NATIONAL ANTARCTIC RESEARCH PROGRAM. Mario Zucchelli Station, Antarctica Geomagnetic Observatory

NATIONAL ANTARCTIC RESEARCH PROGRAM Mario Zucchelli Station, Antarctica Geomagnetic Observatory Magnetic Observation Results 2013-2014 L. Cafarella, M. Di Persio, S. Lepidi, M. Marzocchetti and L. Santarelli 2017

- 1 - Geomagnetic Observation Results 2013-2014 Mario Zucchelli Station - Antarctica Introduction This report deals with activities undertaken at the Antarctic Italian Geomagnetic Observatory during the austral summer 2013-2014. The coordinates of the Observatory at OASI are the following: Geographic latitude: Geographic longitude: Corrected Geomagnetic latitude (IGRF12): Corrected Geomagnetic longitude (IGRF12): Magnetic local time midnight: 74.6936 S 164.0975 E 79.85 S 306.61 E 08:17 UT This report describes the activities performed from November 2, 2013 to December 3, 2013. For the present work H, D and Z INTERMAGNET formatted data from the fluxgate magnetometer EDA have been used. The proton precession magnetometers used to record F total values were Overhauser type; for a description of instruments we refer to geomagnetism text books, for example Parkinson (1983) and Wienert (1970). Since the total intensity F time variations, at polar latitudes, where values of inclination is almost 90, are very close to the vertical component Z time variations, the plots of total intensity time variations are not shown. They can however be obtained from the well known equation: F 2 =H 2 +Z 2 Absolute measurements For the normal absolute measurements-taking at the Observatory, a standard fluxgate magnetometer theodolite for the determination of D, I angles has been used. At OASI three different azimuth marks are available, for the computation of the Declination (please refer to the 2001/2002 report for details). The coordinates of geodetic points (mark piers and measuring location) were established on the basis of GPS measurements. From these coordinates the azimuth values 152 44 04, 60 13 36 and 338 07 59 were found. The proton magnetometer recordings, continuously undertaken during the execution of the DI measurements, have allowed the calculation of the absolute intensive elements. Table 1 shows absolute measurement values for each element; the values of the intensive components H and Z (rounded off to the nt) were computed using the relations: H = F cos I Z = F sin I

- 2 - H0 and D0 reference values computation Since the fluxgate was magnetically oriented in the horizontal plane, as in the previous installations, it was necessary to compute H0 and D0 reference values, comparing absolute and relative measurements, at the same time. For the Z component, once the vertical levelling of the sensor was assured, it was assumed that the variations measured by fluxgate were actually the vertical component of the geomagnetic field variations. In the description the mathematical procedure used for computation of H0 and D0, the following symbols are used: H0, D0 Reference values Habs, Dabs Values of absolute measurements at time t x,y Instantaneous variations recorded by fluxgate system at time t For each absolute measurement, the reference values were computed as: where H0 = Habs cos( ) - x D0 = Dabs - = arcsin (y/habs) In order to reduce this dispersion in the set, the Chauvenet criterion was used. The method, based on the hypothesis of a Gauss probability distribution for the data, consists in the elimination of measurements whose difference from the average is greater than a multiple of the standard deviation fixed by the sample dimension (in this case a value 2.89 σ, corresponding to a sample of about 108 data elements, was used). This method, however, cannot be applied more than once, since an iterative procedure could exclude most of the values up to the complete elimination of the data (Worthing and Jeffner, 1943). The average values of H0 and D0 are: H0 = (8028 3) nt D0 = (136.04 0.01) deg Daily base lines computation After H0 and D0 reference values are found, the computation of the base lines in relation to absolute measurements and then the computation of the daily base lines for all days, can follow. The available data are the H, D and Z magnetic element variations recorded by fluxgate system (sampling rate 1 minute) and the absolute measurements recorded from November 2, 2013 to December 3, 2013.

- 3 - The base lines computation was undertaken by two different procedures. In the case of Z, assuming that the fluxgate recordings show the variations of the vertical components, the base line (BZ) was computed as the difference between the absolute measurements (Zabs) and the fluxgate measurements (z). On the other hand, in the case of H and D, the magnetic orientation of the fluxgate system axes was taken into account. Using H0 and D0 reference values, the H and D base lines were computed for each absolute measurement as: BH = Habs [(H0+x) 2 + y 2 ] 1/2 BD = Dabs D0 arctg[y/(x+ H0)] Mean daily values of the base lines were obtained for those days in which more than one absolute measurement was available. In order to have a daily base line for each magnetic element, a linear regression analysis using the least squares method has been undertaken. The results are shown in Fig. 1, where the experimental data, as well as the best fit lines are reported. Using the daily base lines, one minute values for the three field elements H, D and Z were computed as: H = [(H0+x) 2 + y 2 ] 1/2 + BH D = D0 + arctg[y/(x+ H0)] + BD Z = z + BZ To reduce the measurements to the old site subtracting the following gradient: ΔH=-1.5 nt ΔD=13.0 ΔZ=0.7 nt In Tables 2, 3, 4 all the hourly and daily averages and the total mean values for the H, D and Z elements on the entire measuring period (from November 2, 2013 to December 3, 2013) are reported; the relative plots are shown in Fig. 2. The plots of the one minute data follow in succession. Geomagnetic field trend (1987-2014) The availability of a long series of data since 1987 allows to evaluate the geomagnetic field trend. For each antarctic campaign we computed the average value of H, D, Z and F over the time period in which the absolute measurements were performed. In Fig. 19 we show these values together with the corresponding IGRF values obtained from the web site: http://www.geomag.bgs.ac.uk.

