The Data Access Portal has information in 3 columns. An outline of the content in these columns is provided above. When first entering the search interface, all potential datasets are listed. Datasets are indicated in the map and results tabulation elements which are located in the middle column. The order of results can be modified using the "Sort by" option in the left column. On top of this column is normally relevant guidance information to user presented as collapsible elements.
If the user want to refine the search, this can be done by constraining the bounding box search. This is done in the map - the listing of datasets is automatically updated. Date constraints can be added in the left column. For these to take effect, the user has to push the button marked search. In the left column it is also possible to specific text elements to search for in the datasets. Again pushing the button marked "Search" is necessary for these to take action. Complex search patterns can be constructed by changing the operators used in the text field and prefixing words with '+' and '-' to indicate whether they have to be present or should not be present in the results.
Other elements indicated in the left and right columns are facet searches, i.e. these are keywords that are found in the datasets and all datasets that contain these specific keywords in the appropriate metadata elements are listed together. Further refinement can be done using full text, date or bounding box constraints. Individuals, organisations and data centres involved in generating or curating the datasets are listed in the facets in the right column.
Citation of data and service
If you use data retrieved through this portal, please acknowledge the efforts of the data portal and the data centres contributing.
The information required to properly cite a dataset is normally provided in the discovery metadata the datasets.
author,
title,
year of publication,
publisher (for data this is often the archive where it is housed),
edition or version,
access information (a URL or persistent identifier, e.g. DOI if provided)
Earth Observing System Data Information System, International Program for Antarctic Buoys, Earth Science Information Partners Program, World Climate Research Program (EOSDIS, IPAB, ESIP, WCRP)
Through participating research organizations in various countries, the World Climate Research Programme's (WCRP) International Programme for Antarctic Buoys (IPAB) maintains a network of drifting buoys in the Antarctic sea ice zone to support a better understanding of sea ice motion, meteorology, and oceanography. The IPAB Antarctic Drifting Buoy Data archive, spanning the years 1995 to 1998, includes measurements of buoy position, atmospheric pressure, air temperature, and sea surface temperature. Data are organized by daily and three-hour averages and are provided as raw, instantaneous, non-interpolated data values. Data were collected from buoys initially deployed in the following three study regions: East Antarctica; the Weddell Sea; and the Bellingshausen, Amundsen, and Ross Seas.
The Historical Arctic Rawinsonde Archive (HARA) contains millions of vertical soundings of temperature, pressure, humidity, and wind, representing all available rawinsonde ascents from Arctic land stations poleward of 65 degrees North. HARA includes soundings from the beginning of record through mid-1996. Most stations began recording soundings in the late 1950s, but a few began in 1947 or 1948.
The Antarctic atlas consists of 28 digital elevation maps which cover all of Antarctica north of 72.1 degrees south at a resolution of three kilometers. Each map contains surface elevations and coordinates for one atlas page covering 16 degrees of longitude. Data were acquired by the Geodetic Satellite (GEOSAT) Geodetic Mission (GM) from March 1985 through September 1986 and are available in both Universal Transverse Mercator (UTM) coordinates, and in latitude and longitude coordinates.
Data were mapped using the UTM projection in atlas form to decrease the distortion that usually occurs at the poles. Many features of the Antarctic Ice Sheet are shown in more detail than in previous digital elevation models, especially along the margin of the East Antarctic Ice Sheet. A geostatistical mapping technique (Herzfeld et al. 1993) improved the accuracy of surface elevations compared to previous GEOSAT elevation data sets. This atlas will facilitate the monitoring of changes in surface elevation that could indicate mass changes in the Antarctic Ice Sheet.
The Near-real-time Ice and Snow Extent (NISE) data set provides daily, global maps of sea ice concentrations and snow extent. These data are not suitable for time series, anomalies, or trends analyses. They are meant to provide a best estimate of current ice and snow conditions based on information and algorithms available at the time the data are acquired. Near-real-time products are not intended for operational use in assessing sea ice conditions for navigation.
