Annual Report 2001 - 2002

Autonomous Institutions

Agharkar Research Institute, Pune

The Institute has three research divisions - microbial sciences, plant sciences and animal sciences. The thrust areas in these divisions are: Metal-microbe interactions; bioremediation of chemopollutants using microbial consortia; anaerobic bacteria and their applications; production of industrially important enzymes using microorganisms; biodiversity of plants, fungi and lichens; genetic improvement of wheat, soybean and grapes; phytochemistry and pharmacological studies; human nutrition and health with respect to growth and development of children and adolescents; developmental biology; insect pheromones and palaeobiology.

In microbial research, cultures that can be used for bioremediation of pesticides like monocrotophos and dimethoate have been identified and this capacity of microbes was found to be plasmid-borne. Similarly, microbes capable of removing atrazine from soil have been identified, which can be used in association with plants for phytoremediation strategies. A process comprising of bacterial oxidation of Arsenic [As(111)] followed by adsorption on activated charcoal has been developed for removal of arsenic from contaminated groundwater. A new method for AS(III) - As(V) speciation is developed using silver nitrate reagent for rapid screening of arsenic transfonning microorganisms. Microbial synthesis of metal sulphide nanocrystals was accomplished, which can be used in semiconductor devices. The fibrinolytic enzyme isolated from a bacterium was shown to be free from toxic effects using several tests in animals. The alkaline protease gene from an alkalophilic Bacillus was cloned and expressed in E. coli. Unlike the anaerobic alkane degraders reported so far, a non-SRB culture which can deplete straight chain alkanes in the range of C 14-C 19 has been isolated.

In pheromone work, a "lure" for attracting honeybees was developed from a crude extract of plant Fagara budrunga. The analysis of nasonov gland extracts of honey bee, Apis mellifera indicated the presence of Nerol as a major constituent.

Further progress has been made in biodiversity and bioprospecting of medico- botanical resources. Conservation studies were continued with wild resources like underexploited Carissa, over-exploited group of ayurvedic root drugs like Brihat Panchmula and medicinal herb Aloe. The triterpinoids from leaf extracts of Sterculia foetida, as well as the derivatives from triterpenoids were found to possess anti-inflammatory activity. Similarly the antiinflammatory activity of crude extract of Curcuma amada was found to be located in n-hexane soluble fraction. The JC fraction of roots of Jatropha cureas showed antidiarrhoeal activity through inhibition of prostaglandin biosynthesis and reduction of osmotic pressure in mice. Crude extract of the plant Tetrastigma suleatum, a wild relative grapes was found to have antifungal activity. Several bacterial, fungal and lichen isolates have been collected for biodiversity studies.

In studies on adolescent growth, it was observed that adolescent pregnancy wastage and proportion of underweight babies was more in mothers who delivered before the age of 18 years. Maternal nutrition studies in urban affluent mothers indicated that birth weight of newborns was influenced by maternal weight gain in fat free mass than gain in fat mass. Further studies on iron-folic acid supplementation indicated that there was no significant difference in weight gain and Hb gain in women receiving daily and weekly supplementation. However, it was found that daily supplementation may be more beneficial for women having poor intakes during late pregnancy.

In developmental biology, methylene blue staining was developed for cell differentiation analysis of embryonic neural retina. Using this procedure, it was found that the cell differentiation in embryonic chick retina proceeds in an identifiable temporal sequence. Presence of two separate glands appears to be a special feature of Calotes versicolor, the garden lizard. It is concluded that lacrimal and Harderian glands originate from single primordium and Harderian gland appears as a secondary evagination. Using a combination of embryological and molecular techniques it was shown that FGF and activin signalling play important role in early morphogenesis of chick embryo. Further, it was shown that insulin plays an important role in early morphogenesis of chick embryo. The function of insulin is likely to be mediated by specific genes. The expression of noggin transcripts in Hydra is localized in regions that are considered equivalent to Xenopus organiser since both the hypostomal as well as basal regions induce new axis formation in a host hydra on transplantation. These observations, provide direct molecular evidence that these two regions are homologous to the Spemann's organiser.

Two soybean varieties MACS 740 and MACS 693 gave good performance in coordinated trials in southern zone. Over 592 quintals of soybean breeder seed was supplied during the year. In wheat, a durum variety MACS 3125 performed exceedingly well in coordinated trials. The variety has been accepted for release in Maharashtra by the State Varietal Release Subcommittee. In adaptive trials in farmers' fields, this variety gave 19 % more yield than the existing varieties. Nearly 265 quintals of breeder seed of wheat varieties was supplied. In grape improvement programme, new hybrids were developed and evaluated. Hybrids were identified that are drought and salt tolerant.

Technology for removal of H2S from biogas was developed in collaboration with Sinhgad College of Engineering, Pune. This technology was transferred to SAF Yeast Ltd., Mumbai. A patent for " Lures for Indian Honeybees" was accepted and is in the process of award. Complete specifications for two patents have been filed. Forty research papers were published in national and international journals. Three scientists attended International conferences abroad. Two students were awarded Ph.D. degree of Pune University. Consultancy was provided to H.N. Bhat & Co., for evaluation of anaerobic digesters of sewage treatment plant at Pimpri-Chinchwad Municipal Corporation. Identification service for fungi, authentication of drug samples from plant origin, analysis of water samples etc. was undertaken to generate additional revenue. 20 .research projects from government and private agencies were operated to augment the funds for research.

Birbal Sahani Institute Of Palaeobotany, Lucknow

The Institute has been carrying out researches on various aspects of Palaeobotany (fossil botany) and allied sciences. The main research work is concerned with the understanding of plant evolution through geological time. Emphasis has been made to derive knowledge about the diversification of Precambrian life, diversity, distribution and inter-basinal correlation of Gondwana and Tertiary floras, coal quality and to understand the interaction between the climate and change of vegetation in Quaternary period.

The research activities are being conducted under the approved Thrust Areas programme; such as 1) Antiquity of Life, 2) Gondwana Supercontinent: Regional geology, floristics, terrane accretion, plate tectonics and configuration, 3) Biopetrology of coals in relation to coal bed methane, 4) Floristics of petroliferous basins, and 5) Quaternary vegetation, climate and monsoon. The Institute is working in collaboration and has linkages with many Institutions in accomplishing the problems related with stratigraphic correlation, palaeoclimate, palaeoenvironment, etc.

Some of the important research contributions and discoveries of the Institute (during 2000-2001) could be summarized as follows:

A reasonably diversified macrofossil assemblage along with thallophytic algae has been recorded in Kurnool Group (Andhra Pradesh). Organic Walled Microfossils from Chhatisgarh basin exhibit distinctive size variation through stratigraphy. In the Permian Gondwana deposits of NE Himalaya plant fossils occur along with Botryococcus algal colony. Pollen assemblages of Middle Jurassic-Early Cretaceous age (Spiti Shale) are correlated with the Ammonite zones. Plant fossil assemblages of Satpura and Mand-Raigarh coalfields (MP) indicate the presence of Karharbari floral elements in lower Barakar and their disappearance in upper Barakar flora. Plant fossils along with animal fossils are recorded from the Kota Formation of Pranhita-Godavari graben

The palynological analysis of Gondwana sequence from different coal-bearing area viz., Rajmahal, Birbhum-Deocha-Pachami, Son-Mahanadi basins and Godavari Graben has been done for dating and correlation. Marker pollen species of Permo-Triassic boundary are identified in Talcher coalfield (Orissa). Petrological study of Gondwana coals from Pench-Kanhan, Bokaro and Wardha-Godavari fields has been carried out for their genesis and quality assessment. Coal from East Bokaro field indicates its composition and rank within the threshold of CBM generation. Tertiary coals of Makum and Dilli-Jaypore coalfields (Assam) originated from woody tropical vegetation under mildly alkaline, anoxic milieu.

