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C T Russell - One of the best experts on this subject based on the ideXlab platform.
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intercalibration of solar wind instruments during the International Magnetospheric Study
Journal of Geophysical Research, 1993Co-Authors: S M Petrinec, C T RussellAbstract:Systematic discrepancies have been observed between ion density measurements taken by the electrostatic analyzers on ISEE 3 and the Faraday cup and electrostatic analyzer on board the IMP 8 spacecraft during the International Magnetospheric Study. We have quantified these discrepancies as a function of solar wind bulk velocity and ion temperature, and have developed correction algorithms that should bring all density measurements to a common base. The electron densities from ISEE 3 are used as the intercalibrating base, since these measurements of the solar wind density should not depend on the ion velocity or temperature.
S M Petrinec - One of the best experts on this subject based on the ideXlab platform.
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intercalibration of solar wind instruments during the International Magnetospheric Study
Journal of Geophysical Research, 1993Co-Authors: S M Petrinec, C T RussellAbstract:Systematic discrepancies have been observed between ion density measurements taken by the electrostatic analyzers on ISEE 3 and the Faraday cup and electrostatic analyzer on board the IMP 8 spacecraft during the International Magnetospheric Study. We have quantified these discrepancies as a function of solar wind bulk velocity and ion temperature, and have developed correction algorithms that should bring all density measurements to a common base. The electron densities from ISEE 3 are used as the intercalibrating base, since these measurements of the solar wind density should not depend on the ion velocity or temperature.
A J Lazarus - One of the best experts on this subject based on the ideXlab platform.
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comment on intercalibration of solar wind instruments during the International Magnetospheric Study by s m petrinec and c t russell
Journal of Geophysical Research, 1994Co-Authors: K I Paularena, A J LazarusAbstract:In their paper Petrinec and Russell (PR) (1993) claim to have developed a 'more homogeneous and accurate set of solar wind data' by 'correcting' the reported ion densities from three plasma instruments: the Los Alamos National Laboratory (LANL) ion electrostatic analyzer on ISEE 3 and the LANL electrostatic analyzer and the Massachusetts Institute of Technology (MIT) Faraday cup plasma instrument on Interplanetary Monitoring Platform 8 (IMP 8). Their data manipulation techniques are examined. The foundations on which their data set are built, are discussed. Reanalysis by MIT on the MIT instrument (IMP 8) was done. Initial results have been issued. The Petrinec & Russell (1993) (PR) paper does not provide accurate density estimates and is an exercise that will only bring confusion to users of the data. The results of PR should be treated with skepticism.
K I Paularena - One of the best experts on this subject based on the ideXlab platform.
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comment on intercalibration of solar wind instruments during the International Magnetospheric Study by s m petrinec and c t russell
Journal of Geophysical Research, 1994Co-Authors: K I Paularena, A J LazarusAbstract:In their paper Petrinec and Russell (PR) (1993) claim to have developed a 'more homogeneous and accurate set of solar wind data' by 'correcting' the reported ion densities from three plasma instruments: the Los Alamos National Laboratory (LANL) ion electrostatic analyzer on ISEE 3 and the LANL electrostatic analyzer and the Massachusetts Institute of Technology (MIT) Faraday cup plasma instrument on Interplanetary Monitoring Platform 8 (IMP 8). Their data manipulation techniques are examined. The foundations on which their data set are built, are discussed. Reanalysis by MIT on the MIT instrument (IMP 8) was done. Initial results have been issued. The Petrinec & Russell (1993) (PR) paper does not provide accurate density estimates and is an exercise that will only bring confusion to users of the data. The results of PR should be treated with skepticism.
Kärhä Otto - One of the best experts on this subject based on the ideXlab platform.
