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Norway National Report

Prepared by: Elisabeth Isaksson
email: elli (at) npolar.no

The Norwegian Polar Institute conducts glaciological research in Dronning Maud Land in close collaboration with the Institute for Marine and Atmospheric Research at Utrecht University, University of Copenhagen, LGGE, British Antarctic Survey, AWI, Centre for Isotope Research in Groningen, and Stockholm University. Since 1996 the activities have been related to the EPICA programme. Norway was responsible for the Nordic EPICA pre-site survey 1996/97 and Sweden (with Norwegian participation) for a similar survey in 1997/98, as has previously been reported. Publications from these expeditions are listed below. In 2001/02 a traverse revisited the ground traverse made by the 1996/97 Nordic EPICA pre-site survey (Fig.1). The overall aim was to both extend the shallow firn core record obtained during the last expedition as well as investigate the spatial and temporal accumulation variability at site M on the polar plateau (75°00’ S, 15°00’ E) (Table 1). This was accomplished through the retrieval of one 160 meter deep ice core at site M as well as performing an extensive radar programme around the drill site. Based on the volcanic chronology this core covers about 2500 years.

In order to investigate the spatial variability over a relatively limited area on the polar plateau six 20 meter shallow ice cores were drilled (Fig. 2) and samples from five 2 meter snow pits were collected in the vicinity of site M. This work was part of a Ph. D thesis of Lars Karlöf.

Finally, one 100 meter deep ice core was drilled at a coastal location, S100 (7014’S, 0448’E) and this core is estimated to cover about 300 years. For all these cores DEP, ECM and sampling for δ18 O were performed in an ice laboratory in the field. In addition analysis for major ions have been done. The results from this work are still being evaluated.

Overall aims

Radar programme

The radar programme was conducted in order to obtain a semi-continuous spatial record of accumulation covering the same time interval as the shallow ice cores. The radar data will be used for the construction of old snow surfaces and these surfaces will be dated by the shallow ice cores. Further, the old snow surfaces will serve as boundary conditions for modelling of snow-drift and snow distribution.

The survey domain covered one 8 x 8 km square. Altogether about 400 km of radar surveys was made. The frequencies used were 900, 500, 200, and 50 MHz. The full domain was covered by a 500 m grid for the 900 and 500 MHz frequencies. In addition, two diagonals were surveyed beyond the domain. The diagonals followed the ice ridge and went perpendicular to it, respectively. The domain was oriented so the survey lines run perpendicular to the dominant wind direction. Around each drill site a finer grid (100 m) was surveyed. Further, the diagonals as well as a 1 km grid were covered with lower frequency antennas, 200 and 50 MHz, respectively. The radar systems used were GSSI SIR-2 (900 MHz and 200MHz) and RAMAC (500 MHz and 50MHz). A preliminary interpretation of the radar data suggests low variability of the recorded layers.

IPY

As a part of the Trans-Antarctic Scientific Traverse Expeditions – Ice Divide of East Antarctica (TASTE-IDEA), and the International Partners in Ice Coring Sciences (IPICS), two Norwegian-US traverse will be conducted during the International Polar Year 2007-8.The field expedition for this international partnership involves scientific investigations along two overland traverses in East Antarctica: one going from the Norwegian Troll Station to the United States South Pole Station in 2007-2008; and a return traverse by a different route in 2008-2009. This project will investigate climate change in East Antarctica, with the following goals:
  1. Investigate climate variability in Dronning Maud Land of East Antarctica on time scales of years to centuries.
  2. Establish spatial and temporal variability in snow accumulation over this area of Antarctica to understand its impact on sea level.
  3. Investigate the impact of atmospheric and oceanic variability on the chemical composition of firn and ice in the region.
  4. Revisit areas and sites first explored by traverses in the 1960’s, for detection of possible changes and to establish benchmark data sets for future research efforts.
For more information see http://traverse.npolar.no

