Indian Journal of Radio & Space Physics

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(CODEN : IJRSAK        ISSN : 0367-8393)

VOLUME 37

NUMBER 6

DECEMBER 2008

 

CONTENTS

 

Geo-effective transients and their solar causes during solar cycle 23

379

Santosh Kumar& Simranjit Kaur*

 

 

Ha, EUV and UV analysis of an eruptive 3B/X1.2 flare

386

        Seema Pande, Bimal Pande*, Wahab Uddin & Kavita Pandey

 

 

North-South asymmetry in solar wind & geomagnetic activity and its solar cycle evolution

391

V Sanalkumaran Nair* & S R Prabhakaran Nayar

 

 

Ionosphere near the anomaly crest in Indian zone during magnetic storm on 13-14 March 1989

396

        S K Chakraborty*, R Hajra & A Paul

 

 

Intersystem interference on horizontally polarized radio signals in tropical climate

408

 J S Ojo *, S K Sarkar & A T Adediji

 

 

Test of wave-particle interaction linearity for 2 Hz sidebands of Siple transmitter whistler mode signals observed at Roberval, Canada

414

D P Singh* & U P Singh

 

 

Simulation of local severe storm by mesoscale model MM5

419

        Prosenjit Chatterjee, D Pradhan& U K De*

 

 

Size distribution of trace metals in ambient air of Agra

434

        Anita Lakhani*, R S Parmar, G S Satsangi & Satya Prakash

 

 

Chemical composition of rainwater in Panipat, an industrial city in Haryana

443

        S Tiwari*, Manoj K Srivastava & Deewan Singh Bisht

 

 

Annual Index

 

Subject Index

451

Author Index

 

453

Acknowledgement to Reviewers

 

 

 

__________

455

*Authors for correspondence

 

 

 

 

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp. 379-385

 

 

Geo-effective transients and their solar causes during solar cycle 23

 

Santosh Kumar1,$ & Simranjit Kaur*,1, 2,#

1Department of Physics and Electronics, Rani Durgawati University, Jabalpur (MP) 482 001, India

2Department of Physics, University of Utah, Salt Lake City, UT, USA

E-mail: $s_kumar123@rediffmail.com; #simranhanspal@hotmail.com

Received 20 December 2006; revised 23 August 2007; accepted 28 August 2007

During nine-year period of the current solar cycle 23 from July 1996 to January 2005, geomagnetic storms (GMSs) of Intense if (Dst < -100nT), Major if (-50nT ³ Dst ³ -100nT) and Minor if (-20nT ³ Dst ³ -50nT) have been investigated. It is observed that maximum number of GMSs are associated with coronal mass ejections (CMEs) followed by individual Hα and X-ray solar flare events. When accumulated effect of Hα and X-ray solar flare events are considered, these solar flares are better associated with GMSs than CMEs. A significant decline in the number of Intense and Minor GMSs have been observed from 1998 to 1999, however, there is an increase in Major GMSs. On the contrary, during 1997-98, Intense and Minor GMSs have increased with the ascending phase of solar activity and Major GMSs have decreased. It is observed that an overall northern bias apparently prevails for solar flares and active prominences and disappearing filaments. Hα and X-ray solar flares occurring over the western limb of the solar disk cause larger disturbances in magnetosphere leading to occurrence of Intense GMSs, whereas, solar flares occurring on eastern limb of the solar disk lead to occurrence of Major and Minor GMSs. It is observed that coronal intensity (CI) is maximum for Minor GMSs followed by Major and Intense GMSs, whereas, mean CI is maximum for Intense GMSs followed by Major and Minor GMSs. The results show that the product of solar wind velocity (Vsw) with minimum Bz component (Bzmin) of interplanetary magnetic field (Vsw.Bzmin), product of linear velocity of CMEs (Vcme) with Bzmin (Vcme.Bzmin) along with minimum Dst of the sudden storm commencement day are the reliable indicators of intensity of GMSs.

