Eivind Thrane - Academia.edu (original) (raw)

Papers by Eivind Thrane

Research paper thumbnail of Educational advantages afforded by the ESPRIT project

Research paper thumbnail of High frequency radio communications with emphasis on polar problems

... Corporate Author : ADVISORY GROUP FOR AERONAUTICAL RESEARCH AND DEVELOPMENT PARIS (FRANCE). P... more ... Corporate Author : ADVISORY GROUP FOR AERONAUTICAL RESEARCH AND DEVELOPMENT PARIS (FRANCE). Personal Author(s) : Eriksen, Knut W. ; Landmark, Bjoern ; Lied, Finn ; Machlum, Bernt ; Thrane, Eivind V. Report Date : NOV 1967. ...

Research paper thumbnail of The history of Andøya Rocket Range

History of Geo- and Space Sciences, 2018

Just 5 years after Sputnik, on 18 August 1962, Norway launched the first sounding rocket from And... more Just 5 years after Sputnik, on 18 August 1962, Norway launched the first sounding rocket from Andøya in northern Norway. The establishment of Andøya Rocket Range (ARR), in the Arctic and right in the middle of the night-time auroral zone, gave the scientists unique opportunities for studies of the complex processes in the auroral ionosphere and upper atmosphere. In close cooperation with the users, ARR gradually developed its technical and scientific infrastructure and is now one of the world's leading observatories in this field. ARR has also established a launch site at Svalbard, and sounding rockets from both ranges can reach far into the Arctic to study the cusp region and the daytime aurora. The ground-based instruments comprise sophisticated radars and lidars as well as passive instruments. ARR also plays an active role in space education. In 2014 Andøya Rocket Range changed its name to Andøya Space Center (ASC; https://www.andoyaspace.no, last access: 23 November 2018). This change reflects the fact that the activities now comprise much more than sounding rocket launches. ASC is an important company both nationally and in the local community of Andenes. ASC now has a staff of 95 and an annual turnover of NOK 150 million.

Research paper thumbnail of Propagation 2. Problems in HF propagation

Research paper thumbnail of The electron densities in the E- and D-regions above Kjeller

Journal of Atmospheric and Terrestrial Physics, 1966

Abstract Models of the ionization density and collision frequency in the D - and E -region are co... more Abstract Models of the ionization density and collision frequency in the D - and E -region are constructed for Kjeller, Norway, at a March equinox when the sunspot number was about 110. Data from rocket measurements, wave interaction and from the measurements of absorption and height of reflection of radio waves on a number of frequencies in the h.f. band are used and the agreement with the experimental observations is satisfactory. The models have been compared with v.l.f. and l.f. propagation results.

Research paper thumbnail of In situ measurements of turbulent energy dissipation rates and eddy diffusion coefficients during MAP/WINE

Journal of Atmospheric and Terrestrial Physics, 1987

Zn situ measurements of turbulent energy dissipation rates E and eddy diffusion coefficients in t... more Zn situ measurements of turbulent energy dissipation rates E and eddy diffusion coefficients in the 65120 km altitude range using mass spectrometers, positive ion probes and foil clouds are presented. The mass spectrometer and the ion probe data were both analyzed with two independent theoretical approaches to derive E. In general, the derived quantities agree with the values discussed in the literature, although noticeable differences occur in certain rocket flights. An intercomparison of the spectral power densities derived from the observed neutral gas and positive ion density fluctuations supports the assumption that under certain circumstances positive ions can be used as passive tracers for neutral gas number density fluctuations. The observed E profiles exhibit a local minimum around 80 km altitude.

Research paper thumbnail of High frequency sky-wave prediction methods and observational data for high-latitude communication circuits

Research paper thumbnail of Measurements of Lyman-alpha extinction and energetic charged particle precipitation during the European Winter Anomaly Campaign 1975-76

Research paper thumbnail of Middle Atmosphere Turbulence as Determinded by Ion-Probes

Research paper thumbnail of Ion production and effective loss rate in the mesosphere and lower thermosphere during the Western European Winter Anomaly Campaign 1975/76

Journal of Atmospheric and Terrestrial Physics, 1979

Ion production and effective loss rate in the mesosplme and lower thermosphere durlug the Western... more Ion production and effective loss rate in the mesosplme and lower thermosphere durlug the Western European winter body Campaign 1975176

