Abramov, A., and Coauthors, 2021: Two decades of active layer thickness monitoring in northeastern Asia. Polar Geogr., https://doi.org/10.1080/1088937X.2019.1648581, in press.
AICC, 2020: Alaska fire history data. Alaska Interagency Coordination Center, accessed 10 September 2020, https://fire.ak.blm.gov/predsvcs/intel.php.
Andersen, J. K., and Coauthors, 2019: Update of annual calving front lines for 47 marine terminating outlet glaciers in Greenland (1999-2018). Geol. Surv. Denmark Greenl. Bull., 43, e2019430202, https://doi.org/10.34194/GEUSB-201943-02-02.
Andreu-Hayles, L., B. V. Gaglioti, L. T. Berner, M. Levesque, K. J. Anchukaitis, S. J. Goetz, and R. D'Arrigo, 2020: A narrow window of summer temperatures associated with shrub growth in Arctic Alaska. Environ. Res. Lett., 15, 105012, https://doi.org/10.1088/1748-9326/ab897f.
AOS EOC, 2018: Report of the 4th Arctic observing summit: AOS 2018, Davos, Switzerland, 24-26 June 2018. International Study of Arctic Change (ISAC) Program Office, Arctic Institute of North America, 17 pp., www.arcticobservingsummit.org/sites/default/files/Report%20on%20the%20AOS%202018_FINAL_March2019_0.pdf.
Ballinger, T. J., and Coauthors, 2020: Surface air temperature. NOAA Arctic Report Card 2020, R. L. Thoman, J. Richter-Menge, and M. L. Druckenmiller, Eds., NOAA, https://doi.org/10.25923/gcw8-2z06.
Barrett, K., T. Loboda, A. D. McGuire, H. Genet, E. Hoy, and E. Kasischke, 2016: Static and dynamic controls on fire activity at moderate spatial and temporal scales in the Alaskan boreal forest. Ecosphere, 7, e01572, https://doi.org/10.1002/ecs2.1572.
Berner, L. T., and Coauthors, 2020: Summer warming explains widespread but not uniform greening in the Arctic tundra biome. Nat. Commun., 11, 4621, https://doi.org/10.1038/s41467-020-18479-5.
Bernhard, G., and Coauthors, 2020: Record-breaking increases in Arctic solar ultraviolet radiation caused by exceptionally large ozone depletion in 2020. Geophys. Res. Lett., 47, e2020GL090844, https://doi.org/10.1029/2020GL090844.
Bhartia, P. K., and C. W. Wellemeyer, 2002: TOMS-V8 total O3 algorithm. OMI Algorithm Theoretical Basis Document Volume II, NASA Goddard Space Flight Center Tech. Doc. ATBD-OMI-02, 15-31, http://eospso.nasa.gov/sites/default/files/atbd/ATBD-OMI-02.pdf.
Bhatt, U. S., and Coauthors, 2010: Circumpolar Arctic tundra vegetation change is linked to sea ice decline. Earth Interact., 14, https://doi.org/10.1175/2010EI315.1.
Bhatt, U. S., and Coauthors, 2021: Emerging anthropogenic influences on the South-central Alaska temperature and precipitation extremes and related fires in 2019. Land, 10, 82, https://doi.org/10.3390/land10010082.
Bieniek, P. A., and Coauthors, 2020: Lightning variability in dynamically down-scaled simulations of Alaska's present and future summer climate. J. Appl. Meteor. Climatol., 59, 1139-1152, https://doi.org/10.1175/JAMC-D-19-0209.1.
Biskaborn, B. K., and Coauthors, 2019: Permafrost is warming at a global scale. Nat. Commun., 10, 264, https://doi.org/10.1038/s41467-018-08240-4.
Bjella, K., 2019: Warming and thawing permafrost and impacts on infrastructure [in “State of the Climate in 2018”]. Bull. Amer. Meteor. Soc., 100 (9), S157-S159, 10.1175/2019BAMSStateoftheClimate.1.
Bjorkman, A. D., and Coauthors, 2020: Status and trends in Arctic vegetation: Evidence from experimental warming and long-term monitoring. Ambio, 49, 678-692, https://doi.org/10.1007/s13280-019-01161-6.
Boike, J., and Coauthors, 2018: A 20-year record (1998-2017) of permafrost, active layer, and meteorological conditions at a high Arctic permafrost research site (Bayelva, Spitsbergen). Earth Syst. Sci. Data, 10, 355-390, https://doi.org/10.5194/essd-10-355-2018.
Box, J. E., D. van As, and K. Steffen, 2017: Greenland, Canadian and Icelandic land ice albedo grids (2000-2016). Geol. Surv. Denmark Greenl. Bull., 38, 53-56, https://doi.org/10.34194/geusb.v38.4414.
Box, J. E., D. van As, and Coauthors, 2019: Key indicators of Arctic climate change: 1971-2017. Environ. Res. Lett., 14, 045010, https://doi.org/10.1088/1748-9326/aafc1b.
Brasnett, B., 1999: A global analysis of snow depth for numerical weather prediction. J. Appl. Meteor., 38, 726-740, https://doi.org/10.1175/15200450(1999)038<0726:AGAOSD>2.0.CO;2.
