LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

CREATE AN ACCOUNT

Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
K. Mursula; A. Karinen (2005)
Publisher: Copernicus Publications
Journal: Annales Geophysicae
Languages: English
Types: Article
Subjects: Geophysics. Cosmic physics, Q, [ SDU.STU ] Sciences of the Universe [physics]/Earth Sciences, [ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, Science, Physics, QC1-999, QC801-809
International audience; We have reconstructed a new, homogeneous geomagnetic Dst index for 1932-2002, thus extending the original Dst index by 25 years, i.e. by more than one full solar magnetic cycle. The extension was done by using data from the original set of four low-latitude stations for 1941-1956, and by using the nearby CTO station as a predecessor of the HER station for 1932-1940. Despite some open questions related to the composition of the original Dst index, the reconstructed index is quite similar to the original one during the overlapping time interval (1957-2002). However, the reconstructed Dst index corrects for some known errors in the original Dst index, such as the erroneously large daily UT variation in 1971. Also, despite the overall agreement, the reconstructed index deviates from the original index even on the level of annual averages for several years. For instance, all annual averages of the reconstructed index are negative, and for 1962-1966 they are systematically lower (more stormy) than those of the original index. Accordingly, we disagree with the uniquely positive annual average of the original index in 1965, which most likely is erroneous. We also find somewhat higher (less stormy) values than in the original Dst index for the three lowest annual averages in 1960, 1989 and 1991, out of which the lowest annual average is found in 1989 rather than in 1991. The annual averages of the geomagnetic Ap index and the reconstructed Dst index correlate very well over this time interval, except in the beginning of the series in 1932-1940 and in the declining phase of solar cycles 18, 20 and 21, where high speed solar wind streams cause enhanced geomagnetic activity. Using the superposed epoch method we also find that, on average, the storms in the early extended period (1932-1956) are less intense but tend to have a longer recovery phase, suggesting that there are more HILDCAA-type medium activity intervals during the early period than more recently. We also study the annually averaged storm structure over the 71-year time interval and find that the most stormy years occur during the declining phase of solar cycles 17 and 21 and around the solar maxima of cycles 19 and 22.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Ahluwalia, H. S.: The predicted size of cycle 23 based on the inferred three-cycle quasi-periodicity of the planetary index Ap, J. Geophys. Res., 103, A6, 12103-12109,1998.
    • Alexeev, I. I., Belenkaya, E. S., Kalegaev, V. V., Feldstein, Y. I., and Grafe, A.: Magnetic storms and magnetotail currents, J. Geophys. Res., 101, 7737-7747, 1996.
    • Burton, R. K., Mc Pherron, R. L., and Russell, C. T.: An empirical relationship between interplanetary conditions and Dst, J. Geophys. Res., 80, 4204-4214, 1975.
    • Campbell, W. H.: Dst is not a pure ring current index, EOS., 77, 283-285, 1996.
    • Campbell, W. H.: Failure of the Dst index to represent ring current, Space Weather, 2, S08002, doi:10.1029/2003SW000041, 2004.
    • Clilverd, M. A., Clark, T. D. G., Clarke, E., and Rishbeth, H.: Increased magnetic storm activity from 1868 to 1995, J. Atm. Sol. Terr. Phys., 60, 1047-1056, 1998.
    • Cliver, E. W., Kamide, Y., and Ling, A. G.: Mountains versus valleys: Semiannual variation of geomagnetic activity, J. Geophys. Res., 105, 2413-2424, 2000.
    • Ha¨kkinen, L. V. T., Pulkkinen, T. I., Nevanlinna, H., Pirjola, R. J., and Tanskanen, E. I.: Effects of induced currents on Dst and on magnetic variations at mid-latitude stations, J. Geophys. Res., 107, SMP 7-1, 2002.
    • Ha¨kkinen, L. V. T., Pulkkinen, T. I., Pirjola, R. J., Nevanlinna, H., Tanskanen, E. I., and Niescja, E. T.: Seasonal and diurnal variation of geomagnetic activity, J. Geophys. Res., 108, SMP 2-1, 2003.
    • IGRF.: International Geomagnetic Reference Field (IGRF 2000), The International Association of Geomagnetism and Aeronomy (IAGA), http://www.iugg.org/IAGA/iaga pages/pubs prods, 2000.
