Annual Report 2005-2006

Science & Engineering Research Council

Atmospheric Sciences

The Programme Advisory Committee on Atmospheric Sciences (PAC-AS) held its two meetings during the period of the report and considered 19 new projects (including one training programme) for financial support. Out of these, 14 were recommended for approval, two were for reformulation and three were rejected. 14 ongoing projects were also monitored through physical presentation by the concerned PIs.

Efforts are being made to generate a new programme called "All India Network of ST Radar Facilities (AINSTRAF)" for setting up 11 ST Radar Facilities in different parts of our country during the coming year under the overall umbrella of ESS Division (DST).

Some of the highlights on the progress/achievements related to this program are as detailed below:-

Newly Sanctioned Projects

• Study of Severe Thunder Storms and Intense Rainfall Events in the North- East India
• Study of Regional features of Radiactive forcing over land due to Black carbon aerosols at Anantapur, Andhra Pradesh
• Mathematical Modelling of Dispersion of Atmospheric Aerosols
• Role of Atmospheric boundary layer processes on internal gravity wave modes during thunderstorm development
• Structure and Dynamics of the Ionospheric Irregularities through Radio Beacon Scintillations in the Indian Zone
• Role of space weather events on VHF scintillations and VLF waves.
• Study on precipitation of aerosols and trace gas composition of air in Orissa region
• Graph Theory in The Study of Severe Thunder Storms
• Characteristics of low Latitude Magnetic Pulsations Over 2 solar Cycles-Proxies for space Climate
• Nonlinear Coherent Wave Structures in Magnetospheric and Ionospheric Plasmas
• Occurrence of Norwester and other Forms of Developments over Gangetic West Bengal Statistics and Model Simulation
• Evaluation of Emission Factors and Budgets of Gases and Particulate matter of Relevance to Climate Change Emitted by Fuels particularly biomass used in India by the Rural Sector and Small Scale Industries
• Measurement and study of ozone under different environments (conducive of vegetation and agriculture fields)

Ongoing Projects

• Studies on Indoor/Outdoor Relation of Air Quality in Residential Homes Located in Different Environment by ST John's College, Agra

Sampling sites were selected in study area i.e. Agra. Homes were selected on the basis of location in different microenvironment; urban, rural and roadside. The occupants of the selected homes were asked to complete an activity diary in the form of questionnaire. This questionnaire was providing in formation about timing of different activities such as cooking, cleaning, ventilation, heating, types of fuels used, number of occupants, characteristics and surroundings of homes etc. In each house sampling of targeted pollutants; NO2, NO, SO2, NH3, CO, CO2, H2S, Cl2 and hydrocarbons was carried out simultaneously indoor as well as outdoor. YES 205 multigas and YES 206 monitor were used to detect the Cl2, H2S and CO gases in both indoor and outdoor, while NH3, SO2, NO and NO2 are collected by impinger technique and then determine by using spectrophotometric technique. PM and RSPM are also collected in each house in outdoor and indoor environment. Obtained data from above study is analysed further to ascertain the seasonal variation, influence of meteorological parameters and source apportionment. The sampling and analysis is being continued and the data generated is expected to give an idea and magnitude of exposure to IAP. Such information is needed for different interventions to be applied to reduce the exposure and to improve the health of the people.

• A Study on the Impacts on Initialization of the Cyclonic Vortex in a High Resolution Mesoscale Tropical Cyclone Model by IIT, Kharagpur

The National Center for Atmospheric Research (NCAR)-Air Force Weather Agency (AFWA) synthetic vortex scheme has been implemented and utilized in the NCAR-Pennsylvania State University Fifth Generation Mesoscale Model (MM5) for two tropical cyclones which formed over the Bay of Bengal (10 - 12 November 2002) and over the Arabian Sea (12- 16 November 2003). The approved objectives included devising a scheme which would modify the weak and diffuse initial cyclonic vortex with a vortex which is closer to the observed tropical cyclone intensity. Also the objectives included implementing the above scheme in a mesoscale model, testing the above scheme for several tropical cyclones over India and validating the model results which includes the scheme with actual observations. The approved methodology was to utilize the inclusion of an axisymmetric synthetic vortex to replace the weak and diffuse cyclonic vortex and implement it in MM5 model. The results of the two synthetic vortex runs for Arabian Sea and Bay of Bengal indicate improvement in the simulation of wind asymmetries, warm temperature anomalies and in the track prediction of the tropical cyclone. Also there was lowering of the sea level pressure and increase in the maximum wind speed associated with the cyclone due to inclusion of the synthetic vortex.

• Study of Aerosol and Clouds over Indian Region by IISc, Bangalore

The instrument namely Micro Pulse Lidar is procured and is operational at Bangalore for last one year. The analysis of data is in progress. The aim of the project is the characterization of aerosols and clouds over the Indian region using surface and satellite sensors simultaneous with lidar. The major objectives are (i) to estimate the vertical distribution of aerosols in the troposphere (ii) to estimate the aerosol optical depth (iii) to estimate the clear sky and cloudy sky aerosol radioactive forcing. The satellite part of the project is almost achieved in the case of aerosols. The study of clouds is needed for estimation of cloudy-sky aerosol forcing which is under progress.

• Study of meteor echoes and related ionospheric problems by using MST radar by Osmania University, Hyderabad

The Indian MST radar is capable of acquiring data from about 4500 meteors per day. This number is large enough and adequate for investigating many scientific problems related to astronomical aspects of meteors, wind and temperature fields in the mesopause-lower thermospheric region. Hence, the said project was taken -up for meteor observations and for studies on waves, winds and atmospheric dynamics.

