1975 to 2014, an attempt was made to monitor the same as a Remote Sensing and GIS approach. In the year 1975 the emergent vegetation was only 18sq.hm, in the whole lake. After that in the year 1988 it was 92.12 sq.km. & in the year 2004, after opening the Sipakuda Met the emergent vegetation reduced upto 56.29 sq.km.

006506   Ray K;Joshi B N;Vasoya I M;Chicholikar J R (India Meteorological Department, , New Delhi, Email: kamaljit_ray@rediffmail.com) : Quantitative precipitation forecast for Mahi basin based on synoptic analogue method. Mausam 2014, 65(1), 118-23.

^ssc1 illus, 4 tables, 8 ref

006505   Ray J S;Pande K;Awasthi N (Physical Research Laboratory, , Navrangpura, Ahmedabad-380 009, Email: jsray@prl.res.in) : A minimum age for the active Barren Island volcano, Andaman Sea. Curr Sci 2013, 104(7), 934-9.

Barren Island of Andaman Sea is the only active volcano in the Indian subcontinent. While the volcano has erupted sporadically many times over the last ~70 ka, it is not known when it formed and breached the sea surface. To provide estimates for the timing of these events, authors dated two tephra (ash) layers older than 42 ka and generated by this volcanism in a previously studied marine sediment core collected ~32 km southeast of the island using the newly established modern 40Ar-39Ar facility in India. The 40Ar-39Ar plateau ages of plagioclase separates from successive tephra layers at 310 and 375 cm are 1.8±0.4 <2(F128><115>) Ma and 1.5±1.8 (2σ) Ma respectively. They interpret the more robust age of 1.8 Ma as the time of crystallization of plagioclase grains. As this age is very much older than the depositional age of the tephra layer (~61 ka), they infer that it represents the age of older rocks present in the plumbing system of the volcano that were blown out with later pyroclastic eruptions and therefore, sets a strict younger limit to the time of formation of the volcano.

6 illus, 1 table, 21 ref

006504   Ravindran A A;Ramanujam N (Geology Dep, M.S University, V.O.Chidambaram College, Tuticorin, Email: antonicogeo@gmail.com) : Detection of submarine groundwater discharge to coastal zone study using 2d electrical resistivity imaging study at Manapad, Tuticorin, India. Indian J Geomar Sci 2014, 43(2), 224-8.

Submarine Groundwater Discharge (SGD), is identified at Manapad headland using 2D Electrical Resistivity Imaging study. The study area is covered with the calcareous marine sediments and shells materials formed by the tectonic upliftment. Measured apparent resistivity values are inverted into inversion resistivity pseudosection by using RES2DINV 3.56 software and iterated to calculate resistivity model. Resistivity zones with a range of values from 31 to 174 Ohmm act as permeable pathway for freshwater discharge to the down stream side towards sea.

5 illus, 1 table, 15 ref

006503   Rao P V K;Ramana K V;Seshasai M V R (NO, , ) : Identification of potential areas for horticulture expansion using remote sensing and gis techniques. Res Rev : J Space Sci Technol 2014, 3(1), 1-8.

Horticultural crops play a unique role in India's economy by improving the income of rural people. The cultivation and production of horticultural crops is known as "Golden Revolution" and India has emerged as the second largest producer of fruits and vegetables in the world. The country has abundant sunshine throughout the year, surplus labor and widely varied agroelimatic conditions, which offer high potential for successful and profitable commercial horticulture mainly mango crop. Remote sensing and geographical information systems can be effectively used for generating such information and hence an attempt has been made to map the areas under mango crop and also potential areas for taking up its cultivation and identifying suitable areas for infrastructure development. The study was conducted in the parts of Krishna and West Godavari districts of Andhra Pradesh using temporal digital data sets from AWiFS and LISS-III sensor onboard Resourcesat-I satellite and IKONOS data. The digital analysis of satellite data was carried out in order to derive potential areas suitable for mango crop cultivation based on soil, climatic and edaphic conditions in GIS environment. The IKONOS data was used for identification of mango plantations and also growth pattern in combination with other horticultural crops in the study. The land use/land cover mapping was clone with AWiFS data in Krishna and West Godavari districts of Andhra Pradesh and suitable areas were categorized as category I to 4 for expansion of mango cultivation areas. As horticultural crops are perennial and long-standing with increased commercial importance, long-term database on their extent, distribution, condition and necessary infrastructure is highly essential for strategic planning towards integrated development of horticultural crops in the state.

006502   Rambabu S;Pillai J S;Agarwal A;Goswami H J (Society for Applied Microwave Electronics Engineering & Research (SAM, , IIT Campus, Powai, Mumbai-400 076) : Climatological study of turbulence structure constant over two tropical stations, Mumbai and Guwahati in India. Curr Sci 2013, 104(7), 944-50.