Brown, J., O. J. Ferrians Jr., J. A. Heginbottom, and E. S. Melnikov, 1997: Circum-Arctic map of permafrost and ground-ice conditions. U.S. Geological Survey Circum-Pacific Map CP-45, https://doi.org/10.3133/cp45.
Brown, R. D., and B. Brasnett, 2010: Canadian Meteorological Centre (CMC) Daily Snow Depth Analysis Data, Version 1. NASA National Snow and Ice Data Center Distributed Active Archive Center, accessed 27 July 2020, https://doi.org/10.5067/W9FOYWH0EQZ3.
Brown, R. D, B. Brasnett, and D. Robinson, 2003: Gridded North American monthly snow depth and snow water equivalent for GCM evaluation. Atmos.-Ocean, 41, 1-14, https://doi.org/10.3137/ao.410101.
Brown, R. D, D. Vikhamar Schuler, O. Bulygina, C. Derksen, K. Luojus, L. Mudryk, L. Wang, and D. Yang, 2017: Arctic terrestrial snow cover. Snow, Water, Ice and Permafrost in the Arctic (SWIPA) 2017, Arctic Monitoring and Assessment Programme, 25-64.
Brun, E., V. Vionnet, A. Boone, B. Decharme, Y. Peings, R. Valette, F. Karbou, and S. Morin, 2013: Simulation of Northern Eurasian local snow depth, mass, and density using a detailed snowpack model and meteorological reanalyses. J. Hydrometeor., 14, 203-219, https://doi.org/10.1175/JHM-D-12-012.1.
Buchwal, A., and Coauthors, 2020: Divergence of Arctic shrub growth associated with sea ice decline. Proc. Natl. Acad. Sci. USA, 117, 33 334-33 344, https://doi.org/10.1073/pnas.2013311117.
Butchart, N., and E. E. Remsberg, 1986: The area of the stratospheric polar vortex as a diagnostic for tracer transport on an isentropic surface. J. Atmos. Sci., 43, 1319-1339, https://doi.org/10.1175/1520-0469(1986)043<1319:TAOTSP>2.0.CO;2.
Callaghan, T., and Coauthors, 2011: The changing face of Arctic snow cover: A synthesis of observed and projected changes. Ambio, 40, 17-31, https://doi.org/10.1007/s13280-011-0212-y.
Chen, Y., F. S. Hu, and M. J. Lara, 2021: Divergent shrub-cover responses driven by climate, wildfire, and permafrost interactions in Arctic tundra ecosystems. Global Change Biol., 27, 652-663, https://doi.org/10.1111/gcb.15451.
Christiansen, H., and Coauthors, 2010: The thermal state of permafrost in the Nordic area during the International Polar Year 2007-2009. Permafrost Periglacial Processes, 21, 156-181, https://doi.org/10.1002/ppp.687.
Cohen, J., and Coauthors, 2020: Divergent consensuses on Arctic amplification influence on mid-latitude severe winter weather. Nat. Climate Change, 10, 20-29, https://doi.org/10.1038/s41558-019-0662-y.
DeLand, M. T., P. K. Bhartia, N. Kramarova, and Z. Chen, 2020: OMPS LP observations of PSC variability during the NH 2019-2020 season. Geophys. Res. Lett., 47, e2020GL090216, https://doi.org/10.1029/2020GL090216.
Ednie, M., and S. L. Smith, 2015: Permafrost temperature data 2008-2014 from community based monitoring sites in Nunavut. Geological Survey of Canada Open File 7784, 18 pp., https://doi.org/10.4095/296705.
EEAP, 2019: Environmental Effects and Interactions of Stratospheric Ozone Depletion, UV Radiation, and Climate Change: 2018 Assessment Report. Environmental Effects Assessment Panel, United Nations Environment Programme, 390 pp. https://ozone.unep.org/sites/default/files/2019-04/EEAP_assessment-report-2018%20%282%29.pdf.
Epstein, H. E., and Coauthors, 2021: Spatial patterns of arctic tundra vegetation properties on different soils along the Eurasia Arctic Transect, and insights for a changing Arctic. Environ. Res. Lett., 16, 014008, https://doi.org/10.1088/1748-9326/abc9e3.
Estilow, T. W., A. H. Young, and D. A. Robinson, 2015: A long-term Northern Hemisphere snow cover extent data record for climate studies and monitoring. Earth Syst. Sci. Data, 7, 137-142, https://doi.org/10.5194/essd-7-137-2015.
Etzelmuller, B., and Coauthors, 2020: Twenty years of European mountain permafrost dynamics-The PACE legacy. Environ. Res. Lett., 15, 104070, https://doi.org/10.1088/1748-9326/abae9d.
Fausto, R.S. and D. van As, 2019: Programme for monitoring of the Greenland Ice Sheet (PROMICE): Automatic weather station data, version: v03. Geological Survey of Denmark and Greenland, accessed 14 September 2020, https://doi.org/10.22008/promice/data/aws.
Fetterer, F., K. Knowles, W. N. Meier, M. Savoie, and A. K. Windnagel, 2017: Sea Ice Index, Version 3. Subset: Regional Daily Data (updated daily), National Snow and Ice Data Center, accessed 15 February 2021, https://doi.org/10.7265/N5K072F8.
