Arctic hydroclimate variability during the last 2000 years – current understanding and research challenges
Hans W. Linderholm1, Marie Nicolle2, Pierre Francus3, Konrad Gajewski4, Samuli Helama5, Atte Korhola6, Olga Solomina7, Zicheng Yu8, Peng Zhang1, William J. D'Andrea9, Maxime Debret2, Dmitry Divine10, Björn E. Gunnarson11, Neil J. Loader12, Nicolas Massei2, Kristina Seftifgen1,13, Elizabeth K. Thomas14, and Johannes Werner151Regional Climate Group, Department of Earth Sciences, University of Gothenburg, 40530 Gothenburg, Sweden 2UFR Sciences et Techniques, Université de Rouen Normandie, 76000 Rouen, France 3Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, G1K 9A9, Québec, QC, Canada and GEOTOP Research Center, Montréal, QC Canada 4Département de géographie, Université d’Ottawa, Ottawa, Ontario K1N 6N5, Canada 5Natural Resources Institute Finland, Rovaniemi, Finland 6Environmental Change Research Unit (ECRU), Department of Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland 7Institute of Geography, Russian Academy of Sciences, 119017 Moscow, Russia 8Department of Earth and Environmental Sciences, Lehigh University, Bethlehem PA 18015-3001, USA 9Lamont-Doherty Earth Observatory, Columbia University, Palisades NY 10964 , USA 10Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway 11Department of Physical Geography, Stockholm University, 10691 Stockholm, Sweden 12Department of Geography, Swansea University, Swansea SA2 8PP, Wales, UK 13Earth and Life Institute, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium 14Department of Geology, University at Buffalo, Buffalo NY 14260, USA 15Department of Earth Science, University of Bergen, 5020 Bergen, Norway
Received: 09 Mar 2017 – Accepted for review: 15 Mar 2017 – Discussion started: 17 Mar 2017
Abstract. Along with Arctic amplification, changes in Arctic hydroclimate have become increasingly apparent. Reanalysis data show increasing trends in Arctic temperature and precipitation over the 20th century, but changes are not homogenous across seasons or space. The observed hydroclimate changes are expected to continue, and possibly accelerate, in the coming century, not only affecting pan-Arctic natural ecosystems and human activities, but also lower latitudes through changes in atmospheric and oceanic circulation. However, a lack of spatiotemporal observational data makes reliable quantification of Arctic hydroclimate change difficult, especially in a long-term context. To understand hydroclimate variability and the mechanisms driving observed changes, beyond the instrumental record, climate proxies are needed. Here we bring together the current understanding of Arctic hydroclimate during the past 2000 years, as inferred from natural archives and proxies and palaeoclimate model simulations. Inadequate proxy data coverage is apparent, with distinct data gaps in most of Eurasia and parts of North America, which makes robust assessments for the whole Arctic currently impossible. Hydroclimate proxies and climate models indicate that the Medieval Climate Anomaly (MCA) was anomalously wet, while conditions were in general drier during the Little Ice Age (LIA), relative to the last 2000 years. However, it is clear that there are large regional differences, which are especially evident during the LIA. Due to the spatiotemporal differences in Arctic hydroclimate, we recommend detailed regional studies, e.g. including field reconstructions, to disentangle spatial patterns and potential forcing factors. At present, it is only possible to carry out regional syntheses for a few areas of the Arctic, e.g. Fennoscandia, Greenland and western North America. To fully assess pan-Arctic hydroclimate variability for the last two millennia additional proxy records are required.
Linderholm, H. W., Nicolle, M., Francus, P., Gajewski, K., Helama, S., Korhola, A., Solomina, O., Yu, Z., Zhang, P., D'Andrea, W. J., Debret, M., Divine, D., Gunnarson, B. E., Loader, N. J., Massei, N., Seftifgen, K., Thomas, E. K., and Werner, J.: Arctic hydroclimate variability during the last 2000 years – current understanding and research challenges, Clim. Past Discuss., doi:10.5194/cp-2017-34, in review, 2017.