Helle Astrid Kjær

Helle Astrid Kjær

Associate Professor


  1. Published

    Seasonality of halogen deposition in polar snow and ice

    Spolaor, A., Vallelonga, P., Gabrieli, J., Martma, T., Bjorkman, M. P., Isaksson, E., Cozzi, G., Turetta, C., Kjær, Helle Astrid, Curran, M. A. J., Moy, A. D., Schoenhardt, A., Blechschmidt, A. -., Burrows, J. P., Plane, J. M. C. & Barbante, C., 10 Jan 2014, In: Atmospheric Chemistry and Physics. 14, 18, p. 9613-9622

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. Published

    On the occurrence of annual layers in Dome Fuji ice core early Holocene ice

    Svensson, Anders, Fujita, S., Bigler, M., Braun, M., Dallmayr, R., Gkinis, Vasileios, Goto-Azuma, K., Hirabayashi, M., Kawamura, K., Kipfstuhl, S., Kjær, Helle Astrid, Popp, T., Simonsen, M., Steffensen, Jørgen Peder, Vallelonga, P. & Vinther, Bo Møllesøe, 2015, In: Climate of the Past. 11, 9, p. 1127-1137

    Research output: Contribution to journalJournal articleResearchpeer-review

  3. Published

    Bipolar volcanic synchronization of abrupt climate change in Greenland and Antarctic ice cores during the last glacial period

    Svensson, A., Dahl-Jensen, D., Steffensen, J. P., Blunier, T., Rasmussen, S. O., Vinther, B. M., Vallelonga, P. T., Capron, E., Gkinis, V., Cook, E., Kjær, H. A., Muscheler, R., Kipfstuhl, S., Wilhelms, F., Stocker, T. F., Fischer, H., Adolphi, F., Erhardt, T., Sigl, M., Landais, A. & 6 others, Parrenin, F., Buizert, C., McConnell, J. R., Severi, M., Mulvaney, R. & Bigler, M., 19 Aug 2020, In: Climate of the Past. 16, p. 1565-1580 15 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  4. Published

    Afslørende kemi i Grønlands og Antarktis' iskerner

    Svensson, Anders & Kjær, Helle Astrid, 1 Jun 2018, In: Dansk Kemi. 9, p. 18-21 3 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  5. Published

    Supplementary material to "Bipolar volcanic synchronization of abrupt climate change in Greenland and Antarctic ice cores during the last glacial period"

    Svensson, A., Dahl-Jensen, D., Steffensen, J. P., Blunier, T., Rasmussen, S. O., Vinther, B. M., Vallelonga, P., Capron, E., Gkinis, V., Cook, E., Kjær, H. A., Muscheler, R., Kipfstuhl, S., Wilhelms, F., Stocker, T. F., Fischer, H., Adolphi, F., Erhardt, T., Sigl, M., Landais, A. & 6 others, Parrenin, F., Buizert, C., McConnell, J. R., Severi, M., Mulvaney, R. & Bigler, M., 6 Apr 2020, 32 p. Copernicus/EGU.

    Research output: Other contributionResearch

  6. Published

    Sea-ice reconstructions from bromine and iodine in ice cores

    Vallelonga, P., Maffezzoli, N., Saiz-Lopez, A., Scoto, F., Kjær, Helle Astrid & Spolaor, A., 1 Oct 2021, In: Quaternary Science Reviews. 269, 41 p., 107133.

    Research output: Contribution to journalReviewResearchpeer-review

  7. Published

    Duration of Greenland Stadial 22 and ice-gas Δage from counting of annual layers in Greenland NGRIP ice core

    Vallelonga, P. T., Bertagna, G., Blunier, Thomas, Kjær, Helle Astrid, Popp, T. J., Rasmussen, Sune Olander, Steffensen, Jørgen Peder, Stowasser, C., Svensson, Anders, Warming, E., Winstrup, M., Bigler, M. & Kipfstuhl, S., 20 Nov 2012, In: Climate of the Past. 8, 6, p. 1839-1847 8 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  8. Published

    Initial results from geophysical surveys and shallow coring of the Northeast Greenland Ice Stream (NEGIS)

    Vallelonga, P. T., Christianson, K., Alley, R. B., Anandakrishnan, S., Dahl-Jensen, D., Gkinis, V., Holme, C. T., Jacobel, R. W., Karlsson, N. B., Keisling, B. A., Kipfstuhl, S., Kjær, H. A., Kristensen, M. E., Muto, A., Peters, L. E., Popp, T. J., Riverman, K. L., Svensson, A., Tibuleac, C., Vinther, B. M. & 2 others, Weng, Y. & Winstrup, M., 10 Jan 2014, In: The Cryosphere Discussions. 8, p. 1275-1287

    Research output: Contribution to journalJournal articleResearchpeer-review

  9. Published

    Role of mineral dust in the nitrate preservation during the glacial period: Insights from the RICE ice core

    Venugopal, A. U., Bertler, N. A. N., Pyne, R. L., Kjær, Helle Astrid, Winton, V. H. L., Mayewski, P. A. & Cortese, G., 1 Feb 2022, In: Global and Planetary Change. 209, 10 p., 103745.

    Research output: Contribution to journalJournal articleResearchpeer-review

  10. Published

    Antarctic evidence for an abrupt northward shift of the Southern Hemisphere westerlies at 32 ka BP

    Venugopal, A. U., Bertler, N. A. N., Severinghaus, J. P., Brook, E. J., Cortese, G., Lee, J. E., Blunier, Thomas, Mayewski, P. A., Kjær, Helle Astrid, Carter, L., Weber, M. E., Levy, R. H., Pyne, R. L. & Vandergoes, M. J., 5 Sep 2023, In: Nature Communications. 14, 1, 8 p., 5432.

    Research output: Contribution to journalJournal articleResearchpeer-review

ID: 33355865