Helle Astrid Kjær

Helle Astrid Kjær

Associate Professor


  1. Published

    Past perspectives on the present era of abrupt Arctic climate change

    Jansen, E., Christensen, Jens Hesselbjerg, Dokken, T., Nisancioglu, K. H., Vinther, Bo Møllesøe, Capron, E., Guo, C., Jensen, M. F., Langen, P. L., Pedersen, R. A., Yang, S., Bentsen, M., Kjær, Helle Astrid, Sadatzki, H., Sessford, E. & Stendel, M., 1 Aug 2020, In: Nature climate change. 10, 8, p. 714-721 8 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. Published

    Rapid increase in atmospheric iodine levels in the North Atlantic since the mid-20th century

    Cuevas, C. A., Maffezzoli, N., Corella, J. P., Spolaor, A., Vallelonga, P. T., Kjær, Helle Astrid, Simonsen, M. F., Winstrup, M., Vinther, Bo Møllesøe, Horvat, C., Fernandez, R. P., Kinnison, D., Lamarque, J., Barbante, C. & Saiz-Lopez, A., 1 Dec 2018, In: Nature Communications. 9, 1452.

    Research output: Contribution to journalJournal articleResearchpeer-review

  3. Published

    Rapid reductions and millennial-scale variability in Nordic Seas sea ice cover during abrupt glacial climate changes

    Sadatzki, H., Maffezzoli, N., Dokken, T. M., Simon, M. H., Berben, S. M. P., Fahl, K., Kjær, Helle Astrid, Spolaor, A., Stein, R., Vallelonga, P., Vinther, Bo Møllesøe & Jansen, E., 24 Nov 2020, In: Proceedings of the National Academy of Sciences of the United States of America. 117, 47, p. 29478-29486 9 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  4. 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

  5. Published

    Sea ice fluctuations in the Baffin Bay and the Labrador Sea during glacial abrupt climate changes

    Scoto, F., Sadatzki, H., Maffezzoli, N., Barbante, C., Gagliardi, A., Varin, C., Vallelonga, P., Gkinis, Vasileios, Dahl-Jensen, Dorthe, Kjær, Helle Astrid, Burgay, F., Saiz-Lopez, A., Stein, R. & Spolaor, A., 1 Nov 2022, In: Proceedings of the National Academy of Sciences of the United States of America. 119, 44, 9 p., 2203468119.

    Research output: Contribution to journalJournal articleResearchpeer-review

  6. Published

    Sea ice in the northern North Atlantic through the Holocene: Evidence from ice cores and marine sediment records

    Maffezzoli, N., Risebrobakken, B., Miles, M. W., Vallelonga, P., Berben, S. M. P., Scoto, F., Edwards, R., Kjær, Helle Astrid, Sadatzki, H., Saiz-Lopez, A., Turetta, C., Barbante, C., Vinther, Bo Møllesøe & Spolaor, A., 3 Nov 2021, In: Quaternary Science Reviews. 273, 17 p., 107249.

    Research output: Contribution to journalJournal articleResearchpeer-review

  7. 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

  8. 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

  9. Published

    Supplementary material to "A portable Lightweight In Situ Analysis (LISA) box for ice and snow analysis"

    Kjær, Helle Astrid, Hauge, L. L., Simonsen, M., Yoldi, Zuriñe, Koldtoft, Iben, Hörholdt, M., Freitag, J., Kipfstuhl, S., Svensson, Anders & Vallelonga, P., 2 Mar 2021

    Research output: Other contributionResearch

  10. 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

ID: 33355865