Wind profiling radars operating at VHF and UHF bands are highly sensitive to radio-refractive index variation associated with small-scale atmospheric turbulence. The measurement of atmospheric turbulence at these radar stations may be used to estimate the range of the radar that can be achieved based on its sensitivity. Turbulence structure constant (C^{2_n) is one of the basic parameters to measure turbulence. In the present study, climatological (2000-2011) variation of C2_n from 1 to 20 km height over Mumbai (72°51'E, 19°6'N) and Guwahati (91°34'E, 26°6'N) regions using radiosonde data has been analysed. It has been observed that the mean C2_n values over the two stations are in the range 10-18 to 10-12 m-2/3. The C2_n values are higher in the lower troposphere where both temperature and humidity gradients contribute to refractive index variation, and lower in the middle and upper troposphere where moisture gradient is negligible. The lowest values of C2_n are observed just below the tropopause region between 10 and 16 km over Guwahati and 10 and 13 km over Mumbai region. As a coastal station, Mumbai shows higher values of C2_n(two orders of magnitude) at the surface and lower tropo-sphere compared to Guwahati. It has been observed that over the two tations, in the lower troposphere the C2_n values of summer (March-May) and southwest monsoon period (June-September) are higher than post-monsoon (October-November) and winter (December-February) period.}

5 illus, 2 tables, 13 ref

006501   Rajendran K (Centre for Earth Sciences, Indian Institute of Science, Bangalore-560 01, Email: kusala@ceas.iisc.ernet.in) : On the recurrence of great subduction zone earthquakes. Curr Sci 2013, 104(7), 880-92.

The last decade has witnessed two unusually large tsunamigenic earthquakes. The devastation from the 2004 Sumatra-Andaman and the 2011 Tohoku-Oki earthquakes (both of moment magnitude ≥9.0) and their ensuing tsunamis somes as a harsh reminder on the need to assess and mitigate coastal hazards due to earthquakes and tsunamis worldwide. Along any given subduction zone, megathrust tsunamigenic earthquakes occur over intervals considerably longer than their documented histories and thus, 2004-type events may appear totally `out of the blue'. In order to understand and assess the risk from tsunamis, we need to know their long-term frequency and magnitude, going beyond documented history, to recent geological records. The ability to do this depends on our knowledge of the processes that govern subduction zones, their responses to interseismic and coseismic deformation, and on our expertise to identify and relate tsunami deposits to earthquake sources. In this article, we review the current state of understanding on the recurrence of great thrust earthquakes along global subduction zones.

9 illus, 1 table, 67 ref

006500   Raj A;Sharma P (NO, Sher-e-Kashmir Univ of Agricultural Sciences and Technology of Kashmir, Kargil, Ladakh-194 103, Email: arajleh@yahoo.co.in) : Is Ladakh a 'cold desert'?. Curr Sci 2013, 104(6), 687-8.

1 illus, 14 ref

006499   Prokop P;Suliga I (Geoenvironmental Research Dep, Institute of Geography and Spatial Organization, Polish Academy of Sciences, Jana 22, 31-018, Krakow, Poland, Email: pawel@zg.pan.krakow.pl) : Two thousand years of iron smelting in the Khasi hills, Meghalaya, North East India. Curr Sci 2013, 104(6), 761-8.

Radiocarbon dating of charcoal from iron slag revealed evidence of continuous iron smelting in the Khasi Hills, Meghalaya, NE India spanning the last two millennia. The slag layer, which is dated to 2040 ± 80 years BP (353 BC-AD 128), is the earliest iron smelting site studied in the entire region of NE India. The presence of wustite, fayalite, glass and metal iron, together with spinels such as hercynite in the slag, indicates that it was an acid product of a bloomery iron-making process. The relative isolation of the Khasi people, who inhabited a highly elevated plateau, is evidence of the indigenous origin of this manufacturing technology, although diffusion of knowledge through cultural and technical contacts or population migration cannot be excluded.

4 illus, 2 tables, 43 ref

006498   Prasath B;Nandakumar B R;Jayalakshmi T; Santhanam P (Marine Science Dep, School of Marine Sciences, Bharathidasan University, Tiruchirappalli-620 024, Email: sanplankton@yahoo.co.in) : First report on the intense cyanobacteria Microcystis aeruginosa Ktzing, 1846 bloom at Muttukkadu Backwater, Southeast coast of India. Indian J Geomar Sci 2014, 43(2), 258-62.

Study consists an intense Microcystis aeruginosa bloom was reported in Muttukadu backwater on 1st June 2012. Density of M. aeruginosa was reported an average of 6x108/L. Muttukadu backwater is highly polluted due to discharges from households and industries located along the banks of the estuary. The effect of pollution was reflected on microalgae abundance in the sew age-fed area. This study showed that the M. aeruginosabloom has caused severe fish mass mortality attributed to the toxic effects exerted by this cyanobacteria bloom.

2 illus, 1 table, 27 ref

006497   Pragyan Kumari;Ojha R K;Wadood A;Ramesh Kumar (NO, Agricultural Physics & Meteorology Dep, Kanke, Ranchi-834 006, Email: pragyanbau@yahoo.com) : Rainfall and drought characteristics for crop planning in Palamau region of Jharkhand. Mausam 2014, 65(1), 67-72.

