Helle Astrid Kjær

Publikation

Publikationer pr. år 2009 2014 2015 2018 2019

• 22 Tidsskriftartikel
• 2 Bidrag til bog/antologi
• 2 Konferencebidrag i proceedings
• 1 Ph.d.-afhandling
• 1 Mere
  • 1 Bidrag til rapport

Publikationer pr. år

Publikationer pr. år

Søgeresultater

• 2019

  A 2700-year annual timescale and accumulation history for an ice core from Roosevelt Island, West Antarctica

  Winstrup, M., Vallelonga, P., Kjaer, H. A., Fudge, T. J., Lee, J. E., Riis, M. H., Edwards, R., Bertler, N. A. N., Blunier, T., Brook, E. J., Buizert, C., Ciobanu, G., Conway, H., Dahl-Jensen, D., Ellis, A., Emanuelsson, B. D., Hindmarsh, R. C. A., Keller, E. D., Kurbatov, A. V., Mayewski, P. A., & 7 flereNeff, P. D., Pyne, R. L., Simonsen, M. F., Svensson, A., Tuohy, A., Waddington, E. D. & Wheatley, S., 10 apr. 2019, I: Climate of the Past. 15, 2, s. 751-779 29 s.

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • ice core 100%
  • accumulation rate 85%
  • Antarctica 80%
  • timescale 66%
  • history 52%
  9 Citationer (Scopus)

  45 Downloads (Pure)

• East Greenland ice core dust record reveals timing of Greenland ice sheet advance and retreat.

  Simonsen, M. F., Baccolo, G., Blunier, T., Borunda, A., Delmonte, B., Frei, R., Goldstein, S., Grinsted, A., Kjær, H. A., Sowers, T. A., Svensson, A., Vinther, B. M., Vladimirova, D., Winckler, G., Winstrup, M. & Vallelonga, P. T., 1 dec. 2019, I: Nature Communications. 10, 8 s., 4494.

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Greenland 100%
  • Ice Cover 93%
  • Ice 72%
  • Dust 65%
  • ice 58%
  17 Citationer (Scopus)

  17 Downloads (Pure)
• 2018

  Afslørende kemi i Grønlands og Antarktis' iskerner

  Svensson, A. & Kjær, H. A., 1 jun. 2018, I: Dansk Kemi. 9, s. 18-21 3 s.

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

• 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, H. A., Hutchison, E. & Baisden, W. T., 1 apr. 2018, I: Journal of Glaciology. 64, 243, s. 1-11

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • isotope 100%
  • ice 90%
  • ice core 41%
  • water 40%
  • analysis 35%
  4 Citationer (Scopus)

  50 Downloads (Pure)

• 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 flereWinstrup, M., Wegner, A., Twarloh, B., Wolff, K., Schmidt, K., Goto-Azuma, K., Kuramoto, T., Hirabayashi, M., Uetake, J., Zheng, J., Bourgeois, J., Fisher, D., Zhiheng, D., Xiao, C., Legrand, M., Spolaor, A., Gabrieli, J., Barbante, C., Kang, J. -H., Hur, S. D., Hong, S. B., Hwang, H. J., Hong, S., Hansson, M., Iizuka, Y., Oyabu, I., Muscheler, R., Adolphi, F., Maselli, O. & McConnell, J., 1 dec. 2018, I: Nature Communications. 9, 1476.

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Greenland 100%
  • Aerosols 64%
  • Aerosol 61%
  • aerosols 59%
  • life (durability) 40%
  30 Citationer (Scopus)

  167 Downloads (Pure)

• Laboratory supervision of MSc projects -Qualitative interviews, thematic analysis, and recommendations for the supervisor

  Kjær, H. A., 23 maj 2018, Improving University Science Teaching and Learning Pedagogical Projects 2018. Institut for Naturfagenes Didaktik udg. København, Danmark: Københavns Universitet, Bind 12. s. 91-105 (Improving University Science Teaching and Learning - Pedagogical Projects).

