Arctic hydroclimate variability during the last 2000 years: current understanding and research challenges

Hans W Linderholm (1) , Marie Nicolle (2) , Pierre Francus (3) , Konrad Gajewski (4) , Samuli Helama (5) , Atte Korhola (6) , Olga Solomina (7) , Zicheng Yu (8) , Peng Zhang (1) , William d'Andrea (9) , Maxime Debret (10) , Dmitry Divine (11) , Björn Gunnarson (12) , Neil Loader (13) , Nicolas Massei (2) , Kristina Seftigen (14, 15) , Elizabeth Thomas (16) , Johannes Werner (17) , Sofia Andersson (18) , Annika Berntsson (18) , Tomi Luoto (19) , Liisa Nevalainen (6) , Saija Saarni (20) , Minna Väliranta (6)

1 GU - Göteborgs Universitet = University of Gothenburg
2 M2C - Morphodynamique Continentale et Côtière
3 INRS - ETE - Centre Eau Terre Environnement [Québec]
4 uOttawa - Université d'Ottawa [Ontario]
5 LUKE - Natural Resources Institute Finland
6 Helsingin yliopisto = Helsingfors universitet = University of Helsinki
7 RAS - Russian Academy of Sciences [Moscow]
8 Lehigh University [Bethlehem]
9 LDEO - Lamont-Doherty Earth Observatory
10 EDYTEM - Environnements, Dynamiques et Territoires de Montagne
11 Norwegian Polar Institute
12 Stockholm University
13 Swansea University
14 Regional Climate Group
15 UCL - Université Catholique de Louvain = Catholic University of Louvain
16 CAPS - Cognition, Action, et Plasticité Sensorimotrice [Dijon - U1093]
17 Jacobs University = Constructor University [Bremen]
18 Department of Physical Geography [Stockholm]
19 Faculty of Biological and Environmental Sciences [Helsinki]
20 University of Turku

Reanalysis data show an increasing trend in Arctic 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 the atmospheric and ocean circulations. However, a lack of spatiotemporal observational data makes reliable quantification of Arctic hydroclimate change difficult, especially in a long-term context. To understand Arctic hydroclimate and its variability prior to the instrumental record, climate proxy records are needed. The purpose of this review is to summarise the current understanding of Arctic hydroclimate during the past 2000 years. First, the paper reviews the main natural archives and proxies used to infer past hydroclimate variations in this remote region and outlines the difficulty of disentangling the moisture from the temperature signal in these records. Second, a comparison of two sets of hydroclimate records covering the Common Era from two data-rich regions, North America and Fennoscandia, reveals inter- and intra-regional differences. Third, building on earlier work, this paper shows the potential for providing a high-resolution hydroclimate reconstruction for the Arctic and a comparison with last-millennium simulations from fully coupled climate models. In general, hydroclimate proxies and simulations indicate that the Medieval Climate Anomaly tends to have been wetter than the Little Ice Age (LIA), but there are large regional differences. However, the regional coverage of the proxy data is inadequate, with distinct data gaps in most of Eurasia and parts of North America, making robust assessments for the whole Arctic impossible at present. To fully assess pan-Arctic hydroclimate variability for the last 2 millennia, additional proxy records are required.

Domaines: Climatologie; Hydrologie

Hans W Linderholm, Marie Nicolle, Pierre Francus, Konrad Gajewski, Samuli Helama, et al.. Arctic hydroclimate variability during the last 2000 years: current understanding and research challenges. Climate of the Past, 2018, 14 (4), pp.473 - 514. ⟨10.5194/cp-14-473-2018⟩. ⟨hal-01763335⟩