- 4 - References Azzara R., E. Bozzo, G. Caneva, A. Meloni and G. Romeo, 1989, Geomagnetic Observation results 1986-1987, National Antarctic Research Program, PNRA, 78p. Azzara R., E. Bozzo, G. Caneva, A. Meloni and G. Romeo, 1990, Geomagnetic Observation results 1987-1988, National Antarctic Research Program, PNRA, 80p. Azzara R., E. Bozzo, G. Caneva, A. Meloni and G. Romeo, 1991, Geomagnetic Observation results 1988-1989, National Antarctic Research Program, PNRA, 52p. Baskaradas J. A., L. Cafarella, M. Di Persio, S. Lepidi, M. Pietrolungo and L. Santarelli, 2012, Geomagnetic Observation results 2010-2011, National Antarctic Research Program, PNRA, 26p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Benedetti G., L. Cafarella, G. Dominici, S. Lepidi, M. Pietrolungo, L. Santarelli and A. Zirizzotti, 2015, Geomagnetic Observation results 2011-2012, National Antarctic Research Program, PNRA, 57p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Benedetti G., L. Cafarella, G. Dominici, S. Lepidi, M. Pietrolungo, L. Santarelli and A. Zirizzotti, 2015, Geomagnetic Observation results 2012-2013, National Antarctic Research Program, PNRA, 34p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Bozzo E., L. Cafarella, G. Caneva, C. Falcone, A. Meloni, P. Palangio and A. Zirizzotti, 1995, Geomagnetic Observation results 1991-1992/1992-1993, National Antarctic Research Program, PNRA, 54p. Bozzo E., L. Cafarella, G. Caneva, A. Meloni, P. Palangio and A. Zirizzotti, 1996, Geomagnetic Observation results 1993-1994, National Antarctic Research Program, PNRA, 71p. Bozzo E., G. Caneva, A. Meloni, P. Palangio, B. Palombo, L. Perrone and G. Romeo, 1992, Geomagnetic Observation results 1989-1990, National Antarctic Research Program, PNRA, 79p. Bozzo E., G. Caneva, A. Meloni, P. Palangio, L. Perrone and G. Romeo, 1994, Geomagnetic Observation results 1990-1991, Terra Nova Bay - Antarctica, Terra Antarctica, Vol. 1, 185-217. Cafarella L., M. Chiappini, A. Meloni and P. Palangio, 1997, Geomagnetic Observation results 1994-1995, National Antarctic Research Program, PNRA, 58p. Cafarella L., D. Di Mauro, S. Lepidi, L. Magno, A. Meloni, P. Palangio, L. Santarelli and A.Zirizzotti, 2007, Geomagnetic Observation results 2001-2002 / 2002-2003, National Antarctic Research Program, PNRA, 66p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Cafarella L., D. Di Mauro, S. Lepidi, L. Magno, A. Meloni, P. Palangio, L. Santarelli and A.Zirizzotti, 2007, Geomagnetic Observation results 2003-2004 / 2004-2005, National Antarctic Research Program, PNRA, 36p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Cafarella L., D. Di Mauro, S. Lepidi, A. Meloni, P. Palangio, L. Santarelli and A. Zirizzotti, 2004, Geomagnetic Observation results 2000-2001, National Antarctic Research Program, PNRA, 39p. Cafarella L., S. Lepidi, A. Meloni and P. Palangio, 1998, Geomagnetic Observation results 1995-1996, National Antarctic Research Program, PNRA, 55p. Cafarella L., S. Lepidi, A. Meloni and P. Palangio, 1998, Geomagnetic Observation results 1996-1997, National Antarctic Research Program, PNRA, 56p.

- 5 - Cafarella L., S. Lepidi, A. Meloni, P. Palangio, M. Pietrolungo and L. Santarelli, 2011, Geomagnetic Observation results 2007-2008, National Antarctic Research Program, PNRA, 23p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Cafarella L., S. Lepidi, A. Meloni, P. Palangio, M. Pietrolungo and L. Santarelli, 2011, Geomagnetic Observation results 2008-2009, National Antarctic Research Program, PNRA, 27p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Cafarella L., S. Lepidi, A. Meloni, P. Palangio, M. Pietrolungo, L. Santarelli and J. A. Baskaradas, 2011, Geomagnetic Observation results 2009-2010, National Antarctic Research Program, PNRA, 25p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Cafarella L., S. Lepidi, A. Meloni, P. Palangio, M. Pietrolungo, L. Santarelli and A. Zirizzotti, 2008, Geomagnetic Observation results 2005-2006, National Antarctic Research Program, PNRA, 54p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Cafarella L., S. Lepidi, A. Meloni, P. Palangio, M. Pietrolungo, L. Santarelli and A. Zirizzotti, 2008, Geomagnetic Observation results 2006-2007, National Antarctic Research Program, PNRA, 31p. http://roma2.rm.ingv.it/it/risorse/banche_dati/32/dati_osservatorio_di_stazione_mario_zucchelli/46/ annuari Cafarella L., S. Lepidi, A. Meloni, P. Palangio and L. Santarelli, 2002, Geomagnetic Observation results 1998-1999, National Antarctic Research Program, PNRA, 61p. Parkinson, W. D., 1983. Introduction to Geomagnetism. Scottish Academic Press. Edinburgh, London, 433 pp. Wienert, K. A., 1970. Notes on Geomagnetic Observatory and survey practice, Unesco, Parigi. Worthing, A. G., Jeffner J., 1943. Treatment of experimental data, John Wiley, New York.

