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1 Introduction

Global observations of geomagnetic varia-tions and near-real-time data acquisition arenecessary for effective research on theprocesses of energy accumulation in the mag-netosphere and energy flowing into the polarregion and help us to monitor space weatherconditions.

The information about electric currentsthat flow in the magnetosphere and in the ion-osphere are essential to understanding thestructure and dynamics of the magnetosphere.

The Earth's magnetosphere is formed byinteractions with solar winds. Various electriccurrent systems are generated in the magne-tosphere. Some portions of the electric cur-rent system are significantly enhanced during

periods of geomagnetic disturbances, knownas geomagnetic storms and substorms.Because the system is non-uniform, a multi-point observation of the magnetic field varia-tions generated by the electric currents iseffective in obtaining information on the spa-tial distribution and temporal variations of theelectric current. Since satellites can makemagnetic field observations only at a limitednumber of points and locations, geomagneticobservation stations distributed around theglobe have an important role in such observa-tions.

For nowcasting and forecasting, observa-tion data must be transmitted and collected asquickly as possible for analysis and applica-tion. Geomagnetic data and various geomag-netic activity indices calculated from observa-

KUNITAKE Manabu et al.

3-3 Real-time geomagnetic data acquisitionfrom Siberia region and its application― PURAES project ―

KUNITAKE Manabu, ISHIBASHI Hiromitsu, NAGATSUMA Tsutomu,KIKUCHI Takashi, and KAMEI Toyohisa

Monitoring and nowcasting of geomagnetic disturbance is necessary for conductingspace weather forecast. As the energy from the magnetosphere flows into the ionospheremainly concentrates on the polar region, it is important to watch the polar region. Develop-ing geomagnetic observation points in the polar region and acquiring data in near real-timeway are essentially effective for nowcasting and forecasting. Siberia is a missing regionconcerning near real-time data acquisition. PURAES Project (Project for Upgrading RussianAE Stations) has been conducted to upgrade magnetometer and set near real-time datatransmission instrument in observatories in Siberia. In summer 2002, near real-time dataacquisition from four observatories have been accomplished.

AE index is the index which represents the geomagnetic activities in the polar region.Near real-time data acquisition contributes to that the AE index becomes better in its qualityand quicker in its calculated output. Moreover, near real-time data is useful for variousspace weather forecasting application.

Keywords Geomagnetic observation, Near real-time data acquisition, PURAES project, Siberianregion, Auroral Electrojet index, Geomagnetic disturbance

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tion data are used as input values to estimateother physical quantities. This data alsoenables rapid validation of predictions basedon theory or numerical simulation, resulting infaster progress in this research field. Now-casting and forecasting of geomagnetic activi-ty are needed for enabling warnings of poten-tial hazards resulting from induced currentsand atmospheric heating. Rapid changes inelectric currents flowing in the polar iono-sphere induce currents in conductive installa-tions on the ground. In extreme cases, theycan induce abnormal currents in power trans-mission lines, pipelines, and underwatertelecommunication cables in polar region.These currents are called geomagneticallyinduced currents (GICs). Very powerful GICshave been known to damage transformers inpower transmission systems. The powerblackout in Quebec, Canada, in March 1989 isa typical instance.

The heating of the ionosphere and ther-mosphere by Joule heating caused by electriccurrents significantly contributes to atmos-pheric heating. When the current is excep-tionally large, the atmospheric expansion gen-erated by this heating has various effects.Atmospheric heating will increase atmospher-ic density at a fixed altitude, which in turnincreases atmospheric friction on objects pass-ing through at that altitude. This increase infriction alters the courses of low-orbitingsatellites and space debris. Along with rapidchanges in electric field, atmospheric heatingalso generates ionospheric storms, which limitthe frequencies usable for HF communica-tions. These hazards have led to a demand fornear-real-time acquisition of geomagneticdata, for application to space weather studiesas well as to forecasting.

Energy influx from the magnetosphere isconcentrated in the polar ionosphere, which isthe region of origin for GICs, thermosphericatmosphere expansion, and ionosphericstorms. During substorms, the electric currentin the polar ionosphere rapidly increases, witha rapidly changing distribution. A precise andsimple way to monitor these changes has been

sought for some time. The most effectivemethod devised to date has been to expressthese geomagnetic variations as indices. Theauroral electrojet (AE) index[1] (see 3 fordetailed information) has been proposed as anindex of the development, variation, anddecay of large-scale electric current systemsflowing in the polar ionosphere, based onobservation data of geomagnetic variations at12 stations distributed longitudinally in thepolar region at almost uniform intervals.Although stable, reliable determination of thisAE index with minimal time lag is consideredcrucial, it was difficult to pursue this goalwithout near-real time data from observatoriesin the Siberian region. To resolve this prob-lem, the PURAES (Project for UpgradingRussian AE Stations) was initiated.