Flannigan, M., B. Stocks, M. Turetsky, and M. Wotton, 2009: Impacts of climate change on fire activity and fire management in the circumboreal forest. Global Change Biol., 15, 549-560, https://doi.org/10.1111/j.13652486.2008.01660.x.
Frederikse, T., and Coauthors, 2020: The causes of sea-level rise since 1900. Nature, 584, 393-397, https://doi.org/10.1038/s41586-020-2591-3.
Gearheard, S., L. K. Holm, H. Huntington, J. M. Leavitt, and A. R. Mahoney, Eds., 2013: The Meaning of Ice: People and Sea Ice in Three Arctic Communities. International Polar Institute, 336 pp.
Gelaro, R., and Coauthors, 2017: The Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). J. Climate, 30, 5419-5454, https://doi.org/10.1175/JCLI-D-16-0758.1.
Giglio, L., L. Boschetti, D. P. Roy, M. L. Humber, and C. O. Justice, 2018: The Collection 6 MODIS burned area mapping algorithm and product. Remote Sens. Environ., 217, 72-85, https://doi.org/10.1016/j.rse.2018.08.005.
GMAO, 2015: MERRA-2tavg1_2d_lnd_Nx:2d, 1-Hourly, Time-Averaged, Single-Level, Assimilation, Land Surface Diagnostics V5.12.4. Goddard Earth Sciences Data and Information Services Center, accessed 26 August 2020, https://doi.org/10.5067/RKPHT8KC1Y1T.
Hanes, C. C., X. Wang, P. Jain, M. A. Parisien, J. M. Little, and M. D. Flannigan, 2019: Fire-regime changes in Canada over the last half century. Can. J. For. Res., 49, 256-269, https://doi.org/10.1139/cjfr-2018-0293.
Hanna, E., and Coauthors, 2020: Mass balance of the ice sheets and glaciers-Progress since AR5 and challenges. Earth-Sci. Rev., 201, 102976, https://doi.org/10.1016/j.earscirev.2019.102976.
Hayasaka, H., H. L. Tanaka, and P. A. Bieniek, 2016: Synoptic-scale fire weather conditions in Alaska. Polar Sci., 10, 217-226, https://doi.org/10.1016/j.polar.2016.05.001.
Heim, R. J., A. Bucharova, L. Brodt, J. Kamp, D. Rieker, A. V. Soromotin, A. Yurtaev, and N. Hölzel, 2021: Post-fire vegetation succession in the Siberian subarctic tundra over 45 years. Sci. Total Environ., 760, 143425, https://doi.org/10.1016/j.scitotenv.2020.143425.
Helfrich, S., D. McNamara, B. Ramsay, T. Baldwin, and T. Kasheta, 2007: Enhancements to, and forthcoming developments in the Interactive Multisensor Snow and Ice Mapping System (IMS). Hydrol. Processes, 21, 1576-1586, https://doi.org/10.1002/hyp.6720.
Hersbach, H., and Coauthors, 2020: The ERA5 global reanalysis. Quart. J. Roy. Meteor. Soc., 146, 1999-2049, https://doi.org/10.1002/qj.3803.
Holmes, R. M., and Coauthors, 2013: Climate change impacts on the hydrology and biogeochemistry of Arctic rivers. Global Impacts of Climate Change on Inland Waters, C. R. Goldman, M. Kumagai, and R. D. Robarts, Eds., Wiley, 3-26.
IDA, 2017: International Arctic Observations Assessment Framework. IDA Science and Technology Policy Institute, 73 pp., www.arcticobserving.org/news/268-international-arctic-observations-assessment-framework-released.
Isaksen, K., and Coauthors, 2011: Degrading mountain permafrost in southern Norway: Spatial and temporal variability of mean ground temperatures, 1999-2009. Permafrost Periglacial Processes, 22, 361-377, https://doi.org/10.1002/ppp.728.
Jones, P. D., D. H. Lister, T. J. Osborn, C. Harpham, M. Salmon, and C. P. Morice, 2012: Hemispheric and large-scale land-surface air temperature variations: An extensive revision and an update to 2010. J. Geophys. Res., 117, D05127, https://doi.org/10.1029/2011JD017139.
Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77, 437-471, https://doi.org/10.1175/15200477(1996)077<0437:TNYRP>2.0.CO;2.
Kemppinen, J., P. Niittynen, A.-M. Virkkala, K. Happonen, H. Riihimaki, J. Aalto, and M. Luoto, 2021: Dwarf shrubs impact tundra soils: Drier, colder, and less organic carbon. Ecosystems, https://doi.org/10.1007/s10021-020-00589-2, in press.
Kopec, B., X. Feng, F. A. Michel, and E. Posmentier, 2016: Influence of sea ice on Arctic precipitation. Proc. Natl. Acad. Sci. USA, 113, 46-51, https://doi.org/10.1073/pnas.1504633113.
Kropp, H., and Coauthors, 2021: Shallow soils are warmer under trees and tall shrubs across Arctic and boreal ecosystems. Environ. Res. Lett., 16, 015001, https://doi.org/10.1088/1748-9326/abc994.
Landrum, L., and M. M. Holland, 2020: Extremes become routine in an emerging new Arctic. Nat. Climate Change, 10, 1108-1115, https://doi.org/10.1038/s41558-020-0892-z.