Similarities of Intertrappean flora of Kachchh with that of Central India suggest that the two floras are coeval. The occurrence of moisture loving elements signifies tropical climate with plenty of rainfall during the deposition. Kasauli Formation (H.P.) has yielded well preserved leaf impressions. Drastic change in the climate during upper part of Middle Siwalik has been suggested due to presence of Ctenolophon pollen. Cyanobacterial mats has been observed in basal part of Subathu Formation. Palynoflora of Tertiary deposits of Ratnagiri and Siju Formation (of Meghalaya) indicates fair representation of mangrove vegetation. Integration of dinoflagellate cyst data with other fossil and stratigraphic parameters has helped in establishing a sequence stratigraphy for Late Palaeocene deposits of Meghalaya, which were deposited in sea level high sand.

In Shahdol district (MP) the establishment of modern Sal forest has been dated around 3000 years BP. Concentration of heavy metals, particularly arsenic, have been found in the sediments of Adyar estuary (Tamil Nadu). Anthropogenic factors are decreasing the biodiversity in the area. Record of lichen (Evermiastrum cirrhatum) from a cultural horizon of 1300-800 BC indicates its use in spices and medicines in ancient time. There is evidence for use of Putranjeeva (Drypetes roxburghii) nuts in necklace during the same period. Tree-ring chronology has helped in establishing chronology and climate variation dating back to AD 1721-1998 in different parts of the Himalaya. Determination of radiocarbon dates along with pollen studies has helped in understanding changes in vegetation history of Holocene. Dates of organic mud samples from Sidhi and Sahdol districts, Uttarkashi, Gangotri and Nainital have been integrated with plant data.

During the year, 75 research papers, 24 general articles/reports and 48 abstracts were published and 50 research papers were accepted for publication. 8 scientists were deputed to attend the International conferences, while 18 scientists attended the conferences organized in the country. Scientists in various conferences presented 32 research papers.

Antarctica Expedition- Institute scientist has again participated in the "20th Indian Scientific Expedition to Antarctica" (December 23, 2000-March 22, 2001) to collect the palynological samples to carry out the palaeoclimatic studies of this continent. Pollen analysis of the sediments of Priyadarshini Lake, Antarctica revealed existence of Early Holocene vegetation in the region. Presence of arboreal pollen indicates long transport through upthermic winds.

ILTP Indo-Russian Collaboration- Under the project entitled 'Floral and climatic evolution based on Geologic and Biotic events during Precambrian and Phanerozoic Time' under ILTP co-operation in Science and Technology between India and Russia, one scientist visited Geological Institute, Moscow in January-February, 2001. A monograph on "Precambrian stromatolites of India and Russia" has been finalised. Two ILTP Russian fellows are expected to come at BSIP to carry out collaborative research work.

Forensic Palynology- A draft paper on the objectives and the setting of Forensic Palynology Lab in the Institute is prepared. Prof. Mildenhall (of New Zealand), the internationally reputed expert in Forensic Palynology, when approached for his advice and help in our new endeavor commented that "much of the excellent palynological research coming out of BSIP is directly applicable to forensic palynology and BSIP has a very strong background to build on".

The Institute has gifted fossil specimens to some educational institutions. The researchers from other organisations have made use of the Herbarium and Library facilities. Library is disseminating the information about the latest literature on palaeobotany through Current Awareness Service, a bi-monthly bulletin as well as on web-site. Institute journal "The Palaeobotanist" Volume 49 (Numbers 2 & 3) and Newsletter (June-2001) have been published. The Institute is also rendering technical assistance and consultancy services to various organizations in Palynology, SEM and Carbon Dating and generating some revenue.

Bose Institute, Kolkata

Since its foundation by Acharya Jagadis Chandra Bose in 1917, Bose Institute has emerged as a potential multidisciplinary research Institute in India. Research and training in various fields physical and biological sciences are undertaken by ten different Departments and Sections, viz., Physics, Chemistry, Botany, Microbiology, Biochemistry, Biophysics, Animal Physiology, Plant Molecular and Cellular Genetics, Immunotechnlogy and Environmental Sciences. Many of our faculties are Bhatnagar awardees, Fellows of National Academies and recipients of national and international awards. Our faculties have inter-Institutional research collaboration both in India and aborad.

Bose Institute is conducting research in the following main areas (Institutional projects):

• Improvement of Plant Productivity, Nitrogen Fixation and Photosynthesis using modern Biotechnology and Plant Breeding.
  
• Chemical and biological studies of Plant and Marine organisms;
  
• Studies on structure, function and dynamics of biomolecule;
  
• Studies on ecology, environmental pollution and related problem;
  
• Studies on microbes and parasites for industrial and medical applications.
  
• Problems in condensed matter, intermediate energy physics and related interdisciplinary areas.

Technology Demonstration Projects undertaken in the area of socio-economic development

Bose Institute provides consultancies to different organizations to solve various socio-economic problems. Very often this Institute organizes scientists-farmers meet at its experimental stations at Madhyamgram to make the farmers familiar with the modern technique in cultivation.

Major Achievements

The functional characteristics of the superheated drop detector have been determined in neutron spectrometry and gamma ray detection. First principle study of the optical properties of perovskites has been carried out. The role of [Ca2] in translocation of PKCa from cytosol to membrane induced by E.Coli heat stable enterotoxin (Sta) has been established. The low molecular weight species of a-crystallin is found to be largely responsible for the chaperone activity. Micropropagation protocols for Withania somnifera and coleus forskohlii have been standardized. Submergence tolerance-linked RAPD markers and aroma-linked SSLP markers have been identified in rice. Low glucosinolate containing lines in Brassica juncea have been identified. A novel mechanism by which mycobacterial plasmid replication proteins function has been elucidated. We have observed that both Entamoeba histolytica and Entamoeba invadens, routinely accumulate polyploid cells during their respective cell division cycles. Model complexes of amino acids and nucleotides with adequate hydration has been characterised by x-ray crystallography to understand recognition phenomena in biology at atomic resolution. Recent works indicate that curcumin, the active component of turneric induces selective apoptosis in tumor cells, regulates cell cycle progression and possesses antimetastacic and anti-aging activities. Structural studies of the inositol synthase(s) from Oryza and Porteresia have been done with reference to the salt sensitivity and salt tolerance of the two proteins. Bioaccumulation of aflatoxin from liver of farm animals in the consuming individual is possible and continuous accumulation of the toxin may be determined. A membrane protein (mol. Wt. 44Kd) from mouse T cell having affinity with Protein A of Staphylococcus aureus Cowan-I has been found and is being developed

Patents filed

A process for producing pure curcumine from Curcuma longa Linn and preparation of an antitumore, antitoxic and immuno-modulatory composition containing the same.