This report will introduce the way how toaccomplish near-real-time acquisition of geo-magnetic field data and its utilization, mainlyin the PUREAS project, of which the firststage is complete. A brief summary of thedata transfer method used in the PUREASproject (the INTERMAGNET system) willalso be shown. The section on data applica-tions places a particular emphasis on the effec-tiveness of the AE index and its near-real-timeindexing.

This report focuses on geomagnetic varia-tions and index in the polar region. Details ofthe Dst index, which represents the magnitudeof a geomagnetic storm, and the polar capindex (PC index), which is calculated fromgeomagnetic variations near-pole region, willbe omitted here. Readers are referred to thereference material[2][3][4].

2 Near-Real-Time Data Acquisi-tion

Numerous observation and research insti-tutions both in Japan and abroad have shownobservation data plots on their Web sites.What, then, is our purpose of collecting databy ourselves? We believe an important goalnow is not merely monitoring a phenomenon,but analyzing and processing digital data to

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extract and identify further physical quantitiesand properties. This will give us informationthat cannot be obtained from mere raw dataplots. Furthermore, space weather forecastingrequires real-time processing for current-statemonitoring and predictions. Thus, near-real-time data acquisition by ourselves is essentialfor realizing instantaneous and advanced uti-lization and application of data.

A summary of past efforts to achieve near-real-time acquisition of geomagnetic data atCRL is given elsewhere, by Ishibashi et al.[5]in 1997 and Nagatsuma et al.[6] in 2000. Onlya brief description will be provided in thisreport.

2.1 INTERMAGNETThe INTERMAGNET[7] is a joint interna-

tional project launched in the late 1980s forrapid exchange of data between geomagneticobservatories around the globe and quick deri-vation of geomagnetic activity indices.INTERMAGNET data has been transferredmainly via meteorological satellites. DataCollection Platforms (DCPs) were installed atthe geomagnetic observatories for near-real-time transmission of observation data (1-minute values) to meteorological satellites.The data relayed and downlinked by meteoro-logical satellites is collected at a GeomagneticInformation Node (GIN). Each GIN not onlycollects data in each region but also respondsto requests from users. This system enablesstable near-real-time transmission of data fromremote observatories which have no otherconvenient means of such communication.Participating observatories are required tomeet specific standards for observation,recording, and transmission, for example,observation with a resolution of 0.1 nT, withat least one absolute value measurement aweek. This requirement should ensure high-quality data. As of 2001, the total number ofparticipating observatories was 80. There are6 GINs around the world, one of which CRLoperates.

In Japan, the CRL, the Data Analyses Cen-ter for Geomagnetism and Space Magnetism

of the Kyoto University, and the KakiokaMagnetic Observatory of the Japan Meteoro-logical Agency (JMA) are INTERMAGNETparticipants. The region covered by Japaneseinstitutions corresponds to the area in whichthe Geostationary Meteorological SatellitesHimawari-5 (GMS-5) can relay data. A mem-orandum of understanding exists between theCRL and JMA concerning data transfer via theGMS satellites. The Observations Depart-ment, JMA and the Meteorological SatelliteCenter, JMA cooperate with the CRL. Data iscollected every 12 minutes from the KakiokaMagnetic Observatory (geographic coordi-nates: lat. 36.23˚N and long. 140.18˚E; loca-tions of observatories hereafter will be provid-ed as geographical coordinates, with geo-graphic coordinates in Japan based on theWorld Geodetic System), Memanbetsu(43.90˚N, 144.20˚E), Dumont d'Urville(66.67˚S, 140.01˚E), Amsterdam Is. (37.80˚S,77.57˚E), Alibag (18.63˚N, 72.87˚E). TheVostok observation station (78.45˚S,106.87˚E) also transmits data to GMS-5,although it has some difficulties meeting thespecific standards for observation. The obser-vatories in the Siberian region, which areintroduced in this report, have been added tothese observation points.

2.2 Geomagnetic Data AcquisitionSystem Other Than INTERMAGNET

The CRL is collaborating with other insti-tutions to collect geomagnetic data by systemsother than the INTERMAGNET, via routessuch as the Internet and telephone lines. Onlya brief summary of such systems will be pre-sented here. Readers are referred to Nagat-suma et al.[6] for more detailed information.