ITASE related Publications from Norway

  1. Aldahan, A.A., Possnert, G., Johnsen, S.J., Clausen, H.B., Isaksson, E., Karlén, W., and Hansson, M. 1998. 60 year long 10Be records from Greenland and Antarctica. Earth and Planetary Sciences 107 (2), 139-147.
  2. Stenberg, M., Isaksson, E., Karlén, W., Hansson, M., Gundestrup, N., Mayewski, P.A.,Twickler, M., and Whitlow, S.E. 1998. Spatial and Seasonal Variability of Snow Chemistry in Western Dronning Maud Land, Antarctica. Annals of Glaciology 27, 378-384.
  3. Van den Broeke, M., Winther, J-G., Isaksson, E., Pinglot, J-F., Eiken, T., and Karlöf, L. 1999. Climate variables along a traverse line in Dronning Maud Land, East Antarctica. Journal of Glaciology 45 (150), 295-302.
  4. Isaksson, E., Van den Broeke, M., Winther, J-G., Karlöf, L., Pinglot, J-F., and Gundestrup, N. 1999. Accumulation and proxy-temperature variability in Dronning Maud Land, Antarctica, determined from shallow firn cores. Annals of Glaciology 29, 17-22.
  5. Stenberg, M., M. Hansson, P. Holmlund, L. Karlöf. 1999. Variability in snow layering and snow chemistry in the vicinity of two drill sites in western Dronning Maud Land, Antarctica. Annals of Glaciology, 29, 33-37.
  6. Holmlund, P., Gjerde, K., Gundestrup, N., Hansson, M., Isaksson, E., Karlöf, L., Nyman, M., Petterson, R., Pinglot, J.F., Reijmer, C., Stenberg, M., Thomassen, M.P.A., van der Veen, C., van de Wal, R.S.W., Wilhelms, F. and Winther, J-G. 2000. Spatial gradients in snow layering and ten metre temperatures at potential EPICA-DML drill sites. Annals of Glaciology 30, 13-19.
  7. Karlöf, L., Winther, J-G., Isaksson, E., Kohler, J., Stenberg, M., Thomassen, M.P.A., Wilhelms, F., Pinglot, J.F., Pettersson, R., v.d. Veen, C., Hansson, M., Holmlund, P., van de Wal, R.S.W. 2000. A 1500 years record of accumulation at Amundsenisen Western Dronning Maud Land, Antarctica, derived from electrical and radioactive measurements on an 120 m ice core. Journal of Geophysical Research 105 (D10), 12,471-12,483.
  8. Isaksson, E., Karlén, W., Mayewski, P., Twickler, M., and Whitlow, S. 2001. A high-altitude snow chemistry record from Amundsenisen, Dronning Maud Land, Antarctica. Journal of Glaciology, 47 (158), 489-496.
  9. Isaksson, E., and Melvold, K. 2002. Trends and patterns in the recent accumulation and proxy-temperature in coastal Dronnning Maud Land, Antarctica - interpretations from shallow ice cores. Annals of Glaciology 35, 175-180.
  10. Kaczmarska, M., Isaksson, E., Karlöf, K., Winther, J-G, Kohler, J., Godtliebsen, F., Ringstad Olsen, L., Hofstede, C M., van den Broeke, M.R., Van De Wal, R. S.W., and Gundestrup, N. 2004. Accumulation variability derived from an ice core from coastal Dronning Maud Land, Antarctica. Annals of Glaciology, 39, 339-345.
  11. Hofstede, C.M., R. S. W. van de Wal, K. Kaspers, M. R. van den Broeke, L. Karlöf, J.-G. Winther, E. Isaksson, G. Lappegard, R. Mulvaney, H. Oerter and F. Wilhelms. 2004. Firn accumulation records for the past 1000 years on the basis of dielectric profiling of six cores from Dronning Maud Land, Antarctica. Journal of Glaciology 50 (169), 279-291.
  12. Bertler, N., Mayewski, P., Aristarain, A., Barrett, P., Becagli, S., Bernardo, R. T., Bo, S., Cunde, X., Curran, M., Dahe, Q., Dixon, D., Ferron, F. A., Fischer, H., Frey, M., Frezzotti, M., Fundel, F., Genthon, C., Gragani, R., Hamilton, G., Handley, M., Hong, S., Isaksson, E., Jiancheng, K., Jiawen, R., Kamiyama, K., Kanamori, S., Kärkäs, E., Karlöf, L., Kaspari, S., Kreutz, K., Kurbatov, A., Meyerson, E., Ming, Y., Mingjun, Z., Motoyama, H., Mulvaney, R., Oerter, H., Osterberg, E., Proposito, M., Pyne, A., Ruth, U., Simoes, J. C., Smith, B., Sneed, S., Teinlä, K., Traufetter, F., Udisti, R., Virkkula, A., Watanabe, O., Williamson, B., Winther, J. -G., Yuansheng, L., Wolff, E., Zhongqin, L., Zielinski, A.(2004). Snow chemistry across Antarctica, Annals of Glaciology 41, 167-179.
  13. Karlöf, L., Isaksson, E., Winther, J-G., Gundestrup, N., Meijer, H., A.J., Mulvaney, R., Pourchet, M., Hofstede, C., Lappegard, G., Pettersson, R., van den Broeke, M., van de Wal, .R.S.W.. 2005. Accumulation variability over a small area in east Dronning Maud Land, Antarctica, as determined from shallow firn cores and snow pits: some implications for ice-core records. Journal of Glaciology 51 (174), 343-352.
  14. Kaczmarska, M., E. Isaksson, , L. Karlöf, O.Brandt, J-G., Winther, R. S.W. van de Wal, M. van den Broeke, S. J. Johnsen. 2006. Antarctic coastal climate interpreted from light transmittance in and ice core record. Antarctic Science 18 (2), 271-278. DOI:10.1017/S09544102006000319.
  15. Karlöf, L., Øigård, T. A., Godtliebsen, F., Kaczmarska, M., and Fischer, H. 2006. .Statistical techniques to select thresholds for peak signals in ice core data', To appear in Journal of Glaciology 51, (175), 655-662.
  16. Monaghan,A.J., D. H. Bromwich, R. L. Fogt, S-H. Wang, P. A. Mayewski, D. A. Dixon, A. Ekaykin, M. Frezzotti, I. Goodwin, E. Isaksson, S. D. Kaspari, V. I. Morgan, H. Oerter, T. D. Van Ommen, C. J. Van der Veen, & J. Wen.. 2006. Insignificant change in Antarctic snowfall since the International Geophysical Year. Science, 313, 827-831.
  17. Karlöf, L., Winebrenner, D.P. & Percival, D.B. 2006: How representative is a time series derived from a firn core? A study at a low-accumulation site on the Antarctic plateau. J.Geophys. Res. 111, F04001, doi:10.1029/2006JF000552.
  18. Rotschky, G., P. Holmlund., E. Isaksson, R. Mulvaney, H. Oerter, M.R. Van den Broeke, J-G., Winther. A new surface accumulation map for western Dronning Maud Land, Antarctica, from interpolation of point measurements. Accepted for Journal of Glaciology February 2007.