Indian Association for The Cultivation Of Science, Kolkata

The Indian Association for the Cultivation of Science (IACS), established in 1876, has been continuing its efforts for excellence in scientific research. The various scientific activities and achievements during the year are summarized below :

Materials Science

Research in the areas of thin films and devices will be geared up to strengthen the existing domain of fundamental and industrial research. The coevaporation and post deposition annealing treatment of stacked elemental layers has been adopted for deposition of large area thin film for photovoltaic application. Efforts will be made to control the deposition parameters and bias condition for plasma CVD deposited cubic BN films. Using sol-gel technique preparation of nanocrystalline sulphide films (CdS, ZnS) embedded in insulting matrix and doped MgO films (111) suitable for plasma display panel will be initiated Sol-Gel preparation of nanocrystalline ZnO film has also been initiated. Microstructure characterization of ball milled nano crystalline Ni3Al and TiO2 and martensitic transformation of Fe-Mn-C alloys are being studied adopting Reitveld X-ray profile analysis. The frequency dependent conductivity and dielectric permitivity of polyaniline --polymethyl methacrylate blend are being investigated. The synthesis and structural evaluation of novel inorganic micro and mesophorous materials have been newly started. The liquid phase oxidation and photocatalysis are being performed over titanium based molecular sieves. Research is directed to synthesis an ion exchanger for removal of arsenic from g round water. Synthesis and growth of a new semiorganic NLO crystal, L-arginine acetate were initiated. Studies on mixed crystals of ammonium potassium sulphates will be extended to urea-doped DDP crystals. A program for solving the time-dependent wavepacket propagation in intense laser fields has been developed. Work has also started on the population transfer between molecular levels using stimulated hyper-Raman adiabatic passage.

Solid State Physics

It has been attempted to use conjugated polymers in data-storage device. The relaxation of the storage charges has been studied. Soft mode and related behavior in the SmA and SmC* phases in the ferroelectric liquid crystalline polymers have been investigated by dielectric and optical spectroscopic methods. Quantitative estimation of different interactions present in the geometrically frustrated dysprosium titanate pyrochlore has been made. Magnetic and Mossbauer study of some minerals belonging to orthopyrexene group have been studied. X-Band EPR spectroscopic studies on 0.1% Mn(II) doped calcined SiO2 glass indicated the presence of nano-clusters showing characteristic thermal dependence. It has been observed for the first time, that some typical concentrations of Bi-Sr-Ca-Pb-Cu-O oxide glasses deposited as thin films become high Tc superconductors (Tc-60K) by annealing. Some heavy metal glasses exhibiting transmitting window have been synthesized and their relaxation behavior investigated. Cr. Ag,. Na, K, and K doped GMR materials have been studied under pulsed magnetic field. Experimental arrangement has been set up for the structural study of liquid crystalline materials. Transport and thermal properties of several BaTiO3, KtiO3, doped transition metal oxide glass-nanocrystal composites have been studied showing quite different behavior from that of the usual semiconducting oxide glasses and lass-ceramics. Position annihilation life time measurements on Colossal magnetic and GMR materials are being made.

Spectroscopy

Probing of different parts of microheterogeneous system has been done on the basis of environmental sensitivity of charge transfer band. Total encapsulation of 1:2 complex in restricted cavity could be observed in some system. Critical analysis of several Raman excitation profile of some molecules have shown interesting results. Some compounds mimicking photosynthetic systems have been synthesized and spectroscopic investigations have been extended to conjugated polymeric systems. Work in nano-structured semiconductor films is in progress. Dielectric relaxation spectroscopy and study of electrooptical properties of ferroelectric liquid crystal in polymer network; studies of phase transition and order parameter by X-ray diffraction have been done. Spectroscopic and electrical properties of molecular assemblies and conducting polymers have been done in LB films. Photoinduced charge transfer of molecules in polymer, phase transition, persistent photoconductivity and current oscillation in organometallic materials have shown interesting results. High precision correlated calculation of energy levels and other properties of confined atomic systems have been done. Effects of boundary condition and relativistic corrections in energy levels of confined atomic systems is in process. Monte Carlo simulation has been applied in transient AC response of high-emitting devices. Above threshold ionization in Ar atom in laser field has been explained by non-local QED. Fourier Grid Hamiltonian method has been applied in photodissociation of NaH. Theoretical study of conformational gating on electron transfer process at the bacterial photosynthetic centre of Rd. Sphaeroides has been made.

Theoretical Physics

In atomic physics various calculations are being carried on ortho-Ps atom scattering. This will help us in predicting the s-wave scattering length, which is the only one parameter that can provide information about BEC of Ps atom. The study has been made on the double ionization of a negative hydrogen ion has been made by both electron and proton impact in order to investigate the effect of charge asymmetry in this process. The investigation is under progress. The scattering of a bipolaron by a weak Coulomb field in presence of an external laser field will be investigated to the study of transport phenomena in a dielectric medium. A study has been made on the momentum distributions related to Recoil Ion Momentum Spectroscopy and Ejected Electron Spectroscopy for fully stripped ion projectile are being found out in accordance with the experimental results. The quantum phase transition in a Heisenberg model with long range interaction will be studied with a view to understand the line of Kostcrlitz Thoulcess points. For electrons in magnetic field on the lattice some new results have been found. The results for the word distributions and on the long-range order in DNA sequences are under analysis. In gamma ray astronomy the estimation of gamma rays induced muon production at TeV energies. Investigation of quantum fields for Warmherlies will be made in detail. A search will be made on the particle yields and antiproton scaling at high energy Pb-Pb collisions. In Environmental Science the spectrophotometric analysis of heavy metals in coastal waters of West Bengal has been done. The role of nutrients in phytoplanktom diversity in the coastal zone will be investigated.

Energy Research Unit

Current research activities of the Energy Research Unit are centered around the development of thin film solar cells based on silicon. A project jointly funded by DST and MNES is now going on to develop a completely indigenous prototype plant for production of modules with amorphous silicon double tandem technology. Development of new materials for improvement of the solar cell efficiency is now going on under a project funded by the Indo-French Center for the Promotion of Advanced Research. Development of polycrystalline material for solar cell application is going on. Characterization of the plasma used in the deposition of solar cell that started under a DST project is also going on. Theoretical simulation method has been used to improve the performance of the real solar cells. Other research activities are centered on further improvement of the different layers used in the amorphous silicon solar cell technology.

MLS Processor's Unit

The ac electrical conductivity in the interfacial phase of nanostructured metal core-oxide shell is being investigated. Metal wire junctions of different diameters grown within a silica - based disordered medium are being characterized by dc electrical measurements. Optical properties of nanocomposites containing metal core - oxide shell structures are being delineated.

Biological Chemistry

Synthesis of pentasaccharide repeating units of the antigens from Shigella dysenteria types 3 and 4 and a tetrasaccharide related to be repeating unit of Shigella boydii type 5 have been completed. Synthesis of complex oligo-saccharides related to the repeating units of the antigens from Shigella dysenteria type 9 and Excherichia coli types 0157 and 026 will also be completed. Correlation of lung function text results of the fish allergic patients with those of skin tests has been made. Total IgE levels were found to have elevated 5-9 times in the sera of patients allergic to Rohu, Pomfret and Hilsa fishes compared to control. The specific IgE level in the sera of above patients was also determined. Sharp change in aggulutinin concentration in the culture filtrate of Macrophomina phaseolina in response to application of phytohormones has been quantified by ELISA technique. Chitosan with different degree of deacetylation has been prepared by fermentation of Mucor rouxii. Variation in molecular structure and enzymatic properties of glyceraldehyde 3-phosphate dehydrogenase purified from human normal and leukemic lecucocytes has been studied. Amyloid like fibril forming sheet model short, synthetic peptiders have been studied with an aim to probe the mechanism of amyloid plaque formation related to fatal neurodegenerative deseases.

Inorganic Chemistry

In the current year, the major activities centre around : crystalline sugar vanadates of new mannophranoside systems, silver azo-oximates with unusual nonbonden metal-metal interaction, magentostructural correlations in polynuclear assemblies, novel dimeric oxovana-dium(IV, V) and oxomolybdenum(V, VI) species, catalytic oxygenation of hydroxyben-zenes by manganese(II) complexes, supramolecular copper (II) ensembles with paddle-wheel and honey-comb type structure, crystal engineering, novel fluorescent complexes having Cu1 N8 core, design and synthesis of multidentate dinucleating ligands via metal promoted C-N bond formation.

