2026-04-08T19:01:07Zhttp://nsidc.org/api/dataset/metadata/oaioai:nsidc.org/G02203.0012025-12-04T05:17:25Zv0_otherv0_allnoaa
G02203.001Arctic Sea Ice Charts from Danish Meteorological Institute, 1893 - 1956Danish Meteorological Institute & National Snow and Ice Data Center (Underhill, V. & Fetterer, F. (Comps.))Arctic Sea Ice Charts from Danish Meteorological Institute, 1893 - 19562012-11-15Boulder, Colorado USANSIDC: National Snow and Ice Data Center1false10.7265/N56D5QXChttps://dx.doi.org/10.7265/N56D5QXCG02203Technical ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-61991-303-492-2468CIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAInvestigatorLyngbyvej 100 DK-2100Copenhagen EDenmarkEARTH SCIENCEOceansSea IceIce Extent ICE EXTENTEARTH SCIENCEOceansSea IceSea Ice Concentration SEA ICE CONCENTRATIONClimatology/Meteorology/AtmosphereSea IceSea Ice ConditionsSea Ice ExtentSea Ice Observations and Charts-projectVISUAL OBSERVATIONSGROUND-BASED OBSERVATIONSGROUND-BASED OBSERVATIONSSHIPS1893-04-011956-08-31complete5590-180180OceanArctic OceanEspecially early in the century, these charts are based on relatively sparse data and rely to a large degree on the inference and extrapolation of the lead mapmakers: V. Garde, C. Speerschneider, and H. Thomsen and M.V.L.Lorck (Thomsen, 1947). Direct observations are always clearly marked, but white space denotes the assumed ice edge. Directly observed open water is not shown differently than assumed open water. Details on areas of open water can be found in the notes that accompany the charts. In most cases, this assumed ice edge follows a 30-year climatological average over a period of years that shifts over the record. We do not have a refernce or any more information on the 30-year climatology. However, the assumed ice edge moves independent of the climatological average line. This suggests that the mapmakers incorporated more factors than just an average estimate. As suggested by Kelly (1979), the mapmakers probably extrapolated the annual ice edge in three ways: they probably used their knowledge of ice movement, growth, and melt to project ice conditions from given data points further in both time and space. They also may have used auxiliary data that are not included in the DMI publications themselves; these sources may have included annual climatic or atmospheric circulation data present at the time. The DMI mapmakers were experienced climatologists, so while their inferences are subjective, they are also probably the most reliable of the time.These data are freely, openly, and fully accessible without restrictions.These data are freely, openly, and fully available to use without restrictions, provided that you cite the data according to the recommended citation at https://nsidc.org/about/use_copyright.html.EnglishNOAANational Oceanic and Atmospheric Administrationhttp://nsidc.org/noaa/Data Center ContactNOAAUser Servicesnsidc@nsidc.org1-303-492-61991-303-492-2468National Snow and Ice Data CenterCIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAFTP4.5 MBJPEGChapman, W.L., and J.E. Walsh. 1991, updated 1996. Arctic and Southern Ocean sea ice concentrations. Boulder, CO: National Snow and Ice Data Center http://nsidc.org/data/g00799.html.
Dehn, W. S. 1979. Inadequacies in Archive Sea Ice Data. Glaciological Data Report : Workshop on Snow Cover and Sea Ice Data. GD-5 p 101-106. World Data Center A for Glaciology (Snow and Ice). Boulder, CO.
Kelly, P. M. 1979. An Arctic Sea Ice Data Set: 1901-1956. Glaciological Data Report : Workshop on Snow Cover and Sea Ice Data. GD-5 p 101-106. World Data Center A for Glaciology (Snow and Ice). Boulder, CO.
Walsh, J.E. (1978) A data set on Northern Hemisphere sea ice extent. National Snow and Ice Data Center, "Glaciological Data, Report GD-2", part 1, pp. 49 - 51.
Sear, C. B. 1988. An Index of Sea Ice Variations in the Nordic Seas. Int. J. Climatology 8: 339-55.
Thompson, H. 1947. The Annual Reports on the Arctic Sea Ice issued by the Danish Meteorological Institute. J. of Glaciology 1(3): 140-141. These charts, created by the Danish Meteorological Institute (DMI), provide observed and inferred sea ice extent for each summer month from 1893 to 1956. From 1893 to 1956, the Danish Meteorological Institute (DMI) created charts of observed and inferred sea ice extent for each summer month. These charts are based on compiled observations of ice conditions reported by a variable network of national organizations, shore-based observers, scientific expeditions, and ships as detailed in each report; in cases where no observations were available, the lead mapmakers extrapolated further ice cover using their knowledge of ice movement. Except for where direct observations are indicated, caution is advised in using the charts’ ice edge because there is no way to quantify the assumptions used in extrapolating ice edge or the error involved in this method. See the note on reliability for further discussion of potential error. The charts were scanned at the Icelandic Meteorological Office (IMO) and are being made available here as a service and in cooperation with DMI and other contributors. In all, there are 266 image files containing 291 images.<br/><br/>
<p>For a gridded data set derived from this product, see the <a href="https://nsidc.org/data/g10007/">Arctic Sea Ice Concentration and Extent from Danish Meteorological Institute Sea Ice Charts, 1901-1956</a>data set</p>VIEW RELATED INFORMATIONhttps://dx.doi.org/10.7265/N56D5QXCDocumentationGET DATAhttps://noaadata.apps.nsidc.org/NOAA/G02203/HTTPSCEOS IDN DIFVERSION 9.92012-11-152025-12-04NSIDCVersion SummaryNSIDCMinor VersionNSIDCCurrent Version1NSIDCLevel of ServiceStandardNSIDCFull Dataset CitationDanish Meteorological Institute & National Snow and Ice Data Center. (2012). <i>Arctic Sea Ice Charts from Danish Meteorological Institute, 1893 - 1956</i>. (G02203, Version 1). Underhill, V. & Fetterer, F. (Comps.) [Data Set]. Boulder, Colorado USA. National Snow and Ice Data Center. <a href="https://doi.org/10.7265/N56D5QXC">https://doi.org/10.7265/N56D5QXC</a>. [<i><describe subset used if applicable></i>].NSIDCRetiredfalseNSIDCRelated Servicesapplication/vnd.nasa.cmr.umm+jsonfalsejroebuckmmt_service_32962S2721063021-NSIDCV0NSIDCV01service2023-06-27T14:22:11.750Zhttps://noaadata.apps.nsidc.org/NSIDCV0_NOAA_Data_HTTPS_File_SystemNOT PROVIDED1NOAA@NSIDC HTTPS File SystemAccess and download NOAA@NSIDC data using a web browser, or through a command line utility such as WGET, or using programming languages such as R or Python.https://nsidc.org/data/user-resources/help-center/how-access-and-download-noaansidc-dataVIEW RELATED INFORMATIONNOAA@NSIDC HTTPS Access GuidePublicationURLUSER SERVICESNSIDC User ServicesEmailnsidc@nsidc.orgDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESThis is the most current release of this service.AUTHORDEVELOPERPUBLISHERSERVICE PROVIDERNational Oceanic and Atmospheric Administration at the National Snow and Ice Data CenterNSIDC_NOAAhttps://cdn.earthdata.nasa.gov/umm/service/v1.4UMM-S1.4https://noaadata.apps.nsidc.org/NOAA/G02203/