- 6 - Table captions Table 1: Absolute measurement values 2013/2014 Table 2: Horizontal intensity hourly and daily means (from November 2 to December 3, 2013) Table 3: Declination hourly and daily means (from November 2 to December 3, 2013) Table 4: Vertical intensity hourly and daily means (from November 2 to December 3, 2013)

- 7 - Figure Captions Fig 1: Scatter plot and linear regression for daily H, D and Z 1 base lines. Fig 2: Hourly means of the H, D and Z 1 elements during the whole campaign. Fig. 3 18: Daily plots of the one minute values of the H, D and Z 1 elements. Fig. 19: Geomagnetic field trend since 1987. 1 Z values must be considered negative

- 8 - TNB Geomagnetic Observatory Mean values (-) Campaign H(nT) D(deg min) Z(nT) F(nT) 1986/1987 7391 136 49 64494 64916 1987/1988 7432 136 54 64452 64879 1988/1989 7444 136 40 64355 64784 1989/1990 7509 136 48 64325 64762 1990/1991 7522 136 45 64254 64693 1991/1992 7564 136 29 64228 64672 1992/1993 7582 136 40 64166 64612 1993/1994 7610 136 41 64148 64598 1994/1995 7643 136 46 64112 64566 1995/1996 7682 136 29 64062 64521 1996/1997 7716 136 33 64018 64481 1997/1998 7756 136 27 63979 64447 1998/1999 7789 136 24 63932 64405 1999/2000 7829 136 14 63886 64364 2000/2001 7861 136 18 63848 64330 2001/2002 7889 136 02 63794 64280 2002/2003 7916 58 63761 64251 2003/2004 7929 48 63729 64220 2004/2005 7976 47 63697 64194 2005/2006 8002 40 63624 64125 2006/2007 8027 44 63587 64092 2007/2008 8062 38 63521 64031 2008/2009 8102 20 63467 63981 2009/2010 8136 14 63417 63936 2010/2011 8181 09 63370 63897 2011/2012 8231 134 41 63306 63840 2012/2013 8264 134 42 63292 63828 2013/2014 8316 134 27 63235 63779

- 9 - Table 1 TNB Geomagnetic Observatory Absolute measurements 2013/2014 D (+) I (-) (+) (+) (-) date beg end D beg end I F H Z julian day (UT) (deg min) (UT) (deg min) (nt) (nt) (nt) 306 02:40 02:44 134 41.0 02:47 02:52 82 28.0 63710 8346 63161 306 02:58 03:02 134 46.0 03:04 03:08 82 27.0 63725 8365 63174 306 05:37 05:41 134 42.0 05:43 05:47 82 26.0 63765 8395 63210 306 05:52 05:56 134 37.0 05:58 06:01 82 25.0 63769 8398 63214 306 20:10 20:13 134 15.0 20:15 20:18 82 32.0 63821 8291 63280 306 20:30 20:33 54.0 20:35 20:39 82 31.0 63784 8290 63243 306 20:42 20:46 52.0 20:48 20:51 82 32.0 63781 8288 63240 306 21:01 21:04 52.0 21:06 21:09 82 31.0 63745 8298 63203 307 23:18 23:21 134 43.0 23:23 23:27 82 30.0 63726 8301 63183 307 23:32 23:35 134 31.0 23:37 23:40 82 30.0 63722 8313 63178 307 23:44 23:47 134 31.0 23:49 23:53 82 30.0 63720 8317 63174 309 02:56 02:59 03.0 03:01 03:05 82 28.0 63679 8339 63130 309 03:09 03:12 05.0 03:14 03:18 82 27.0 63703 8366 63152 309 03:23 03:26 05.0 03:28 03:33 82 26.0 63713 8387 63159 309 03:40 03:43 05.0 03:45 03:49 82 26.0 63710 8389 63155 310 05:53 05:56 134 28.0 05:58 06:02 82 29.0 63787 8335 63240 310 06:05 06:08 134 25.0 06:10 06:13 82 29.0 63787 8337 63240 310 06:15 06:19 134 27.0 06:21 06:24 82 29.0 63787 8340 63240 310 06:28 06:31 134 30.0 06:33 06:36 82 29.0 63789 8341 63241 311 04:43 04:46 14.0 04:48 04:51 82 24.0 63780 8418 63222 311 04:57 05:00 05.0 05:02 05:05 82 23.0 63784 8438 63223 311 05:11 05:15 134 57.0 05:17 05:21 82 21.0 63807 8478 63242 311 05:25 05:28 134 42.0 05:30 05:33 82 20.0 63820 8512 63249 312 05:17 05:20 134 18.0 05:22 05:26 82 25.0 63759 8408 63202 312 05:29 05:32 134 16.0 05:34 05:37 82 25.0 63762 8406 63205 312 05:39 05:42 134 18.0 05:44 05:48 82 26.0 63755 8392 312 05:51 05:54 134 21.0 05:56 05:59 82 26.0 63752 8393 63197 313 05:40 05:42 06.0 05:44 05:47 82 15.0 63777 8598 63195 313 05:51 05:53 134 39.0 05:55 05:58 82 17.0 63751 8551 63175 313 06:01 06:03 134 40.0 06:05 06:08 82 19.0 63756 8522 63184 313 06:15 06:17 134 52.0 06:19 06:23 82 19.0 63767 8521 63195 314 05:27 05:30 134 37.0 05:32 05:35 82 28.0 63786 8361 63236 314 05:38 05:42 134 34.0 05:44 05:47 82 28.0 63789 8354 63239 314 05:50 05:53 134 31.0 05:55 05:59 82 28.0 63787 8353 63238 314 06:01 06:04 134 20.0 06:06 06:09 82 28.0 63786 8354 63236 315 07:26 07:29 134 23.0 07:31 07:34 82 22.0 63820 8476 63254 315 07:37 07:40 134 19.0 07:42 07:45 82 23.0 63810 8456 63247 316 05:10 05:12 134 31.0 05:14 05:17 82 27.0 63762 8366 63210 316 05:21 05:24 134 36.0 05:26 05:29 82 28.0 63747 8357 63197 316 05:32 05:35 134 32.0 05:37 05:41 82 27.0 63751 8360 316 05:44 05:47 134 33.0 05:49 05:52 82 27.0 63755 8362 63205 318 04:28 04:31 134 25.0 04:33 04:36 82 28.0 63773 8350 63224 318 04:40 04:43 134 23.0 04:45 04:49 82 28.0 63775 8354 63225 318 05:14 05:17 134 20.0 05:19 05:22 82 28.0 63786 8349 63238 318 05:28 05:31 134 17.0 05:33 05:36 82 29.0 63781 8338 63234 318 04:38 04:40 134 37.0 04:42 04:45 82 20.0 63775 8499 63207 319 05:21 05:24 134 29.0 05:25 05:29 82 23.0 63730 8439 63169 319 05:31 05:33 134 27.0 05:35 05:38 82 23.0 63733 8436 63172

