UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY PRELIMINARY GEOMAGNETIC DATA COLLEGE OBSERVATORY FAIRBANKS, ALASKA SEPTEMBER 1982 OPEN FILE REPORT 82-03001 THIS REPORT WAS PREPARED UNDER THE DIRECTION OF JOHN B, TOWNSHEND, CHIEF OF THE COLLEGE OBSERVATORY, WITH THE ASSISTANCE OF THE OBSERVATORY STAFF MEMBERS: JnE, PAPP, E,A, SAUTER, LIY, TORRENCEt TtK, CUNNINGHAM AND IN COOPERATION WITH THE GEOPHYSICAL INSTITUTE OF THE UNIVERSITY OF ALASKA, THE COLLEGE OBSERVATORY IS A PART OF THE BRANCH OF ELECTROMAGNETISM AND GEOMAGNETISM OF THE U,S, GEOLO- GICAL SURVEY, ORDER OF CONTENTS Explanation of Data and Reports Magnetic Activity Report Outstanding Magnetic Effects Principal Magnetic Storms Preliminary Calibration Data and Monthly Mean Absolute Values Magnetogram Hourly Scalings Sample Format for Normal and Storm Magnetograms Normal Magnetograms Storm Mignetogsams (When Normal is too disturbed to read) C01 I FGF OBSFRVATORY PRFl IMIFIARY GFOMAWC DATA OBSERVATORY LOCATION The preliminary geomagnetic dgta incl idcd .?ere is The College Observatory, operated by the U.S. .made available to scientific personnel and or5aniza:io:ls Seological :j\lr.iey, is located at the Univer~ityof as part of a cooperative effort an6 on a data ex2mnge ALaska, Fairb:i~lks, Alaska. It is near the Auroral basis bec?use of the early need by come users. ;> Zone and the northern limit of the world's greatest " avoid delay, all of the data is 2opied from ori~irai esrthquakc belt, tho circum-Pacific Seismic belt. forms processed at the observatory; therefor.: it should Althouqh the observatory's bash oper?tion Is in geo- be regarded as preliminary. Inquiries about this report magnetism and seismology, it cooperates wlth other or ?bout the College Observatory should be addressed to: scientists 3nd organizations in areas where the facil- ity and personnel can be of service. Chief, College Observatory The observatory 16 one of three operated by the U.S. Geological Survey USGS in Alaska. The others are located at Barrow SO0 Yukon Drive and Sitka. Fairbanks, Alaska 99701 The position of the observatory site is: Geographic latitude....... 64"51.6'N Requests for copies of the maynetograms except for Geographic longitude ......147'50.2'W the current month should be addressed to: Geomagnetic latitude ......+64.bo Geomagnetic longitude.. .*?56. ? ':/orld Data Center A Elevation .................200 meters NOAA D63, 325 Broadway Boulder, Colorado 80303 GEOMAGNETIC 3ATP. Norml, Storm and Rapid Run mgnetograms and Selected Phenomena & Outst,anding k~gneticEffects appropriate calibration data are processed daily at Prior to January 1, 1976, the Norm31 and Rspid the observatory and are available for analysis or Run records were reviewed at the observatory for copyiq. Also available, are mean hourlj scalings, selected magnetic phenomena and the events identified K-Indices, selected magnetic phenomena reports and were forwarded to the IUGG Commission on Magnetic on a real-time basis are recordiws from a 3-compo- Variations and Disturbances. This wss discontinued neat Il,axgate magnetometer and F-component proton on January 1, 1976, but a report on Outstandiw naqetometer. hgnetic Effects is prepared monthly for this report. 