Research paper thumbnail of The determination of D-region electron densities from observations of cross modulations

Journal of Atmospheric and Terrestrial Physics, 1962

Theoretical expressions for the relationship between cross modulation and electron densities and ... more Theoretical expressions for the relationship between cross modulation and electron densities and collision frequencies of the D-region are considered. It is found that expressions such as that derived by BAILEY and MARTIN (1934U, b, 1935) from the classical magneto-ionic theory are approximations which are not sufficiently accurate for interpreting cross modulation observations. On the other hand expressions based on Boltzmann's equation and the recent laboratory measurements by P~ELPS and PACK (1960) of the electron neutral collision frequency predict cross modulation curves which fit the observations fairly well. These new expressions for cross modulation are used along with a trial-and-error method to decide D-region electron densities. It is found that rapid changes in the D-region occur around sunrise, but that there are no striking changes during the rest of the day. Around sunrise a nearly uniform layer extending from about 60 to 80 kzn is created ahnost simultaneously at all heights. The implication of this result for theories of the production of D-region ionization are discussed.

Research paper thumbnail of Measurements of D-region electron densities during the international quiet sun years

Journal of Atmospheric and Terrestrial Physics, 1968

This paper presents some height distributions of D-region electron density, derived from measurem... more This paper presents some height distributions of D-region electron density, derived from measurements of partial reflections and pulsed ionospheric cross modulation. The measurements were made during sunspot minimum conditions at four different latitudes: 19°S, 35°N, 60°N and 69°NE Particular attention was given to the study of diurnal changes in the D-region. It is concluded that the electron densities in the

Research paper thumbnail of The diurnal variation in the mid-latitude D-region

Journal of Atmospheric and Terrestrial Physics, 1970

The observed diurnal variation of electron density at a height of 77.5 km is examined in the ligh... more The observed diurnal variation of electron density at a height of 77.5 km is examined in the light of two hypotheses for electron-ion recombination. In one of these p a N2, where p is the electron production and N the electron density, in the other (I CC N. The latter assumption gives the better agreement between theory and experiment, when the electron production mechanism is ionization of nitrio oxide by solar Lyman-a radiation, or ionization of O,('Ag) by solar ultraviolet.

Research paper thumbnail of Development of D-region electron and ion densities under various auroral conditions during the Energy Budget Campaign (EBC)

Journal of Atmospheric and Terrestrial Physics, 1985

ABSTRACT D-region electron density profiles and time variations were obtained during the Energy B... more ABSTRACT D-region electron density profiles and time variations were obtained during the Energy Budget Campaign 1980 by a partial reflection radar at Ramfjordmoen, Tromsø, located between the rocket ranges at Andøya and Kiruna. The observations were made under various geophysical conditions which are illustrated by riometer observations. The partial reflection measurements indicate that the rockets were launched into a relatively stable D-region on two occasions, while it was somewhat more disturbed on the third. A comparison between the electron density profiles derived by the partial reflection technique and rocket borne probes and Faraday rotation experiments does indicate fair agreement during the quiet conditions, but relatively large discrepancies during disturbed conditions.Simultaneously derived electron density profiles, by use of the Faraday technique, and ion density profiles, by gridded electrostatic spheres mounted on the rocket payload, have made it possible to estimate the negative ion to electron density ratio A versus height. These values of λ are within the range of model calculations.

Research paper thumbnail of A study of ion-pair production rates and electron number densities in the ionospheric D-region

Journal of Atmospheric and Terrestrial Physics, 1972

Abstract The objective of this report is to explore how the quantities q (1 + λ) and Ne2 are rela... more Abstract The objective of this report is to explore how the quantities q (1 + λ) and Ne2 are related at 74 and 80 km. Ground-based and rocket measurements are used in the analysis. The results indicate significant deviations from a ‘classical’ square-law dependence. A better representation is offered by the two-ion model recently suggested by Haug and Landmark (1970).

Research paper thumbnail of Partial reflection results in the auroral D-region explained in terms of acoustic waves

Journal of Atmospheric and Terrestrial Physics, 1980

Certain features in partial reflection height-time diagrams-the occurrence of moving reflection m... more Certain features in partial reflection height-time diagrams-the occurrence of moving reflection maxima, called traces-are described. Probably these traces can be interpreted in terms of interfering acoustic waves. Estimates of the frequency of these waves yield values in the infrasonic range. The formation of the traces and the origin of the acoustic waves are discussed.