The positions and special features of theobservation stations are as follows. The Eure-ka observation station (80.0˚N, 274.10˚E) islocated near the north magnetic pole. Dataobserved there is used to produce an indexsimilar to the PC index[4], an indicator of elec-tric field variations in the polar cap region[8].The Yap observation station (9.49˚N,138.09˚E) is located near the magnetic equa-

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tor. Since the magnetic equator has a peculiarelectric conductivity, Yap observation data isused to detect specific magnetic variations.The King Salmon observation station(58.68˚N, 203.35˚E) is located at the sameplace where the CRL installed a large HFradar in 2001. The St. Paratunka (52.94˚N,158.25˚E), Hiraiso (36.37˚N, 140.63˚E), Oki-nawa (26.75˚N, 128.22˚E), Guam (13.58˚N,144.87˚E), and Yap (9.49˚N, 138.09˚E) obser-vation stations are well-suited to monitoringthe penetration of electric fields from the highlatitudes into the range from the mid-latitudesto low latitudes, and even into the equator[9],because they are located in almost the samelongitudinal zone.

3 The AE Index

This section will describe the AE index, animportant indicator for monitoring the currentstate of geomagnetic disturbances, and closelyrelated to PURAES project. Detailed informa-tion on the AE index is provided in the DataBook[10] published by the Data Analyses Cen-ter for Geomagnetism and Space Magnetism,Kyoto University.

3.1 SummaryBecause the influx of energy from the

magnetosphere is concentrated in the polarionosphere, monitoring of the variations in theionospheric electric current is critical forunderstanding the overall variations in energyinflux from the magnetosphere. In the polarregion, aurora activity sometimes developsexplosively (a phenomenon known as auroralbreakup), accompanied by sudden increases inionospheric electric current. Such currents arecalled auroral electrojets, and the disturbancesin the polar regions are called substorms. TheAE (Auroral Electrojet) index was proposedas an indicator for the enhancement and decayof auroral electrojets[1]. The geomagneticdata used to calculate the AE index is collect-ed at 12 observatories, which are selected tocreate the most even distribution possiblealong the auroral zone encircling the magnetic

pole. This distribution usually satisfies therequirement that at least one observatory willbe positioned near the region of strong auroralelectrojet at any universal time (UT), therebymaking the AE index an indicator that closelyreflects the enhancement and decay of theauroral electrojet.

3.2 EffectivenessThe AE index has been used by numerous

scientists, including studies of the response ofthe magnetosphere to variations in the solarwind and interplanetary magnetic field(IMF)[11], and studies on the effects of sub-storms on geomagnetic storms[12].

The AE index is also useful in practicalapplications such as GIC prediction. Real-time derivations of the AE index are alsorequired to produce an input parameter forreal-time predictions of energetic electron fluxvariations in geostationary orbits[13]. Variousother physical quantities have been correlatedto the AE index, and numerous empiricalmodels have been proposed based on the rela-tionships. When a correlation between the AEindex and a physical quantity has been con-firmed statistically, predictions can be madeby using the AE index as an input parameterfor the empirical model and calculating thephysical quantity as the output. As it is

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Distribution of observation stations forAE index. Map shown in geographiccoordinates

Fig.1

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believed that the number of methods forprompt forecasting will be increased by theadoption of empirical models using near-real-time AE index as input parameters, demandfor the realization of the near-real-time deriva-tion of the AE index is increasing.

3.3 Derivation MethodFig.1 and Table 1 show the distribution of

observatories, whose data is used to calculatethe AE index. Note that the Cape Wellen(CWE) observatory was closed in 1996, andwas replaced by Pebek (PBK) (70.09˚N,170.93˚E) in 2001.

The input parameters are the 1-minute val-ues of the horizontal (H) geomagnetic fieldcomponent at each observatory. First, thebaseline (the value for the quiet condition) issubtracted from the daily data at each observa-

tory. Then, the data from all the observatoriesis superposed by aligning the time to universaltime, and the maximum and minimum valuesare determined for each minute to obtain theupper and lower envelope curves. (Fig.2shows an actual example of the superpositionof data for Apr.10, 1978.) The maximum andminimum values are the AU and AL values,respectively. The difference and average ofthe AU and AL values are the AE and AO val-ues, respectively. In a broad sense, the AEindex consists of the AU, AL, AE, and AOindices. This report will discuss the AE indexin this broad sense. Fig.3 shows the AE indexcalculated for April 10, 1978.