Organic Chemistry

The major activities in the Department include the synthesis of bioactive natural products dihydrosesamin, acuminatin, the sesquiterpenes zizaene, (+)-herbertene. In addition novel synthetic methodolo-gies based on Pd, in and Ce reagents, photochemistry and directed ortho metalation have been developed for the synthesis of novel carbo- and heterocyclic skeleta.

Physical Chemistry

Experimental Physical Chemistry : Two-colour experiments on clusters produced in a jet-cooled stream of molelcules have been carried out. Large magnetic field has been noted in radical pairs produced by electron transfer from biphenyl to pyrylium cation. Solvation dynamics and rotational relaxation of a number of interesting molecules have been studied by Picosecond spectroscopy. A rather unusual example of H-bond strengthening by steric repulsion has been observed spectroscopicalloy.

Theoretical Chemistry : Development and application of relativistic coupled cluster formalism for producing spectroscopic properties of stripped ions including hyperfined splitting, formulation and implementation of explicitly spinadapted intruder free potential energy surfaces with direct or avoided crossings highlight our work in electronic structure theories. In addition a significant contribution has been the establishment of a relation between entropy and properties of noise-processes in nonequilibrium systems. Some progress has been achieved in introducing Genetic Algorithm in handling a number of problems of quantum chemistry, e.g. diagonalization of a Hamiltonian.

Undergraduate Training Programme Sponsored by IACS

Several undergraduate students visited our laboratory for pursuing short term (2-3 months) projects. Two of them were sponsored by the Indian Academy of Sciences.

Polymer Science Unit

Conducting polymer colloids and gels : Investigations were carried out to exert control on the polymerization of aniline in dispersion from with the object of producing polyaniline of desired molecular weight and low polydispersity. The structure and properties of polyaniline gels prepared by treating the emeraldine base form of polyaniline with different sulfonic acids have been elucidated.

Dispersion polymerization for water soluble polymers :Polyacryla-mide, a commercially important water soluble polymer, was prepared earlier in our laboratory in an easily dissovable form by the dispersion polymerization route. However, there was a problem of anomalous solubility which has now been solved.

Polymer crystallization : The thermodynamics and kinetics of crystallization of PET in its blends with poly(vinylidene fluoride); a piezoelectric polymer, have been studied and thermodynamic interaction parameters were evaluated.

Novel elastomer networks : Covulcanization of elastomers containing high and low levels of unsaturation is a challenging problem. A two stage vulcanization technique has been successfully developed for the purpose. The mechanical properties of the covulcanizates are found to be much better than those of the component elastomers.

Polymer-surfactant interactions : Thermodynamics of interactions between furfactants or between furfactants and polymers in their mixtures have been studied in order to elucidate these complex systems.

Indian Institute Of Geomagnetism, Mumbai

The Indian Institute of Geomagnetism (IIG) is a premier research organization under the Department of Science and Technology devoted to the study of geomagnetism from all possible point of views. modern geomagnetism is truly multidisciplinary science encompassing various disciplines like geophysics, fluid dynamics, space plasma physics, applied mathematics, aeronomy and atmospheric sciences etc. The study of geomagnetism at longest time scales is relevant to understand the origin of planetary magnetism. The short-term geomagnetic variability, on the other hand, has found several important applications related to Sun-Earth connection as well as for geophysical prospecting, earthquake precursor mechanisms, satellite communication and for space weather forecasting. With new technological breakthroughs for accurate geomagnetic field measurements on ground and in space and the advent of modem computers, it is now possible to monitor even weak magnetic and electromagnetic precursory signals in the earthquake prone region. State of the art instrumentation like digital magnetometers and long period magneto telluric units have been acquired to study the complex physical problems related to space weather and precursory signals.

Objectives and Functions

• to promote, guide and conduct research in all branches of Geomagnetism
  
• to establish and maintain in the country, suitably located geomagnetic observatories.
  
• to establish, maintain and manage laboratories, workshops and/or other units to assist scientific research in Geomagnetism.
  
• to record, collect, scrutinize, process, publish and supply geomagnetic data.
  
• to undertake the design, development, construction calibration and standardization of magnetic instruments.
  
• to organize training facilities and to train the staff of the Institute and other interested organizations in geomagnetic work and arrange lectures, seminars and symposia in pursuance of the academic work of the Institute and for diffusion of scientific knowledge.
  
• to invite Scientists from India and abroad who are actively engaged in research in geomagnetism, to deliver lectures and participate in the research activities of the Institute.
  
• to institute and award fellowships, scholarships, prizes and medals.
  
• to cooperate and collaborate with other National and/or foreign institutions and international organizations in the field of Geomagnetism.
  
• to publish scientific papers, bulletins and journals.
  
• to disseminate information on matters concerning geomagnetism.

The Research activities of the Institute are divided into three areas:

• Observatory and Data Analysis
  
• Upper Atmospheric Sciences
  
• Solid Earth Geomagnetism

Activities during last Year and current Year

State of the art instrumentation like digital magnetometers and long period magneto telluric units were acquired to study the complex physical problems related to space weather and precursory signals.

The Institute has taken the first step towards establishing the Geomagnetic Research Laboratory at Allahabad and to develop infra-structural facilities for Co-seismic studies under a new DST project with an initial funding of the 1 crore. A temporary working office of GRL has become functional at Allahabad and currently digital magnetometer and GPS experiments are operational.

The Institute has established a Broad Band Seismological Observatory at Rewa as a part of national programme of DST on "Establishment of Seismological Observatories". The second Broad Band Seismological Observatory is being set up at Kohlapur and it will become operational during 2001. The Rewa Observatory functioned well during the year and provided useful data of major and after shock activity of the January 26, 2001,Bhuj Earthquake.

The Institute chalked out an extensive program of geophysical studies in the Bhuj region, on the priority basis, subsequent to the devastating earthquake of January 26, 2001. The investigations included GPS measurements in the Bhuj region to monitor post earthquake crustal deformations, a regional scale magnetic survey covering Kutch Main Land, a localized 10-station magnetometer array in and around epicentral zone, and Long period magneto telluric measurements at four sites extending across the mesoseismal zone. The on-going analysis and numerical modelling of all these investigations would provide better understanding of the seismotectonics of the region.

Continuous recording of the ground magnetic measurements are carried out at permanent magnetic observatories, Tirunelveli, Pondicherry, Alibag, Ujain, Nagpur, Visakhapatnam, Shillong, Gulmarg, Silchar, and a semi-permanent magnetic observatory at Maitri, in Antarctica. Under the Geomagnetic Activity Forecasting Program, two state of the art digital magnetometers have been installed at Tirunelveli and Pondicherry Magnetic Observatory. The data from these magnetometers will be used for research and for predicting geomagnetic activity, especially from low latitudes.

The phenomenon of geomagnetic bays, which give important information on the onset time of sub storms, was studied using INTERMAGNET data for the years 1997-98. Data from a chain of magnetic observatories in the Indo-Russian longitudinal belt, encompassing regions from the magnetic equator to the high latitude were used to investigate the effect of the geomagnetic disturbances during main phase of the magnetic storm on the daily variations of the three components H, Z and D of the magnetic field. Magnetic storm of December 31, 1967- January 1,1968, was studied using data of ground based magnetometers and ionosonde stations in Indian, African and American sectors.

The Institute participated in the summer and winter expeditions to Antarctica. Data of three fluxgate magnetometers operating simultaneously at Maitri, Dakshin Gangotri and Sigurd Mountains in January 2001 have been analyzed for the magnetic pulsations with periods between 30 sec and 3000 sec. A Fluxgate magnetometer and a Rio meter recording the 30 MHz cosmic radio noise were simultaneously operated at Maitri to study the characteristics of ionospheric absorption caused by magnetosphere-ionosphere particle precipitation. A new experiment on atmospheric electric current as a part of the global electric circuit (GEC) study was started at Maitri.