Research paper thumbnail of Diurnal and Seasonal Variations in D -Region Electron Densities Derived from Observations of Cross Modulation

Canadian Journal of Physics, 1963

Pulsed cross modulation, arising in the region from 60 to 80 km, has been observed during undistu... more Pulsed cross modulation, arising in the region from 60 to 80 km, has been observed during undisturbed days in the spring, summer, and fall of 1960. The manner in which these observations were obtained and the uncertainties associated with the electron-density profiles determined from them are discussed.Average electron-density profiles for each hour of quiet spring days have been deduced. These show that the most rapid changes in electron density occur within one hour of ground sunrise and sunset. Around sunrise a rather uniform layer of about 100 electrons/cc is created almost simultaneously throughout the entire region from 60 to 80 km. As the day progresses, the average electron density between 70 and 80 km changes by a factor of about 10, while the average density between 60 and 70 km changes by only a factor of 2.These features of the D region are discussed in the light of theoretical predictions which assume that cosmic rays and solar Lyman-alpha radiation account for the norm...

[Research paper thumbnail of D region predictions. [effects on radio propagation](https://a.academia-assets.com/images/blank-paper.jpg)

Research paper thumbnail of Synopsis of D- and E-region electron densities during the energy budget campaign

Advances in Space Research, 1982

Electron density profiles from ground based and rocket borne measurements are presented which wer... more Electron density profiles from ground based and rocket borne measurements are presented which were derived at three sites in northern Scandinavia under various degrees of geophysical disturbance. These data are checked against the instantaneous picture of the ionospheric absorption as observed with the dense riometer network.

Research paper thumbnail of The role of charged aerosols in connection with noctilucent clouds and polar mesosphere summer echoes

ESA Symposium on European …, 1995

Tom A Blix, Eivind V Thrane, Jan Troim, Ulf-Peter Hoppe ESA Symposium on European Rocket and Ball... more Tom A Blix, Eivind V Thrane, Jan Troim, Ulf-Peter Hoppe ESA Symposium on European Rocket and Balloon Programmes and Related Research, 12 ... The difference in the estimated size may explain why a visible NLC was observed only in case 2. (Author) 46 GEOPHYSICS(AH ...

Research paper thumbnail of Educational advantages afforded by the ESPRIT project

Research paper thumbnail of High frequency radio communications with emphasis on polar problems

... Corporate Author : ADVISORY GROUP FOR AERONAUTICAL RESEARCH AND DEVELOPMENT PARIS (FRANCE). P... more ... Corporate Author : ADVISORY GROUP FOR AERONAUTICAL RESEARCH AND DEVELOPMENT PARIS (FRANCE). Personal Author(s) : Eriksen, Knut W. ; Landmark, Bjoern ; Lied, Finn ; Machlum, Bernt ; Thrane, Eivind V. Report Date : NOV 1967. ...

Research paper thumbnail of The history of Andøya Rocket Range

History of Geo- and Space Sciences, 2018

Just 5 years after Sputnik, on 18 August 1962, Norway launched the first sounding rocket from And... more Just 5 years after Sputnik, on 18 August 1962, Norway launched the first sounding rocket from Andøya in northern Norway. The establishment of Andøya Rocket Range (ARR), in the Arctic and right in the middle of the night-time auroral zone, gave the scientists unique opportunities for studies of the complex processes in the auroral ionosphere and upper atmosphere. In close cooperation with the users, ARR gradually developed its technical and scientific infrastructure and is now one of the world's leading observatories in this field. ARR has also established a launch site at Svalbard, and sounding rockets from both ranges can reach far into the Arctic to study the cusp region and the daytime aurora. The ground-based instruments comprise sophisticated radars and lidars as well as passive instruments. ARR also plays an active role in space education. In 2014 Andøya Rocket Range changed its name to Andøya Space Center (ASC; https://www.andoyaspace.no, last access: 23 November 2018). This change reflects the fact that the activities now comprise much more than sounding rocket launches. ASC is an important company both nationally and in the local community of Andenes. ASC now has a staff of 95 and an annual turnover of NOK 150 million.