The mathematical expression for the AUindex is as follows:

where Hi(t) is the horizontal componentobserved at the ith observatory at time t withthe baseline subtracted. The AL, AE, and AOindices are:

The AU and AL indices, respectively, cor-respond mainly to the eastward and westwardauroral electrojets. Since long-term trendsaffect the baseline, absolute value measure-ments are required at least once a week tomonitor these trends.

KUNITAKE Manabu et al.

Observing stations for AE indexTable 1

Superposed plot for derivation of AE index on April 10, 1978Fig.2

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The disadvantage of having only a singleobservatory in each longitudinal zone for cal-culating the AE index is that the resultingindex must be handled with care, especially inthe following case. When the geomagneticactivity is extremely high (low), the electrojettends to flow at lower (higher) latitudes thanthe observatories. Therefore, the latitude ofthe observatory does not necessarily coincidewith the latitude of the center of the auroralelectrojet. In this case, the auroral electrojetestimated by the calculated AE index underes-timates the actual current.

3.4 History of the AE Index Derivationand Reduction of the Derivation Time

After the AE index calculation was initial-ly developed at the NASA/Goddard FlightCenter (GSFC), the 1-hour values of the AEindex from 1957 to 1964 were calculated andpublished by the Geophysical Institute of theUniversity of Alaska, Fairbanks. 2.5-minutevalues from Sept. 1964 to 1968 were calculat-ed experimentally at NASA/GSFC. The 2.5-minute values for 1966-1974 and 1-minutevalues from 1975 to April 1976 were pub-lished by the World Data Center for STP,Boulder (NOAA/NGDC). Thereafter, theData Analyses Center for Geomagnetism andSpace Magnetism, Kyoto University, calculat-ed and published the 1-minute values from

1978 to June 1988. (The National Institute ofPolar Research has been in charge of the pub-lishing since the late 1980s.) The AE indexcalculated and published by the above institu-tions have been strictly controlled in quality,for example, check for anomalous observationvalues and are referred to as the final AEindex. It took months to derive the AE index, aprocess that required enormous time and effortinvolving the digitizing of analog observationdata and checking for anomalous values.

To promote the calculation and publicationof the AE index, the provisional AE index wasadopted to reduce the enormous effort neededto convert data into checked digital data. Pro-visional AE index data is calculated evenwhen no data is available for 1 or 2 observato-ries. The 1-minute values of provisional AEindex from 1990 to 1995 have been calculatedin this way by the Data Analyses Center forGeomagnetism and Space Magnetism, KyotoUniversity and have been published by theNational Institute of Polar Research.

Since then, the need for the most currentAE index possible has arisen in various fields.The Data Analyses Center for Geomagnetismand Space Magnetism, Kyoto University, triedto fill these demands by making plots ofQuick-look AE index on the Web. These areupdated as soon as geomagnetic data has beenreceived from observatories. In the past, sinceit took days or even months for data to arrivefrom the observatories in the Siberian region,the Quick-look AE index had to be calculatedbefore data for the four Siberian observatorieswas available. This meant that one-third ofthe data from the observation circle consistingof 12 observatories was lacking, creating atime period in which it was difficult to moni-tor the enhancement and decay of the auroralelectrojet. Especially if a geomagnetic distur-bance develops in the polar region when theSiberian region is on the nightside magneticlocal time zone, the disturbance may be under-estimated or even missed entirely when moni-tored by the Quick-look AE index.

A near-real-time transmission of data fromthe Siberian region over a broad range of lon-

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Plot of AU , AL, AE and AO indices onApril 10, 1978

Fig.3

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gitudes was expected to minimize these inac-curacies by the Quick-look AE index and openthe way for speeding up the AE index deriva-tion from the Quick-look to near-real-time AEindex. As near-real-time AE index derivationwas desired for space weather forecasting andresearch, near-real-time data acquisition fromthe Siberian geomagnetic observatories wascrucial to its realization. The PURAES proj-ect, introduced in the following section, wasintended to provide a solution.