Lavergne, T., and Coauthors, 2019: Version 2 of the EUMETSAT OSI SAF and ESA CCI sea-ice concentration climate data records. Cryosphere, 13, 49-78, https://doi.org/10.5194/tc-13-49-2019.
Lawrence, D. M., A. G. Slater, R. A. Tomas, M. M. Holland, and C. Deser, 2008: Accelerated Arctic land warming and permafrost degradation during rapid sea ice loss. Geophys. Res. Lett., 35, L11506, https://doi.org/10.1029/2008GL033985.
Lawrence, Z. D., J. Perlwitz, A. H. Butler, G. L. Manney, P. A. Newman, S.H. Lee, and E. R. Nash, 2020: The remarkably strong Arctic stratospheric polar vortex of winter 2020: Links to record-breaking Arctic oscillation and ozone loss. J. Geophys Res. Atmos., 125, e2020JD033271, https://doi.org/10.1029/2020JD033271.
Lee, C. M., and Coauthors, 2019: A framework for the development, design and implementation of a sustained Arctic ocean observing system. Front. Mar. Sci., 6, 451, https://doi.org/10.3389/fmars.2019.00451.
Liljedahl, A. K., I. Timling, G. V. Frost, and R. P. Daanen, 2020: Arctic riparian shrub expansion indicates a shift from streams gaining water to those that lose flow. Commun. Earth Environ., 1, 50, https://doi.org/10.1038/s43247-020-00050-1.
Lund, M., K. Raundrup, A. Westergaard-Nielsen, E. López-Blanco, J. Nymand, and P. Aastrup, 2017: Larval outbreaks in West Greenland: Instant and subsequent effects on tundra ecosystem productivity and CO2 exchange. Ambio, 46, 26-38, https://doi.org/10.1007/s13280-016-0863-9.
Mankoff, K. D., A. Solgaard, W. Colgan, A. P. Ahlstrøm, S. A. Khan, and R. S. Fausto, 2020: Greenland ice sheet solid ice discharge from 1986 through March 2020. Earth Syst. Sci. Data, 12, 1367-1383, https://doi.org/10.5194/essd-12-1367-2020.
Manney, G. L., and Z. D. Lawrence, 2016: The major stratospheric final warming in 2016: Dispersal of vortex air and termination of Arctic chemical ozone loss. Atmos. Chem. Phys., 16, 15 371-15 396, https://doi.org/10.5194/acp-16-15371-2016.
Manney, G. L., and Coauthors, 2020: Record-low Arctic stratospheric ozone in 2020: MLS observations of chemical processes and comparisons with previous extreme winters, Geophys. Res. Lett., 47, e2020GL089063, https://doi.org/10.1029/2020GL089063.
McClelland, J. W., S. J. Deìry, B. J. Peterson, R. M. Holmes, and E. F. Wood, 2006: A pan-arctic evaluation of changes in river discharge during the latter half of the 20th century. Geophys. Res. Lett., 33, L06715, https://doi.org/10.1029/2006GL025753.
McClelland, J. W., R. M. Holmes, K. H. Dunton, and R. Macdonald, 2012: The Arctic Ocean estuary. Estuaries Coasts, 35, 353-368, https://doi.org/10.1007/s12237-010-9357-3.
McElhinny, M., J. F., Beckers, C. Hanes, M. Flannigan, and P. Jain, 2020: A high-resolution reanalysis of global fire weather from 1979 to 2018-Overwin-tering the drought code. Earth Syst. Sci. Data, 12, 1823-1833, https://doi.org/10.5194/essd-2019-248.
Meier, W., J. Stroeve, and F. Fetterer, 2007: Whither Arctic sea ice? A clear signal of decline regionally, seasonally and extending beyond the satellite record. Ann. Glaciol., 46, 428-434, https://doi.org/10.3189/172756407782871170.
Meier, W., F. Fetterer, M. Savoie, S. Mallory, R. Duerr, and J. Stroeve, 2017: NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration, Version 3. National Snow and Ice Data Center, accessed 1 January 2020, https://doi.org/10.7265/N59P2ZTG.
Moon, T. A., and Coauthors, 2019: The expanding footprint of rapid Arctic change. Earth's Future, 7, 212-218, https://doi.org/10.1029/2018EF001088.
Morlighem, M., and Coauthors, 2017: BedMachine v3: Complete bed topography and ocean bathymetry mapping of Greenland from multibeam echo sounding combined with mass conservation. Geophys. Res. Lett., 44, 11 051-11 061, https://doi.org/10.1002/2017GL074954.
Mote, T., 2007: Greenland surface melt trends 1973-2007: Evidence of a large increase in 2007. Geophys. Res. Lett., 34, L22507, https://doi.org/10.1029/2007GL031976.
Mouginot, J., and Coauthors, 2019: Forty-six years of Greenland ice sheet mass balance from 1972 to 2018. Proc. Natl. Acad. Sci. USA, 116, 9239-9244, https://doi.org/10.1073/pnas.1904242116.
