Fridrich Valach

Geomagnetic Observatory Hurbanovo
Earth Science Institute of the Slovak Academy of Sciences

Address:
Komárňanská 108, 947 01 Hurbanovo, Slovakia

E-mail: geoffval@savba.sk

ResearchGate profile

Curriculum Vitae

Research interests:
space weather, magnetic storms, geomagnetic observations

Downloadable papers and post-prints:

F. Valach, M. Váczyová, D. Výberči, E. Koči: Regular observations of the geomagnetic field at the Ógyalla observatory (present-day Hurbanovo) near the turn of the 20th century, including magnetic storms accompanied by auroras in March 1894, September 1898, and October 1903. Contributions to Geophysics and Geodesy, 2024, vol. 54/1, pp. 23–46. https://doi.org/10.31577/congeo.2024.54.1.2 pdf (open access), supplement

E. Koči, F. Valach: The record of the magnetic storm on 15 May 1921 in Stará Ďala (present-day Hurbanovo) and its compliance with the global picture of this extreme event. Annales Geophysicae, 2023, vol. 41, pp. 355–368. https://doi.org/10.5194/angeo-41-355-2023 pdf (open access)

P. Hejda, F. Valach, M. Revallo: Historical geomagnetic observations from Prague observatory (since 1839) and their contribution to geomagnetic research. History of Geo- and Space Sciences, 2023, vol. 14, pp. 51–60. https://doi.org/10.5194/hgss-14-51-2023 pdf (open access)

P. Hejda, M. Revallo, F. Valach: Magnetic storm and term-­day observations at the Prague observatory Clementinum in the mid-­19th century. Geoscience Data Journal, 2023, vol. 10, pp. 39–44. https://doi.org/10.1002/gdj3.141 pdf (open access)

P. Hejda, M. Revallo, F. Valach: Data of magnetic storms and term-day observations from the Prague-Clementinum observatory (1839-1849). PANGAEA, 2021. https://doi.org/10.1594/PANGAEA.936921 pdf (open access)

P. Hejda, F. Valach, M. Revallo: The geomagnetic data of the Clementinum observatory in Prague since 1839. Annales Geophysicae, 2021, vol. 39, pp. 439–454. https://doi.org/10.5194/angeo-39-439-2021 pdf (open access)

F. Valach, P. Hejda, M. Revallo, J. Bochníček: Possible role of auroral oval-related currents in two intense magnetic storms recorded by old mid-latitude observatories Clementinum and Greenwich. Journal of Space Weather and Space Climate, 2019, vol. 9, A11. DOI:10.1051/swsc/2019008 pdf (open access)

Fridrich Valach: The intense magnetic storm of March 1918 as recorded by observatory Ógyalla (present day Hurbanovo). Acta Geodaetica et Geophysica, (2017) Volume 52, Issue 4, pp 457–465. DOI: 10.1007/s40328-016-0177-1 preprint publisher's version

A. M. Jorgensen, B. Heilig, M. Vellante, J. Lichtenberger, J. Reda, F. Valach, I. Mandic: Comparing the dynamic global core plasma model with ground-based plasma mass density observations. J. Geophys. Res. Space Physics, 2017, 122, 7997–8013. doi:10.1002/2016JA023229 publisher's version

Patrick Arneitz, Roman Leonhardt, Elisabeth Schnepp, Balázs Heilig, Franziska Mayrhofer, Peter Kovacs, Pavel Hejda, Fridrich Valach, Gergely Vadasz, Christa Hammerl, Ramon Egli, Karl Fabian, Niko Kompein The HISTMAG database: combining historical, archaeomagnetic and volcanic data. Geophysical Journal International, 2017, vol. 210, issue 3, p. 1347-1359. DOI: 10.1093/gji/ggx245 publisher's version

Fridrich Valach, Magdaléna Váczyová, Tomáš Šoltis, Melinda Vajkai: Report on the magnetic survey in Slovakia for the 2014.5 epoch. Contributions to Geophysics and Geodesy, Vol. 46/1, 2016, pp. 51-60. doi: 10.1515/congeo-2016-0004 pdf (open access)

Fridrich Valach, Pavel Hejda, Miloš Revallo, Josef Bochníček, Magdaléna Váczyová: Testing the interactive computer method (IM) for producing K indices with the data of the Hurbanovo and Budkov magnetic observatories. Journal of Atmospheric and Solar-Terrestrial Physics, 147 (2016) pp. 90-97. DOI: 10.1016/j.jastp.2016.07.010 post-print, publisher's version

Fridrich Valach, Magdaléna Váczyová, Miloš Revallo: Producing K indices by the interactive method based on the traditional hand-scaling methodology - preliminary results. Journal of Atmospheric and Solar-Terrestrial Physics, 137 (2016) pp. 10-16. DOI: 10.1016/j.jastp.2015.11.009 post-print, publisher's version

Miloš Revallo, Fridrich Valach, Pavel Hejda, Josef Bochníček: Modeling of CME and CIR driven geomagnetic storms by means of artificial neural networks. Contributions to Geophysics and Geodesy, Vol. 45/1, 2015, pp. 53-65. doi:10.1515/congeo-2015-0013 pdf (open access)