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Magneettinen ympäristö arktisella alueella: Skandinavian SMA-verkon historiallisten magneettisten tallenteiden elpyminen
2019Co-Authors: Kärhä OttoAbstract:The Earth has a magnetic field that protects it from particles that mainly come from the Sun. Changes in the properties of solar wind and the response of the magnetosphere to these changes form the geomagnetic activity on the Earth. This activity occurs mainly as magnetic storms and substorms. A major magnetic storm can break down electricity distribution and communication satellites. The only way to learn to understand the magnetic field and its phenomena is to measure the changes in it. Fluctuations in the magnetic field have been measured for over a hundred years. In the 1960s, researchers presented the idea that magnetometer stations could be installed in a dense chain in a north-south direction. The concept of the Alaskan meridian chain was introduced in 1968. This chain proved the presence of the Auroral Oval. But the problem with the meridian chain is that it cannot be used to completely Study phenomena that move in an east-west direction. The International Magnetospheric Study (IMS) took place from 1977 to 1979. The aim was to Study the magnetosphere everywhere in the Earth at the same time. The Scandinavian Magnetometer Array (SMA), where a dense magnetometer chain was placed in the northern part of Scandinavia, was part of the IMS. This chain extended both in north-south as well as east-west directions. The SMA-instruments contained a camera with 35mm film and three wire-suspended magnets. The movement of the magnets were recorded optically on the film. In order to utilize the optical data recorded on the film, it must be digitized. Regarding local and precise magnetic disturbances, the current digitized results are generally one hour-periods. The main goal of this thesis is to track down and digitize the strongest magnetic storm in 1977 that lasted for several days. The results are compared with the data of the permanent magnetometer station located in Abisko. When the magnitude of the magnetic storm is determined as the lowest Disturbance Storm Time (Dst) index peak value, the digitized storm is the 4th largest during the IMS and the 6th largest during the available SMA data.Maapallolla on magneettikenttä, joka suojelee sitä pääosin Auringosta tulevilta hiukkasilta. Muutokset aurinkotuulen ominaisuuksissa ja magnetosfäärin reagoiminen näihin muutoksiin muodostavat geomagneettisen aktiivisuuden Maapallolla. Tämä aktiivisuus ilmenee pääosin magneettisina myrskyinä ja alimyrskyinä. Suuri magneettinen myrsky voi lamauttaa sähkönjakelun sekä tietoliikennesatelliitit. Ainoa keino oppia ymmärtämään magneettikentän toimintaa ja ilmiöitä on mitata sen muutoksia. Magneettikentän muutoksia on mitattu jo yli sata vuotta. 1960-luvulla tutkijat esittivät ajatuksen, että magnetometrejä voitaisiin asentaa tiheään ketjuun pohjois-eteläsuunnassa. Alaskan meridiaaniketjun konsepti esitettiin vuonna 1968. Tämä ketju todisti revontuliovaalin olemassaolon. Meridiaaniketjun ongelmana on, että sitä ei voida käyttää itä-länsisuunnassa kulkevien ilmiöiden täydelliseen tutkimiseen. International Magnetospheric Study (IMS) kesti vuodesta 1977 vuoteen 1979. Sen tavoitteena oli tutkia magnetosfääriä kaikkialla Maapallolla samanaikaisesti. Scandinavian Magnetometer Array (SMA), jossa tiheä magnetometriketju sijoitettiin Skandinavian pohjoisosaan, oli osa IMS-tutkimusta. Ketju muodosti ketjuja sekä pohjois-etelä- että itä-länsisuunnissa. SMA-ketjun instrumentit sisälsivät kameran 35 mm optisella filmillä ja kolme langoista riippuvaa magneettia. Magneettien liike nauhoitettiin optisesti filmille. Jotta filmille nauhoitettua optista dataa voidaan hyödyntää, se täytyy digitoida. Tämänhetkiset digitoidut tulokset paikallisista ja tarkoista magneettisista häiriöistä ovat yleensä noin yhden tunnin mittaisia. Tämän työn päätavoite on jäljittää ja digitoida vuoden 1977 voimakkain magneettinen myrsky, joka kesti useita päiviä. Tuloksia verrataan Abiskossa sijaitsevan pysyvän magnetometriaseman dataan. Kun magneettisen myrskyn suuruus määritetään alimmalla Disturbance Storm Time -indeksin (Dst) huippuarvolla, digitoitu myrsky on 4. suurin IMS-tutkimuksen aikana ja 6. suurin saatavilla olevan SMA-datan aikana