Keywords Geomagnetic storms, Solar flares, Active prominences and disappearing filaments, Coronal mass ejections, Coronal intensity, Disturbance storm time

PACS No.: 92.60.Qx; 96.60.ph; 96.60.qe; 96.60.qf

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp. 386-390

 

 

Ha, EUV and UV analysis of an eruptive 3B/X1.2 flare

Seema Pande1, Bimal Pande*,1,#, Wahab Uddin2 & Kavita Pandey1

1Department of Physics, DSB Campus, Kumaun University, Nainital 263 002

2Aryabhatta Research Institute of Observational Sciences (ARIES), Naintal

#E-mail: pandebimal@yahoo.co.in

Received 17 April 2007; revised 18 August 2008; accepted 5 September 2008

The present paper presents observational results of an extremely energetic eruptive flare 3B/X1.2 from superactive region NOAA 10486. The observations were taken on 26 October 2003 with 15 cm Solar Tower Telescope at Aryabhatta Research Institute of Observational Sciences (ARIES). Hα observations of the flare show long multi ribbon eruptions along a large twisted (sigmoid) filament in a high gradient (~90°) magnetic field and shear. The evolution pattern of this flare is similar in EUV and UV. Four eruptive centers or kernels in Hα have been chosen, wherein K1 shows two prominent peaks while K3 exhibits only one prominent peak with gradual decay. The analysis shows that this is a classical long duration event (LDE). The results have been discussed in the light of existing theories.

Keywords: Solar flare, Eruptive flare, Long duration event, Coronal mass ejection, Microwave bursts

PACS No.: 96.60.ph; 96.60.qe

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp. 391-395

 

 

North-South asymmetry in solar wind & geomagnetic activity and its
solar cycle evolution

V Sanalkumaran Nair*,1,$ & S R Prabhakaran Nayar2

1Department of Physics, V T M N S S College, Dhanuvachapuram, Thiruvananthapuram 695 503, Kerala

2Department of Physics, University of Kerala, Kariavattom, Thiruvananthapuram 695 581, Kerala

$Email: sanalkumar.nair@yahoo.co.in

Received 10 October 2006; revised 22 August 2008; accepted 2 September 2008

The unequal distribution of various aspects of solar activity between the north and south hemisphere of the Sun is well known for over a century. Analysis of solar wind data observed during 1964 - 2004 showed that solar wind velocity (Vsw), interplanetary magnetic field (IMF) Bz component and geomagnetic activity index (Ap) exhibit a clear heliospheric north-south asymmetry. In general, amplitude of the north-south asymmetry is maximum during the minimum phase of solar cycle. For Vsw and IMF Bz component, amplitude of the asymmetry is greater during even cycles 20 and 22 compared to the odd cycles 21 and 23. The phase of the asymmetry of IMF Bz reverses every cycle with a northern dominance in even cycles and southern dominance in odd cycles. The asymmetry of Vsw has a northern dominance during cycles 20 and 23 and southern dominance during cycles 21 and 22. Thus, for Vsw, the amplitude of the asymmetry and IMF Bz, both the amplitude and phase exhibit a 22-year period. The asymmetry of Ap index appears similar to that of solar wind velocity. The asymmetry in solar wind velocity and geomagnetic activity may be due to the existence of a relic solar magnetic field in the solar convection zone.

Keywords: Solar wind velocity, Geomagnetic activity index, Interplanetary magnetic field, Solar activity, Solar North-South asymmetry

PACS No.: 96.60.Vg; 96.60.qd; 96.50.Bh

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp. 396-407

 

 

Ionosphere near the anomaly crest in Indian zone during magnetic storm
on 13-14 March 1989

S K Chakraborty*,1,$, R Hajra1 & A Paul2

1Department of Physics, Raja Peary Mohan College, Uttarpara, Hooghly 712 258

2Institute of Radiophysics and Electronics, University of Calcutta, Calcutta 700 009