Reports

  1. Holmlund, P., M. Stenberg, L. Karlöf, M. Nyman, K. Gjerde, M. Thomassen..1994. Glaciological studies in East Antarctica. In Grônlund, E. ed. Cruise report from SWEDARP 1997798. Stockholm, Svenska Polarforskningssekretariatet, 37-45.
  2. Winther, J.-G., and 9 others. 1998. EPICA Dronning Maud land pre site survey 1996/97. In Report of the Norwegian Antarctic Research Expedition 1996/97 (Ed.: J-G. Winther), Meddelser No. 148.
  3. Winther, J.-G, and 10 others. 2002. European Project for Ice Coring in Antarctica (EPICA) –Nordic traverse in 2000/01(Ed.: J-G. Winther). Norsk Polarisntitutt Rapportserie 120.
  4. Karlöf, L. 2004. Temporal and spatial variability of snow accumulation and redistribution and its impact on the interpretation of the ice cores. Ph. D Thesis, University of Oslo.

Table 1. Location of NARE 2000/01 drill sites.

Drill site

Latitude

Longitude

Drilled depth (m)

Measurements
M20 75°0'S 15°0'E
19.2		 DEP,ECM, stratigraphy, δ18O
δD, major ions, radionucleids
         
MA20 74°59'S 15°6'E 20.6 DEP,ECM, stratigraphy, δ18O
δD, major ions, radionucleids
         
MB20 75°1'S 15°2'E 20.1 DEP, ECM, stratigraphy, δ18O
δD, major ions, radionucleids
         
MC20 75°0'S 14°53'E 20.2 DEP, ECM, stratigraphy, δ18O
δD, major ions, radionucleids
         
MD20 74°58'S 14°57'E 20.3 DEP, ECM, stratigraphy, δ18O
δD, major ions, radionucleids>
         
M150 75°0'S 15°0'E 160 DEP, ECM, stratigraphy, δ18O
δD, major ions, radionucleids
         
M100 70°14’S 04°48’E 100 DEP, ECM, stratigraphy, δ18O

drill locations map

Figure 1. Map over the study area. On the enlarged area around site M the drill locations for shallow cores as well as the corners in the radar survey domain is shown (from Winther et al., 2002). (click on figure to enlarge)

Accumulation record graph

Figure 2. Accumulation record from five firn cores, based on dating from the ECM record (from Winther et al., 2002).
(click on figure to enlarge)

graph

Figure 3. a) Annual accumulation rates (thin black solid line) derived from the δ18O records for S100 core smoothed with 7-year running mean (black solid curve) and 31-year running mean (black dashed curve). b) SiZer analysis of trends (Chaudhurri and Marron, 1999) in accumulation record. Upper panel: dots - annual accumulation values derived from the S100 ice core, lines - family of smooths obtained for various versions of the bandwidth (h). Lower panel: SiZer significance test (confidence level: 95%) showing decreasing trend in accumulation since 1920 at long time scales (app. 30 years). Color coding in SiZer: grey – no significant trend; black – significant increase; white – significant decrease. (from Kaczmarska et al., 2004).

graph

Figure 4. The normalized wavelet power spectra for two MSA time-series from Dronning Maud Land (M150 and B32 cores). Thick contours enclose the regions where the wavelet power is above the red noise background with the 95% confidence levels. White areas indicate the “cone of influence” where the edge effects become important. (From Divine, D. and others. MSA records from the Antarctic polar plateau suggest similar variability on century time scales. In prep.)

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