  Publikation: Bidrag til bog/antologi/rapport › Bidrag til bog/antologi › Undervisning

  64 Downloads (Pure)

• 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 flereAudette, Y., Bertrand, I., Beyhaut, E., Boitt, G., Bradshaw, N., Brearley, C. A., Bruulsema, T. W., Cozzolino, V., Duran, P. C., Mora, M. L., de Menezes, A. B., Dodd, R. J., Dunfield, K., Engl, C., Frazao, J. J., Jimenez, J. L. G., Harrison, A. F., Hou, E. Q., Johnes, P. J., Kaiser, K., Kjaer, H. A., Klumpp, E., Lamb, A. L., Macintosh, K. A., Nelson, L. A., Tibbett, M., Wallander, H., Wang, L., Wasaki, J. & Haygarth, P. M., jun. 2018, I: Plant and Soil. 427, 1-2, SI, s. 209-211

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  2 Citationer (Scopus)

• 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., Kjaer, H. A., Potenza, M., Svensson, A. & Vallelonga, P., 3 maj 2018, I: Climate of the Past. 14, 5, s. 601-608

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • ice core 100%
  • dust 69%
  • particle 46%
  • calibration 25%
  • mineral dust 22%
  7 Citationer (Scopus)

  41 Downloads (Pure)

• 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, H. A., Simonsen, M. F., Winstrup, M., Vinther, B. M., Horvat, C., Fernandez, R. P., Kinnison, D., Lamarque, J-F., Barbante, C. & Saiz-Lopez, A., 1 dec. 2018, I: Nature Communications. 9, 1452.

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Iodine 100%
  • iodine 99%
  • Ozone 39%
  • Northern Hemisphere 28%
  • climate 26%
  36 Citationer (Scopus)

  115 Downloads (Pure)

• 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 flereDadic, R., Kjaer, H. A., Kurbatov, A., Zhang, D., Waddington, E. D., Baccolo, G., Beers, T., Brightley, H. J., Carter, L., Clemens-Sewall, D., Ciobanu, V. G., Delmonte, B., Eling, L., Ellis, A., Ganesh, S., Golledge, N. R., Haines, S., Handley, M., Hawley, R. L., Hogan, C. M., Johnson, K. M., Korotkikh, E., Lowry, D. P., Mandeno, D., McKay, R. M., Menking, J. A., Naish, T. R., Noerling, C., Simonsen, M. & Wang, S., 21 feb. 2018, I: Climate of the Past. 14, 2, s. 193-214

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • snow accumulation 100%
  • sea ice 72%
  • Antarctica 70%
  • sea 43%
  • climate 30%
  21 Citationer (Scopus)

  100 Downloads (Pure)
• 2016

  A High-Resolution Continuous Flow Analysis System for Polar Ice Cores

  Dallmayr, R., Goto-Azuma, K., Kjær, H. A., Azuma, N., Takata, M., Schüpbach, S. & Hirabayashi, M., 2016, I: Bulletin of Glaciological Research. 34, s. 11-20

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • ice core 100%
  • systems analysis 97%
  • electrical conductivity 57%
  • efficiency measurement 48%
  • isotope 46%
  1 Citationer (Scopus)

• An Optical Dye Method for Continuous Determination of Acidity in Ice Cores

  Kjær, H. A., Vallelonga, P. T., Svensson, A., Kristensen, M. E., Tibuleac, C., Winstrup, M. & Kipfstuhl, S., 4 okt. 2016, I: Environmental Science & Technology. 50, 19, s. 10485-10493

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • ice core 100%
  • acidity 90%
  • dye 85%
  • Dye 58%
  • conductivity 37%
  8 Citationer (Scopus)

• Ice core evidence for a 20th century increase in surface mass balance in coastal Dronning Maud Land, East Antarctica

  Philippe, M., Tison, J-L., Fjosne, K., Hubbard, B., Kjær, H. A., Lenaerts, J. T. M., Drews, R., Sheldon, S. G., De Bondt, K., Claeys, P. & Pattyn, F., 25 okt. 2016, I: Cryosphere. 10, 5, s. 2501-2516 16 s.