The Equatorial Geophysical Research Laboratory (EGRL) at Tirunelveli made good progress during the year. Second partial reflection radar at the Shivaji University Campus, Kolhapur became operational. The two radars at Tirunelveli and Kolhapur constitute a unique pair for studying structure of tidal mode, planetary scale oscillations and gravity waves. Important results on the characteristics of the mesospheric 3.5-day ultra-fast Kelvin waves, which carry eastward momentum into the upper atmosphere, were obtained and the results presented in the PSMOS workshop. It is planned to set up some new atmospheric electricity experiments.

Spaced receiver observations of amplitude scintillations on a 244 MHz signal, at an equatorial station, were used to study random temporal changes associated with the scintillation-producing irregularities and the variability of their motion. The computed drift of the scintillation pattern shows the presence of velocity structures associated with equatorial bubbles in the early phase of their development. The power spectra of the most highly correlated scintillations recorded by spaced receivers indicate that the associated irregularities are confined to a thin layer on the bottom side of the equatorial F region. In an other study, it was found that during the high solar activity period (1989-1991), an increase in geomagnetic activity suppressed the occurrence of scintillation activity at Trivandrum and Mumbai stations, whereas the electro jet strength is found to have no association on the occurrence of scintillations.

An analysis of low order mode coupling equations was used to describe the non-linear behaviour of the Rayleigh-Taylor (RT) instability in order to understand the generation of equatorial spread-F. The non-linear evolution of RT instability leads to the development of shear flow. It is found that there is an interplay between the non-linearity and the shear-flow which compete with each other and saturate the RT mode both in the collision less and collisional regime.

An airglow monitoring station has been operating at Kolhapur to study various characteristics of F-region irregularities using an all-sky camera, tilting photometers, scanning photometer and VHF scintillation experiment. The importance of studies of ionospheric plasma irregularities grew because of their strong influence on ionospheric and trans-ionospheric communications The bubbles observed during the different phases of geomagnetic storms show unusual structures (bifurcated and twisting). The continuous movement of the high rise bubbles across the zenith gives rise to strong VHF scintillations.

The characteristics of geomagnetic pulsations undergo appreciable changes as they pass through the ionosphere. These changed properties at the low and equatorial stations are distinctly different from those at the high latitudes. It was found that polarization directions of PC3-4 (period 10 to 100 seconds) pulsation changed during the counter electro jet time. The amplitude of these pulsation is enhanced by equatorial electro jet. The response of magnetospheric transverse modes to the solar wind dynamic pressure induced oscillations of the surface current flowing at the magnetopause has been computed based on the technique of spectral representation of the Green's function.

Boundary layers, commonly encountered in space and astrophysical plasmas, are the site where energy and momentum are exchanged between two distinct plasmas. Broadband plasma waves spanning a frequency range of a few mHz to 100 kHz and beyond have been observed in the Earth's magnetopause boundary layer, the Jovian magnetopause boundary layer, the plasma sheet boundary layer, and the Earth's polar cap boundary layer. The most intense waves were detected coincident with the strongest magnetic field gradients (field-aligned currents). The rapid pitch angle scattering of energetic particles via cyclotron resonant interactions with the waves can provide sufficient precipitated energy flux to the ionosphere to create the dayside aurora at Earth and a weak high-latitude auroral ring at Jupiter.

Recent exciting high time resolution results coming from Geotail, Viking, Polar and FAST show that broadband plasma wave emissions consist of bipolar and monopolar solitary structures. A model for the non-linear evolution of electron-acoustic waves into solitary structures was developed. The predicted properties of the electron acoustic solitons are found to be in good agreement with the observation of spiky electric field structures by the spacecraft. Further, an analytical model of the coupled non-linear ion cyclotron and ion-acoustic waves has been developed to explain the strong spiky waveforms in the parallel electric field in association with ion cyclotron oscillations observed by FAST satellite.

The properties of Magnetic Decreases (MDs) observed by Ulysses over both solar north and south poles were investigated. It is found that charged particle interactions with the MDs can lead to particle guiding center displacements and particle cross-field diffusion. A theory of cross-magnetic field diffusion due to particle interactions with MDs is developed.

The deep electrical structure beneath the Vindhyan basin and Deccan Volcanic province was studied over the Damoh-Jabalpur-Mandla-Anjaneya region using the magneto telluric techniques. These studies have delineated about 5 km thick Vindhyan sediments in the Damoh-Katangi region. An anomalous conductivity is observed at depths of 10-12 km in the Vindhyan crust. Two crustal conductors are delineated below the Deccan volcanics, one in the immediate south of Jabalpur and the second about 40 km south east of Jabalpur.

Existing sets of magnetovariational data from the large numbers of sites distributed across the Peninsular India and those in the Bay of Bengal were reanalysed to obtain inter-site vertical and horizontal field transfer functions. Maps of induction arrows relocate the earlier reported conductive zones beneath the Palk Strait and a regional scale anomaly in the offshore region, immediately southwest of the southern tip of Indian Peninsula, named South India Offshore Conductivity Anomaly (SIOCA). Several lines of geophysical evidence favour the hypothesis that SIOCA, low velocity zone, low magnetization anomaly, all centered near the southern tip of the India, are the relics of the interaction of Marion Plume outburst with Indian lithosphere.

For the first time, a regional aero magnetic anomaly map, depicting the NW-SE structural features north of the orthopyroxene isograd with the essentially E-W features to the south of it and revealing several well known structures, was prepared.

Global Positioning System (GPS) measurements were made to estimate the crustal deformation strain rate for the Deccan trap region.. Estimated horizontal velocity vectors are in the range of 40-60 mm/yr with an average of 51 mm/yr in N47' E. An extension is observed along the west coast and south of Koyna and Warna reservoirs, transcending in to a region of compressive regime towards the interior of the shield area.

The Instrumentation Laboratory developed various instruments that are used in the Observatories as well as in surveys. A PC Controlled Proton Magnetometer with 0.1 not sensitivity and on-screen graphical viewing capability was fabricated and supplied to Space Physics Laboratory at Trivandrum. A prototype of the Micro-controller based, Digital Portable Proton magnetometer has been made. Fabrication of a Fluxgate Magnetometer using a small sized, high sensitivity sensor has been completed and is currently on test.

Future Plans

• To develop the new campus at Panvel
  
• To establish Geomagnetic Research Laboratory, a regional center for Solid Earth and Co-seismic studies, at Allahabad.
  
• To start International training school in Geomagnetism and Earth Sciences and set up Geomagnetic Science Museum at the Colaba campus.
  
• To upgrade the calibration facility for magnetometers and allied instruments at Alibag.
  
• To provide the real time information about the level of Geomagnetic Activity in the equatorial and low latitude regions in India to the scientific user community and evolve this programme into space weather prediction.
  
• Regular forecasting of the magnetic Indices associated with the Equatorial electro jet characteristics and low latitude K-indices using the magnetic data from Indian chain of magnetic observatories.
  
• To equip all the magnetic observatories with the state of the art digital magnetometer and link them with the HQ.

Indian Institute Of Tropical Meteorology, Pune

The Indian Institute of Tropical Meteorology functions as a National Centre for basic and applied research in Tropical Meteorology. Its primary functions are to promote, guide and conduct research in the field of Meteorology and Atmospheric Sciences in all its aspects with special reference to the tropics and sub-tropics.