- 10-319 05:41 05:44 134 34.0 05:46 05:50 82 23.0 63741 8447 63179 320 05:19 05:21 134 11.0 05:23 05:27 82 24.0 63749 8422 63190 320 05:29 05:32 134 02.0 05:34 05:37 82 25.0 63742 8399 63187 320 05:39 05:41 134 06.0 05:43 05:46 82 26.0 63741 8391 63186 320 05:48 05:50 134 05.0 05:52 05:55 82 27.0 63743 8374 63190 321 05:25 05:27 134 23.0 05:29 05:32 82 25.0 63747 8408 63190 321 05:35 05:37 134 31.0 05:39 05:42 82 25.0 63746 8408 63190 321 05:45 05:47 134 34.0 05:49 05:52 82 25.0 63746 8405 63189 322 06:10 06:12 134 23.0 06:14 06:16 82 24.0 63782 8424 63223 322 06:18 06:20 134 21.0 06:22 06:25 82 25.0 63779 8415 63221 322 06:26 06:29 134 17.0 06:30 06:33 82 25.0 63773 8405 63216 322 06:34 06:37 134 18.0 06:39 06:42 82 25.0 63769 8401 63213 323 05:09 05:12 134 16.0 05:14 05:17 82 27.0 63759 8371 63207 323 05:19 05:21 134 15.0 05:23 05:26 82 27.0 63762 8367 63210 323 05:27 05:29 134 15.0 05:31 05:33 82 28.0 63759 8359 63209 323 05:37 05:39 134 21.0 05:41 05:43 82 28.0 63758 8349 63209 324 05:34 05:37 134 16.0 05:39 05:42 82 28.0 63748 8350 63199 324 05:47 05:50 134 07.0 05:52 05:54 82 27.0 63758 8367 63207 324 05:57 05:59 134 01.0 06:01 06:04 82 27.0 63738 8372 63185 324 06:07 06:09 59.0 06:11 06:14 82 25.0 63741 8398 63185 325 05:12 05:14 134 22.0 05:16 05:19 82 27.0 63749 8365 63198 325 05:20 05:23 134 21.0 05:25 05:27 82 27.0 63756 8369 63204 325 05:29 05:31 134 16.0 05:33 05:35 82 27.0 63756 8367 63205 325 05:37 05:39 134 12.0 05:41 05:43 82 27.0 63756 8360 63205 326 03:53 03:55 134 12.0 03:57 04:00 82 27.0 63724 8362 63173 326 04:01 04:03 134 13.0 04:05 04:07 82 27.0 63739 8370 63187 326 04:09 04:11 134 11.0 04:13 04:16 82 27.0 63747 8363 63196 326 04:18 04:20 134 07.0 04:21 04:24 82 27.0 63746 8358 63196 328 20:11 20:13 134 37.0 20:15 20:18 82 32.0 63785 8287 63244 328 20:21 20:23 134 26.0 20:25 20:28 82 33.0 63814 8270 63276 328 20:30 20:32 134 16.0 20:34 20:37 82 33.0 63803 8268 63265 328 20:39 20:41 134 23.0 20:43 20:46 82 33.0 63792 8269 63254 330 03:41 03:44 134 32.0 03:45 03:48 82 29.0 63758 8339 63211 330 03:51 03:54 134 33.0 03:56 03:58 82 28.0 63756 8344 63208 330 04:00 04:03 134 31.0 04:04 04:07 82 28.0 63752 8343 63203 330 04:09 04:11 134 32.0 04:13 04:16 82 28.0 63752 8346 63203 331 05:18 05:21 134 21.0 05:23 05:26 82 28.0 63784 8344 63235 331 05:28 05:30 134 19.0 05:32 05:35 82 28.0 63791 8346 63243 331 05:37 05:39 134 18.0 05:41 05:44 82 29.0 63785 8336 63238 331 05:47 05:49 134 21.0 05:51 05:54 82 29.0 63788 8334 63241 332 03:23 03:25 134 15.0 03:27 03:30 82 26.0 63776 8384 63222 332 03:32 03:34 134 15.0 03:36 03:38 82 28.0 63776 8359 63226 332 03:40 03:42 134 14.0 03:44 03:47 82 28.0 63774 8347 63225 332 03:49 03:51 134 11.0 03:53 03:56 82 29.0 63775 8341 63228 333 03:46 03:49 01.0 03:51 03:53 82 26.0 63702 8377 63149 333 03:56 03:58 01.0 04:00 04:04 82 26.0 63706 8378 63153 333 04:07 04:09 02.0 04:11 04:14 82 25.0 63714 8392 63159 333 04:16 04:18 05.0 04:20 04:22 82 26.0 63697 8387 63142 334 04:07 04:10 134 56.0 04:12 04:15 82 29.0 63797 8332 63251 334 04:17 04:19 134 48.0 04:21 04:24 82 29.0 63798 8335 63251 334 04:27 04:29 134 45.0 04:31 04:34 82 28.0 63797 8351 63248 334 04:36 04:39 134 54.0 04:40 04:43 82 28.0 63797 8356 63247 336 03:55 03:57 134 26.0 03:59 04:02 82 27.0 63778 8373 63226 336 04:05 04:07 134 24.0 04:09 04:11 82 27.0 63763 8366 63212 336 04:13 04:15 134 14.0 04:17 04:19 82 27.0 63776 8376 63223 336 04:21 04:23 134 13.0 04:24 04:26 82 27.0 63772 8365 63221 337 03:58 04:00 05.0 04:02 04:05 82 28.0 63759 8358 63208 337 04:07 04:09 01.0 04:11 04:14 82 28.0 63755 8344 63207 337 04:16 04:18 07.0 04:19 04:22 82 28.0 63748 8341 337 04:24 04:27 06.0 04:28 04:31 82 27.0 63755 8359 63205