E-mail: $skchak2003@yahoo.com

Received 26 June 2007; revised 18 August 2008; accepted 3 September 2008

The storm time responses of the ionosphere near equatorial anomaly crest in the Indian longitude zone during super magnetic storm on 13-14 March 1989 have been studied using (i) total electron content (TEC) and VHF/UHF scintillation data from location near the equatorial anomaly crest (Calcutta), (ii) h/F, foF2 data from an equatorial station Kodaikanal, and (iii) ion density data from Defense Meteorological Satellite Program (DMSP) satellites. Some distinctive features in the storm time variation of the Indian low latitude ionosphere compared to those of the East Asian and western longitude sectors are revealed through the analysis of DMSP ion density data. The h/F and foF2 data of Kodaikanal exhibit some unusual features, i.e. abnormal height rise and corresponding drop of plasma density at equatorial F-layer in the midnight-post-midnight period of both the main and recovery phases of the storm. From Calcutta large depressions in diurnal variation of TEC for two consecutive days marked the disturbed conditions. An abnormal post-midnight enhancement of TEC is also detected. A remarkable feature of storm time responses of the equatorial low latitude ionosphere is the preferential occurrence of scintillation in the path of trans-ionospheric signals from a particular satellite out of two (ETS-2 and FSC) with a longitude separation of 50. VHF/UHF scintillation observations in the post-midnight period from Calcutta exhibit the longitudinally confined nature of the storm induced ionospheric irregularities. A distinctive feature of scintillation occurrence near the anomaly crest of the Indian and East Asian longitude sectors justifies typical local time dependence of disturbance electric field components. Combined studies on scintillation, TEC, ion density, h/ F, foF2 data produce a coherent picture of the storm time equatorial ionosphere over Indian longitude sector.

Keywords: Ionospheric disturbances, Ionospheric irregularities, Storms, Space weather

PACS No.: 94.20.Vv; 94.05.Sd

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp. 408-413

 

 

Intersystem interference on horizontally polarized radio signals in tropical climate

 

J S Ojo*,1,2, #, S K Sarkar1 & A T Adediji2

1Radio and Atmospheric Sciences Division, National Physical Laboratory, New Delhi 110 012

2Department of Physics, Federal University of Technology, Akure, Ondo State, Nigeria

#E-mail: josnno@yahoo.com

Received 4 December 2007; revised 12 May 2008; re-revised and accepted 8 July 2008

The nature and characteristics of tropical rainfall have called for the need to investigate horizontally polarized radio signals from Earth-to-Satellite link and to estimate intersystem interference due to hydrometeor in the tropical climate. Two rain cells, Awaka and Capsoni models, are used and results obtained from these models are compared. A difference of 5 dB has been observed between effective transmission loss (Le) and transmission loss (L) for Awaka model, whereas it is about 8 dB for Capsoni model at 0.01% of time unavailability (outage time). This suggests higher interference level in Awaka model for terrestrial and satellite communication operating at frequency above 10 GHz. The statistics of effective transmission loss over frequencies variation, station separation and terrestrial antenna gains have also been considered.

Keywords: Intersystem interference, Horizontal polarization, Tropical climate, Effective transmission loss.

PACS No.: 84.40.Ua; 95.85.Bh

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp. 414-418

 

 

Test of wave-particle interaction linearity for 2 Hz sidebands of Siple transmitter whistler mode signals observed at Roberval, Canada

D P Singh*,1,$ & U P Singh2,#

1Department of Physics, F G M Government College, Adampur (Hisar) 125 052

2Department of Physics, S J M Institute of Engineering & Technology, Radaur (Yamunanagar) 135 133

E-mail: $singh-dinesh@indiatimes.com; #singh-umesh@indiatimes.com

Received 4 July 2007; revised received and accepted 10 September 2007

It is well known that non-linear interaction between whistler mode signals from a VLF transmitter and energetic electrons can successfully explain the generation of sideband spacings of 20 Hz or more. However, Park [J Geophys Res (USA), 86 (1981) 2286] has observed side band spacings of 2 Hz in the whistler mode signals transmitted by Siple station transmitter and received at the conjugate ground station of Roberval, Canada. It is shown that such small spacing need wave magnetic field amplitude of 1.5 pT, which is lower than threshold for non-linear amplification. The results indicate that linear amplification is able to explain such sideband spacings.

Key words: Wave-particle interaction, Whistler waves, Wave propagation

PACS No.: 94.30.Tz, 52.35.Hr, 94.20.Bb

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp. 419-433

 

 

Simulation of local severe storm by mesoscale model MM5

Prosenjit Chatterjee1, D Pradhan2 & U K De*,1,$

1School of Environmental Studies, Jadavpur University, Kolkata 700032

2Cyclone Detection Radar, New Secretariat Building, 1 K S Roy Road, Kolkata 700001