Miloš Revallo, Fridrich Valach, Pavel Hejda, Josef Bochníček: A neural network Dst index model driven by input time histories of the solar wind-magnetosphere interaction. Journal of Atmospheric and Solar-Terrestrial Physics, 110-111 (2014) 9-14. DOI:10.1016/j.jastp.2014.01.011 post-print, publisher's version

Fridrich Valach, Magdaléna Váczyová, Peter Dolinský, Melinda Vajkai: Substitution for lost one-hour means of the geomagnetic elements for the first half of the 20-th century at the Hurbanovo Geomagnetic Observatory by means of neural networks. Contributions to Geophysics and Geodesy, Vol. 43, no. 2 (2013), pp. 125-140. DOI:10.2478/congeo-2013-0008 pdf (open access)

Fridrich Valach, Josef Bochníček, Pavel Hejda, Miloš Revallo: Strong geomagnetic activity forecast by neural networks under dominant southern orientation of the interplanetary magnetic field. Advances in Space Research, Volume 53, Issue 4, 2014, p. 589-598. DOI:10.1016/j.asr.2013.12.005 post-print, publisher's version

E. Saiz, Y. Cerrato, C. Cid, V. Dobrica, P. Hejda, P. Nenovski, P. Stauning, J. Bochnicek, D. Danov, C. Demetrescu, W. D. Gonzalez, G. Maris, D. Teodosiev, F. Valach: Geomagnetic response to solar and interplanetary disrurbances. Journal of Space Weather and Space Climate, 2013, vol. 3, p. A26. DOI:10.1051/swsc/2013048 pdf (open access)

G. Duma, B. Leichter and the MagNetE Group: Magnetic Declination Chart 2006 of Europe - produced by the MagNetE Group. Annals of Geophysics, 55, 6, 2012, Pages 1053-1059. DOI: 10.4401/ag-5575 pdf (open access)

Fridrich Valach, Miloš Revallo, Pavel Hejda, Josef Bochníček: Predictions of SEP events by means of a linear filter and layer-recurrent neural network. Acta Astronautica, 2011, vol. 69, issue 9-10, p. 758-766. DOI:10.1016/j.actaastro.2011.06.003 post-print, publisher's version

Miloš Revallo, Fridrich Valach, Magdaléna Váczyová: The geomagnetic storm of August 2010 as a lesson of the space weather modeling. Contributions to Geophysics and Geodesy, 2010, vol. 40, no. 4, p. 313-322. DOI:10.2478/v10126-010-0013-5 pdf (open access)

Peter Dolinský, Fridrich Valach, Magdaléna Váczyová, Milan Hvoždara: Geomagnetic ground survey in Slovakia for the 2007.5 epoch. Contributions to Geophysics and Geodesy, 2009, vol. 39, no. 3, p. 255-272. pdf (open access)

Fridrich Valach, Miloš Revallo, Josef Bochníček, Pavel Hejda: Solar energetic particle flux enhancement as a predictor of geomagnetic activity in a neural network-based model. Space Weather, 2009, vol. 7, no. 4, Article number S04004. DOI:10.1029/2008SW000421 pdf (open access)

Fridrich Valach, Pavel Hejda, Josef Bochníček: Geoeffectiveness of XRA events associated with RSP II and/or RSP IV estimated using the artificial neural network. Studia Geophysica et Geodaetica, 2007, vol. 51, no. 4, p. 551-562. DOI:10.1007/s11200-007-0032-5 post-print, publisher's version

Josef Bochníček, Pavel Hejda, Fridrich Valach: Solar energetic events in the years 1996-2004. The analysis of their geoeffectivennes. Studia Geophysica et Geodaetica, 2007, vol. 51, no. 3, p. 439-447. DOI:10.1007/s11200-007-0025-4 publisher's version

Fridrich Valach, Magdaléna Váczyová, Peter Dolinský: Slovak geomagnetic repeat stations - the 2006.5 epoch. Contributions to Geophysics and Geodesy, 2007, vol. 37, no. 4, p. 377-385. pdf (open access)

Fridrich Valach, Magdaléna Váczyová, Peter Dolinský: New Slovak geomagnetic repeat station network. Earth Planets Space, 2006, vol. 58, no. 6, p. 751-755. DOI:10.1186/BF03351978 pdf (open access)

Magdaléna Váczyová, Fridrich Valach: The effect of the geomagnetic activity on the geomagnetic measurement's accuracy. Contributions to Geophysics and Geodesy, Vol. 36, no. 2 (2006), p. 229-237. pdf (open access)

Dana Jankovičová, Peter Dolinský, Fridrich Valach, Zoltán Vörös: Neural network based nonlinear prediction o magnetic storms. Journal of Atmospheric and Solar Terrestrial Physics, Vol. 64, no. 5-6 (2002), p. 651-656. publisher's version

Fridrich Valach, Magdaléna Váczyová: Analysis of the geomagnetic anomaly within the Kolárovo basin using GMINV. Physics and Chemistry of the Earth : Part A : Solis Earth and Geodesy, Vol. 24, no. 5 (1999), p. 461-462. publisher's version