Research paper thumbnail of Propagation 2. Problems in HF propagation

Research paper thumbnail of The electron densities in the E- and D-regions above Kjeller

Journal of Atmospheric and Terrestrial Physics, 1966

Abstract Models of the ionization density and collision frequency in the D - and E -region are co... more Abstract Models of the ionization density and collision frequency in the D - and E -region are constructed for Kjeller, Norway, at a March equinox when the sunspot number was about 110. Data from rocket measurements, wave interaction and from the measurements of absorption and height of reflection of radio waves on a number of frequencies in the h.f. band are used and the agreement with the experimental observations is satisfactory. The models have been compared with v.l.f. and l.f. propagation results.

Research paper thumbnail of In situ measurements of turbulent energy dissipation rates and eddy diffusion coefficients during MAP/WINE

Journal of Atmospheric and Terrestrial Physics, 1987

Zn situ measurements of turbulent energy dissipation rates E and eddy diffusion coefficients in t... more Zn situ measurements of turbulent energy dissipation rates E and eddy diffusion coefficients in the 65120 km altitude range using mass spectrometers, positive ion probes and foil clouds are presented. The mass spectrometer and the ion probe data were both analyzed with two independent theoretical approaches to derive E. In general, the derived quantities agree with the values discussed in the literature, although noticeable differences occur in certain rocket flights. An intercomparison of the spectral power densities derived from the observed neutral gas and positive ion density fluctuations supports the assumption that under certain circumstances positive ions can be used as passive tracers for neutral gas number density fluctuations. The observed E profiles exhibit a local minimum around 80 km altitude.

Research paper thumbnail of High frequency sky-wave prediction methods and observational data for high-latitude communication circuits

Research paper thumbnail of Measurements of Lyman-alpha extinction and energetic charged particle precipitation during the European Winter Anomaly Campaign 1975-76

Research paper thumbnail of Middle Atmosphere Turbulence as Determinded by Ion-Probes

Research paper thumbnail of Ion production and effective loss rate in the mesosphere and lower thermosphere during the Western European Winter Anomaly Campaign 1975/76

Journal of Atmospheric and Terrestrial Physics, 1979

Ion production and effective loss rate in the mesosplme and lower thermosphere durlug the Western... more Ion production and effective loss rate in the mesosplme and lower thermosphere durlug the Western European winter body Campaign 1975176

Research paper thumbnail of The determination of D-region electron densities from observations of cross modulations

Journal of Atmospheric and Terrestrial Physics, 1962

Theoretical expressions for the relationship between cross modulation and electron densities and ... more Theoretical expressions for the relationship between cross modulation and electron densities and collision frequencies of the D-region are considered. It is found that expressions such as that derived by BAILEY and MARTIN (1934U, b, 1935) from the classical magneto-ionic theory are approximations which are not sufficiently accurate for interpreting cross modulation observations. On the other hand expressions based on Boltzmann's equation and the recent laboratory measurements by P~ELPS and PACK (1960) of the electron neutral collision frequency predict cross modulation curves which fit the observations fairly well. These new expressions for cross modulation are used along with a trial-and-error method to decide D-region electron densities. It is found that rapid changes in the D-region occur around sunrise, but that there are no striking changes during the rest of the day. Around sunrise a nearly uniform layer extending from about 60 to 80 kzn is created ahnost simultaneously at all heights. The implication of this result for theories of the production of D-region ionization are discussed.

Research paper thumbnail of Measurements of D-region electron densities during the international quiet sun years

Journal of Atmospheric and Terrestrial Physics, 1968

This paper presents some height distributions of D-region electron density, derived from measurem... more This paper presents some height distributions of D-region electron density, derived from measurements of partial reflections and pulsed ionospheric cross modulation. The measurements were made during sunspot minimum conditions at four different latitudes: 19°S, 35°N, 60°N and 69°NE Particular attention was given to the study of diurnal changes in the D-region. It is concluded that the electron densities in the

Research paper thumbnail of The diurnal variation in the mid-latitude D-region

Journal of Atmospheric and Terrestrial Physics, 1970

The observed diurnal variation of electron density at a height of 77.5 km is examined in the ligh... more The observed diurnal variation of electron density at a height of 77.5 km is examined in the light of two hypotheses for electron-ion recombination. In one of these p a N2, where p is the electron production and N the electron density, in the other (I CC N. The latter assumption gives the better agreement between theory and experiment, when the electron production mechanism is ionization of nitrio oxide by solar Lyman-a radiation, or ionization of O,('Ag) by solar ultraviolet.