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • ice core 100%
  • mass balance 82%
  • Antarctica 80%
  • land 51%
  • history 14%
  18 Citationer (Scopus)

  75 Downloads (Pure)
• 2015

  Greenland 2012 melt event effects on CryoSat-2 radar altimetry

  Nilsson, J., Vallelonga, P., Simonsen, S. B., Sorensen, L. S., Forsberg, R., Dahl-Jensen, D., Hirabayashi, M., Goto-Azuma, K., Hvidberg, C. S., Kjaer, H. A. & Satow, K., 28 maj 2015, I: Geophysical Research Letters (Online). 42, 10, s. 3919-3926

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Greenland 100%
  • altimetry 99%
  • CryoSat 88%
  • radar altimetry 84%
  • radar 63%
  37 Citationer (Scopus)

• Greenland ice cores constrain glacial atmospheric fluxes of phosphorus

  Kjær, H. A., Dallmayr, R., Gabrieli, J., Goto-Azuma, K., Hirabayashi, M., Svensson, A. & Vallelonga, P. T., 27 okt. 2015, I: Journal of Geophysical Research: Earth Surface. 120, 20

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Greenland 100%
  • ice core 63%
  • phosphates 59%
  • ice 58%
  • phosphorus 57%
  3 Citationer (Scopus)

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

  Svensson, A., Fujita, S., Bigler, M., Braun, M., Dallmayr, R., Gkinis, V., Goto-Azuma, K., Hirabayashi, M., Kawamura, K., Kipfstuhl, S., Kjaer, H. A., Popp, T., Simonsen, M., Steffensen, J. P., Vallelonga, P. & Vinther, B. M., 15 sep. 2015, I: Climate of the Past. 11, 9, s. 1127-1137

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • ice core 100%
  • dome 90%
  • Holocene 72%
  • ice 62%
  • Antarctica 34%
  6 Citationer (Scopus)

  161 Downloads (Pure)

• The summer 2012 Greenland heat wave: In situ and remote sensing observations of water vapor isotopic composition during an atmospheric river event

  Bonne, J-L., Steen-Larsen, H. C., Risi, C., Werner, M., Sodemann, H., Lacour, J-L., Fettweis, X., Cesana, G., Delmotte, M., Cattani, O., Vallelonga, P. T., Kjær, H. A., Clerbaux, C., Svienbjörndóttir, Á. E. & Masson-Delmotte, V., 1 apr. 2015, I: Journal of Geophysical Research: Earth Surface. 120, 7, s. 2970-2989

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Greenland 100%
  • rivers 76%
  • summer 71%
  • heat wave 69%
  • remote sensing 64%
  52 Citationer (Scopus)
• 2014

  A novel method for the detection of acidity in ice cores

  Kjær, H. A., Vallelonga, P. T. & Svensson, A., 27 apr. 2014, European Geosciences Union General Assembly 2014, 16, 27 April – 02 May 2014. European Geosciences Union udg. Vienna, Austria, 1526

  Publikation: Bidrag til bog/antologi/rapport › Konferencebidrag i proceedings › Forskning › peer review

• Constraining Glacial input of phosphorus to the oceans based on Greenland ice core evidence

  Kjær, H. A., Gotto-Azuma, K., Dallmayr, R., Hirabayashi, M., Vallelonga, P. T. & Svensson, A., 27 apr. 2014, European Geosciences Union General Assembly 2014, 16, 27 April – 02 May 2014. European Geosciences Union udg. Vienna, Austria, 1524

  Publikation: Bidrag til bog/antologi/rapport › Konferencebidrag i proceedings › Forskning › peer review

• Continuous Chemistry in Ice Cores: Phosphorus, pH and the Photolysis of Humic Like Substances

  Kjær, H. A., 2014, The Niels Bohr Institute, Faculty of Science, University of Copenhagen.