'kqnetic Activity Principal &gnet,ic St,or~s The K-Index: The K-Index is a. logaritkmic measure- Gradual and sudden comencernent magnetic distur- ment of the ranae- of the most disturbed comnonen? (3 qr bances with at least one K-Index of 5 or greater, which H) of the geomagnetic field for eight intervals beginniw are believed to be part of a world-wide disturbance, 0000-0700, 0300-0600 ...2100-2400 UT. It is a neasure of are classified as principal magnetic storms. The time the difference between the highest and lowest deviation of the storm beginning and ending; direction and from a smooth curve to be expected for a component on a amplitude of sudden comencements; period of maximum magnetically quiet day, within a three hour interval. activity; and storm range are reported. Monthly reports The Equivalent Daily Amplitude, AK: The K-Index of these data are forwarded to the World Data Center A is converted into an equivalent range, ak, which is near in aoulder, Colorado. the center of the limiting gamma ranges for a given K. The average of the eight values is called equivalent Magnetogram Horurly Scaliws daily amplitude AK. The unit 1Oy has been chosen so as Magnetogram- - hourly scalings are averaees for not to give the illusion of an accuracy not justified. successive periods of one hour for the D, H and 2 The schedule for converting gamma range to K, and elements. The Value in the colwnn headed "01" is the K to ak is as follows: averaee for the hour beginning 0000 and ending 0100. Gamma Range K - Index -ak Note that the Tralues on the scaling sheess are in tenths O< 25 0 0 of mm with the decimal point 3mitte;i. The user of these 25 c 50 1 3 scalings should keep in mind that the tabular values are 50< 100 2 7 hourly means and if he is interested in the detailed 100 c 200 3 15 morphology of the magnetic field, he should refer directly 200 c 350 4 27 to the magnetograms. 3TO< 600 5 48 600 c 1000 6 80 Magnetograms 1000 < 1650 7 140 The normal magnetograms in this report are repro- 1650 < 2500 8 2LO duced at about one-third the size of the originals. 2500+ 9 400 (lor ) Preliminary base-line values and scale values adopted for use with the original magnetograms are included. For The kgnetic Daily Character Figure, C: To each days when the magnetic field is too disturbed for the Universal day a character is assigned on the basis Normal magnetogram to be readable, Storm magnetograms C=O, if it is quiet; C=l, if it is moderately are reproduced. disturbed; C-2, if it is greatly disturbed. The method used to assign characters at the College Absolutes, Base-lines and Scale Values Observatory is based on AK as follows: To determine the absolute value of the magnetic AK C field from the hourly means or from point scalings the o= 11 i3 following equations should be llsed: lla5O 1 D=RD+d.SD; H=qi+h-SH; ZTB +z*SZ 50+ 2 where D, H and 2 are absofute values; !,,, $ and B, are base-line values; Routine assignment of C :.