IJCRR - 5(12), June, 2013
STUDIES ON THE OCCURRENCE OF DUCT AND SUPERREFRACTION OVER INDIAN REGION
Author: N. Radha Krishna Murthy , S. Vijaya Bhaskara Rao
Category: General Sciences
Cosmic GPS data for the years 2007 and 2008 is taken to analyze the occurrence of ducts and super refraction over Indian region corresponding to latitudes -5o to 40o and longitudes from 60o to 100o up to a height of 5Km from sea level. Number of duct regions, high duct strength regions and superrefraction regions are counted over Arabian Sea, Bay of Bengal and land regions. Arabian sea region has more number of duct regions during postmonsoon (September, October, and November), premonsoon (March, April, May) and winter (December, January, February) seasons and less number during summer monsoon (June, July, August,) season. More number of duct regions observed over Bay of Bengal during winter than other seasons. Land region has more number of duct regions during post monsoon season. More number of superrefraction regions occurs over Arabian Sea in pre monsoon season; over Bay of Bengal during winter and Pre monsoon seasons and over land region during post monsoon season. Majority of duct regions are found to occur at heights less than 1.5 Km and majority of superrefraction regions at heights less than 2 Km from sea level.
N. Radha Krishna Murthy , S. Vijaya Bhaskara Rao. STUDIES ON THE OCCURRENCE OF DUCT AND SUPERREFRACTION OVER INDIAN REGION International Journal of Current Research and Review. 5(12), June, 12-20
1. Almond, T., and Clarke, J., 1973, Considerations of the usefulness of the microwave prediction methods on air-toground paths, IEEE Proc., Part F, 130, 649–656.
2. Brooks, I., A. Goroch, and D. Rogers, Observations of strong surface radar ducts over the Persian Gulf, J. Appl. Meteor., 38, 1293–1310, 1999.
3. Babin, S. M., 1996: Surface duct height distributions for Wallops Island,Virginia, 1985–1994. J. Appl. Meteor., 35, 86–93.
4. Brooks, I. M., A. K. Goroch, and D. P. Rogers, 1999: Observations of strong radar ducts over the Persian Gulf. J. Appl.Meteor., 38, 1293–1310.
5. Bech, J., D. H. Bebbington, B. Codiba, A. Sairouini, and J.Lorente, 1998: Evaluation of atmospheric anomalous propagation conditions: An application for weather radars. Remote Sensing for Agriculture, Ecosystems, and Hydrology. E. T.Engman, Ed., International Society for Optical Engineering (SPIE Proceedings Vol. 3499), 111–113.
6. Bech, J., A. Sairouni, B. Codina, J. Lorente, and D. Bebbington,2000: Weather radar anaprop conditions at a Mediterranean coastal site. Phys. Chem. Earth, 25B (10–12), 829–832.
7. Bech, J., B. Codina, J. Lorente, and D. Bebbington, 2002: Monthly and daily variations of radar anomalous propagation conditions: How “normal” is normal propagation? Proc. Second European Conf. of Radar Meteorology, Delft, Netherlands,ERAD Publication Series, Vol. 1, Copernicus GmbH, 35–39.
8. Craig, K. H., 1996: Clear air characteristics of the troposphere.Propagation of Radio Waves, M. P. Hall, L. W. Barclay, and M. T. Hewitt, Eds., The Institution of Electrical Engineers,105–130.
9. Craig, KH., and T. G. Hayton, 1995: Climatic mapping of refractivity parameters from radiosonde data. Proc. Conf. 567 on Propagation Assessment in Coastal Environments, Bremerhaven, Germany, AGARD-NATO, 43-1–43-14.
10. Gossard, E. E., 1977: Refractive index variance and its height distribution in different air masses. Radio Sci., 12, 89– 105.
11. Ghouse Basha, M. Venkat Ratnam, G. Manjula, and A. V. Chandra Sekhar, 2013, Anomalous propagation conditions observed over a tropical station using high-resolution GPS radiosonde observations, RADIO SCIENCE, VOL. 48, 1–8, doi:10.1002/rds.20012.
12. Jaswal. A. K. et al., 2012, Relationship between sea surface temperature and surface air temperature over Arabian Sea, Bay of Bengal and Indian Ocean, J. Ind. Geophys. Union Vol.16, No.2, pp. 41-53, April 2012.
13. Klein, S., and D. Hartmann, 1993, The seasonal cycle of low stratiform clouds, J. Climate, 6, 1587–1606.
14. Kursinski, E., G. Hajj, J. Schofield, R. Linfield, and K. Hardy, 1997, Observing Earth’s atmosphere with radio occultation measurements using GPS, J. Geophys. Res., 102, 23,429–23,465.
15. Patterson, W., 1982, Climatology of marine atmospheric refractive effects:a compendium of the Integrated Refractive Effects Prediction System (IREPS) historical summaries, NOSC Tech. Doc.573, Naval Ocean Systems Center, San Diego, CA, USA,522 pp.
16. S¸. Sibel Mentes and Zerefsan Kaymaz , 2007, Investigation of Surface Duct Conditions over Istanbul, Turkey, Journal of Applied Meteorology and climatology,46,318-337, DOI: 10.1175/JAM2452.1
17. Smith, E., and S. Weintraub, 1953, The constants in the equation for atmospheric refractive index at radio frequencies, Proceedings of the I.R.E., 41, 1035–1037.
18. Tomczak, M., and J. Godfrey, 2003. Regional Oceanography: an Introduction, 2nd ed., Daya Publishing House, Delhi, 390 pp.
19. Turton, J. D., D. A. Bennets, and S. F. G. Farmer, 1988: An introduction to radio ducting, Meteor. Mag., 117, 245–254.
20. von Engeln, A., and J. Teixeira (2004), A ducting climatology derived from the European Centre for Medium-Range Weather Forecasts global analysis fields, J. Geophys.
21. Res.,109, D18104, doi:10.1029/2003JD004380.von Engeln, A., G. Nedoluha, and J. Teixeira (2003), An analysis of the frequency and distribution of ducting events in simulated radio occultation measurements based on ECMWF fields, J. Geophys. Res., 108(D21), 4669, doi:10.1029/ 2002JD003170.