4 The PURAES Project

4.1 Background and the Collabora-tion Framework

As part of the effort to realize near-real-time derivation of the AE index, the 1stPURAES Project Meeting held in Sapporo inOct. 2000 sought to improve the quality ofobservation data by upgrading the magne-tometer at Siberian observatories, and toestablish a way for near-real-time data trans-mission. Research institutes from Japan, Rus-sia, and the U.S. participated in the discus-sions, resulting in the official launch of theProject for Upgrading Russian AE Stations/Space Weather Magnetometer Experiment(PURAES/SWME). The institutes cooperat-ing in the project included the CRL and theData Analyses Center for Geomagnetism andSpace Magnetism, Kyoto University, of Japan,the Institute of Dynamics of Geospheres andthe Arctic and Antarctic Research Institute(AARI) of Russia, and the Geophysical Insti-tute of the University of Alaska Fairbanks andthe Applied Physics Laboratory of the JohnsHopkins University in the U.S.

4.2 StrategyThe magnetometers at the observatories

were upgraded to more reliable models. ADCP, an instrument that can transmit dataevery 12 minutes, was also installed. SinceSiberian observatories are located in remoteareas without ready Internet access, data istransmitted to satellite. Data transmitted byDCPs is relayed by the GMS (Himawari satel-

lite) and downlinked to the MeteorologicalSatellite Center, JMA. Then it is sent to theCRL through the Japan Weather Association(JWA). In short, the transfer method is identi-cal to that used by INTERMAGNET. Thedata received at CRL is archived and also sentto Kyoto University.

From there, the data is distributed instantlyto cooperating institutes. The CRL and KyotoUniversity are to work together in makingnear-real-time calculations of the AE indexbased on this data.

4.3 Project PlansThe positions of the PURAES geomagnet-

ic observatories are shown by stars in Fig.4.The geographical coordinates for each obser-vatory are as follows: Pebek (PBK: 70.09˚N,170.93˚E); Tixie (TIK: 71.58˚N, 129.00˚E);Cape Chelyuskin (CCS: 77.72˚N, 104.28˚E);and Norilsk (NOK: 69.20˚N, 88.00˚E).

A PURAES project is given below.

2001 Apr. Installation and adjustment ofmagnetometers for observation, exceptfor an absolute value measurement, atPebek. Data Collection Platform (DCP)

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Distribution of PURAES stations withother AE stations

Fig.4

☆mark:PURAES geomagnetic observatories●mark:Other AE stations○×mark:Position of Cape Wellen station,

which was closed in 1996.

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is also installed. Start of test transmis-sion.

June Data transmission from Pebekbecomes part of regular operations.

Sept. Adjustment of magnetometersand DCPs in Japan

Oct. Transport of magnetometers andDCPs to Russia

Nov. Testing is performed on thetime calibration function of the instru-ment at St. Petersburg, where the AARIheadquarters is located. Two scientistsfrom Japan are participants in this test-ing.

Dec. Operation test is performed onthe revised sensor of the proton magne-tometer near St. Petersburg. Three sci-entists from Japan are participants.

2002 Feb. Installation and adjustment ofmagnetometers for observation, includ-ing an absolute value measurement, atTixie. Data Collection Platform (DCP)is also installed. Start of test transmis-sion.

Mar. Installation and adjustment ofmagnetometer for observation, includ-ing an absolute value measurement, atNorilsk. Data Collection Platform(DCP) is also installed. Start of testtransmissions.

May Data transmissions from Tixieand Norilsk become part of routineoperations.Installation and adjustment of magne-tometer for absolute value measurementat Pebek.

Aug. Installation and adjustment ofmagnetometer for observations, includ-ing an absolute value measurement, at

Cape Chelyuskin. Data Collection Plat-form (DCP) is also installed. Start oftest transmission.

Oct. Data transmission from CapeChelyuskin becomes part of routineoperations.

4.4 Outcome of the Availability ofNear-Real-Time Geomagnetic Data

Fig.5 shows an example of actual geomag-netic variations data. Both the observationand data transfer are nearly free of interrup-tions. Data acquisition appears to be com-mencing smoothly.

The geomagnetic H component on this dayshifts significantly towards the positive duringthe period of 10:00-12:00 UT, or during theperiod of 18:00-20:00 in magnetic local time(MLT) at Tixie. This indicates a strong east-ward electrojet in the ionosphere.

Fig.6 shows improvements in the underes-timated AE index following the availability ofnear-real-time data from the PURAES obser-vatories. The top two panels show calculatedAE indices, excluding data from the PURAESobservatories, to simulate conditions prior toPURAES project. The bottom two panels

Journal of the Communications Research Laboratory Vol.49 No.4 2002

Geomagnetic variation at Tixie from0hUT to 24hUT on Sept. 17, 2002. Toppanel shows H (horizontal) component.Middle panel shows D component.Bottom panel shows Z component.