  Publikation: Bog/antologi/afhandling/rapport › Ph.d.-afhandling

• 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., Kjaer, H. A., Sapolaite, J., Barbante, C. & Druteikiene, R., 10 jan. 2014, I: Journal of Analytical Atomic Spectrometry. 29, 10, s. 1827-1834

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Sector Field Mass Spectroscopy 100%
  • Inductively Coupled Plasma 57%
  • Ion Chromatography 31%
  • Iodine 24%
  • Column Like Crystal 17%
  13 Citationer (Scopus)

• 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 flereWeng, Y. & Winstrup, M., 10 jan. 2014, I: The Cryosphere Discussions. 8, s. 1275-1287

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  32 Citationer (Scopus)

  124 Downloads (Pure)

• 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., Kjaer, H. A., Curran, M. A. J., Moy, A. D., Schoenhardt, A., Blechschmidt, A. -M., Burrows, J. P., Plane, J. M. C. & Barbante, C., 16 sep. 2014, I: Atmospheric Chemistry and Physics. 14, 18, s. 9613-9622

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • bromine 100%
  • halogen 95%
  • iodine 92%
  • seasonality 78%
  • snow 67%
  22 Citationer (Scopus)
• 2013

  Continuous Flow Analysis Method for Determination of Dissolved Reactive Phosphorus in Ice Cores

  Kjær, H. A., Vallelonga, P. T., Svensson, A., Elleskov L. Kristensen, M., Tibuleac, C. & Bigler, M., 5 nov. 2013, I: Environmental Science & Technology (Washington). 47, 21, s. 12325-12332

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Flow Analysis 100%
  • ice core 77%
  • Phosphorus(.) 60%
  • phosphorus 52%
  • Molybdate 22%
  7 Citationer (Scopus)

• 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 flereDitlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Goto-Azuma, K., Grinsted, A., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, M., Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Iizuka, Y., Jenk, T. M., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, S., Kjær, H. A., Koutnik, M., Kuramoto, T., Köhler, P., Laepple, T., Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, H., Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Orsi, A. J., Paden, J., Panton, C., Pattyn, F., Petit, J-R., Pol, K., Popp, T. J., Possnert, G., Prié, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Röckmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schwander, J., Schüpbach, S., Seierstad, I. K., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, D., Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjörnsdottir, A., Svensson, A., Tison, J-L., Uetake, J., Vallelonga, P. T., Van De Wal, R. S. W., Van Der Wel, G., Vaughn, B. H., Vinther, B. M., Waddington, E., Wegner, A., Weikusat, I., White, J. W. C., Wilhelms, F., Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C. & Zheng, J., 24 jan. 2013, I: Nature. 493, 7433, s. 489-494 6 s.

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • Greenland 100%
  • Ice 79%
  • Ice Cover 61%
  • Antarctic Regions 19%
  • Climate 15%
  403 Citationer (Scopus)
• 2012

  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, T., Kjær, H. A., Popp, T. J., Rasmussen, S. O., Steffensen, J. P., Stowasser, C., Svensson, A., Warming, E., Winstrup, M., Bigler, M. & Kipfstuhl, S., 20 nov. 2012, I: Climate of the Past. 8, 6, s. 1839-1847 8 s.

  Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

  • interstadial 100%
  • ice core 88%
  • ice 55%
  • chronology 50%
  • NorthGRIP 49%
  14 Citationer (Scopus)
• 2011

  Iskerner-et indblik i fortidens klimaforandringer

  Kjær, H. A. & Balslev-Clausen, D., 2 apr. 2011, Aspekter af dansk kemi i det 20. og 21. århundrede. 1 udg. København: Kemi Forlaget, s. 65-70 5 s.

  Publikation: Bidrag til bog/antologi/rapport › Bidrag til bog/antologi › Formidling

  390 Downloads (Pure)
• 2009

  Assessment of the temperature, precipitation and snow in the RCM HIRHAM4 at 25 km resolution: Danish Climate Centre Report 09-08

  Kjær, H. A., 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)

  Publikation: Bidrag til bog/antologi/rapport › Bidrag til rapport › Forskning