Basic Research Projects

An assessment of the JMA analysis of summer monsoon over India during the GEWEX Asian Monsoon Experiment (GAME) period (April to September 1998) was carried out to bring out the usefulness of this special data set for NWP research. Comparison with observed features of Indian summer monsoon 1998, as reported by IMD, indicated that in general, the large scale meteorological conditions were depicted well in the analysis. Seasonal as well as monthly precipitation showed substantial skill for thresholds up to 1cm/day.

Using satellite microwave radiometry data obtained from IRS P4 MSMR, evolution of the complete life cycle of monsoon depression (17-24 August 2000) in terms of geophysical parameters i.e. sea surface winds, sea surface temperatures, integrated water vapour and cloud liquid water content was made over the Indian region. Intensification of sea surface winds (12-16 ms-1) to the south of low pressure area prior to the formation of depression, sea surface temperatures ranging from 30-32°C throughout the life cycle of the depression and higher values of integrated water vapour (6-8 gm/cm2) in the area of depression over the southwest Bay of Bengal were the characteristic features observed in the study.

Long term variability of sea surface temperature (SST) of Arabian sea, Bay of Bengal and North Indian Ocean were examined by using the data of 92 years (1903-1994). The specific areas of the ocean viz., Arabian Sea (60°-80°E and 8°-30°N,) Bay of Bengal (80°-100°E and 8°-30°N) and Indian Ocean (60°- 100°E and 0°- 8°N), which are adjacent to Indian coast were considered for analysis. The annual sea surface temperature series of Arabian Sea, Bay of Bengal and North Indian Ocean showed significant increasing trend over the period 1903-1994, the corresponding trend values being 0.5°C, 0.4°C and 0.5°C per hundred years. Significant warming trend in SST was also observed in seasonal mean temperatures for all the regions.

The pre-monsoon season thunderstorms for five years' period i.e.1973-77 were analyzed to study the association of the lightning with precipitation. The average frequency of the lightning discharges and corresponding rainfall were subjected to the statistical analysis. The correlation between lightning discharges and rainfall was found to be significant at 5% level.

The pressure pattern and associated lifting condensation level (LCL) in the marine boundary layer over the Bay of Bengal region (15º-19ºN, 87º-91ºE) were studied utilizing the aerological observations collected from the erstwhile USSR research vessels in stationary polygon position at four locations (E,N,W & S) during 11-18 August 1977. The results showed marked fall in surface pressure from 14 August onwards which is considered to be due to intensification of north-south trough along the east coast of India during that period. The mean LCL over the study region is found to be 964 hPa which is high as compared to 980 hPa observed over the Pacific Ocean and Deccan Plateau regions during the same period.

Technologies Transferred/Commercialized

Design storm study over the Middle Siang river basin covering an area of 5110 km2 in Arunachal Pradesh, sponsored by the National Hydroelectric Power Corporation (NHPC), Ltd., Faridabad, Haryana, was carried out by hydrometeorological and statistical methods. Generalized maps of mean seasonal (May - October), annual and highest 1, 2 and 3 day rainfall over the study region were prepared for their use in this study. Five severe rainspells over the basin were analysed by Depth-Duration (DD) method. DD analysis showed that 2-3 July 1979 rainstorm contributed maximum average raindepths of 9.3 cm and 12.7 cm in 1 and 2-day respectively over the basin while 21-23 June 1978 contributed maximum raindepths of 19.4 cm in 3-day duration. Similarly Depth-Area-Duration (DAD) analysis of 10 severe rainstorms which occurred in the nearby region of the basin was carried out and raindepths obtained from these rainstorms were adjusted with proper elevation correction factor to have raindepths over the basin. DAD raindepths after elevation correction showed that 24-25 June 1931 rainstorm gave a maximum raindepths of 17.0 cm and 28.0 cm in 1 and 2-day respectively while 13-15 September 1982 rainstorm gave 36.3 cm raindepth over the basin in 3-day duration. Envelope raindepths obtained from DD and DAD analysis were then maximised with proper moisture maximization factors to obtain probable maximum storms (PMS) raindepths over the basin. Areal probable maximum precipitation (PMP) raindepths over the basin were also worked from the generalized charts of 1, 2 and 3-day PMP using Hershfield statistical technique.

Special observations of atmospheric aerosols, ozone and precipitable water vapour using the lidar and radiometric techniques were carried out at the Institute and at Khadakwasla dam sites on 28 January, 21 February and 17 March 2001 in synchronization with observations of IRS-P3 satellite passes over Pune. In addition, high-resolution radiometric observations were carried out at the Institute site on 43 days in synchronization with the IRS-P4 satellite -passes over Pune.

As a part of IITM-SHAR (ISRO) collaborative research project a Vector Electrical Field Mill for measuring N-S, E-W and vertical components of electric field has been developed for thunderstorm warning and dynamic protection. These field mills have been installed at Rocket Launching site at SHAR, Shriharikotta and are being operated continuously since last six months and its performance is being evaluated.

A joint field experiment to study the coastal atmospheric boundary layer characteristics was conducted in collaboration with Indira Gandhi Centre for Atomic Research (IGCAR), Health and Safety Division, Kalpakkam during 19 June- 6 July 2001. Observations on wind speed, wind direction, temperature, humidity and solar incoming and outgoing radiation were taken using sensors on a 30 and 50 m high tower and system. Standard Pyranometers were used to measure solar radiation. In the above experiment measurements were taken by using sonic, anemometer, Air temperature relative humidity, SW, LW and net radiation and kytoon system.

Technology Demonstration Projects undertaken in the area of Socio-economic Development

Following the interesting results obtained from the air pollution measurements made in the Pune city during 1-5 May 2000, an extensive field observational campaign with additional parameters for determining urban effects on air pollution levels was undertaken during 29 January-3 February 2001. The main aim of the campaign was to investigate the influence of close-to-ground inversion-included winter haze on pollutant structures at six major traffic junctions (University Gate, Simla Office, Swar Gate, Kothrud, Hadapsar and Yerwada) in the city. The parameters included the total column and surface ozone, aerosol, water vapour, total suspended particulates, Aitken nuclei, wind, temperature, humidity, short wave radiations, net radiation and traffic density. The data sets were being examined also to study the contrast between the present pollution potential during winter months and the potential observed during the summer month.

Observations of aerosols, A.N., surface ozone and some selected meteorological parameters were made during 20 May-,5 June 2000 at Mohal, Kothi and New Delhi. The preliminary results revealed that the average concentration of TSP was 141 mg/m3 at Mohal, 109 mg/m3 at Kothi and 445 mg/m3 at New Delhi. The concentration of TSP at New Delhi was about three and half times higher than that in the Himalayan region and also the contraction of A.N. was one order more at Delhi indicating that Delhi region is more polluted. The average concentration of A.N. was 1845/cm3 at Mohal, 1500/cm3 at Kothi and 21650/cm3 at New Delhi. High TSP levels at New Delhi were found during the summer period associated with hot and dry weather in this region and low TSP were found during the monsoon period. Most of the TSP were associated with natural soil elements, such as Fe, Al, Mn, Ca and K. Only a fraction of the mass of the TSP comprised of elements from anthropogenic sources e.g. Pb, Ni, Cd, Sb, Cu and Zn. In overall, the chemistry of aerosols at Delhi region was potentially alkaline in nature.

The pH of 38 rain water samples collected at Pune during the monsoon season of 2000, varied from 5.98 to 7.50 with an average of 6.39 indicating alkaline rain. In the Himalayan region, 23 samples of rain water were collected at Kothi (2530 amsl) and 11 samples at Jagatsukh (2040 m asl). Forty three percent of the samples were found to be acidic at Kothi and the pH of rain water varied between 4.42 and 6.95 with an average of 5.07, indicating slightly acid rain at Kothi. Whereas, at Jagatsukh pH varied between 5.60 and 6.87 with an average of 6.32 indicating alkaline rain.