Mudryk, L., M. Santolaria-Otín, G. Krinner, M. Menegoz, C. Derksen, C. Brutel-Vuilmet, M. Brady, and R. Essery, 2020a: Historical Northern Hemisphere snow cover trends and projected changes in the CMIP-6 multi-model ensemble. Cryosphere, 14, 2495-2514, https://doi.org/10.5194/tc-14-2495-2020.
Mudryk, L., R. Brown, C. Derksen, K. Luojus, and B. Decharme, 2020b: Terrestrial snow cover [in “State of the Climate in 2019”]. Bull. Amer. Meteor. Soc., 101 (8), S263-S265, https://doi.org/10.1175/BAMS-D-20-0086.1.
Muller, R., J.-U. Grooß, C. Lemmen, D. Heinze, M. Dameris, and G. Bodeker, 2008: Simple measures of ozone depletion in the polar stratosphere. Atmos. Chem. Phys., 8, 251-264, https://doi.org/10.5194/acp-8-251-2008.
Murray, M. S., R. D. Sankar, and G. Ibarguchi, 2018: The Arctic observing summit, background and synthesis of outcomes 2013-2016. International Study of Arctic Change Program Office, Arctic Institute of North America, 8 pp., www.arcticobservingsummit.org/sites/default/files/AOS_Synthesis_FinalReport. pdf.
Myers-Smith, I. H., and Coauthors, 2020: Complexity revealed in the greening of the Arctic. Nat. Climate Change, 10, 106-117, https://doi.org/10.1038/s41558-019-0688-1.
NRC, 2006: Toward an Integrated Arctic Observing Network. The National Academies Press, 128 pp., https://doi.org/10.17226/11607.
Neale, R. E., and Coauthors, 2021: Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate: UNEP Environmental Effects Assessment Panel, Update 2020. Photochem. Photobiol. Sci., 20, 1-67, https://doi.org/10.1007/s43630-020-00001-x.
OSTP, 2014: National Plan for Civil Earth Observations. National Science and Technology Council, 71 pp., https://obamawhitehouse.archives.gov/sites/default/files/microsites/ostp/NSTC/2014_national_plan_for_civil_earth_observations.pdf.
Overland, J. E., and M. Wang, 2021: The 2020 Siberian heat wave. Int. J. Climatol., 41, E2341-E2346, https://doi.org/10.1002/joc.6850.
Overland, J. E., and Coauthors, 2021: How do intermittency and simultaneous processes obfuscate the Arctic influence on midlatitude winter extreme weather events? Environ. Res. Lett., 16, 043002, https://doi.org/10.1088/1748-9326/abdb5d.
Partain, J. L., and Coauthors, 2016: An assessment of the role of anthropogenic climate change in the Alaska fire season of 2015 [in “Explaining Extremes of 2015 from a Climate Perspective”]. Bull. Amer. Meteor. Soc., 97 (12), S14-S18, https://doi.org/10.1175/BAMS-D-16-0149.1.
Peltier, W. R., D. F. Argus, and R. Drummond, 2018: Comment on “An assessment of the ICE-6G_C (VM5a) glacial isostatic adjustment model” by Purcell et al. J. Geophys. Res. Solid Earth, 123, 2019-2018, https://doi.org/10.1002/2016JB013844.
Peng, G., W. N. Meier, D. J. Scott, and M. H. Savoie, 2013: A long-term and reproducible passive microwave sea ice concentration data record for climate studies and monitoring. Earth Syst. Sci. Data, 5, 311-318, https://doi.org/10.5194/essd-5-311-2013.
Peterson, B. J., R. M. Holmes, J. W. McClelland, C. J. Vorosmarty, R. B. Lammers, A. I. Shiklomanov, I. A. Shiklomanov, and S. Rahmstorf, 2002: Increasing river discharge to the Arctic Ocean. Science, 298, 2171-2173, https://doi.org/10.1126/science.1077445.
Petty, A. A., M. Webster, L. Boisvert, and T. Markus, 2018: The NASA Eulerian Snow on Sea Ice Model (NESOSIM) v1.0: Initial model development and analysis. Geosci. Model Dev., 11, 4577-4602, https://doi.org/10.5194/gmd-11-4577-2018.
Petty, A. A, N. T. Kurtz, R. Kwok, T. Markus, T. A. Neumann, 2020. Winter Arctic sea ice thickness from ICESat‐2 freeboards. J. Geophys. Res. Oceans, 125, e2019JC015764. https://doi.org/10.1029/2019JC015764.
Pinzon, J., and C. Tucker, 2014: A non-stationary 1981-2012 AVHRR NDVI3g time series. Remote Sens., 6, 6929-6960, https://doi.org/10.3390/rs6086929.
Prendin, A. L., and Coauthors, 2020: Immediate and carry‐over effects of insect outbreaks on vegetation growth in West Greenland assessed from cells to satellite. J. Biogeogr., 47, 87-100, https://doi.org/10.1111/jbi.13644.
Rawlins, M. A., and Coauthors, 2010: Analysis of the arctic system freshwater cycle intensification: observations and expectations. J. Climate, 23, 5715-5737, https://doi.org/10.1175/2010JCLI3421.1.
Raynolds, M. K., D. A. Walker, H. E. Epstein, J. E. Pinzon, and C. J. Tucker, 2012: A new estimate of tundra-biome phytomass from trans-Arctic field data and AVHRR NDVI. Remote Sens. Lett., 3, 403-411, https://doi.org/10.1080/01431161.2011.609188.