- 11 - Table 2 TNB Antarctica, Italian Geomagnetic Observatory Hourly H values (nt) from Nov 2 to Dec 3, 2013 UT 0 1 2 3 4 5 6 7 8 9 10 11 DAILY MEAN 12 13 14 15 16 17 18 19 20 21 22 23 julian day 306 8312 8335 8345 8377 8386 8407 8388 8366 8344 8326 8316 8311 8304 8295 8296 8306 8292 8293 8293 8289 8311 8226 8274 8321 307 8298 8306 8348 8369 8400 8437 8455 8388 8352 8332 8306 8283 8296 8302 8293 8292 8299 8272 8278 8232 8212 8281 8318 308 8319 8342 8351 8342 8340 8369 8406 8357 8343 8332 8349 8320 8308 8306 8304 8262 8227 8233 8212 8220 8254 8289 8272 8279 8306 309 8328 8353 8326 8375 8391 8390 8374 8354 8353 8350 8336 8330 8311 8303 8285 8276 8260 8257 8271 8241 8228 8278 8263 8278 8313 310 8297 8321 8319 8344 8349 8347 8341 8365 8350 8319 8303 8287 8304 8294 8294 8299 8280 8265 8240 8239 8197 8204 8234 8249 8292 311 8290 8331 8341 8344 8383 8514 8487 8424 8425 8394 8370 8286 8276 8263 8269 8305 8308 8317 8341 8312 8299 8278 8258 8263 8337 312 8303 8297 8361 8392 8409 8404 8396 8344 8316 8321 8312 8301 8302 8301 8295 8309 8291 8295 8303 8316 8313 8282 8262 8290 8321 313 8363 8388 8422 8471 8542 8614 8533 8501 8462 8421 8369 8319 8280 8248 8244 8232 8234 8230 8269 8306 8269 8307 8263 8255 8356 314 8284 8278 8335 8312 8342 8362 8345 8360 8391 8360 8378 8305 8278 8296 8287 8263 8250 8217 8238 8197 8170 8075 8117 8176 8276 315 8181 8265 8321 8382 8516 8559 8527 8469 8407 8375 8391 8358 8311 8298 8234 8231 8242 8204 8204 8376 8311 8323 8311 8323 8338 316 8357 8437 8451 8432 8374 8362 8343 8330 8340 8304 8298 8325 8291 8284 8280 8296 8292 8293 8278 8303 8296 8295 8280 8294 8326 317 8308 8320 9999 8361 8374 8390 8405 8384 8359 8344 8344 8318 8327 8283 8274 8251 8244 8236 8229 8296 8301 8287 8294 8314 318 8320 8340 8349 8353 8352 8345 8337 8343 8351 8346 8333 8322 8308 8288 8290 8292 8290 8239 8292 8272 8289 8275 8266 8262 8311 319 8261 8319 8349 8400 8494 8448 8425 8407 8405 8392 8361 8342 8311 8281 8273 8248 8241 8233 8244 8232 8191 8183 8099 8145 8304 320 8161 8210 8325 8386 8413 8407 8337 8349 8369 8357 8317 8353 8261 8265 8286 8294 8319 8340 8368 8298 8227 8237 8415 8318 321 8405 8344 8388 8384 8384 8403 8435 8441 8391 8344 8353 8316 8317 8295 8280 8285 8287 8297 8284 8281 8254 8268 8293 8288 8334 322 8333 8357 8372 8367 8364 8376 8413 8404 8380 8349 8313 8312 8316 8307 8303 8286 8296 8298 8289 8310 8288 8291 8301 8302 8330 323 8313 8319 8340 8364 8385 8359 8358 8343 8324 8309 8317 8316 8312 8311 8295 8279 8295 8239 8243 8259 8291 8280 8304 8295 8310 324 8289 8336 8377 8373 8405 8381 8388 8384 8404 8384 8359 8350 8303 8285 8294 8295 8303 8316 8320 8305 8309 8293 8280 8304 8335 325 8335 8361 8375 8354 8358 8365 8366 8341 8329 8313 8306 8317 8319 8305 8285 8284 8287 8295 8306 8311 8288 8297 8274 8291 8319 326 8279 8326 8355 8367 8363 8358 8355 8338 8325 8294 8297 8312 8308 8305 8302 8291 8293 8286 8231 8247 8252 8298 8319 8335 8310 327 8338 8336 8346 8373 8440 8446 8427 8453 8430 8399 8357 8344 8310 8293 8284 8281 8283 8281 8278 8328 8283 8289 8294 8319 8342 328 8331 8351 8371 8351 8335 8340 8362 8354 8335 8327 8345 8323 8320 8298 8312 8311 8323 8314 8289 8285 8275 8298 8324 8315 8325 329 8336 8332 8346 8360 8351 8352 8353 8356 8345 8324 8329 8333 8333 8314 8297 8290 8292 8289 8283 8297 8319 8308 8306 8318 8323 330 8327 8341 8337 8343 8354 8356 8345 8330 8323 8323 8322 8308 8304 8302 8288 8310 8295 8276 8267 8242 8259 8295 8318 8311 331 8338 8351 8359 8346 8355 8344 8341 8324 8316 8307 8299 8306 8297 8297 8290 8291 8294 8309 8316 8327 8305 8302 8306 8320 8318 332 8341 8352 8362 8367 8350 8355 8351 8335 8323 8321 8324 8326 8301 8299 8296 8263 8260 8228 8203 8203 8194 8226 8252 8272 8296

