Part 1 High latitude ionosphere: electron density - ionospheric mapping in the polar and equatorial zones, K. Rawer including auroral oval boundaries in the IRI model, D. Bilitza high latitude digisonde measurements and their relevance to... more
Part 1 High latitude ionosphere: electron density - ionospheric mapping in the polar and equatorial zones, K. Rawer including auroral oval boundaries in the IRI model, D. Bilitza high latitude digisonde measurements and their relevance to IRI, B.W. Reinisch et al EISCAT data base for ionospheric modelling - F-region and topside ionosphere, P.N. Collis main ionization through parameters for ionosphere modelling by HF radio network observations, D.V. Blagoveshchensky and T.D. Borisova typical behaviour of the high latitude lower ionosphere, M. Friedrich and K.M. Torkar temperatures and ion composition - morphology of electron temperature in the high latitude plasmasphere, K.-I. Oyama and T. Abe high latitude ion composition, J.M. Grebowsky and W.R. Hoegy vibrational kinetics of molecular nitrogen and its role in the composition of the polar thermosphere, G.A. Aladjev and A.S. Kirillov. Part 2 Mid and low latitude ionosphere: a regional model of E- and F-layer critical frequencies, G.A...
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During July of 1999, two sequences of rockets were launched from the Norwegian rocket range in Andoya, Norway. The purpose of these studies was to investigate the properties of the polar summer mesosphere, particularly relating to polar... more
During July of 1999, two sequences of rockets were launched from the Norwegian rocket range in Andoya, Norway. The purpose of these studies was to investigate the properties of the polar summer mesosphere, particularly relating to polar mesospheric summer echoes (PMSE) and their possible relationship to noctilucent clouds (NLC). Each of two sequences was anchored with a DROPPS Black Brant payload, consisting of 20 instruments to measure the electrodynamic and optical structure of the mesosphere and lower thermosphere. These were provided by participants from five American and two European scientific laboratories. The DROPPS (Distribution and Role of Particles in the Polar Summer) payloads were each accompanied by a sequence of meteorological rockets, and by several European payloads designed to study electrodynamics structure of the same region. ALOMAR (Arctic Lidar Observatory for Middle Atmosphere Research) Lidars, and MF (Medium Frequency) and MST (Mesosphere, Stratosphere, and T...
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The technical design of the mobile SOUSY-VHF-Radar and the layout of the new antenna version presently under construction for future operation in Norway is described.
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Research Interests: Engineering and Radar
During 2004 and 2005 measurements of mesospheric lower thermospheric 80-100 km winds have been carried out above Germany using 4 different ground-based systems These are a meteor radar 36 2 MHz at the Collm Observatory 51 3 r N 13 r E the... more
During 2004 and 2005 measurements of mesospheric lower thermospheric 80-100 km winds have been carried out above Germany using 4 different ground-based systems These are a meteor radar 36 2 MHz at the Collm Observatory 51 3 r N 13 r E the OSWIN VHF radar 53 5 MHz operated in all-sky meteor mode at K u hlungsborn 54 1 r N 11 8 r E the MF radar 3 18 MHz at Juliusruh 54 6 r N 13 4 r E and the LF D1 measurements using a transmitter 177 kHz at Zehlendorf near Berlin and receivers at Collm with the reflection point at 52 1 r N 13 2 r E This provides the possibility to compare the results of different radar systems in nearly the same measuring volume Generally the seasonal and long-period 2-30 days patterns of wind variability are well reproduced by each of these systems Differences are found for amplitudes of winds and waves Meteor radar winds are generally stronger than the winds observed by MF and especially LF radars In particular the semidiurnal tidal amplitudes of these systems are i...
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... Janches, D., SE Palo, EM Lau, SK Avery, JP Avery, S. de la Pena, and NA Makarov (2004), Diurnal and seasonal variability of the ... Lau, EM, SK Avery, JP Avery, D. Janches, SE Palo, R. Schafer, and NA Makarov (2006), Statistical... more
... Janches, D., SE Palo, EM Lau, SK Avery, JP Avery, S. de la Pena, and NA Makarov (2004), Diurnal and seasonal variability of the ... Lau, EM, SK Avery, JP Avery, D. Janches, SE Palo, R. Schafer, and NA Makarov (2006), Statistical characterization of meteor trail distri-bution ...