Daily rainfall data of 56 years (1956-2011) of Palamau district of Jharkhand have been considered to analyse the long term average and its temporal variability on weekly, monthly, seasonal and annual basis. The average annual rainfall at Palamau was 1138 mm with 34 per cent coefficient of variation indicating thereby that the rainfall was not much stable over the years. July was the highest rainfall recipient month (332 mm) followed by August (310 mm) during the monsoon period. Trend analysis on rainfall of past 56 years exhibited a decreasing pattern of 8.33 mm and 7.04 mm per year in annual and kharif season rainfall, respectively. Agricultural drought was most frequently observed in early (23-26 SMW) as well as late (37-40 SMW) stages of kharif crops. Meteorological droughts of different intensities, viz., mild, moderate and severe over the observed periods showed that station is prone to rnild-moderate type of drought. Short duration, low water requiring but high value crops like maize, pulses, oilseeds andi some vegetables can be opted for this region to minimize the production risk.

7 ref

006496   Pai D S;Sridhar L;Rajeevan M;Sreejith O P; Satbhai N S;Mukhopadhyay B (NO, , India Meteorological Dep, Pune, Email: sivapai@hotmail.com) : Development of a new high spatial resoution (0.25° x 0.25°) long period (1901-2010) daily gridded rainfall data set over India and its comparison with existing data sets over the region. Mausam 2014, 65(1), 1-18.

Study discusses development of a new daily gridded rainfall data set (IMD4) at a high spatial resolution (0.25° x 0.25°, latitude x longitude) covering a longer period of 110 years (1901-2010) over the Indian main land. A comparison of IMD4 with 4 other existing daily gridded rainfall data sets of different spatial resolutions and time periods has also been discussed. For preparing the new gridded data, daily rainfall records from 6955 rain gauge stations in India were used, highest number of stations used by any studies so far for such a purpose. The gridded data set was developed after making quality control of basic rain-gauge stations. The comparison of IMD4 with other data sets suggested that the climatological and variability features of rainfall over India derived from IMD4 were comparable with the existing gridded daily rainfall data sets. In addition, the spatial rainfall distribution like heavy rainfall areas in the orographic regions of the west coast and over northeast, low rainfall in the lee ward side of the Western Ghats etc. were more realistic and better presented in IMD4 due to its higher spatial resolution and to the higher density of rainfall stations used for its development.

12 illus, 4 tables, 24 ref

006495   Neeraj Kumar;Suman Kumar;Nain A S (N.M. College of Agriculture, Navsari Agricultural Univ, Navsari-396 450, Email: neeraj34012@gmail.com) : Response of CERES-wheat and CROPGRO-urd model (DSSAT model v 4.5) for tarai region of Uttarakhand. Mausam 2014, 65(1), 109-14.

Study aimed response of CERES-wheat and CROPGRO-urd model for tarai region of Uttarakhand. Field experiments were conducted at N. E. Borlaug, Crop Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand during rabi and kharif seasons 2007 and 2008. CERES-wheat and CROPGRO-urd models version v 4.5 were used in this study. Cultivar specific genotypic coefficients were derived for wheat and urd during calibration. Model validation based on several independent sets of growth and yield data, including different nitrogen and irrigation levels. For all parameters t-test was found non-significant ('t' calculated values were smaller than t tabulated values at 5% level of significance), indicating that there were least differences between observed and predicted values. The result obtained with the model demonstrated satisfactorily prediction of phenology, growth and yield and thus it can be used for the prediction of wheat and urd growth as well as yield in this region.

1 illus, 3 tables, 21 ref

006494   Mohanty U C et al (Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, New Delhi-110 016, Email: ucmohanty@gmail.com) : Real-time experimental extended range forecast system for Indian summer monsoon rainfall: a case study for monsoon 2011. Curr Sci 2013, 104(7), 856-70.

The variability of Indian summer monsoon rainfall (ISMR; both at interannual as well as intraseasonal timescales) has a direct impact on various sectors of public interest and economy such as agriculture, water resource, etc. So, the need of real-time extended range forecast system of the ISMR (monthly to seasonal scale) is not overstated. The present study is aimed at developing such a forecast system to predict rainfall (monthly and seasonal mean) one month in advance over 34 meteorological subdivisions of India for climate risk management in agriculture. Three different statistical approaches, viz. singular value decomposition-based multiple regression, supervised principal component regression and canonical correlation analysis are applied on rainfall products obtained from eight global models. The hindcast (1982-2010skills of all the three methods are found to be better than the simple ensemble mean of all models for all-India level. However, a large variation in the skill of each of the techniques is noticed when studied over smaller regions, i.e. at meteorological subdivision level. Therefore, a combination of all the three methods has been developed for real-time experimental forecast of rainfall. In order to incorporate uncertainties in the predictions, the final forecast is also prepared as probability values. These extended range predictions have been evaluated for the monsoon-2011 against India Meteorological Department observed rainfall. It is found that the extended range experimental forecasts of rainfall are usable for more than 50% of the meteorological subdivisions as well as the whole of India at monthly and seasonal scale.

10 illus, 4 tables, 50 ref