- 12-333 8291 8314 8330 8373 8386 8378 8382 8400 8386 8341 8347 8314 8292 8266 8285 8260 8224 8244 8211 8176 8162 8285 8291 8283 8301 334 8271 8301 8284 8306 8342 8373 8410 8406 8393 8368 8347 8313 8254 8268 8274 8207 8205 8190 8212 8208 8186 8105 8092 8160 8270 335 8245 8296 8269 8343 8412 8372 8473 8464 8390 8321 8285 8257 8284 8291 8281 8290 8277 8287 8325 8328 8314 8290 8269 8251 8317 336 8275 8338 8357 8372 8362 8336 8339 8355 8326 8338 8294 8279 8289 8280 8285 8279 8268 8228 8234 8227 8245 8272 8278 8304 8298 337 8325 8326 8328 8337 8353 8351 8346 8327 8364 8396 8445 8397 8351 8314 8248 8246 8252 8205 8205 8255 8284 8259 8315 8319 8315 TOTAL MEAN = 8316 nt 9999 indicates missing value

- 13 - Table 3 TNB Antarctica, Italian Geomagnetic Observatory Hourly D values from Nov 2 to Dec 3, 2013 (deg:first three digit, minutes: second two digits) UT 0 1 2 3 4 5 6 7 8 9 10 11 DAILY MEAN 12 13 14 15 16 17 18 19 20 21 22 23 julian day 306 13447 13468 13465 13473 13463 13471 13453 13431 13425 13426 13423 13428 13432 13438 13442 13424 13419 13428 13421 13421 97 13406 13494 13488 13441 307 13472 08 22 22 04 13454 13447 13447 13435 13439 13441 13434 13445 13450 13451 13454 13441 13438 13416 85 13438 13455 13448 13461 13454 308 13449 13442 13461 13483 13488 13480 13472 13436 13448 13438 13424 13415 13436 13448 13425 13404 13409 95 13422 13427 99 96 13420 13459 13436 309 13498 00 19 06 13483 13442 13419 13426 13431 13443 13434 13430 13434 13437 13446 13447 13457 13452 13451 13452 13476 13488 03 19 13462 310 13497 08 13476 13444 13438 13450 13450 13443 13442 13437 13439 13440 13439 13446 13445 13428 13448 13434 13456 13470 13498 10 14 13410 13460 311 35 11 54 32 22 13457 13453 13432 99 89 57 17 94 13465 13471 13438 13423 13420 13402 93 98 13449 13463 13477 13444 312 13487 13471 13447 13440 13440 13434 13414 13403 13427 13435 13438 13443 13442 13438 13437 13422 13433 13436 13435 13463 13488 13490 13498 13446 13446 313 10 13410 13478 13475 02 20 13466 13422 84 70 80 65 75 13454 13453 13488 13469 13488 13498 13476 13494 13450 13493 13494 13450 314 18 34 33 13489 13485 13459 13435 13433 99 68 88 13418 13437 13440 13440 13453 13414 13450 13474 13453 13453 13499 37 66 13462 315 83 39 64 13600 90 24 13470 13431 71 63 70 85 13408 13435 13407 13429 13443 13467 02 13445 13459 13403 13426 91 13459 316 83 61 74 13424 13452 13458 13470 13459 13458 13453 13446 13444 13452 13453 13458 13452 13448 13447 13458 13465 13484 13488 13499 13486 13449 317 13459 13479 99999 13471 13492 13486 13474 13458 13448 13434 13427 13432 13417 13418 13436 13443 13458 13442 13452 13474 13473 13483 13493 13457 13456 318 13430 13431 13441 13438 13442 13430 13438 13446 13432 13427 13426 13437 13435 13442 13444 13434 13421 13452 10 13402 93 13407 13432 13458 13431 319 13476 13481 13497 13479 13463 13451 13433 13434 13420 13416 13401 13405 13409 13436 13426 13411 13411 95 13429 13426 13443 13441 01 12 13441 320 43 69 51 13485 13442 13416 13407 13410 13407 89 78 66 13413 13425 13423 98 13403 90 81 13434 13491 13478 04 51 13431 321 85 13424 13484 13435 13438 13440 13408 13422 13408 13403 13420 96 13417 13434 13450 13450 13443 13428 13440 13427 13429 13417 13463 07 13432 322 13479 13466 13488 13451 13444 13440 13439 13437 13408 13407 13411 13422 13423 13422 13424 13440 13419 13425 13449 13450 13480 13482 13471 13480 13444 323 13465 13440 13430 13428 13433 13431 13432 13429 13429 13430 13433 13439 13439 13422 13431 13445 13401 13408 79 64 38 48 88 13473 13419 324 13460 13486 04 13428 13434 13419 13402 13423 13421 93 10 13406 13412 13410 13432 13439 13420 91 97 13418 13437 13467 13478 13437 13430 325 13437 13429 13431 13444 13449 13432 13423 13428 13436 13439 13434 13433 13429 13440 13450 13450 13445 13441 13405 13402 13407 82 71 13409 13427 326 13470 13447 13419 13414 13419 13449 13461 13451 13444 13438 13435 13440 13441 13442 13440 13437 13427 13433 13457 13452 13436 58 98 13442 13435 327 13468 13478 11 13490 13434 13402 80 99 13423 82 71 59 13406 13402 13414 13426 13433 87 94 13425 22 07 13485 13456 13431 328 13447 13444 13449 13470 13498 13476 13448 13423 13437 13438 13420 13406 13428 13447 13439 13423 13404 13411 13410 13454 13443 13409 13406 13418 13435 329 13405 13455 13465 13456 13446 13442 13413 13409 13407 13418 13428 13430 13427 13428 13429 13433 13430 13431 13429 13424 13436 13469 13439 13408 13432 330 13412 13425 13426 13451 13459 13454 13435 13431 13435 13436 13436 13435 13440 13444 13440 13447 13422 13436 13437 13468 13494 02 13478 13461 13446

