Author: Flavio Gori

Abstract.

Hessdalen Phenomena (HP) is recognised as a sort of enigma, since it has usually showed a very particular behaviour, apparently with no possible connection with other known physical phenomena. This was since 1984, when Norwegian Researcher Erling Strand began his Scientific Research in the Hessdalen Valley (15). Now we are analysing a possible data accord: in the Northern hemisphere during months around winter solstice we have higher electron density in the Plasmasphere (7) and, in the same time, higher HP as sightings reported by witnesses (1a). In the months around the summer solstice we have the lower electron density in the higher ionosphere (7) as well as the lower Hessdalen lights reported. Is it electron density able to play an important role in the so called HP?
Some very powerful man-made (even not far from Hessdalen) radio waves injections in the atmosphere are reported in order to evaluate if and how such emissions may play any role (though unexpected) in the triggering of the Phenomena, even during low electron density season. Powerful radio injections might add energy to get the needed atmospheric overall resource in order to trigger such phenomena. Reported times of the radio experiments, appear to be in the 1980 - 1990 years. Just the time HP got worldwide knowledge, because the sightings number got its higher value.
Whatever HP and its origin may be, it seems that electron density in the Earth ionosphere as well as its fluctuations in short time, have something to share with it and its triggering cause, to turn SCEBs (2) in to the optical phenomena we are investigating.

Riassunto (Traduzione di Alessandro Zabini)

Sin dal 1984, allorchè il ricercatore norvegese Erling Strand iniziò l'indagine scientifica nella valle di Hessdalen (15), il fenomeno che lì viene riportato è considerato una sorta di enigma a causa del comportamento molto peculiare che manifesta di solito, a causa del quale pare essere privo di qualunque connessione possibile con altri fenomeni fisici conosciuti.
In questi articolo si analizza una serie di dati che sembrano offrire una possibile analogia: nei mesi del solstizio invernale si constata nell'emisfero settentrionale l'aumento della densità degli elettroni nella plasmasfera (7), al quale si accompagna l'aumento delle osservazioni del fenomeno di Hessdalen da parte dei testimoni (1a). Nei mesi del solstizio d'estate, invece, la densità degli elettroni è inferiore nella zona alta della ionosfera (7), come lo è il numero delle osservazioni. Ci si domanda dunque se la densità elettronica possa avere un ruolo importante in relazione al fenomeno di Hessdalen. Si considera anche l'immissione nell'atmosfera di energia a frequenza radio con emissioni molto potenti di origine non naturale emesse anche non molto lontano da Hessdalen, allo scopo di valutare se e come tali emissioni, possano avere qualche ruolo, seppure imprevisto, nella produzione del fenomeno, anche nei periodi in cui la densità degli elettroni è bassa. E' possibile infatti che potenti emissioni radio contribuiscano a produrre il livello di accumulo energetico necessario a provocare il fenomeno.
Gli esperimenti radio di cui si ha notizia sono avvenuti nel periodo fra il 1980 e il 1990, proprio quando si verificava il maggior numero di osservazioni e il fenomeno di Hessdalen diveniva noto in tutto il mondo. Quale che possa essere la natura del fenomeno, sembra che la densità degli elettroni nell'alta ionosfera terrestre, come pure la sua fluttuazione nel breve periodo, abbia qualcosa a che fare con la sua origine, ossia nel trasformare le SCEB (2) nei fenomeni ottici che stiamo indagando.

It is known that Very low frequency (VLF) waves, which have frequency in the radio range 3-30 kHz, are emitted, between other sources, by natural phenomena earth and space based connected through the atmosphere and by very powerful man-made VLF transmitters. In the last twenty years did arise the capability to generate VLF/ELF waves using powerful ground based HF (High Frequency) radar. This is to modulate the intense auroral electroject currents that flow in the D and E ionospheric regions, causing natural currents to radiate ELF/VLF waves from an altitude range of 70/100 km, though these altitude are strictly depending upon the HF frequency used (6). A number of such experiments were carried out near the Norwegian town of Tromsø, around 700 km north/west from the Hessdalen valley, during the 1980-1990 and beyond years (6a).

Below we list the most important features of these experiments, as shown in the PARS Project article by Inan and Bell at Star Lab, Stanford University (6a):

1) The Tromsø HF ionospheric heating facility successfully produced electromagnetic waves in the 200 Hz to 6.5 kHz frequency range with an amplitude of approximately 1 pT as measured on the ground. The ELF/VLF wave amplitude was roughly constant between 2­6 kHz, but dropped by 3 dB at the lower end of the frequency range.

2) The HF heater frequency generally lay within the three frequency bands: 2.75 - 4 MHz, 3.85 - 5.6 MHz, and 5.5 - 8 MHz, and the HF signal was generally 100% amplitude modulated with a square wave.

3) The HF radiated power was approximately 1 MW, and the effective radiated power (ERP) generally lay in the range of 200 to 300 MW.

4) It was generally found that X-mode polarization of the HF signal resulted in a more intense radiated ELF/VLF signal than O-mode polarization.