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ABSTRACT Structures of wind fields at high latitudesComparisons of Antarctic and Arctic wind fieldsClear existence of long-period oscillations of wind fields at high latitudes
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Abstract The Di Giovanni/Radicella model (DGR) /1/ determines a bottom side electron densty profile alone from the set of routinely scaled ionogram parameters foE, foF1, foF2 and M(3000)F2 and the total electron content; the smoothed... more
Abstract The Di Giovanni/Radicella model (DGR) /1/ determines a bottom side electron densty profile alone from the set of routinely scaled ionogram parameters foE, foF1, foF2 and M(3000)F2 and the total electron content; the smoothed sunspot number R12 appears in the calculation. Present designations are DGR2/2/ and DRR3 /3/ [see Appendix]; they are valid in the northern hemisphere. DGR is compared with electron density profiles derived from ionograms obtained at Juliusruh (54.6°N, 13.4°E), and with the (URSI-based) IRI90 at different conditiones. Experimental total electron content (TEC) data are compared to both models. At the considered station, the profiles obtained by both models are reasonably in agreement amongst themselves and with the experimental data. The TEC derived from the DGR3 model is in good agreement with experimental TEC, whereas, at high solar activity, IRI90 gives too high TEC values, especially during daytime.
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This article was published in an Elsevier journal. The attached copy is furnished to the author for non-commercial research and education use, including for instruction at the author’s institution, sharing with colleagues and providing to... more
This article was published in an Elsevier journal. The attached copy is furnished to the author for non-commercial research and education use, including for instruction at the author’s institution, sharing with colleagues and providing to institution administration. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit:
An international conference on high-latitude ionospheric modeling produced 27 papers in the areas of ionospheric mapping, electron density and distribution, ion density and distribution, ionospheric storems, ionospheric composition, and... more
An international conference on high-latitude ionospheric modeling produced 27 papers in the areas of ionospheric mapping, electron density and distribution, ion density and distribution, ionospheric storems, ionospheric composition, and ionospheric sounding techniques. Upgrades to the International Reference Ionosphere (IRI) model were proposed in several papers.
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Abstract Climatological structure of the quasi-2-day wave (Q2DW) at middle latitudes in temperature and horizontal winds in the mesosphere and lower thermosphere (MLT) was compared between the northern and southern hemispheres.... more
Abstract Climatological structure of the quasi-2-day wave (Q2DW) at middle latitudes in temperature and horizontal winds in the mesosphere and lower thermosphere (MLT) was compared between the northern and southern hemispheres. Determination of the Q2DW in temperature was based on observation data by the Microwave Limb Sounder (MLS) onboard NASA's Earth Observing System (EOS) Aura satellite over 17 years from 2004 to 2021 and the Q2DW in horizontal winds was derived from Aura/MLS geopotential height data using balance equations. Amplitudes were maximized in summer in the southern hemisphere and in the meridional wind in the northern hemisphere, but in winter in the zonal wind in the northern hemisphere. Summer amplitudes were larger in the meridional wind than the zonal wind in the southern hemisphere, but zonal amplitudes in winter were larger than meridional amplitudes in summer in the northern hemisphere. Westward propagating zonal wavenumber 3 (W3) was largest in both hemispheres, but in addition to well-known W4, W3, W2 and eastward propagating zonal wavenumber 2 (E2), we also found W1, zonally symmetric standing (S0), and E1. Eliassen-Palm fluxes were derived for each mode. W3, W2, W1, and E2 fluxes were exhibited upward and poleward in January in the southern hemisphere while only W3 fluxes were exhibited clearly upward and poleward in July in the northern hemisphere. Comparison between Q2DW balance winds and radar winds showed modulations in amplitudes and phase of the Q2DW from the W3 by accumulating other modes. Furthermore, the balance winds and radar winds agreed in both amplitude and phase in the southern hemisphere and at lower latitudes in the northern hemisphere in January, and at lower latitudes in both hemispheres in July.