Fig.5

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show the AE indices calculated with data fromthe PURAES observatories, which completionof the project has made available. As can bepredicted from the large variations seen in thegeomagnetic H component from Tixie data inFig.5, the AU index during the period of10:00-12:00 UT in the top panel is estimatedwith improved precision in the third panel.Fig.7 shows the degree to which the underesti-mated AU index between 7:00-12:00 UT inthe top panel is improved in the third panel.Fig.8 shows the improved accuracy of the ALindex during the period of 19:00-22:00 UT.Near-real-time acquisition of data from theSiberian region over a broad longitudinalrange has improved the precision of AE indexcalculations and enabled more accurate now-casting of polar geomagnetic disturbances.

KUNITAKE Manabu et al.

Comparison of conditions on Sept. 17,2002Upper half: Simulated calculation ofAU, AE, AL, and AO indices, excludingdata of PURAES stations.Lower half: Simulated calculation ofAU, AE, AL, and AO indices, includingdata of PURAES stations.

Fig.6

Comparison of conditions on Oct. 14,2002

Fig.7

Comparison of conditions on Aug. 20,2002

Fig.8

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5 Other Applications of Near-Real-Time Geomagnetic Data

Essential for near-real-time AE index deri-vations, the Siberian geomagnetic data alsopresents the potential for creating new prod-ucts through advanced utilization of data.Here, two examples of comprehensive use ofgeomagnetic data are given, as well as oneexample of geomagnetic data combined withother types of observation data.

Comparing geomagnetic data from theSiberian observatories with geomagnetic datafrom existing observation station set by CRLfrom mid-latitude regions to the equatormakes it possible to know characteristics ofelectric field penetration from the polar regionto the equator in the eastern Eurasian longitu-dinal zone[9].

With some additional physical constraints,geomagnetic data from multiple observationstations around the globe has been used asinput parameters for near-real-time inversioncalculations (KRM algorithm[14]) to estimatethe 2-dimensional distribution of ionosphericelectric currents, electric fields, Joule heating,and so on. Previously, observation data forinput had been confined to North America andEurope. The Siberian region had been devoidof data. The addition of observation data fromPUREAS stations is expected to improve theaccuracy of estimates.

One example of combining geomagneticdata with data from other observation methodsinvolves combination with data from HF radarobservations. In the summer of 2001, theCRL installed a radar in King Salmon, Alaska,as part of SuperDARN, the large HF radar net-

work. The observation area of this radar cov-ers the ionosphere above the Pebek geomag-netic observatory of PUREAS project. How-ever, the other three observatories in the Siber-ian region are positioned in areas not coveredby any radar in the SuperDARN network. Amore precise picture of the status of magnetos-pheric convection can be determined by com-plementing the SuperDARN radar observa-tions data with geomagnetic data from thesethree observatories.

6 Conclusions

The PUREAS project has improved thequality of data at geomagnetic observatories inthe Siberian region and enabled near-real-timedata acquisition. This has improved qualityand enabled near-real-time derivation of theAE index, an indicator based on polar geo-magnetic data, and contributed significantly tonowcasting of geomagnetic disturbances. TheSiberian geomagnetic data can also be used inadvanced applications other than the deriva-tion of the AE index. It is expected to proveuseful in a wide spectrum of space weatherforecasting applications.

Acknowledgments

The authors wish to express their gratitudeto the staff of the Observations Departmentand the Meteorological Satellite Center of theJapan Meteorological Agency for their invalu-able and generous assistance with the testingand operation of the data relay system via theGMS (Himawari) satellite for the PURAESproject.

Journal of the Communications Research Laboratory Vol.49 No.4 2002

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KUNITAKE ManabuSenior Researcher, Space WeatherGroup, Applied Research and Stand-ards Division

Upper Atmosphere Physics, Magnetos-pheric Physics

NAGATSUMA Tsutomu, Ph. D.

Senior Researcher, Space WeatherGroup, Applied Research and Stand-ards Division

Solar-Terrestrial Physics

ISHIBASHI Hiromitsu

Senior Researcher, Solar and SolarWind Group, Applied Research andStandards Division

Solar Wind, Space Weather

KIKUCHI Takashi, Ph. D.

Research Supervisor, Applied Researchand Standards Division

Magnetosphere-Ionosphere Physics

KAMEI Toyohisa

Research Associate, Data AnalysesCenter for Geomagnetism and SpaceMagnetism, Kyoto University

Geomagnetism, Space Physics