- 14-331 13442 13445 13458 13445 13448 13435 13437 13434 13442 13435 13434 13439 13445 13444 13446 13447 13428 13420 13432 13445 13478 13493 13486 13448 13446 332 13439 13437 13427 13424 13439 13406 13414 13420 13426 13428 13430 13428 13437 13440 13441 13446 13458 13450 13481 02 09 32 27 31 13453 333 40 10 06 09 10 13497 13458 13429 13416 90 13405 13411 13426 13438 13419 13431 13473 92 13416 13438 13489 11 13 34 13461 334 28 22 13484 13410 13486 13479 13453 13458 13450 13445 13437 13429 13438 13447 13441 13445 13460 13490 13446 20 88 59 83 63 13485 335 84 81 13602 58 30 24 13471 13481 13476 13447 13453 13446 13447 13443 13440 13420 13436 13430 13429 13467 13410 23 13473 13410 13486 336 13468 61 13417 13431 13422 13427 13440 13446 13454 13452 13459 13456 13456 13465 13454 13457 13461 13470 13472 13486 13491 13497 06 13498 13456 337 08 30 51 44 07 13459 13427 13415 13437 13433 93 94 81 84 81 88 13404 13440 13457 13418 13468 13466 13417 13449 13444 TOTAL MEAN = 134 27 99999 indicates missing value

- 15 - Table 4 TNB Antarctica, Italian Geomagnetic Observatory Hourly Z values (nt) from Nov 2 to Dec 3, 2013 (values must be considered negative) UT 0 1 2 3 4 5 6 7 8 9 10 11 DAILY MEAN 12 13 14 15 16 17 18 19 20 21 22 23 julian day 306 63126 63145 63164 63188 63207 63215 63222 63234 63241 63246 63256 63265 63268 63268 63269 63278 63256 63251 63266 63284 63264 63183 63189 63150 63226 307 63156 63150 63150 63140 63155 63209 63233 63237 63246 63254 63267 63268 63262 63276 63267 63268 63273 63273 63273 63228 63209 63192 63199 63190 63224 308 63190 63188 63197 63187 63207 63224 63234 63242 63253 63261 63266 63277 63295 63302 63310 63315 63291 63312 63285 63224 63188 63126 63090 63074 63231 309 63100 63116 63110 63151 63186 63211 63225 63230 63238 63259 63272 63279 63293 63303 63292 63300 63284 63275 63246 63234 63204 63217 63169 63197 63225 310 63219 63213 63214 63230 63232 63240 63251 63260 63264 63272 63264 63254 63261 63259 63274 63281 63288 63258 63212 63226 63231 63215 63219 63245 311 63224 63197 63169 63201 63218 63253 63242 63254 63271 63281 63309 63340 63361 63326 63293 63282 63247 63231 63231 63187 63136 63 63100 63078 63232 312 63103 63124 63124 63163 63188 63197 63212 63217 63221 63236 63256 63263 63265 63273 63273 63275 63237 63251 63247 63218 63262 63270 63253 63229 63223 313 63162 63138 63117 63134 63147 63166 63202 63232 63260 63280 63288 63312 63338 63353 63335 63328 63311 63291 63184 63218 63241 63290 63304 63226 63244 314 63193 63161 63184 63206 63231 63228 63242 63258 63262 63277 63319 63297 63294 63317 63302 63305 63298 63314 63286 63234 63145 63191 63281 63165 63250 315 63124 63176 63167 63187 63205 63219 63236 63249 63276 63296 63328 63337 63346 63341 63315 63298 63330 63337 63310 63282 63328 63276 63279 63235 63270 316 63165 63081 63074 63123 63190 63204 63222 63246 63260 63271 63274 63274 63268 63276 63284 63269 63269 63258 63254 63236 63233 63247 63251 63211 63227 317 63227 63204 99999 63197 63212 63223 63233 63243 63253 63267 63279 63282 63296 63301 63339 63342 63351 63330 63301 63261 63249 63260 63248 63243 63269 318 63215 63198 63209 63220 63222 63229 63234 63243 63251 63254 63269 63284 63286 63292 63290 63289 63278 63280 63257 63236 63211 63193 63143 63140 63238 319 63146 63130 63120 63138 63165 63167 63193 63217 63233 63237 63250 63256 63272 63293 63323 63333 63270 63258 63236 63208 63172 63138 63175 63168 63213 320 63130 63115 63130 63157 63174 63185 63207 63217 63202 63227 63230 63259 63253 63242 63237 63221 63181 63165 63168 63158 63237 63213 63229 63167 63199 321 63156 63166 63128 63159 63171 63189 63221 63236 63261 63262 63247 63268 63269 63278 63292 63274 63268 63272 63269 63248 63237 63178 63193 63207 63227 322 63187 63158 63128 63148 63181 63217 63217 63226 63243 63243 63238 63237 63244 63261 63294 63302 63290 63260 63253 63255 63207 63201 63203 63197 63225 323 63177 63190 63219 63221 63206 63208 63224 63229 63232 63240 63258 63262 63269 63255 63265 63276 63296 63292 63213 63184 63150 63120 63153 63153 63221 324 63051 63073 63090 63117 63151 63193 63194 63203 63231 63250 63254 63258 63268 63265 63297 63291 63291 63276 63270 63270 63264 63244 63196 63175 63216 325 63178 63157 63160 63189 63195 63201 63210 63221 63238 63248 63258 63250 63250 63266 63260 63261 63269 63274 63292 63272 63249 63242 63145 63109 63225 326 63 63119 63138 63163 63198 63224 63248 63255 63268 63264 63255 63248 63256 63255 63266 63272 63266 63267 63253 63230 63237 63233 63248 63184 63229 327 63142 63158 63156 63144 63177 63175 63176 63187 63225 63260 63274 63308 63285 63279 63251 63238 63228 63248 63234 63203 63234 63214 63227 63215 63218 328 63205 63216 63183 63173 63215 63242 63252 63246 63243 63258 63246 63242 63267 63269 63279 63293 63288 63277 63305 63271 63261 63249 63244 63180 63246