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ABSTRACT
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Donnees et analyse des sondages de radar continu (3,18 MHz) a Juliusruh (54,6° N, 13,4° E) en 1982/83: connection avec l'anomalie hivernale, avec l'ionisation par les particules magnetospheriques precipitees apres un orage;... more
Donnees et analyse des sondages de radar continu (3,18 MHz) a Juliusruh (54,6° N, 13,4° E) en 1982/83: connection avec l'anomalie hivernale, avec l'ionisation par les particules magnetospheriques precipitees apres un orage; augmentation des concentrations en NO
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Research Interests: Remote Sensing and Radar
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The aspect sensitivity of mesospheric scatterers at a frequency of 53.5 MHz is studied during the presence of polar mesosphere summer echoes using simultaneous multi-beam Doppler observations and spaced antenna observations. The height... more
The aspect sensitivity of mesospheric scatterers at a frequency of 53.5 MHz is studied during the presence of polar mesosphere summer echoes using simultaneous multi-beam Doppler observations and spaced antenna observations. The height variation of aspect sensitivity throughout the PMSE season is studied by MST radar observations at Andenes in 1999. The highest degree of aspect sensitivity occurs in general in the lower part of a PMSE layer. Studies of the measured total spectral width compared to the beam broadened spectral width show that the spectral width increases as the altitude increases but the spectral width is often dominated by beam broadening especially in the lower part of the PMSE layer at altitudes below of about 85 km. In addition, the thetas approach allows direct estimations of the length-to-depth ratio of the scatterers. The relation between aspect sensitivity of the scattered radiation and the average shape of the scatterers (length-to-depth ratio) are discussed.
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ABSTRACT Ground-based observations of the wind field in the mesosphere/lower thermosphere have been used to investigate long-lasting wind variations at mid-latitudes. Besides small solar activity induced variations (11 yr cycle),... more
ABSTRACT Ground-based observations of the wind field in the mesosphere/lower thermosphere have been used to investigate long-lasting wind variations at mid-latitudes. Besides small solar activity induced variations (11 yr cycle), non-solar induced long-term trends were clearly detected, which could be a hint of anthropogenically caused variations in the wind field near the mesopause region. Comparisons with other observations qualitatively confirm the derived trends, thus indicating common long-term global changes of the dynamical state of the middle atmosphere.
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During the PSMOS Global-scale tidal variability experiment campaign of June 1–August 31, 1999, a network of radars made measurements of winds, waves and tides in the mesosphere/lower-thermosphere region over a wide range of latitudes.... more
During the PSMOS Global-scale tidal variability experiment campaign of June 1–August 31, 1999, a network of radars made measurements of winds, waves and tides in the mesosphere/lower-thermosphere region over a wide range of latitudes. Clear evidence was found that fluctuations in tidal amplitudes occur on a global scale in both hemispheres, and that at least some of these fluctuations are periodic in nature. Modulation of the amplitude of the 12 h tide was particularly evident at periods of 10 and 16 days, suggesting a non- ...
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The mesospheric response on severe solar activity storms with strongly enhanced proton fluxes and X/M-class X-ray flares in the period July 2000 to December 2006 has been studied in detail using meteor radar and MF radar observations at... more
The mesospheric response on severe solar activity storms with strongly enhanced proton fluxes and X/M-class X-ray flares in the period July 2000 to December 2006 has been studied in detail using meteor radar and MF radar observations at latitudes between 69° N and 22° S. Neutral air temperatures at mesopause heights are decreased or increased by 5-10 K during these
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... The good CRISTA/HRDI comparison (if the November 1994 HRDI data are taken into account) demonstrates that geostrophic wind fields from CRISTA temperature data well describe the basic wind features in the stratosphere and mesosphere.... more
... The good CRISTA/HRDI comparison (if the November 1994 HRDI data are taken into account) demonstrates that geostrophic wind fields from CRISTA temperature data well describe the basic wind features in the stratosphere and mesosphere. 4.1.2. CRISTA 2. ...