In this project, the in-phase (I) and quadrate (Q) of the receiver output are recorded simultaneously. Since MST radar data format has the advantage of observing the meteor trails simultaneously in different range bins, the meteor trail signatures and Es are recorded with E and NA beams with pulse widths of 2 µsec. To identify the meteor echoes, variations in I and Q of radar echoes in each range bin are obtained. The records of corresponding Doppler spectra, of I and Q data, and their moments are obtained by using ADP package. The Es formations are identified from the spectra obtained from I and Q data of NA beam. These Es formations are thoroughly studied for their origin relating to meteor shower activity. These observations are carried out regularly during the active periods, of major nighttime and day-time meteor showers, to establish the feasibility of MST radar for meteor observations and also to establish the meteoric origin of sporadic E at low latitudes.

After procuring the instruments, ADP (Atmospheric Data Processor) soft ware has been loaded and analysis work has been started. The analysis of the data is in good progress and it is expected to obtain many valuable results on the meteoric activity and its influence on the formation of sporadic-E layers. This will also give rise to important results on waves, winds and temperatures at E-region heights.

Completed Projects

• Weather Forecasting using Distributed Neutral Network by IIT, Kanpur

A neural network model has been developed for the purpose of short term forecasting of daily rainfall. The model was tested at several stations spread over India which included Delhi, Pune, Hyderabad, Bangalore and Bhubaneshwar. The input variables were chosen from the time evolved variables using the atmospheric model T-80. The variables were chosen on the basis of their physical correlation with the output. In order to develop a correlation of the grid input data with the output rain gauge data it is necessary to find an optimal value of the variable at the location of the rain gauge. This was done by making a surface quadratic fit to the nine nearest grid locations surrounding the position of the rain gauge. Extensive neural network simulations were carried out for all the test stations. The performance of the neural network was tested by evaluating several measures for the validation set such as the square error (B.S.), H. K. index and ratio of correct predictions to the total number of data points. It was generally found that for a sufficiently complex network the training error continues to decrease with increase in the number of iterations. However the validation error goes down in the beginning but beyond a certain number of iterations it starts to increase. The process of training was stopped at the point where the validation error begins to deteriorate. The results of the neural network were compared with those obtained with linear regression. For the case of Delhi we also compared the results of a single rain gauge with those obtained for the average of three rain gauges at different locations in the city of Delhi. Our results suggest that the predictability may be considerably improved if we average over a large number of rain gauges within a grid cell.

• Fine Structure analysis of VLF and triggered spectra and coupling of ionosphere -magnetosphere by BHU, Varanasi

The recorded VLF waves are analyzed to obtain the dynamic spectra which depends upon the path of propagation and propagation mode. To explain the observed dynamic spectra, we have developed simulation technique for the propagation of VLF wave through the inhomogeneous magnetoplasma. In this method, Maxwell's equation along with the equation of motion have been solved to obtain the wave equation. The source current is considered as the lightning discharge current, which is represented by the Dirac delta function. W.K.B. method has been used to obtain the expression for the wave electric field. Numerical method has been developed and computed results could simulate the observed dynamic spectra of whistlers observed in the ionosphere and magnetosphere. Non-liner theory of wave-particle interaction has been worked out and detailed computations have been made, which can explain some features of triggered emission.

• Entrainment in Cloud-Like Plumes by IISc, Bangalore

The entrainment and mixing in clouds remained a puzzle - observations show that there is significant dilution, and at the same time some mass of air in cumulus clouds ascends practically unaffected by dilution taking place elsewhere. This proposal was motivated by an interest to understand this process through a detailed investigation of the consequence of local volumetric heating in plumes. The study brought out the important fact that significant dilution due to entrainment and immunity from ambient fluid can co-exist within the same flow when there is heat release inside the flow. The physical mechanism of entrainment and mixing undergoes a major change. This means that the standard laterally entraining plume model, prototype for modeling cumulus clouds by a majority of studies at present, needs to be modified before applying it to parameterize entrainment into clouds. Science & Engineering Research Council

Mathematical Sciences

Following major activities were supported during the year:

• Three Group Discussions, one each on "New Methods of Computing" (IIT, Madras), "Signed Discrete Structures and their Applications" (RIE, Mysore), "Group Discussion on Natural Computing" (IIT, Chennai), and "CARDMATH Group Discussion on Logic in Computing Science" (IMSc, Chennai).
  
• CARDMATH Core Projects at Mysore and Krishnankoil were formulated.
  
• Initiation of setting up a Core Research Group at the Centrer for Mathematical Sciences (CMS), Trivandrum at its campus in St. Thomas College, Pala (Kerala).
  
• First International Conference in Logic (IIT, Bombay) was held as a new initiative toward evolving an R&D programme on Mathematical Modelling in Behavioural/Cognitive/Social Sciences (BCSS).
  
• Setting up Touch-Screen Kiosks on the Life and Works of Srinivasa Ramanujam launched as a new initiative in the premises of the Ramanujan Institute of Advanced Studies (RIASM), University of Madras, Chennai.
  
• Two SERC Chairs entitled "DST Srinivasa Ramanujan National Chairs in Mathematical Sciences" were instituted at Srinivasa Ramanujan Center (SRC), SASTRA, Kumbakonam (Tamil Nadu)