- 16-329 63143 63132 63120 63161 63171 63186 63209 63213 63221 63227 63225 63234 63246 63252 63269 63284 63293 63289 63292 63273 63250 63218 63212 63199 63222 330 63166 63165 63185 63201 63203 63217 63233 63238 63243 63253 63254 63248 63256 63255 63263 63258 63253 63271 63257 63230 63162 63187 63208 63210 63226 331 63209 63207 63197 63213 63223 63236 63246 63248 63249 63253 63243 63240 63251 63253 63257 63260 63242 63230 63222 63246 63257 63244 63235 63224 63237 332 63223 63218 63214 63213 63248 63248 63228 63224 63225 63237 63254 63253 63263 63257 63281 63289 63288 63321 63263 63215 63230 63219 63205 63242 333 63213 63233 63227 63178 63164 63213 63238 63239 63235 63244 63256 63280 63293 63291 63296 63316 63306 63260 63220 63229 63204 63219 63146 63146 63235 334 63174 63195 63186 63239 63248 63257 63274 63265 63283 63299 63306 63305 63291 63291 63344 63396 63379 63312 63265 63331 63228 63284 63199 63290 63277 335 63253 63182 63151 63172 63198 63238 63295 63280 63277 63306 63309 63287 63244 63267 63265 63254 63235 63216 63213 63221 63238 63254 63329 63250 63247 336 63199 63194 63191 63224 63226 63228 63223 63247 63255 63264 63268 63270 63277 63283 63287 63300 63304 63289 63245 63199 63184 63158 63177 63168 63236 337 63149 63159 63176 63198 63204 63218 63239 63243 63240 63252 63325 63352 63376 63366 63344 63407 63383 63379 63355 63208 63249 63215 63174 63 63265 TOTAL MEAN = 63235 nt 99999 indicates missing value

6.368 x 104 Mario Zucchelli Station Z, H and D base lines 2013/2014 BaseZ (nt)= 0.2156 * dd + 63633.9398 6.366 6.364 6.362 6.36 6.358 BaseZ (nt) 6.356 6.354 60 55 50 45 40 35 30 25 BaseH (nt)= 0.1633 * dd + 7.3001 40 20 0 20 BaseH (nt) 40 60 55 50 45 40 35 30 25 BaseD (deg)= 3.9548e 005 * dd + 0.0024098 0.2 0.1 0 0.1 0.2 BaseD (deg) 60 55 50 45 40 35 30 25 Fig. 1 Days(dd)

TNB hourly means 2013/2014 63500 63300 63100 Z (nt) 02/11/13 07/11/13 12/11/13 17/11/13 22/11/13 27/11/13 03/12/13 8600 8400 8200 H (nt) 02/11/13 07/11/13 12/11/13 17/11/13 22/11/13 27/11/13 03/12/13 136 134 D (deg) 02/11/13 07/11/13 12/11/13 17/11/13 22/11/13 27/11/13 03/12/13 Fig. 2 Days

Fig. 3 18 8700 Hours [UT], nov 2 2013 8700 Hours [UT], nov 3 2013

8700 Hours [UT], nov 4 2013 8700 Hours [UT], nov 5 2013

8700 Hours [UT], nov 6 2013 8700 Hours [UT], nov 7 2013

8700 Hours [UT], nov 8 2013 8700 Hours [UT], nov 9 2013

8700 Hours [UT], nov 10 2013 8700 Hours [UT], nov 11 2013

8700 Hours [UT], nov 12 2013 8700 Hours [UT], nov 13 2013

8700 Hours [UT], nov 14 2013 8700 Hours [UT], nov 15 2013

8700 Hours [UT], nov 16 2013 8700 Hours [UT], nov 17 2013

8700 Hours [UT], nov 18 2013 8700 Hours [UT], nov 19 2013

8700 Hours [UT], nov 20 2013 8700 Hours [UT], nov 21 2013

8700 Hours [UT], nov 22 2013 8700 Hours [UT], nov 23 2013

8700 Hours [UT], nov 24 2013 8700 Hours [UT], nov 25 2013

8700 Hours [UT], nov 26 2013 8700 Hours [UT], nov 27 2013

8700 Hours [UT], nov 28 2013 8700 Hours [UT], nov 29 2013

8700 Hours [UT], nov 30 2013 8700 Hours [UT], dec 1 2013

8700 Hours [UT], dec 2 2013 8700 Hours [UT], dec 3 2013

Fig. 19 H(nT) 8400 8200 8000 7800 7600 DATA IGRF D(degrees) 138 136 DATA IGRF 7400 7200 1987 1991 1995 1999 2003 2007 2011 2015 Year 134 1987 1991 1995 1999 2003 2007 2011 2015 Year Z(nT) 63300 63500 63700 63900 64100 64300 64500 DATA IGRF 64700 1987 1991 1995 1999 2003 2007 2011 2015 Year F(nT) 65200 65000 64800 64600 64400 64200 64000 63800 DATA IGRF 63600 1987 1991 1995 1999 2003 2007 2011 2015 Year