Helle Astrid Kjær
Associate Professor
Physics of Ice, Climate and Earth
Tagensvej 16
2200 København N.
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The summer 2012 Greenland heat wave: In situ and remote sensing observations of water vapor isotopic composition during an atmospheric river event
Bonne, J., Steen-Larsen, H. C., Risi, C., Werner, M., Sodemann, H., Lacour, J., Fettweis, X., Cesana, G., Delmotte, M., Cattani, O., Vallelonga, P. T., Kjær, Helle Astrid, Clerbaux, C., Svienbjörndóttir, Á. E. & Masson-Delmotte, V., 1 Apr 2015, In: Journal of Geophysical Research: Biogeosciences. 120, 7, p. 2970-2989Research output: Contribution to journal › Journal article › Research › peer-review
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The Ross Sea Dipole - temperature, snow accumulation and sea ice variability in the Ross Sea region, Antarctica, over the past 2700 years
Bertler, N. A. N., Conway, H., Dahl-Jensen, D., Emanuelsson, D. B., Winstrup, M., Vallelonga, P. T., Lee, J. E., Brook, E. J., Severinghaus, J. P., Fudge, T. J., Keller, E. D., Baisden, W. T., Hindmarsh, R. C. A., Neff, P. D., Blunier, T., Edwards, R., Mayewski, P. A., Kipfstuhl, S., Buizert, C., Canessa, S. & 30 others, , 21 Feb 2018, In: Climate of the Past. 14, 2, p. 193-214Research output: Contribution to journal › Journal article › Research › peer-review
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The Ross Sea Dipole – Temperature, Snow Accumulation and Sea Ice Variability in the Ross Sea Region, Antarctica, over the Past 2,700 Years
Bertler, N. A. N., Conway, H., Dahl-Jensen, D., Emanuelsson, D. B., Winstrup, M., Vallelonga, P. T., Lee, J. E., Brook, E. J., Severinghaus, J. P., Fudge, T. J., Keller, E. D., Baisden, W. T., Hindmarsh, R. C. A., Neff, P. D., Blunier, T., Edwards, R., Mayewski, P. A., Kipfstuhl, S., Buizert, C., Canessa, S. & 51 others, , 1 Aug 2017, In: Climate of the Past Discussions. 31 p.Research output: Contribution to journal › Journal article › Research › peer-review
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Surface velocity of the Northeast Greenland Ice Stream (NEGIS): assessment of interior velocities derived from satellite data by GPS
Hvidberg, Christine Schøtt, Grinsted, Aslak, Dahl-Jensen, Dorthe, Khan, S. A., Kusk, A., Andersen, Jonas Kvist, Neckel, N., Solgaard, Anne Munck, Karlsson, N. B., Kjær, Helle Astrid & Vallelonga, P., 22 Oct 2020, In: Cryosphere. 14, 10, p. 3487-3502 16 p.Research output: Contribution to journal › Journal article › Research › peer-review
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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, , 6 Apr 2020, 32 p. Copernicus/EGU.Research output: Other contribution › Research
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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 2021Research output: Other contribution › Research
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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. 9613-9622Research output: Contribution to journal › Journal article › Research › peer-review
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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 journal › Review › Research › peer-review
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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 journal › Journal article › Research › peer-review
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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 journal › Journal article › Research › peer-review
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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 journal › Journal article › Research › peer-review
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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 journal › Journal article › Research › peer-review
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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 journal › Journal article › Research › peer-review
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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 journal › Journal article › Research › peer-review
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Particle shape accounts for instrumental discrepancy in ice core dust size distributions
Simonsen, M. F., Cremonesi, L., Baccolo, G., Bosch, S., Delmonte, B., Erhardt, T., Kjær, Helle Astrid, Potenza, M., Svensson, Anders & Vallelonga, P., 3 May 2018, In: Climate of the Past. 14, 5, p. 601-608Research output: Contribution to journal › Journal article › Research › peer-review
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Organic phosphorus in the terrestrial environment: a perspective on the state of the art and future priorities