Research paper thumbnail of Development of D-region electron and ion densities under various auroral conditions during the Energy Budget Campaign (EBC)

Journal of Atmospheric and Terrestrial Physics, 1985

ABSTRACT D-region electron density profiles and time variations were obtained during the Energy B... more ABSTRACT D-region electron density profiles and time variations were obtained during the Energy Budget Campaign 1980 by a partial reflection radar at Ramfjordmoen, Tromsø, located between the rocket ranges at Andøya and Kiruna. The observations were made under various geophysical conditions which are illustrated by riometer observations. The partial reflection measurements indicate that the rockets were launched into a relatively stable D-region on two occasions, while it was somewhat more disturbed on the third. A comparison between the electron density profiles derived by the partial reflection technique and rocket borne probes and Faraday rotation experiments does indicate fair agreement during the quiet conditions, but relatively large discrepancies during disturbed conditions.Simultaneously derived electron density profiles, by use of the Faraday technique, and ion density profiles, by gridded electrostatic spheres mounted on the rocket payload, have made it possible to estimate the negative ion to electron density ratio A versus height. These values of λ are within the range of model calculations.

Research paper thumbnail of A study of ion-pair production rates and electron number densities in the ionospheric D-region

Journal of Atmospheric and Terrestrial Physics, 1972

Abstract The objective of this report is to explore how the quantities q (1 + λ) and Ne2 are rela... more Abstract The objective of this report is to explore how the quantities q (1 + λ) and Ne2 are related at 74 and 80 km. Ground-based and rocket measurements are used in the analysis. The results indicate significant deviations from a ‘classical’ square-law dependence. A better representation is offered by the two-ion model recently suggested by Haug and Landmark (1970).

Research paper thumbnail of Partial reflection results in the auroral D-region explained in terms of acoustic waves

Journal of Atmospheric and Terrestrial Physics, 1980

Certain features in partial reflection height-time diagrams-the occurrence of moving reflection m... more Certain features in partial reflection height-time diagrams-the occurrence of moving reflection maxima, called traces-are described. Probably these traces can be interpreted in terms of interfering acoustic waves. Estimates of the frequency of these waves yield values in the infrasonic range. The formation of the traces and the origin of the acoustic waves are discussed.

Research paper thumbnail of Diurnal and Seasonal Variations in D -Region Electron Densities Derived from Observations of Cross Modulation

Canadian Journal of Physics, 1963

Pulsed cross modulation, arising in the region from 60 to 80 km, has been observed during undistu... more Pulsed cross modulation, arising in the region from 60 to 80 km, has been observed during undisturbed days in the spring, summer, and fall of 1960. The manner in which these observations were obtained and the uncertainties associated with the electron-density profiles determined from them are discussed.Average electron-density profiles for each hour of quiet spring days have been deduced. These show that the most rapid changes in electron density occur within one hour of ground sunrise and sunset. Around sunrise a rather uniform layer of about 100 electrons/cc is created almost simultaneously throughout the entire region from 60 to 80 km. As the day progresses, the average electron density between 70 and 80 km changes by a factor of about 10, while the average density between 60 and 70 km changes by only a factor of 2.These features of the D region are discussed in the light of theoretical predictions which assume that cosmic rays and solar Lyman-alpha radiation account for the norm...

[Research paper thumbnail of D region predictions. [effects on radio propagation](https://a.academia-assets.com/images/blank-paper.jpg)

Research paper thumbnail of Synopsis of D- and E-region electron densities during the energy budget campaign

Advances in Space Research, 1982

Electron density profiles from ground based and rocket borne measurements are presented which wer... more Electron density profiles from ground based and rocket borne measurements are presented which were derived at three sites in northern Scandinavia under various degrees of geophysical disturbance. These data are checked against the instantaneous picture of the ionospheric absorption as observed with the dense riometer network.

Research paper thumbnail of The role of charged aerosols in connection with noctilucent clouds and polar mesosphere summer echoes

ESA Symposium on European …, 1995

Tom A Blix, Eivind V Thrane, Jan Troim, Ulf-Peter Hoppe ESA Symposium on European Rocket and Ball... more Tom A Blix, Eivind V Thrane, Jan Troim, Ulf-Peter Hoppe ESA Symposium on European Rocket and Balloon Programmes and Related Research, 12 ... The difference in the estimated size may explain why a visible NLC was observed only in case 2. (Author) 46 GEOPHYSICS(AH ...