Terry V. Callaghan,^* Margareta Johansson,^** Ross D. Brown,^*** Pavel Ya. Groisman,^**** Niklas Labba,^***** Vladimir Radionov,^****** Raymond S. Bradley,^******* Sylvie Blangy,^******** Olga N. Bulygina,^********* Torben R. Christensen,^********** Jonathan E. Colman,^*********** Richard L. H. Essery,^************ Bruce C. Forbes,^{*************} Mads C. Forchhammer,^{**************} Vladimir N. Golubev,^{***************} Richard E. Honrath,^{****************} Glenn P. Juday,^{*****************} Anna V. Meshcherskaya,^{******************} Gareth K. Phoenix,^{*******************} John Pomeroy,^{********************} Arja Rautio,^{*********************} David A. Robinson,^{**********************} Niels M. Schmidt,^{***********************} Mark C. Serreze,^{************************} Vladimir P. Shevchenko,^{*************************} Alexander I. Shiklomanov,^{**************************} Andrey B. Shmakin,^{***************************} Peter Sköld,^{****************************} Matthew Sturm,^{*****************************} Ming-ko Woo,^{******************************} Eric F. Wood<sup>*******************************


*</sup>Terry V.Callaghan () is a Distinguished Research Professor at the Royal Swedish Academy of Sciences and Professor of Arctic Ecology at Universities of Sheffield, UK and Lund, Sweden. He specializes in arctic ecology, and climate and UV-B radiation impacts on arctic ecosystems. Address: Royal Swedish Academy of Sciences, 104 05 Stockholm, Sweden. e-mail: terry_callaghan@btinternet.com
^**Margareta Johansson is a researcher at the Department of Earth and Ecosystem Sciences, Lund University and at the Royal Swedish Academy of Sciences, Stockholm, Sweden. She specializes in permafrost dynamics in relation to climate change and its impact on ecosystems. Address: Department of Earth and Ecosystem Sciences, Division of Physical Geography and Ecosystem Analyses, Lund University, Sölvegatan 12, 223 62 Lund, Sweden. e-mail: margareta.johansson@nateko.lu.se
^***Ross D. Brown is a Research Scientist with the Climate Research Division of Environment Canada located at the Ouranos Climate Consortium in Montreal, Canada. His research interests include documenting and understanding snow cover variability and change, the representation of snow processes in climate and hydrological models and the validation of snow cover in regional and global climate models. Address: Ouranos, 550 Sherbrooke St. West, 19th Floor, Montréal, QC H3A 1B9, Canada. e-mail: ross.brown@ec.gc.ca
^****Pavel Ya. Groisman is a Research Scientist with the Global Climate Applications Division of the National Climatic Data Center/NOAA, Asheville, North Carolina USA. His research interests include climate, data synthesis and analysis, the diagnosis of climate variations, and Arctic climate. Address: National Climatic Data Center, NOAA, Asheville, NC, USA e-mail: Pasha.Groisman@noaa.gov
^*****Niklas Labba is the leader of Gáisi Sámi Centre in Tromsø Norway. His research interests include traditional Sámi ecological knowledge and reindeer herding economy. Address: Gáisi Sámi Centre, Lakselvbukt, 9042 Laksvatn, Norway, e-mail: n.labba@gmail.com
^******Vladimir Radionov is the Head of the Department of Meteorology at Arctic and Antarctic Research Institute, Saint Petersburg. His research interests include analysis and generalization of hydrometeorological and solar radiation data in both polar regions. Address: AARI, 38 Bering Str., St. Petersburg 199397, Russia. e-mail: vradion@aari.ru
^*******Raymond S. Bradley is a Distinguished Professor in the Department of Geosciences, and Director of the Climate System Research Center at the University of Massachusetts, Amherst. He specializes in Arctic climate and paleoclimate. Address: Department of Geosciences, 233 Morrill Science Center, University of Massachusetts, 611 North Pleasant Street, Amherst, MA 01003-9297, USA. e-mail: rbradley@geo.umass.edu
^********Sylvie Blangy is a researcher and an associate professor at the Tourism Chair at UQAM. Her research interests are adaptation to climate change for the tourism industry, impact of mining development on Caribou and human health and she is exploring new research methodologies linking local expertise and scientific knowledge, addressing community concerns and priorities. Address: Université du Québec à Montréal, Case postale 8888, Succursale Centre-ville, Montréal, QC H3C 3P8, Canada, e-mail: sblangy@gmail.com