Reynolds, R. W., N. A. Rayner, T. M. Smith, D. C. Stokes, and W. Wang, 2002: An improved in situ and satellite SST analysis for climate. J. Climate, 15, 1609-1625, https://doi.org/10.1175/1520-0442(2002)015<1609:AIISAS>2.0.CO;2.
Reynolds, R. W., T. M. Smith, C. Liu, D. B. Chelton, K. S. Casey, and M. G. Schlax, 2007: Daily high-resolution-blended analyses for sea surface temperature. J. Climate, 20, 5473-5496, https://doi.org/10.1175/2007JCLI1824.1.
Ricker, R., S. Hendricks, L. Kaleschke, X. Tian-Kunze, J. King, and C. Haas, 2017: A weekly Arctic sea-ice thickness data record from merged CryoSat-2 and SMOS satellite data. Cryosphere, 11, 1607-1623, https://doi.org/10.5194/tc-11-1607-2017.
Robinson, D. A., T. W. Estilow, and NOAA CDR Program, 2012: NOAA Climate Data Record (CDR) of Northern Hemisphere (NH) Snow Cover Extent (SCE), Version 1 [r01]. NOAA National Centers for Environmental Information, accessed 27 July 2020, https://doi.org/10.7289/V5N014G9.
Romanovsky, V., and Coauthors, 2017: Changing permafrost and its impacts. Snow, Water, Ice and Permafrost in the Arctic (SWIPA) 2017, Arctic Monitoring and Assessment Programme, 65-102.
Romanovsky, V, and Coauthors, 2020: Terrestrial permafrost [in “State of the Climate in 2019”]. Bull. Amer. Meteor. Soc., 101(8), S265-S269, https://doi.org/10.1175/BAMS-D-20-0086.1
Sasgen, I., and Coauthors, 2020: Return to rapid ice loss in Greenland and record loss in 2019 detected by the GRACE-FO satellites. Commun. Earth. Environ., 1, 8, https://doi.org/10.1038/s43247-020-0010-1.
Schaaf, C. B., and Z. Wang, 2015: MCD43A4 MODIS/Terra+Aqua BRDF/Albedo Nadir BRDF Adjusted Ref Daily L3 Global - 500m V006. NASA EOSDIS Land Processes DAAC, accessed 21 February 2021, https://doi.org/10.5067/MODIS/MCD43A4.006.
Scholten, R., R. Jandt, E. A. Miller, B. M. Rogers, and S. Veraverbeke, 2021: Overwintering fires in boreal forests. Nature, 593, 399-404, https://doi.org/10.1038/s41586-021-03437-y.
Schroeder, W., P. Oliva, L. Giglio, and I. A. Csiszar, 2014: The new VIIRS 375m active fire detection data product: Algorithm description and initial assessment. Remote Sens. Environ., 143, 85-96, https://doi.org/10.1016/j.rse.2013.12.008.
Schuur, E. A. G., 2020: Permafrost carbon [in “State of the Climate in 2019”]. Bull. Amer. Meteor. Soc., 101 (8), S270-S271, https://doi.org/10.1175/BAMSD-20-0086.1.
Serreze, M. C., and R. G. Barry, 2011: Processes and impacts of Arctic amplification: A research synthesis. Global Planet. Change, 77, 85-96, https://doi.org/10.1016/j.gloplacha.2011.03.004.
Shevtsova, I., B. Heim, S. Kruse, J. Schröder, E. I. Troeva, L. A. Pestryakova, E. S. Zakharov, and U. Herzschuh, 2020: Strong shrub expansion in tundra-taiga, tree infilling in taiga and stable tundra in central Chukotka (north-eastern Siberia) between 2000 and 2017. Environ. Res. Lett., 15, 085006, https://doi.org/10.1088/1748-9326/ab9059.
Shiklomanov, N. I., D. A. Streletskiy, and F. E. Nelson, 2012: Northern Hemisphere component of the global Circumpolar Active Layer Monitoring (CALM) program. Proc. 10th Int. Conf. on Permafrost, Vol. 1, Salekhard, Russia, Tyumen Oil and Gas University, 377-382.
Shiklomanov, A. I., S. J. Deìry, M. V. Tretiakov, D. Yang, D. Magritsky, A. Georgiadi, and W. Tang, 2021: River freshwater flux to the Arctic Ocean. Arctic Hydrology, Permafrost and Ecosystem, Y. Daqing and K. Douglas, Eds., Springer, 703-738.
Shupe, M. D., and Coauthors, 2020: The MOSAiC expedition: A year drifting with the Arctic sea ice. NOAA Arctic Report Card 2020, R.L. Thoman, J. Richter-Menge, and M. L. Druckenmiller, Eds., NOAA, https://doi.org/10.25923/9g3vxh92.
Simonsen, S. B., V. R. Barletta, W. T. Colgan, and L. S. Sørensen, 2021: Greenland Ice Sheet mass balance (1992-2020) from calibrated radar altimetry. Geophys. Res. Lett., 48, 105-110, https://doi.org/10.1029/2020GL091216.