George, T. S., Giles, C. D., Menezes-Blackburn, D., Condron, L. M., Gama-Rodrigues, A. C., Jaisi, D., Lang, F., Neal, A. L., Stutter, M. I., Almeida, D. S., Bol, R., Cabugao, K. G., Celi, L., Cotner, J. B., Krueger, J., Plassard, C., Rosling, A., Darch, T., Fraser, T., Tamburini, F. & 30 others, , Jun 2018, In: Plant and Soil. 427, 1-2, SI, p. 209-211Research output: Contribution to journal › Journal article › Research › peer-review
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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. 1127-1137Research output: Contribution to journal › Journal article › Research › peer-review
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New data from the 40 year old Dye3 core
Blunier, Thomas, Venkatesh, J., Soestmeyer, D. A., Liisberg, J. B., Rhodes, R., Menking, J. A., Severinghaus, J. P., Harlan, Meg, Kjær, Helle Astrid & Vallelonga, P., 23 Mar 2020. 1 p.Research output: Contribution to conference › Conference abstract for conference › Research › peer-review
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Nanoplastics measurements in Northern and Southern polar ice
Materic, D., Kjær, Helle Astrid, Vallelonga, P., Tison, J., Rockmann, T. & Holzinger, R., 15 May 2022, In: Environmental Research. 208, 9 p., 112741.Research output: Contribution to journal › Journal article › Research › peer-review
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Melt in the Greenland EastGRIP ice core reveals Holocene warming events
Westhoff, Julien, Sinnl, Giulia, Svensson, Anders, Freitag, J., Kjær, Helle Astrid, Vallelonga, P., Vinther, Bo Møllesøe, Kipfstuhl, S., Dahl-Jensen, Dorthe & Weikusat, I., 16 Jul 2021, 36 p. Copernicus/EGU.Research output: Other contribution › Research
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Melt in the Greenland EastGRIP ice core reveals Holocene warm events
Westhoff, Julien, Sinnl, Giulia, Svensson, Anders, Freitag, J., Kjær, Helle Astrid, Vallelonga, P. T., Vinther, Bo Møllesøe, Kipfstuhl, S., Dahl-Jensen, Dorthe & Weikusat, I., 10 May 2022, In: Climate of the Past. 18, 5, p. 1011-1034 24 p.Research output: Contribution to journal › Journal article › Research › peer-review
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Magnitude, frequency and climate forcing of global volcanism during the last glacial period as seen in Greenland and Antarctic ice cores (60–9 ka)
Lin, Jiamei, Svensson, Anders, Hvidberg, Christine Schøtt, Lohmann, Johannes Jakob, Kristiansen, S., Dahl-Jensen, Dorthe, Steffensen, Jørgen Peder, Rasmussen, Sune Olander, Cook, Eliza, Kjær, Helle Astrid, Vinther, Bo Møllesøe, Fischer, H., Stocker, T., Sigl, M., Bigler, M., Severi, M., Traversi, R. & Mulvaney, R., 9 Aug 2021, 45 p. Copernicus/EGU.Research output: Other contribution › Research
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Magnitude, frequency and climate forcing of global volcanism during the last glacial period as seen in Greenland and Antarctic ice cores (60-9 ka)
Lin, Jiamei, Svensson, Anders, Hvidberg, Christine Schøtt, Lohmann, Johannes Jakob, Kristiansen, S., Dahl-Jensen, Dorthe, Steffensen, Jørgen Peder, Rasmussen, Sune Olander, Cook, Eliza, Kjær, Helle Astrid, Vinther, Bo Møllesøe, Fischer, H., Stocker, T., Sigl, M., Bigler, M., Severi, M., Traversi, R. & Mulvaney, R., 15 Mar 2022, In: Climate of the Past. 18, 3, p. 485-506 22 p.Research output: Contribution to journal › Journal article › Research › peer-review
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Laboratory supervision of MSc projects -Qualitative interviews, thematic analysis, and recommendations for the supervisor
Kjær, Helle Astrid, 23 May 2018, Improving University Science Teaching and Learning Pedagogical Projects 2018. Institut for Naturfagenes Didaktik ed. København, Danmark: Københavns Universitet, Vol. 12. p. 91-105 (Improving University Science Teaching and Learning - Pedagogical Projects).Research output: Chapter in Book/Report/Conference proceeding › Book chapter › Education
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Iskerner-et indblik i fortidens klimaforandringer
Kjær, Helle Astrid & Balslev-Clausen, D., 2 Apr 2011, Aspekter af dansk kemi i det 20. og 21. århundrede. 1 ed. København: Kemi Forlaget, p. 65-70 5 p.Research output: Chapter in Book/Report/Conference proceeding › Book chapter › Communication
ID: 33355865
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On the occurrence of annual layers in Dome Fuji ice core early Holocene ice
Research output: Contribution to journal › Journal article › Research › peer-review
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177
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Greenland records of aerosol source and atmospheric lifetime changes from the Eemian to the Holocene
Research output: Contribution to journal › Journal article › Research › peer-review
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138
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Rapid increase in atmospheric iodine levels in the North Atlantic since the mid-20th century
Research output: Contribution to journal › Journal article › Research › peer-review
Published