^*********Olga N. Bulygina is Lead Scientist at the Department of Climatology at the All-Russian Institute for Hydrometeorological Information, Obninsk, Kaluga Region, The Russian Federation. Her research interests include climatic data quality control, archiving, synthesis, analysis and dissemination for the territory of the Commonwealth of Independent States. Address: All-Russian Research Institute of Hydrometeorological Information - World Data Centre (RIHMI-WDC), 6 Koroleva Street, Obninsk, Kaluga Region 249035, The Russian Federation, e-mail: bulygina@meteo.ru
^**********Torben R. Christensen is a Professor at the Department of Earth and Ecosystem Sciences, Lund University, Sweden. He specializes in how vegetation and ecosystem processes respond and provide feedback effects on climate under changing environmental conditions. Address: Department of Earth and Ecosystem Sciences, Division of Physical Geography and Ecosystem Analyses, Lund University, Sölvegatan 12, 223 62 Lund, Sweden. e-mail: torben.christensen@nateko.lu.se
^***********Jonathan E. Colman is a senior scientist at the Department of Biology, University of Oslo and an Associate Professor at the Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management. His research includes wild and semidomestic reindeer ecology, large herbivore pasture dynamics and wildlife interactions with anthropogenic development. Address: Department of Biology, UiO, Pb. 1066 Blindern, 0316 Oslo, Norway. Address: Department of Ecology and Natural Resource Management, UMB, P.O. Box 5003, 1432 Ås, Norway. e-mail: j.e.colman@bio.uio.no; jonathan.colman@umb.no
^************Richard L. H. Essery is a Reader in the School of GeoSciences at the University of Edinburgh with research interests in modelling and observation of land—atmosphere interactions in cold regions. Address: School of Geosciences, University of Edinburgh, Scotland, UK. e-mail: ressery@staffmail.ed.ac.uk
^{*************}Bruce C. Forbes is Research Professor in Global Change at the Arctic Centre, University of Lapland. His research interests encompass land use and climate change in arctic ecosystems. He works closely with indigenous reindeer herders (Nenets, Sámi) and specializes in understanding anthropogenic disturbance regimes, reindeer rangeland dynamics, shrub tundra responses to warming, and resilience in linked social-ecological systems. Address: P.O. Box 122, 96101 Rovaniemi, Finland. e-mail: bforbes@ulapland.fi
^{**************}Mads C. Forchhammer is a Professor and Head of Ecosystem Ecology at Department of Bioscience, Aarhus University. He has a comprehensive statistical and theoretical background in population ecology. Recent work focuses on advanced multivariate and nonlinear analyses of climate-ecology interactions in time and space, including species ecology, population dynamics and ecosystem functioning. Address: Department of Bioscience, Aarhus University, Denmark and Greenland Climate Research Center, Nuuk, Greenland. e-mail: mcf@dmu.dk
^{***************}Vladimir N. Golubev is Lead Scientist at the Laboratory of Snow Avalanches and Mudflows at Geographical Faculty of Moscow State University, Moscow, the Russian Federation. His research interests include ice crystal formation in atmosphere, solid precipitation and snowfalls, modelling of vapour transfer and isotopic content of snow cover. Address: Laboratory of Snow Avalanches and Mudflows, Faculty of Geography, Moscow State University, Leninskie Gory, 1, 119991 Moscow, The Russian Federation. e-mail: golubev@geol.msu.ru
^{****************}Richard E. Honrath (Deceased) was a Professor at Michigan Technological University at the Department of Geological and Mining Engineering and Sciences and Department of Civil and Environmental Engineering. Address: Departments of Geological and Mining Engineering and Sciences, and Civil and Environmental Engineering, Michigan Technological University, Houghton, USA.