Skarin, A., M. Verdonen, T. Kumpula, M. Macias-Fauria, M. Alam, J. T. Kerby, and B. C. Forbes, 2020: Reindeer use of low Arctic tundra correlates with landscape structure. Environ. Res. Lett., 15, 115012, https://doi.org/10.1088/17489326/abbf15.
Slats, R., and Coauthors, 2019: Voices from the front lines of a Changing Bering Sea: An indigenous perspective for the 2019 Arctic Report Card. Arctic Report Card 2019, J. Richter-Menge, M. L. Druckenmiller, and M. Jeffries, Eds., NOAA, www.arctic.noaa.gov/Report-Card/Report-Card-2019.
Smith, S. L., C. Duchesne, and A. G. Lewkowicz, 2019: Tracking changes in permafrost thermal state in Northern Canada. Cold Regions Engineering 2019, J.-P. Bilodeau et al., Eds., American Society of Civil Engineers, 670-677, https://doi.org/10.1061/9780784482599.077.
Strand, S., H. Christiansen, M. Johansson, J. Akerman, and O. Humlum, 2020: Active layer thickening and controls on interannual variability in the Nordic Arctic compared to the circum-Arctic. Permafrost Periglacial Processes, 32, 47-58, https://doi.org/10.1002/ppp.2088.
Stroeve, J., and D. Notz, 2018: Changing state of Arctic sea ice across all seasons. Environ. Res. Lett., 13, 1-23, https://doi.org/10.1088/1748-9326/aade56.
Stroh, J. N., G. Panteleev, S. Kirillov, M. Makhotin, and N. Shakhova, 2015: Sea-surface temperature and salinity product comparison against external in situ data in the Arctic Ocean. J. Geophys. Res. Oceans, 120, 7223-7236, https://doi.org/10.1002/2015JC011005.
Swanson, D. K., 2021: Permafrost thaw‐related slope failures in Alaska's Arctic National Parks, c. 1980-2019. Permafrost Periglacial Processes, https://doi.org/10.1002/ppp.2098, in press.
Takala, M., K. Luojus, J. Pulliainen, C. Derksen, J. Lemmetyinen, J.-P. Karna, and J. Koskinen, 2011: Estimating northern hemisphere snow water equivalent for climate research through assimilation of space-borne radiometer data and ground-based measurements. Remote Sens. Environ., 115, 3517-3529, https://doi.org/10.1016/j.rse.2011.08.014.
Tedesco, M., X. Fettweis, T. Mote, J. Wahr, P. Alexander, J. Box, and B. Wouters, 2013: Evidence and analysis of 2012 Greenland records from spaceborne observations, a regional climate model and reanalysis data. Cryosphere, 7, 615-630, https://doi.org/10.5194/tc-7-615-2013.
The IMBIE Team, 2020: Mass balance of the Greenland Ice Sheet from 1992 to 2018. Nature, 579, 233-239, https://doi.org/10.1038/s41586-019-1855-2.
Thoman, R. L., J. Richter-Menge, and M. L. Druckenmiller, Eds., 2020: Arctic Report Card 2020. NOAA, 143 pp., https://doi.org/10.25923/mn5p-t549.
Timmermans, M.-L., Z. Labe, and C. Ladd, 2020: Sea surface temperature [in “State of the Climate in 2019”]. Bull. Amer. Meteor. Soc., 101 (8), S249-S251, https://doi.org/10.1175/BAMS-D-20-0086.1.
Treharne, R., J. W. Bjerke, H. Tømmervik, and G. K. Phoenix, 2020: Extreme event impacts on CO2 fluxes across a range of high latitude, shrub-dominated ecosystems. Environ. Res. Lett., 15, 104084, https://doi.org/10.1088/1748-9326/abb0b1.
Tschudi, M., W. N. Meier, J. S. Stewart, C. Fowler, and J. Maslanik, 2019: EASE-Grid Sea Ice Age, Version 4. NASA National Snow and Ice Data Center Distributed Active Archive Center, accessed 15 February 2021, https://doi.org/10.5067/UTAV7490FEPB.
Tschudi, M., W. N. Meier, J. S. Stewart, 2020: An enhancement to sea ice motion and age products at the National Snow and Ice Data Center (NSIDC). Cryosphere, 14, 1519-1536, https://doi.org/10.5194/tc-14-1519-2020.
USGS, 2019: Demonstrating the Value of Earth Observations-Methods, Practical Applications, and Solutions-Group on Earth Observations Side Event Proceedings. USGS Open-File Rep. 2019-1033, 33 pp., https://pubs.usgs.gov/of/2019/1033/ofr20191033.pdf.
U.S. National Ice Center, 2008: IMS Daily Northern Hemisphere Snow and Ice Analysis at 1 km, 4 km, and 24 km Resolutions, Version 1. National Snow and Ice Data Center, accessed 27 July 2020, https://doi.org/10.7265/N52R3PMC..
van As, D., R. S. Fausto, J. Cappelen, R. S. van de Wal, R. J. Braithwaite, and H. Machguth, 2016: Placing Greenland ice sheet ablation measurements in a multi-decadal context. Geol. Surv. Denmark Greenl. Bull., 35, 71-74, https://doi.org/10.34194/geusb.v35.4942.