5) The ELF/VLF signal strength was highly correlated with magnetic activity, and significantly more intense ELF/VLF waves were produced during periods of moderate geomagnetic disturbance with Kp~ 3.

6) The amplitude of the ELF waves was essentially independent of the ERP of the HF signal, but depended only on the total HF power delivered to the ionosphere.

7) The ratio of heating to cooling time constants ranged from 1 at 510 Hz to 0.3 at 6 kHz.

The Tromsø facility was also used to excite ULF waves in the 1.67 - 700 mHz frequency range [Stubbe and Kopka, 1981; Stubbe et al., 1985; Maul et al., 1990]. A variety of HF modulation schemes were attempted. The amplitude of the excited ULF waves were of the order of 100 - 10,000 pT (6a).

Once the VLF waves are sent out, they travel up through the ionosphere to the Earth's magnetosphere. Because of this disturbance, they cause many natural emissions such as Whistlers, waves in the audio range. The electrons caught in the Whistlers spiral along the lines of force in the Earth's magnetic field until they reach the opposite hemisphere, in the magnetic conjugate point. When they reach the magnetic pole and hit the Earth's atmosphere, they precipitate into the atmosphere. This phenomenon of electron precipitation causes the aurora borealis or Northern Lights.

Physical Data Analogies.

Northern Lights are an astonish natural phenomena, showing a number of colors in the atmosphere, at about the same geographical and magnetical coordinates than the Hessdalen valley, worldwide. But we are experiencing Hessdalen Phenomena just in that Norwegian area. Moreover Northern Lights appear to be a slow motion or even an almost still phenomena, facing the very fast changing and moving Hessdalen Lights. A pretty different phenomena, it is well known. Anyway composition or triggering causes might have something to share.

In this perspective we should take in account the ongoing influence of a high speed solar wind stream I.M.F. in order to understand the eventually Bz based influence in the Hessdalen area. Not only.
Following information from the Valley as well statistical studies (1a), data from observations in the Hessdalen Valley refer about a fall-winter time as the higher sightings season (months around the Winter Solstice). In particular it seems involve October to February as the most important sightings season, while the June to July, maybe first August week too, as the minor one (months around the Summer Solstice). Beside it may be due to the most dark and light seasons through the year in that northern State (15), these two times appear to be in good accord, even the peak-time during the day, around midnight (1-1a-3-15), with Electron Density through the seasons in the Ionospheric F layer and beyond, the Plasmasphere.

In the October-March season, according the reported sources, we measure the highest electron density for cubic meter with a peak in the beginning of January. In the June to July season we experienced the lowest density rate.

These data did appear since the R.A. Helliwell at Stanford University observations in the '60s (7) as shown in various sources (9-14-16), though it is not possible collecting electronic density data just over the Hessdalen area, lacking any Observatory. For this purpose we have used the Ny Alesund Observatory, though far North from Hessdalen (11.8700 East; 78.9200 North), it is the only Norwegian Electron Observatory available for report through time. Though the F layers is the highest ionospheric region and Plasmasphere is even higher, a strong electric field builds up on the ground, whose polarity is most often such that it pushes the F layer aside, allows energetic electrons from the higher ionospheric layers to penetrate to lower levels. This may recall the very high electricity reported in the very low atmosphere, during all the EMBLA Missions (1­2 and 2b), as well as L.E.P. phenomena (11-12) and, on the other hand, the Whistler propagation path (7), reaching the lower atmospheric layers and the ground itself. Electrical ducts can actually push downward particles as well.

In the PARS Project, Authors Inan and Bell (StarLab at Stanford University) proposing a possible accompanying ionospheric effects due to induced precipitation of energetic electrons, generated by HAARP HF emissions, able to stimulate ELF/VLF signals as well as such ionospheric effects (6a). So manmade activity may excite (though unexpected) the needed overall condition in ionosphere and atmosphere, to get the one usually created by nature, to induce higher electron temperature and precipitation of energetic electrons toward the lower ionospheric as well as atmospheric layers.

This situation may induce electron fluctuations, able to produce most favorable condition to trigger optical phenomena in the low atmosphere, breaking SCEBs, with no (or partial) need of natural seasonal connections.

1) EMBLA 2001 : THE OPTICAL MISSION, by Massimo Teodorani, Erling Strand and Bjørn Gitle Hauge.)
http://www.itacomm.net/PH/, (October 2001);

1a) ANALISI dei DATI di FENOMENI LUMINOSI ANOMALI a HESSDALEN, by M. Teodorani and E. Strand; http://www.itacomm.net/PH (2000);

2) EMBLA 2001: VLF RADIO REPORT, by Flavio Gori
http://www.loscrittoio.it/Pages/FG-1201.html and
http://www.itacomm.net/PH , (December 2001);

2a) A VLF/ELF proposal for on the field research at Hessdalen, by Flavio Gori, Proceeding Hessdalen Project at Medicina (May 1999);

3) EMBLA_2002: AN OPTICAL AND GROUND SURVEY IN HESSDALEN, by Massimo Teodorani and Gloria Nobili.
http://www.hessdalen.org/reports/EMBLA_2002_2.pdf, (0ctober 2002);