Eight samples of fog water were collected at the Institute's Rain and Cloud Physics Research Centre (RCPRC), New Delhi during January 2001. The pH and chemical analysis of fog water revealed that (i) the average pH of fog water was alkaline (6.9). Among the cations, Ca was the dominant ion and among the anions NO3 was the dominant ion, (ii) the cations dominated over the anions which leads to the alkaline nature of fog at Delhi, (iii) the excess of cations indicates the dominance of natural sources i.e. mainly soil and (iv) on comparison of these results with the earlier results of chemical composition of fog water in 1984-85, the pH of fog water in 2001 was found to be slightly reduced compared to 1984-85 period. This is attributed to the decrease in the concentrations of soil oriented components in 2001 than those in 1984-85.

Research Highlights

The Institute has made significant contributions in the challenging areas of Atmospheric Sciences like Weather Forecasting, Climatology, Hydrometeorology, Monsoon Studies, Climate Modelling, Weather Modification, Cloud Physics, Atmospheric Chemistry, Atmospheric Electricity and studies relating to Land-Surface processes. The important highlights are summarised below:

NWP Modelling and Model Diagnostics

Three hourly digitized INSAT IR data for seven days of May 1997 and March 1998 were used to detect deep convective cloud clusters over Indian land mass. The data were analysed to study genesis, maturity and dissipation of the convective cloud clusters. The maturity of the convective clusters was verified with the weather reports of IMD observatories falling within the convective region at 1200 UTC and weather during past six hours from 1200 UTC. The study revealed that digitized data can be used to get signature of mesoscale severe weather associated with intense convective activity over a certain region.

Objective Analysis including Satellite input for NWP Models

Satellite-derived Water Vapour Wind Vectors (WVWVs) obtained from GMS-5 satellite (1995-96) over the Bay of Bengal were compared with the radiosonde winds of Port Blair for the development of regression relationship. Using this relationship, upper tropospheric winds at 150, 200, 250 and 300 hPa levels were generated for the complete life cycle of tropical cyclone (12-20 May 1997) over the Indian region. Impact of these winds on objective analysis of wind fields for vortex, depression, cyclonic storm and dissipation stages was evaluated. These analysed wind fields were compared with the subjective and NCEP analysis. It was found that there was a positive impact of WVWVs on wind speed, circulation and center of anticyclone than subjective and NCEP analysis.

Extended Range Prediction

Seasonal summer monsoon data for 120 stations over East Asia (China, Japan, Mongolia, Korea) varying from 1881 to 1998 were utilized to understand their interannual and climate characteristics, and to investigate their teleconnections with South Asian (in particular, India's) monsoon rainfall. Contemporaneous relations on an interannual time-scales have revealed that the rainfall variations over North China (Southern Japan) are in-phase (out-of-phase) with South Asian rainfall. Based on the instrumental data available, regional rainfall anomaly time series for the 118-year period for the two coherent regions, over North China and Southern Japan were prepared.

The impact of winter Soviet snow depth on summer monsoon rainfall over South Korea has been investigated by lag correlation coefficients and composite analysis. Results revealed that winter-time snow depth over western Eurasia (over Kazakhstan) is negatively related, while snow depth over eastern Eurasian (over Manchuria - eastern Siberia) is positively related with Changma i.e. Korean monsoon rainfall. This dipole configuration is indicative of a mid-latitude longwave pattern with an anomalous ridge (trough) over north Asia prior to a weak (strong) Korean monsoon as revealed by the NCEP/NCAR Reanalysis data. Further the reanalysis data showed that heavy snow over eastern Eurasia and light snow over western Eurasia is conducive for good monsoon activity over Korea (early onset and late withdrawal of Changma, more than normal rainfall) while the reverse situation is unfavourable.

Monsoon Studies and Forecasting

Energetics of lower tropospheric zonal waves during onset, established and withdrawal phases of monsoon were studied for monsoon seasons of 1994 to 1996. It was found that region R1 (10°S-10°N) is dominated by the zonal mean flow (wave 0), region R2 (10°N-30°N) is dominated by the long waves (waves 1-2) and region R3 (30°N-50°N) is dominated by the short waves (waves 3-10). Strengthening of wave 0 over R1 and long waves over R2 results into strengthening of monsoon activity over India while strengthening of short waves over R3 results in weakening of monsoon activity over India and vice-versa.

A characteristic rise in the weekly running cummulative thunderstorm frequencies over four stations of south peninsula was observed about 5-8 weeks prior to the onset of monsoon over Kerala. The occurrence of this event has been used for onset prediction by developing a regression equation using the data for the period (1961-1992). Daily thunderstorm data for 23 well spread stations of south India for the pre-monsoon period (March-June), for the years 1989 and 1998 were collected and analysed to test the representativeness of the sample stations. The selected four stations were found to be sufficient in identifying the characteristic peak in thunderstorm activities over the region.

Secondary Data Utilization Centre

Various satellite images and the satellite data products like CMV, OLR, QPE received at SDUC were displayed and archived. Specially transmitted hourly cloud images during May 2001 cyclone were monitored and archived. The archived images were consulted by various scientists of the institute and the typical images were supplied to them for the research purpose. The transition of cloud pattern during onset phase of monsoon 2001 was also monitored by the scientists utilizing satellite images received at SDUC.

Dendroclimatological Studies

It was demonstrated that in addition to ring width, density parameters of tree-ring, particularly earlywood and minimum density of Cedrus deodara from western Himalaya are sensitive to the pre-monsoon (March-April-May) temperature and precipitation. The densitometric analysis of few more species of Himalayan conifers {Abies pindrow, Picea smithiana, Pinus roxburghii) was carried out. Total six density parameters namely, earlywood and latewood densities, maximum, minimum and mean densities and ring width of each ring were measured. About 50 tree-core samples of different species were analysed for density measurement. Tree growth climate relationship based on response function analysis showed that pre-monsoon temperature and precipitation are major climate parameters influencing the earlywood density and total ring width of all the species. This is mainly because of moisture stress condition (high temperature and low precipitation) occurring during the early growing season of the Himalayan conifers.

Diagnostic of AGCM simulations for understanding the variability of Asian Monsoon and its global teleconnections

A six member ensemble Atmospheric General Circulation Model (AGCM) runs made with observed global sea surface temperatures (SSTs) during 1949-1997 were analysed to examine the ability of the model to simulate various global climatic features such as the Indian summer monsoon, North Atlantic Oscillation (NAO) etc and their interannual variability. These runs were made recently at the Meteorological Research Institute (MRI) of the Japan Meteorological Agency (JMA), Tsukuba, Japan. Apart from the general climatological features, emphasis was given to examine in detail the Indian monsoon rainfall simulation in the model and its tele-connections with El Nino-Southern Oscillation (ENSO). The analyses showed several encouraging positive aspects of the model simulations while the inherent deficiencies brought out suggested the need for further improvements in the model physics and parameterizations. These highly computationally expensive 6 member ensemble runs were also utilized to study the predictability (internal vs SST forced variability) aspects of various global meteorological variables such as the precipitation, surface temperature, sea level pressure etc.

Hydrometeorological Studies

Short duration rainfall analysis was carried out for 5 stations, Pune, Kolhapur, Mahabaleshwar, Sangli and Solapur in Upper Krishna Catchment. Diurnal variations of hourly rainfall were studied for the months of May to October. Maximum rainfall, for continuous 24 hours duration was compared with that of observational days contribution of 1, 3, 6, 12 hr. rainfall to 24-hr. rainfall. It has been observed that during monsoon months of June to September, hour to hour variation is less, while in May and October, afternoon hours contribute more to daily rainfall. It was also seen that maximum observed one day rainfall has to be increased by 10-20% to get 24-hr. maximum rainfall for stations like, Pune, Kolhapur and Mahabaleshwar, whereas for Solapur and Sangli daily maximum rainfall can directly be considered as maximum 24-hr. rainfall. This study has also shown that 6-hr. rainfall can contribute 60 to 80% of 24-hr. rainfall.