Email: $deutpal2003@yahoo.com

Received 9 January 2007; revised 26 October 2007; accepted 4 June 2008

Simulation of three severe local storms occurring over Gangetic West Bengal and surrounding areas in pre-monsoon season has been attempted with the help of mesoscale model MM5. All three storms are associated with wind squall and propagating type thunderstorm cell formation. It has been noted that the simulation is closest when the cumulus cloud parameterization scheme of Grell, cloud microphysics scheme of Schultz, Hong-Pan scheme for planetary boundary layer process, 5-layer soil model for land surface process and no shallow convection scheme are considered. The simulation is validated by 24 h accumulated rain observation at various surface observatories, by location, duration, and magnitude of maximum rain; by location, time of occurrence and magnitude of maximum wind; and by two products of the Doppler radar located at Kolkata. It has been noted that the model can reproduce wide spread rain as well as wind squall, even with limited regional data input, though there is spatial and temporal shift. Verification with the help of Doppler radar seems to be better, particularly close to the time of occurrence of the system. The model can simulate the propagation of thunder cell as noted by the radar though there is spatial as well as temporal shift. Therefore, one can simulate the broad features of severe local storm even with limited input of regional data

Keywords: Simulation, Cumulus parameterization, Boundary layer process, Land surface process, Doppler radar

PACS No.: 92.60.Ox, 92.60.Qx

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp 434-442

 

 

Size distribution of trace metals in ambient air of Agra

Anita Lakhani*, R S Parmar, G S Satsangi & Satya Prakash

Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Dayalbagh, Agra 282 005 (UP), India

E-mail: anitasaran2003@yahoo.co.in; ravi_parmarin@yahoo.co.in; gursumiran@hotmail.com

Received 7 November 2006; revised 31 August 2007; accepted 6 September 2007

Trace metals, viz. Al, Si, Ca, Mg, Fe, Mn, Pb, Ni, V, Cd, Sn, Cr, Cu and Zn were identified in size-fractionated aerosols of urban atmosphere of Agra. The metals that are largely soil derived, e.g. Al, Si, Ca and Mg had highest concentrations and exhibited a bimodal pattern with larger fraction in the coarse mode. Other metals, viz. Fe, Mn, Pb, Ni, V, Cd, Sn, Cr, Cu and Zn were found to dominate in the fine mode consistent with their anthropogenic origin. Source identification has been further confirmed by enrichment factor calculations.

Keywords: Trace metal concentration, Aerosol, Size distribution, Enrichment factor

PACS No.: 92.60.Mt

 

 

Indian Journal of Radio & Space Physics

Vol. 37, December 2008, pp. 443-449

 

 

Chemical composition of rainwater in Panipat, an industrial city in Haryana

 

S Tiwari1,$,*, Manoj K Srivastava2 & Deewan Singh Bisht1

1Indian Institute of Tropical Meteorology, New Delhi Branch, New Rajinder Nagar, New Delhi 110 060, India

2Department of Geophysics, Banaras Hindu University, Varanasi 221 005, India

$Email: smbtiwari@yahoo.co.uk

Received 5 July 2007; revised 27 February 2008; accepted 28 July 2008

Chemical composition of rainwater at Panipat, an industrial city in India, during the south-west monsoon seasons 2003-2005 has been studied. The collected samples have been analyzed for major anions, cations and pH along with conductivity. The volume weighted pH of rainwater varied from 5.02 to 6.86 with a mean value of 5.51, which is slightly acidic. About 37% of rain samples were observed to be acidic due to high SO2 emissions from industries. The trend of average ionic concentration in precipitation (µeq/l) showed SO42-> Ca2+> NH4+> Cl-> NO3-> Na+> Mg2+> F-> K+ >HCO3-. The percentage contribution to the total ionic concentration is found to be 51% to cations and 49% to anions. Sulphate, calcium and ammonium shared maximum contribution. Major part of sulphate ion in rainwater at Panipat was of anthropogenic origin, i.e. by the oxidation of sulphur dioxide emitted from burning of fossil fuels from thermal power plant, oil refinery, fertilizer plant, etc. The major source of nitrate was biomass burning, automobile and soil. Ammonium in precipitation was due to bacterial action on nitrogen compounds in the soil, urine and from industrial sources. The ratio of sea salt (Na+ and Cl-) was equal to the seawater, suggesting that it was mostly influenced by marine air.

Keywords: Rainwater chemistry, Ion concentration

PACS No.: 92.60.Ls; 92.40.eg