4) PROJECT HESSDALEN, by Erling Strand
http://www.hessdalen.org/reports/ProjectHessdalen-story-April2002.pdf, (April 2002);

5) HESSDALEN IS A NORWEGIAN VALLEY, by Flavio Gori
http://www.loscrittoio.it/Pages/FG-0901.html and http://www.itacomm.net/PH, (September 2001);

6) VLF INTERFEROMETRY, By Umran S. Inan, STAR Lab at Stanford University (June 2001)
http://www-star.stanford.edu/~vlf/interferometry/VLFinfer.html

6a) POLAR AERONOMY AND RADIO SCIENCE (PARS)
ULF/ELF/VLF PROJECT by U. S. Inan and T. F. Bell from STAR Laboratory, Stanford University
http://www-star.stanford.edu/~vlf/pars/pars.htm#A.2%20Troms%20Experiments

7) WHISTLERS AND RELATED PHENOMENA, by R.A. Helliwell:, Stanford University Press 1965.

8) ESA SPACE SCIENCE DEPARTMENT, Noordwijk, The Netherlands

9) USING GPS TO MONITOR IONOSPHERIC IRREGULARITIES IN THE SOUTHERN HIGHLATITUDE REGION by Yue-Jin Wang, P. Wilkinson and J. Caruana (1997), IPS Radio and Space Services (Australia)

10) ON THE FIELD REPORT by Matteo Leone (2003), under development

11) LIGHTNING-INDUCED ELECTRON PRECIPITATION
H. D. Voss*, W. L. Imhof*, M. Walt*, J. Mobilia*, E. E. Gaines*, J. B. Reagan*, U. S. Inan**, R. A. Helliwell*, D. L. Carpenter**, J. P. Katsufrakis** & H. C. Chang**
* Lockheed Palo Alto Research Laboratory, Palo Alto, California 94303. USA ** STAR Laboratory, Stanford University, California 94305, USA
20 December 1984 © Macmillan Journals Ltd.. 1985

12) SATELLITE OBSERVATIONS OF LIGHTNING-INDUCED ELECTRON PRECIPITATION
H. D. Voss, M. Walt, W. L. Imhof, J. Mobilia, and U. S. Inan
1. Taylor University, Upland, IN
2. STAR Laboratory, Stanford University, Stanford, CA 94305

13) A COMPARISON STUDY OF THE AURORAL LOWER THERMOSPHERIC NEUTRAL WINDS DERIVED BY THE EISCAT UHF RADAR AND THE TROMSØ MEDIUM FREQUENCY RADAR
S. Nozawa,1 A. Brekke,2 A. Manson,3 C. M. Hall,2 C. Meek3 K. Morise,1 S. Oyama,4 K. Dobashi,5 and R. Fujii1
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. A8, 10.1029/2000JA007581, 2002

14) THE ELECTRON DENSITY DISTRIBUTION IN THE POLAR CAP:
ITS VARIABILITY WITH SEASONS, AND ITS RESPONSE TO MAGNETIC ACTIVITY
Harri Laakso and Réjean Grard
ESA SPACE SCIENCE DEPARTMENT, NOORDWIJK, THE NETHERLANDS

15) HESSDALEN: TECHNICAL REPORT, by Erling Strand, 1984
http://www.hessdalen.org;

16) SPACE WEATHER WEB - Facilities for Radio Communications Users Vertical TEC across Scandinavia for the last 24 hours
http://ionosphere.rcru.rl.ac.uk/scandinavia.html.

Renzo Cabassi and ICPH/CIPH (Italian Commitee for Projetc Hessdalen or Comitato Italiano per il Progetto Hessdalen), for their friendship, assistance and financial support to let me be in Hessdalen;

Matteo Leone a very friendly mate and great on the field researcher;

Stelio Montebugnoli for his UHF radar and very precious advises;

Gloria Nobili and Massimo Teodorani for their scientific discussion and advises;

Marsha Adams of Times Research Inc., a great researcher, involved in a lot of fields: VLF, chemical, optics and radon;

Erling Strand, leader of Hessdalen Project, for the informations he gave me during my days in the valley and during data analysis.

Luciano Cianchi, Luigi Ciraolo and Paolo Moretti, all from CNR-IROE-Firenze; as well as Cesare Tagliabue, I5TGC; for their scientific support before and after my Hessdalen times;

Dennis Gallagher from NASA Marshall Space Flight Center for his scientific advises;

William Taylor and William Pine from NASA-INSPIRE Project, Goddard Space Flight Center for their scientifical assistance during data analysis;

Stanislav Klimov, I.K.I., Russian Space Research Institute, for his scientific advises;

Peder and Sig Skogaas for their lovely friendship and important help to coordinate our work with the inhabitants, a very important item;

Jonathan Tisdall AFTENPOSTEN daily Journalist, for his help in find out news about the valley and Norway;

Ellin with Birger Brattas and Bjiorne with Hallfrid Lillevold, Ruth Mary Moe with her daughter Randi, Hessdalen valley residents, for giving us so many informations about lights in the valley and how inhabitants feel about, even in the previous times.