Helle Astrid Kjær
Associate Professor
Physics of Ice, Climate and Earth
Tagensvej 16
2200 København N.
- 2009
Assessment of the temperature, precipitation and snow in the RCM HIRHAM4 at 25 km resolution: Danish Climate Centre Report 09-08
Kjær, Helle Astrid, 2009, Assessment of the temperature, precipitation and snow in the RCM HIRHAM4 at 25 km resolution: Danish Climate Centre Report 09-08. Danmarks Meterologiske Institut (DMI)Research output: Chapter in Book/Report/Conference proceeding › Report chapter › Research
- 2011
- Published
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
- 2012
- 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 journal › Journal article › Research › peer-review
- 2013
- Published
Eemian interglacial reconstructed from a Greenland folded ice core
Dahl-Jensen, D., Albert, M. R., Aldahan, A., Azuma, N., Balslev-Clausen, D. M., Baumgartner, M., Berggren, A-M., Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M. & 113 others, , 24 Jan 2013, In: Nature. 493, 7433, p. 489-494 6 p.Research output: Contribution to journal › Journal article › Research › peer-review
- Published
Continuous Flow Analysis Method for Determination of Dissolved Reactive Phosphorus in Ice Cores
Kjær, Helle Astrid, Vallelonga, P. T., Svensson, Anders, Elleskov L. Kristensen, M., Tibuleac, C. & Bigler, M., 5 Nov 2013, In: Environmental Science & Technology (Washington). 47, 21, p. 12325-12332Research output: Contribution to journal › Journal article › Research › peer-review
- 2014
- Published
Determination of 129I in Arctic snow by a novel analytical approach using IC-ICP-SFMS
Ezerinskis, Z., Spolaor, A., Kirchgeorg, T., Cozzi, G., Vallelonga, P., Kjær, Helle Astrid, Sapolaite, J., Barbante, C. & Druteikiene, R., 10 Jan 2014, In: Journal of Analytical Atomic Spectrometry. 29, 10, p. 1827-1834Research output: Contribution to journal › Journal article › Research › peer-review
- Published
A novel method for the detection of acidity in ice cores
Kjær, Helle Astrid, Vallelonga, P. T. & Svensson, Anders, 27 Apr 2014, European Geosciences Union General Assembly 2014, 16, 27 April – 02 May 2014. European Geosciences Union ed. Vienna, Austria, 1526Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review
- Published
Constraining Glacial input of phosphorus to the oceans based on Greenland ice core evidence
Kjær, Helle Astrid, Gotto-Azuma, K., Dallmayr, R., Hirabayashi, M., Vallelonga, P. T. & Svensson, Anders, 27 Apr 2014, European Geosciences Union General Assembly 2014, 16, 27 April – 02 May 2014. European Geosciences Union ed. Vienna, Austria, 1524Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review
- Published
Continuous Chemistry in Ice Cores: Phosphorus, pH and the Photolysis of Humic Like Substances
Kjær, Helle Astrid, 2014, The Niels Bohr Institute, Faculty of Science, University of Copenhagen.Research output: Book/Report › Ph.D. thesis › Research
- 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. 9613-9622Research output: Contribution to journal › Journal article › Research › peer-review
- 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, , 10 Jan 2014, In: The Cryosphere Discussions. 8, p. 1275-1287Research output: Contribution to journal › Journal article › Research › peer-review
- 2015
- Published
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
- Published
Greenland ice cores constrain glacial atmospheric fluxes of phosphorus
Kjær, Helle Astrid, Dallmayr, R., Gabrieli, J., Goto-Azuma, K., Hirabayashi, M., Svensson, Anders & Vallelonga, P. T., 29 Oct 2015, In: Journal of Geophysical Research: Biogeosciences. 120, 20Research output: Contribution to journal › Journal article › Research › peer-review
- Published
Greenland 2012 melt event effects on CryoSat-2 radar altimetry
Nilsson, J., Vallelonga, P., Simonsen, S. B., Sorensen, L. S., Forsberg, R., Dahl-Jensen, Dorthe, Hirabayashi, M., Goto-Azuma, K., Hvidberg, Christine Schøtt, Kjær, Helle Astrid & Satow, K., 28 May 2015, In: Geophysical Research Letters (Online). 42, 10, p. 3919-3926Research output: Contribution to journal › Journal article › Research › peer-review
- 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. 1127-1137Research output: Contribution to journal › Journal article › Research › peer-review
- 2016
- Published
A High-Resolution Continuous Flow Analysis System for Polar Ice Cores
Dallmayr, R., Goto-Azuma, K., Kjær, Helle Astrid, Azuma, N., Takata, M., Schüpbach, S. & Hirabayashi, M., 2016, In: Bulletin of Glaciological Research. 34, p. 11-20Research output: Contribution to journal › Journal article › Research › peer-review
- Published
An Optical Dye Method for Continuous Determination of Acidity in Ice Cores
Kjær, Helle Astrid, Vallelonga, P. T., Svensson, Anders, Kristensen, M. E., Tibuleac, C., Winstrup, M. & Kipfstuhl, S., 1 Sep 2016, In: Environmental Science & Technology. 50, 19, p. 10485-10493Research output: Contribution to journal › Journal article › Research › peer-review
- Published
Ice core evidence for a 20th century increase in surface mass balance in coastal Dronning Maud Land, East Antarctica
Philippe, M., Tison, J., Fjosne, K., Hubbard, B., Kjær, Helle Astrid, Lenaerts, J. T. M., Drews, R., Sheldon, S. G., De Bondt, K., Claeys, P. & Pattyn, F., 2016, In: Cryosphere. 10, 5, p. 2501-2516 16 p.Research output: Contribution to journal › Journal article › Research › peer-review
- 2017
- Published
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
- 2018
- Published
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
- 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 journal › Journal article › Research › peer-review
- Published
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
- Published
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
- Published
A novel approach to process brittle ice for continuous flow analysis of stable water isotopes
Pyne, R. L., Keller, E. D., Canessa, S., Bertler, N. A., Pyne, A. R., Pyne, A. R., Mandeno, D., Vallelonga, P. T., Semper, S., Kjær, Helle Astrid, Hutchison, E. & Baisden, W. T., 16 Mar 2018, In: Journal of Glaciology. 64, 243, p. 1-11Research output: Contribution to journal › Journal article › Research › peer-review
- Published
Greenland records of aerosol source and atmospheric lifetime changes from the Eemian to the Holocene
Schupbach, S., Fischer, H., Bigler, M., Erhardt, T., Gfeller, G., Leuenberger, D., Mini, O., Mulvaney, R., Abram, N. J., Fleet, L., Frey, M. M., Thomas, E., Svensson, A., Dahl-Jensen, D., Kettner, E., Kjaer, H., Seierstad, I., Steffensen, J. P., Rasmussen, S. O., Vallelonga, P. & 30 others, , 16 Apr 2018, In: Nature Communications. 9, 1476.Research output: Contribution to journal › Journal article › Research › peer-review
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
Published -
174
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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
Published -
137
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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