{as discontinued at an, and S; are scale values; College on January 1, 1976. and d, h and"z are scalings in millimeters. U. S. DEPARTMENTOF COMMERCE OBSERVATORY A ORl3 NATIONAL OCEANIC AND ATMOSPHE8IC ADMINISTRATION 19-72] COLLEGE OBSERVATORY --.-- -- MAGNETIC ACTlVlT Y MONTH AND YFAR (Greenwich civil time, counted from midnight to midnight) September 1982 K-INDlCES TIME SCALE UN MAGNETOGRAMS DATE YLm-u ". m -N --w ?' SUM AK $s%*&A&-+r-N - 20 mmhr 1 2212 5422 2O 14 SUDDEN COMMENCEMENTS 2 2346 5332 28 27 d h m 3 3446 3332 28 2 5 4 3456 6533 5 3 41 5 4475 6636 41 62 6 6679 6864 52 141 7 5477 6773 46 51 8 2433 2223 21 13 9 5436 6444 36 41 10 3211 1222 14 07 11 2234 5322 23 1'7 12 2324 1222 18 10 13 4324 5512 26 23 14 2322 2371 18 10 1s 2323 3332 21 12 16 3132 3222 18 10 17 2256 3321 24 23 18 28 3433 5454 31 POSSIBLE SOLAR-FLARE 19 3344 5653 33 34 EFFECTS BASED ON INSPECTION OF GRAMS 20 2366 5513 3 3 3 9 ALONE (WITHOUT REFERENCE TODATA FROM OTHER SOURCES) 2 1 5675 7546 5 4 76 2 2 5878 7534 47 I 112 23 3556 4423 32 73 24 3456 5621 32 39 BEGIN END 2 5 18 10 2123 3331 d II m d hm 2 6 2257 8864 4 2 99 27 1,366 4542 34 39 2 8 4423 2112 19 12 2 9 1165 4121 2 1 2 2 30 0144 4533 24 20 31 K SCALE USED: D H Z LOWER LIMIT FOR K = 9.. .. 683.8 321.7 (mm) -"- 7.79 CURRENT SCALE VALUE ........ 3.73 - (Y/mm) LOWER LIMIT FOR K = 9 ..... ,.. 2550 2Ti3 (to neare~t10~) SCA LIN GS AND COMPUTATIONS HAVE BEEN CHECKED. APPROVED JOHN B. TOWNSHEND, CHIEF, COLLEGE OBSERVATORY OBSERVER IN CHARGE - NOAA FORM 76-193 SUPERSEDES CLGS FORM 815 * U.S. GOVERNMENT PRINTING OFFICE: 1973-761-857 pg, ~i 1, pi 2, sfe. .. .. .. .. ., , ... -- - . .- ..... -- ... -.- FT.f(IOD .PA..- .. ~.. ...... -... -- TO -- ... - ,A - ., -. - - D ... -,-. .- .. -- ,- .A - -- .." .... ...... .......... - ..-. ......... .... -... ..... -...... ,.. - -. ", ...... .... .... ..-...- -. " .- - . - . ,.. , .. -- .... - .- . ..-- ... - .--.- 2 ....... ............. ....... ..... ..... .. -. .- - - -- ...... ............ ..... -. ...... - - - - .. -- ki3hm ?EM kESOIl7E VAIIES* - -. --- . -- ...... - ....... - . -- ...... - .... ..... - - D .....- T-..*" . -. - ...-.- ...--.- ... A- 954 " .- - 27' ,57.'3 E---- --.- - , . - .- ...... ... ... -1 ..e02 ........-. - s,D 17( QUETEST ,DX1Y5 VJAuZ HDm. DAYS USED: SEP - ---,8 -lo -12 _,14 .-.--,15 ,25 , _,%~(QDEBELCNJ- ,- . - -. ,- - %r%To VETC~DI~?TURBWWGI-lEmC CDLJP\vohlS ?xIRIC-\G Mm SEWEMBER \9@, ONLY 7 PAY5 AKE USW m cowRXE MoCHLY L%,Au /+B%UIE Vua -. - -. - -.A,- -1 FORMAT FOR NORMAL. & STORM MAGNETOGRAMS (SAMPLE ONLY) COLLEGE. ALASKA SEE PRELIMINARY CALIBRATION DATA FOR SCALE VALUES BASELINE VALUES COLLEGE ALASKA I SEP 1 1902 SEP 2. 1983 1 dl/-- 1 I ----A - 20 24 UT 4 I V -- Pa 16 --L- --L- -. 7- -- -- . - COLLEGE. ALASM fl SEP 2. 1982 I ' 8, ' : I: , .. , +' . 10 -- 24 U.T 18 , I -.- I' , ,* COLLEGE, ALASKA SEP 6. 1982 ', * I ', I' ' ' Srnarn I, m1w.m '8 ! i 'I, 'I ;-. r m 12 16 ' .-.- -, .,. 8, I I I , 8 . .. I I I ' '8 COLLEGE. AL4SKA I' I' I SEP 8. 1982 ?"-7-x/~?ccr I, I, 7 ; ' I m 12 ( 1: -. --- ,s'. h:' , A' - . ... 14 ), ' I . , ! i, - COLLEGE,ALASI(A V !: ' 'T SSP 8. 1982 1 : SEP I ', 7. 1862 *i;4 ' . -.. 24 U.T. 4 I 'I 'i' * , *Y , m 8 Sas earn rnagwtqvam 11 ! .