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The Leibniz-Institute of Atmospheric Physics (IAP) in Kühlungsborn started to install a new MST radar on the North-Norwegian island Andøya (69.30° N, 16.04° E) in 2009. The new Middle Atmosphere Alomar Radar System (MAARSY) replaces the... more
The Leibniz-Institute of Atmospheric Physics (IAP) in Kühlungsborn started to install a new MST radar on the North-Norwegian island Andøya (69.30° N, 16.04° E) in 2009. The new Middle Atmosphere Alomar Radar System (MAARSY) replaces the previous ALWIN radar which has been successfully operated for more than 10 years. The MAARSY radar provides increased temporal and spatial resolution combined with a flexible sequential point-to-point steering of the radar beam. To increase the spatiotemporal resolution of the observations a 16-port Butler matrix has been built and implemented to the radar. In conjunction with 64 Yagi antennas of the former ALWIN antenna array the Butler matrix simultaneously provides 16 individual beams. The beam forming capability of the Butler matrix arrangement has been verified observing the galactic cosmic radio noise of the supernova remnant Cassiopeia A. Furthermore, this multi beam configuration has been used in passive experiments to estimate the cosmic noi...
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During the PSMOS Global-scale tidal variability experiment campaign of June 1–August 31, 1999, a network of radars made measurements of winds, waves and tides in the mesosphere/lower-thermosphere region over a wide range of latitudes.... more
During the PSMOS Global-scale tidal variability experiment campaign of June 1–August 31, 1999, a network of radars made measurements of winds, waves and tides in the mesosphere/lower-thermosphere region over a wide range of latitudes. Clear evidence was found that fluctuations in tidal amplitudes occur on a global scale in both hemispheres, and that at least some of these fluctuations are periodic in nature. Modulation of the amplitude of the 12 h tide was particularly evident at periods of 10 and 16 days, suggesting a non- ...
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The presence of a diurnal variation in meteor activity is well established. The sporadic meteor count rates are higher on the local dawn side and lower on the local dusk side. This phenomenon is caused by the Earth’s orbital motion and... more
The presence of a diurnal variation in meteor activity is well established. The sporadic meteor count rates are higher on the local dawn side and lower on the local dusk side. This phenomenon is caused by the Earth’s orbital motion and rotation. Meteor radar measurements have been compared from Esrange, Kiruna, Sweden, at 68° N, from Juliusruh, Germany, at 55° N, and from Ascension Island, at 8° S, to investigate how the diurnal variation depends on season at different latitudes. Data have been used from vernal and autumnal equinoxes and summer and winter solstices to locate the largest seasonal differences.
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ABSTRACT A case study of Noctilucent Cloud (NLC) occurrence above the north part of Sweden is examined. This occasion was characterized by clear wave dynamics and gravity waves are considered to be responsible for the observed modulation... more
ABSTRACT A case study of Noctilucent Cloud (NLC) occurrence above the north part of Sweden is examined. This occasion was characterized by clear wave dynamics and gravity waves are considered to be responsible for the observed modulation in the NLC area. With the Esrange MST Radar data (NLC were located just above Esrange) and Andoya MF Radar data we have managed to find gravity waves which propagated upward from the upper stratosphere to the NLC altitude and these waves should not have suffered saturation. The wave parameters estimated by the photogrammetric technique and by the radar measurements are close to the same. We conclude that gravity waves could be responsible for the observed complex wave dynamics in the NLC for this case.
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... Keywords: Radar echoes; Mesosphere; Polar and mid-latitudes; Solar and geomagnetic disturbances; Turbulence. Article Outline. 1. Introduction 2. Experimental results 2.1. Occurrence rate, echo height, duration, and height range of... more
... Keywords: Radar echoes; Mesosphere; Polar and mid-latitudes; Solar and geomagnetic disturbances; Turbulence. Article Outline. 1. Introduction 2. Experimental results 2.1. Occurrence rate, echo height, duration, and height range of PMWE 2.2. Seasonal variation of PMWE 2.3. ...