^{*****************}Glenn P. Juday is Professor of Forest Ecology in the School of Natural Resources and Agricultural Sciences of the University of Alaska Fairbanks. His research interests include: climate sensitivity of boreal forest growth and forest health, structure and biodiversity of older forest communities, and forest development following disturbance. Address: School of Natural Resources and Agricultural Sciences, P.O. Box 757200, Fairbanks, AK 99775-7200, USA. e-mail: gjuday@alsaska.edu
^{******************}Anna V. MeshcherskayaAddress: 7 Karbysheva Street, St. Petersburg 194021, Russia. e-mail: meschers@main.mgo.rssi.ru
^{*******************}Gareth K. Phoenix is a Senior Lecturer at the Department of Animal and Plant Sciences, University of Sheffield, UK. His research interests include the impacts of global change on vegetation and ecosystem process (in particular carbon and nutrient cycling), and how these ecosystem processes are impacted by plant community structure. Address: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK. e-mail: g.phoenix@sheffield.ac.uk
^{********************}John Pomeroy is the Canada Research Chair in Water Resources and Climate Change and Director of the Centre for Hydrology at the University of Saskatchewan, Saskatoon, Canada with a research base, the Coldwater Centre, on the campus of the Biogeoscience Institute in Canadian Rocky Mountains. His research interests include snow accumulation, redistribution and melt processes with relevance to cold regions hydrological modelling, climate and ecohydrology. Address: Centre for Hydrology, University of Saskatchewan, 117 Science Place, Saskatoon, SASK S7N 5C8, Canada. e-mail: john.pomeroy@usask.ca
^{*********************}Arja Rautio is research professor in Centre for Arctic Medicine at Thule Institute in University of Oulu, Finland, with research interests in human health and well-being in circumpolar area. Address: Centre for Arctic Medicine, Thule Institute, University of Oulu, P.O. Box 7300, 90014 Oulu, Finland. e-mail: arja.rautio@oulu.fi
^{**********************}David A. Robinson is a Professor at the Department of Geography at Rutgers, The State University of New Jersey. His research interests include regional to global snow cover kinematics and dynamics, interactions of snow cover with other climate elements, and the collection and archiving of accurate climatic data. Address: Department of Geography, Rutgers University, 54 Joyce Kilmer Avenue, Piscataway 08854, NJ, USA. e-mail: david.robinson@rutgers.edu
^{***********************}Niels M. Schmidt is a senior researcher at the Department of Bioscience, Aarhus University, Denmark. He is in charge of the biological monitoring at Zackenberg, and his research interests include environmental impacts on the population dynamics of arctic organisms. Address: Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark. e-mail: nms@dmu.dk
^{************************}Mark C. Serreze is Director of the National Snow and Ice Data Center and Professor of Geography at the University of Colorado Boulder. His Arctic research interests include atmosphere—sea ice interactions, synoptic climatology, boundary layer problems, numerical weather prediction and climate change. Efforts over the past 10 years have increasingly focused on trying to make sense of the rapid environmental changes being observed in the Arctic. Address: CIRES/NSIDC, University of Colorado, Campus Box 449, Boulder, CO 80309-0449, USA. e-mail: serreze@nsidc.org
^{*************************}Vladimir P. Shevchenko is a Leading Scientist at the Geological Department of P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia. His research interests include studies of processes of modern marine sedimentation (aerosols, snow, ice, suspended matter), especially in the Arctic. Address: P.P. Shirshov Institute of Oceanology RAS, 36 Nakhimovsky Prospect, 117997 Moscow, Russia. e-mail: vshevch@ocean.ru
^{**************************}Alexander I. Shiklomanov is a Research Scientist at the University of New Hampshire. His research is focusing on cold regions runoff formation and discharge of surface waters to the Arctic seas. Address: Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, NH 03824-3525, USA. e-mail: Alex.Shiklomanov@unh.edu
^{***************************}Andrey B. Shmakin is the head of Laboratory of Climatology at the Institute of Geography, Russian Academy of Sciences. His research interests include diagnosis of contemporary changes of climate and snow cover characteristics, numerical modelling of the soil—vegetation—snow—atmosphere heat/water transfer, and applied climatic research. Address: Institute of Geography, 29 Staromonetny St, Moscow 119017, Russia. e-mail: ashmakin@igras.ru
^{****************************}Peter Sköld is a Professor of History, Sami Culture and Society Development and executive director of the Northern Studies Centre of Excellence at Umeå University. He specializes in historical demography, health and vulnerability among indigenous peoples. Address: Centre for Sami Research, Umeå University, SE-901 87 Umeå, Sweden. e-mail: peter.skold@cesam.umu.se
^{*****************************}Matthew Sturm is a Research Scientist at the Cold Regions Research and Engineering Laboratory (CRREL). His research is focusing on thermal effects of snow cover, snow cover's effect on the environment particularly in polar and sub-polar areas, and snow and vegetation. Address: USA-CRREL-Alaska, P.O. Box 35170, Ft. Wainwright, AK 99703-0170, USA. e-mail: Matthew.Sturm@usace.army.mil
^{******************************}Ming-ko Woo is Professor Emeritus at the McMaster University, Canada. His specialization is in snow, permafrost, wetlands and water-related research. Address: School of Geography & Earth Sciences, Building 206 McMaster University 1280 Main Street, West Hamilton, ON L8S 4K1, Canada. e-mail: woo@mcmaster.ca
^{*******************************}Eric F. Wood is the Susan Dod Brown Professor of Civil and Environmental Engineering at Princeton University. His research interests include global scale modelling and remote sensing of the terrestrial water and energy cycles. Over the Arctic domain, he and his group have studied the hydrologic trends and impacts from climate change over the last 50 years. Address: Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA. e-mail: efwood@princeton.edu