    • Karinen A., Mursula, K., and Ulich, Th.: An erroneous Dst index in 1971, Proc. of the SOLSPA 2001 Conference, ESA-SP-477, 443-446, 2001.
    • Lockwood, M., Stamper, R., and Wild, M.: A doubling of the Sun's coronal magnetic field during the past 1000 years, Nature, 399, 437-439, 1999.
    • Lui, A. T. Y, McEntire, R. W., and Krimigis, S. M.: Evolution of the ring current during two geomagnetic storms, J. Geophys. Res., 92, 7459-7470, 1987.
    • MATLAB.: The Language of Technical Computing Version 6.1, 18 May 2001.
    • Mayaud, P.-N.: The annual and daily variations of the Dst index, Geophys. J. R. Astr. Soc., 55, 193-201, 1978.
    • Mayaud, P.-N.: Derivation, meaning, and use of geomagnetic indices, Geophys. Monogr. Ser., 22, AGU, Washington D.C., 1980.
    • NGDC.: Geomagnetic Sudden Storm Commencements, via anonymous FTP (ftp://ftp.ngdc.noaa.gov) from the National Geophysical Data Center (NGDC), Boulder, Colorado, USA, 2004.
    • O'Brien, P., and McPherron, R. L.: An empirical phase analysis of ring current dynamics: Solar wind control of injection and decay, J. Geophys. Res., 105, 7707-7719, 2000.
    • Saroso, S., Iyemori, T., and Sugiura, M.: Universal time variations in the ap and Dst indices and their possible cause, J. Geomag. Geoelectr., 1993.
    • Siscoe, G. and Crooker, N.: Diurnal oscillation of Dst: A manifest of the Russell-McPherron effect, J. Geophys. Res., 1010, 24 985- 24 989, 1996.
    • SPIDR.: Hourly mean geomagnetic data, Space Physics Interactive Data Resource (SPIDR) by National Geophysical Data Center (NGDC), (http://spidr.ngdc.noaa.gov/spidr/index.html), Boulder, Colorado, USA, 2004.
    • Sugiura, M.: Hourly values of equatorial Dst for IGY, Ann. Int. Geophys. Year, 35, 9, 1964.
    • Sugiura, M. and Hendricks, S.: Provisional hourly values of equatorial Dst for 1961, 1962 and 1963, NASA Tech. note D-4047, 1967.
    • Sugiura, M.: IAGA Resolution 2, in: IAGA Bulletin 27, Madrid, p. 123, 1969.
    • Sugiura, M. and Kamei, T.: Equatorial Dst index 1957-1986, in IAGA Bull., vol. 40, edited by Berthelier, A. and Menvielle, M., ISGI Publ. Off., Saint-Maur-des-Fosse´s, France, 1991.
    • Søraas, F., Aarsnes, K., Oksavik, K., Sandanger, M. I., Evans, D. S., and Greer, M. S.: Evidence for particle injection as the cause of Dst reduction during HILDCAA events, J. Atm. Sol. Terr. Phys., 66, 177-186, 2004.
    • Takalo J. and Mursula, K.: A model for the diurnal UT variation of the Dst index, J. Geophys. Res., 106, 10 905-10 914, 2001a.
    • Takalo J. and Mursula, K.: On the diurnal variation of the Dst index, Proc. of the SOLSPA 2001 Conference, ESA-SP-477, 483-486, 2001b.
    • Tsurutani, B. T. and Gonzales, W. D.: The cause of the high intensity long duration continuous AE activity (HILDCAA's): Interplanetary Alfve´n wave trains, Planet. Space Sci., 35, 405-412, 1987.
    • Turner, N. E., Baker, D. N., Pulkkinen, T. I., and McPherron, R. L.: Evaluation of the tail current contribution to Dst, J. Geophys. Res., 105, 5431-5439, 2000.
    • WDC-C1.: Hourly mean geomagnetic data, the World Data Center for Geomagnetism (WDC-C1), (http://web.dmi.dk/fsweb/ projects/wdcc1), Copenhagen, Denmark, 2004.
    • WDC-C2.: Definition of the Dst index, and hourly mean geomagnetic data, the World Data Center for Geomagnetism (WDC-C2), (http://swdcdb.kugi.kyoto-u.ac.jp), Kyoto, Japan, 2004.
  • No related research data.
  • Discovered through pilot similarity algorithms. Send us your feedback.