Vasiliev, A. A., D. S. Drozdov, A. G. Gravis, G. V. Malkova, K. E. Nyland, and D. A. Streletskiy, 2020: Permafrost degradation in the western Russian Arctic. Environ. Res. Lett., 15, 045001, https://doi.org/10.1088/1748-9326/ab6f12.
Veraverbeke, S., B. M. Rogers, M. L. Goulden, R. R. Jandt, C. E. Miller, E. B. Wiggins, and J. T. Randerson, 2017: Lightning as a major driver of recent large fire years in North American boreal forests. Nat. Climate Change, 7, 529534, https://doi.org/10.1038/nclimate3329.
Verdonen, M., L. T. Berner, B. C. Forbes, and T. Kumpula, 2020: Periglacial vegetation dynamics in Arctic Russia: decadal analysis of tundra regeneration on landslides with time series satellite imagery. Environ. Res. Lett., 15, 105020, https://doi.org/10.1088/1748-9326/abb500.
Vickers, H., K. A. Høgda, S. Solbø, S. R. Karlsen, H. Tømmervik, R. Aanes, and B. B. Hansen, 2016: Changes in greening in the high Arctic: insights from a 30 year AVHRR max NDVI dataset for Svalbard. Environ. Res. Lett., 11, 105004, https://doi.org/10.1088/1748-9326/11/10/105004.
Vickers, H., S. R. Karlsen, and E. Malnes, 2020: A 20-year MODIS-based snow cover dataset for Svalbard and its link to phenological timing and sea ice variability. Remote Sens., 12, 1123, https://doi.org/10.3390/rs12071123.
Vihma, T., and Coauthors, 2016: The atmospheric role in the Arctic water cycle: A review on processes, past and future changes, and their impacts. J. Geophys. Res. Biogeosci., 121, 586-620, https://doi.org/10.1002/2015JG003132.
Weatherhead, B., A. Tanskanen, and A. Stevermer, 2005: Ozone and ultraviolet radiation. Arctic Climate Impact Assessment, Cambridge University Press, 152-182, www.amap.no/documents/download/1086/inline.
Webster, M. A., C. Parker, L. Boisvert, and R. Kwok, 2019: The role of cyclone activity in snow accumulation on Arctic sea ice. Nat. Commun., 10, 5285, https://doi.org/10.1038/s41467-019-13299-8.
Wegmann, M., and Coauthors, 2015: Arctic moisture source for Eurasian snow cover variations in autumn. Environ. Res. Lett., 10, 054015, https://doi.org/10.1088/1748-9326/10/5/054015.
Wheeling, K., 2020: The rise of zombie fires. Eos, 101, https://doi.org/10.1029/2020EO146119.
WHO, 2002: Global solar UV index: A practical guide. WHO/SDE/OEH/02.2, 28 pp., www.who.int/uv/publications/en/GlobalUVI.pdf.
WMO, 2018: Scientific Assessment of Ozone Depletion: 2018. World Meteorological Organization, Global Ozone Research and Monitoring Project Rep. 58, 588 pp., https://csl.noaa.gov/assessments/ozone/2018/.
Wotton, B. M., 2009: Interpreting and using outputs from the Canadian forest fire danger rating system in research applications. Environ. Ecol. Stat., 16, 107-131, https://doi.org/10.1007/s10651-007-0084-2.
Wu, W., X. Sun, H. Epstein, X. Xu, and X. Li, 2020: Spatial heterogeneity of climate variation and vegetation response for Arctic and high-elevation regions from 2001-2018. Environ. Res. Commun., 2, 011007, https://doi.org/10.1088/25157620/ab6369.
York, A., U. S. Bhatt, E. Gargulinski, Z. Grabinski, P. Jain, A. Soja, R. L. Thoman, and R. Ziel, 2020: Wildland fire in high Northern latitudes. Arctic Report Card 2020, R. L. Thoman, J. Richter-Menge, and M. L. Druckenmiller, Eds., NOAA, https://doi.org/10.25923/2gef-3964.
Young, A. M., P. E. Higuera, P. A. Duffy, and F. S. Hu, 2017: Climatic thresholds shape northern highlatitude fire regimes and imply vulnerability to future climate change. Ecography, 40, 606617, https://doi.org/10.1111/ecog.02205.
Yu, Y., J. P. Dunne, E. Sheviakova, P. Ginoux, S. Malyshev, J. G. John, and J. P. Krasting, 2021: Increased risk of the 2019 Alaskan July fires due to anthropogenic activity [in “Explaining Extreme Events of 2019 from a Climate Perspective”]. Bull. Amer. Meteor. Soc., 102 (1), S1-S7, https://doi.org/10.1175/BAMS-D-20-0154.1.
Yue, X., L. J. Mickley, J. A. Logan, R. C. Hudman, M. V. Martin, and R. M. Yantosca, 2015: Impact of 2050 climate change on North American wildfire: Consequences for ozone air quality. Atmos. Chem. Phys., 15, 1003310055, https://doi.org/10.5194/acp-15-10033-2015.
Zhang, X., J. He, J. Zhang, I. Polyakov, R. Gerdes, J. Inoue, and P. Wu, 2013: Enhanced poleward moisture transport and amplified northern high-latitude wetting trend. Nat. Climate Change, 3, 47-51, https://doi.org/10.1038/nclimate1631.