Studies of the Atmospheric Boundary Layer

A study was taken up to examine the influence of transient disturbances on the vertical structure of convective boundary layer (CBL) using the radiosonde data recorded during the pilot BOBMEX-98. The results revealed not only significant changes in the surface air layer characteristics during fair and disturbed weather conditions but also enhancement in the CBL height by about 130 hPa during disturbed weather conditions.

The thermodynamic structure of the marine boundary layer over the region 80º - 87ºE along 13ºN of the Bay of Bengal was studied using Radiosonde measurements made during the Phase II of Bay of Bengal Monsoon Experiment-99 (BOBMEX-99) i.e. 27 - 30 August. The observational area was divided into three regional groups depending upon the surface pressure distribution and total cloud amount viz. region I (87º - 85ºE), region II (85º- 82ºE) and region III (82º-80ºE). The distributions of surface pressure and total cloud amount in these three regions are well brought out by the study. In order to investigate the boundary layer characteristics the approaches, viz. saturation point concept, mixing line analysis and conserved variable diagrams, have been used. The vertical profiles of q, qv, qe and qes thus obtained over the Bay of Bengal during cloudy conditions are obtained. The results of the analysis of the above radiosonde data showed relatively dry air near the ocean surface between 1000 to 950 hPa.

Studies in Upper Atmosphere

Analysis of Strat Alert messages from Free University of Berlin for December 2000 - March 2001 revealed existence of major warming from 1 February 2001 to 12 February 2001 with reverse temperature gradient between 60ºN and the pole in middle stratosphere with very cold mesopause temperatures (up to -80ºC) over Berlin.

Analysis of M-100 rocketsonde data of 20 years (1972 to 1992) revealed temperature rise of 8ºC from 1972 to 1992 in the layer between 12 and 20 km. Also a strong mesospheric cooling (-15 to 20ºC) at Thumba was observed in association with increase in surface temperature in the 5ºS to 5ºN latitude belt.

Studies in Air Pollution and Atmospheric Chemistry

Round-the-clock measurements of Aitken Nuclei (A.N.) were carried out on 5 days during the months of May and June 2001 to study the diurnal variation of A.N. and its relationship with meteorological parameters i.e. wind speed, direction, temperature and relative humidity (R.H.). The study revealed that i) A.N. showed high concentrations during day time and low concentrations during night time. The higher concentrations during day time could be attributed to photochemical reactions. The concentrations of A.N. were found to be quite low on a rainy day compared to those on a clear day due to the washout effect. The average concentrations of A.N. was also found to be higher in the month of May (4680/cm3) than that in June (2515/cm3). The low concentrations of A.N. in June were due to the comparatively low temperatures and also due to the washout by rain. (ii) A.N. showed a direct relationship with temperature (r=0.66 at 1% significant level) and an inverse relationship with R.H. (r=0.45, 1% significant levels). At higher humidity the Aitken particles grow into bigger size particles and hence the concentration of A.N. would be low. No significant correlation was observed between A.N. and wind speed. However, the concentration of A.N. were high when the wind speeds were in the range of 1-1.5 m/s. A.N. concentrations were found to be the highest when the wind flow was from north/westerly and low when the wind flow was from S/SW. The low concentrations of A.N. during S/SW winds, can be attributed to the maritime air mass which is relatively less polluted than the continental air mass.

Spectroscopic Measurements of Atmospheric Minor Constituents

The daily twilight spectroscopic observations were collected from May to December 2000 using automatic visible spectrometer for monitoring of atmospheric constituents like NO2, O3, H2O and O4. A computer algorithm was developed to derive slant column densities and computed percentage differential optical depth for NO2, O3, H2O and O4 with higher accuracy. To study annual variation of the above trace gases, the total column densities at 90 solar zenith angle were computed and compared with Dobson spectrophotometer ozone data of the India Meteorological Department (IMD). A good agreement was observed.

Atmospheric Monitoring using the Lidar and Radiometric Techniques

Special radiometric observation of atmospheric aerosols were carried out during a dust-storm event occurred between 3 and 5 June 2000 over a metropolitan city, Delhi. The columnar aerosol optical depth (AOD) measured at six wavelengths (380, 440, 500, 675, 870 and 1020 mm) and corresponding aerosol size distribution inverted from the above observations were examined to investigate significant changes in the aerosol optical and physical properties due to dust-storm activity. The salient results of the study indicated i) greater AOD (about 50%) on the dust- storm day as compared to the days before and after the event. ii) enhancement in AOD, on an average, was about 19% from the pre dust-storm period and decreased upto about 30% during post dust- storm period and iii) presence of larger particles (radius ³ 1.0 mm) during the period of dust-storm as compared to the quiescent period.

The lidar derived vertical distribution of aerosol number density obtained during the three-year period (1977-2000) were analyzed to study the contrast between aerosol properties during the pre- sunrise and post- sunset period over Pune. The results of the study revealed that i) the monthly mean aerosol column content was found to be more in morning hours during December, January, February (winter months) and in the evening hours during March, April, May (pre-monsoon months), ii) Aerosol column content was found to decrease from morning to evening in winter months and increases from morning to evening in post- monsoon months by about 10% during the period of observations, and iii) The aerosol column content showed minimum values on the days associated with precipitation.

Studies using Coupled Neutral-Ion Photochemical Model

A study was undertaken using the coupled neutral-ion photochemical model to demonstrate that gas-phase sulfur chemistry played a vital role in perturbations of the stratospheric ion composition following the Pinatubo eruption. Charged aerosol particles, which become significant only under volcanic perturbations, were proposed to be included in ion-chemical schemes. Model calculations indicate that immediately after the eruption, the large amount of SO2 injected directly into the tropical stratosphere produced additional sulfuric acid vapor which increased the abundance of heavy negative ion family (called HSO4-- core) by several orders of magnitude over the ambient. After 2 to 3 months, most of the sulfuric acid vapor gets condensed and converted to HSO4 / H2O droplets (aerosols) and the density of ultra-fine charged aerosol (which are driven by aerosol) also increases several folds in the tropics for 20-30 km. The perturbation (now weaker) in ion composition continued to be unabated even after one year of eruption but settled down to background level after 2 years. Domination of heavy charged species in the stratosphere following the volcanic eruption must have reduced the mobility of atmospheric medium and hence also the conductivity which might have played a significant role in influencing the Global Electric Circuit (GEC).

Development of Instruments and Observational Techniques for Cloud Electrification Studies

The validity of the atmospheric electric conductivity - aerosol concentration relation is being investigated from the data obtained during the Antarctica Expedition. The aerosol concentrations were theoretically computed from the polar conductivity by including the effect of change in the aerosol size, ionization rates and electrical mobility. Their behavior was studied for different values of conductivity. The results were compared with the oceanic measurements of submicron size aerosols and polar conductivity.

A model program was developed to study the atmospheric scavenging of aerosol particles of different sizes by raindrops.

Development of Simulation Techniques for Cloud Physics Studies

The data collected on the evaporation of water drops suspended in a vertical wind tunnel and subjected to different horizontal electric field were analysed. Results showed that the increase in the value of the electric field caused the decrease in the ventilation coefficient of the drops.

Land Surface Processes Studies

The daytime interaction of the land-surface with the atmospheric boundary layer (ABL) for two cases representing pre-monsoon and monsoon conditions during the LASPEX (LAnd