T.Arunamani'>Enclosure 1: Brief Account of work done by Dr.T.Arunamani
I have been actively involved in the investigations of lower ionospheric phenomena and middle atmospheric minor constituent and ion modeling for over 20 years. Salient features of some of these investigations are given below.
For my doctoral work, the lower ionospheric phenomena were investigated using LF amplitude measurements. Model the D – region profiles were developed ( based on existing neutral and ion chemical schemes) which would successfully explain the diurnal seasonal and transient ( flare time) behavior of the region.
After obtaining Ph.D ., work on the development of one dimensional middle atmospheric minor constituent modeling was initiated , as part of the Indian Middle Atmosphere Program( IMAP) at Waltair. Minor constituents of aeronomic interest Viz., odd oxygen, odd hydrogen and odd nitrogen in the mesosphere and n the stratosphere , in addition to the above Odd chlorine and some of the trace gases like CCl4, CF2Cl2,CFCl3, CH4 etc were computed. Basing on these species, the ion composition models were developed. The neutral species were found to represent the low latitude lower ionosphere fairly accurately.
Studies on the sensitivity of the model calculations of mesospheric minor constituents to variations in certain input parameters like Vertical eddy diffusion coefficient, temperature, water vapor and initially assumed values of the minor constituents showed that the minor constituents do not have any effect on their concentrations. On the other hand these are sensitive to changes in both temperature and water vapor
The effect of solar activity on the minor constituents in the mesosphere and lower thermosphere
The one dimensional models developed were profitably used in a study of the effects of artificial heating in the D- region ion composition.
A study of the seasonal variation of LF propagation data in conjunction with variations in Ozone concentrations, used in the calculation of model D – region profiles brought out very clearly the significance of ozone in the mesospheric processes.
The investigation on the diurnal asymmetry in the D – region electron density also showed that mesospheric ozone variability has greater role to play.
A Two – dimensional middle atmospheric model was developed which involves the use of realistic chemistry schemes and two dimensional transport processes.. The transport schemes involves meridional and vertical wind velocities. The wind velocities were calculated using the diabatic heating rates. Important input parameters for the calculation of heating rates are Ozone and temperature.
Using the two dimensional SOCRATES ( Simulation of Chemistry Radiation and Transport of Environmentally important Species) Model developed at NCAR, and also the Ion chemistry of George Reid, the Transition Heights , which are defined as the height where the dominance of water cluster ions to Molecular ions is observed, are calculated and the results were published
Upper Atmospheric Photo chemistry and Ozone modeling, TSN Somayaji & T.Arunamani, Proc of the international workshop on Ozone, INSA,115-135, 1988
A Steady state Chemical Diffusive Model for the Stratospheric minor constituents, TSN Somayaji, T. Arunamani, ISRO – IMAP – SR 32-88, 185 -192, 1988
Sensitivity of Model calculations of mesospheric Minor constituents to variations in certain input parameters, TSN Somayaji, T.Arunamani & CSVS Murthy, Ind. J.Radio & Space Phys., 18,180-187, 1989.
One and Two dimensional Models for middle atmospheric minor constituents, TSN Somayaji, T.Arunamani, Ind.J.Radio & Space Phys., 18,220-231,1989
A Model study of Effect of Electron temperature enhancement on D and E region electron density , BP Rao, DNM Rao, T.Arunamani, TSN Somayaji & KVV Ramana, Current Science, 58,1194-1195, 1989
A One dimensional Model for minor neutral constituents in the mesosphere and Lower thermosphere, TSN Somayaji & T Arunamani Ind.J.Radio & Space Phys., 19,154-165, 1990
Similarities in the seasonal variability of Obliquely incident LF Radio wave Amplitude and mesospheric ozone at low latitudes T Arunamani, TSN Somayaji, DNM Rao & KVV Ramana, Current Science, 59,738 – 740, 1990
Effect of Solar activity on the minor constituents in the mesosphere and Lower thermosphere., TSN Somayaji & T Arunamani, Current Science, 59,988-991,1990
Artificial heating effects on the lower ionosphere ion composition – A Model study., T Arunamani, DN Madhusudhana Rao, TSN Somayaji & KVV Ramana, Indian Journal of Physics, 66 Part –B No. 3, June 1992
Effect of NO transport on radiowave propagation KVV ramana, M.Indira Devi, DNM Rao, TSN Somayaji & T Arunamani., Ind. J Radio & Space Phys. , 22,380 – 387, 1993
Contribution of mesospheric ozone variability to the diurnal asymmetry in D – region electron density., T.Arunamani, TSN Somayaji & DNM Rao, Current Science, 70, 391, 1996 ( This paper was awarded best paper prize for its new results)
Travelling planetary scale waves in the lower ionosphere derived from A3 absorption measurements, DNM Rao, T. Arunamani & P Indira, Viskha Sci Jour. 2 , 47,1998
Ozone in mesosphere, T.Arunamani, Research Notes, 3, 5, 1998.
A Synoptic study of VLF sudden phase animalies recorded at Visakhapatnam Ibrahim Khan, M.Indira Devi, T.Arunamani and DN Madhusudhana Rao, Earth Planets Space 57,1073-1081, 2005
Earth – ionosphere wave guide model for Rugby – Visakhapatnam path consistent with VLF Phase variation measurements. Ibrahim Khan, M.Indira Devi, T.Arunamani and DN Madhusudhana Rao, Indian J. Physics, 80,201-204, 2006
A two dimensional model study of latitudinal, seasonal and solar activity variation in transition height in the D – region., K.Durga Prasad, TSN somayaji, P.Appala Naidu, DN MadhusudhanaRao, T.Arunamani & M.Indira Devi., Ind. J.Phys., 2007, 81(5&6),521-530(2007)
T.Arunamani, BSN Murthy, & Somayaji TSN, Digital Communication techniques, Course material for Post Graduate Diploma in Tele Communications ( PGDTC), Centre for Distance Education, University of Hyderabad, 2004
T.Arunamani, DSVVD Prasad, & M. Indira Devi, Digital electronics and Microprocessors M.Sc Physics (Final year) School of Distance Education, Andhra University, 2007
T. Arunamani, & BSN Murthy Communication Electronics M.Sc Physics (Final year), SDE, Andhra University, 2006