This NISE Version 5 product contains DMSP-F18, SSMIS-derived sea ice concentrations and snow extents derived from the Special Sensor Microwave Imager/Sounder (SSMIS) aboard the Defense Meteorological Satellite Program (DMSP) F18 satellite. For DMSP-F16, SSMIS-derived data, see <a href="https://doi.org/10.5067/JAQDJKPX0S60"> NISE Version 3</a>. For DMSP-F17, SSMIS-derived data, see <a href="https://nsidc.org/data/nise/versions/4"> NISE Version 4</a>. For the older, DMSP-F13, Special Sensor Microwave Imager (SSMI) derived data, see <a href="https://doi.org/10.5067/4FSODMDM1WEJ">NISE Version 2</a>.
The Historical Soviet Daily Snow Depth (HSDSD) product is based on observations from 284 World Meteorological Organization (WMO) stations throughout Russia and the former Soviet Union from 1881 through 1995. Other parameters include snow cover percent, snow characteristics, site characterization, and quality flags.
This data set provides a Digital Elevation Model (DEM) for Antarctica to 81.5 degrees south latitude, at a resolution of 5 km. Approximately twenty million data points were used to generate this data set. Data points were derived from ERS-1 radar altimetry during the geodetic phase from March 1994 to May 1995.
The SMMR Antenna Temperatures (Nimbus-7) data set consists of antenna temperatures from passive microwave radiometers aboard NOAA's Nimbus-7 satellite. The instrument is the Scanning Multichannel Microwave Radiometer (SMMR). Each file consists of one days worth of data in swath format, i.e. the portion of the Earth's surface viewed by the scanning radiometer. Antenna temperature data are available from NSIDC from October 1978 to August 1987. SMMR was a ten channel passive microwave instrument using six conventional Dicke-type radiometers. It delivered orthogonally polarized antenna temperature data at five frequencies: 6.6, 10.69, 18.0 21.0 and 37.0 GHz. The two 37.0 GHz radiometers operated
continuously for each polarization. The other radiometers alternated polarizations on alternate scans. The size of each daily file is 35 MBytes. The data are distributed on FTP.
The scanner operated only on alternate days, due to spacecraft power limitations. There are typically at least 14 days of coverage per month, although major data gaps occur in August: in August, 1982, the 4th, 8th, and 16th are missing for both polar regions; in August,
1984, the 13th through the 23rd are missing for both polar regions.
NOAA/NASA Pathfinder Program, Earth Science Information Partners Program, Earth Observing System Data Information System (NOAA/NASA PATHFINDER, ESIP, EOSDIS)
The Nimbus-7 SMMR Pathfinder Brightness Temperatures data set contains global brightness temperatures in swath format (level 1b) from 25 October 1978 to 20 August 1987. The instrument obtained near-global coverage at five frequencies (6.6, 10.7, 18, 21, and 37 GHz) in both horizontal and vertical polarizations, at a constant incidence angle of 50.3 degrees, every six days. Data are stored as daily orbit files in compressed Hierarchical Data Format (HDF) and are available on FTP.
The Nimbus-7 SMMR Level 1B Pathfinder data set was created at the Jet Propulsion Laboratory (JPL) from a level 1A 'TAT' data set provided by the Goddard Space Flight Center (GFSC). The SMMR operated continuously from 25 Oct 1978 through 16 November 1987, at which time it began alernate-day operation. The processed level 1B SMMR data are stored as orbit files in HDF format. Each level 1B orbit file covers a time period of approximately 104.16 minutes. The file size for an uncompressed orbit file is approximately 4.3 megabytes. The total volume of the level 1B data set is approximately 70 gigabytes (compressed).
NCEP/NCAR Arctic Marine Rawinsonde Archive contains 17,659 marine rawinsonde reports for the region north of 65 degrees North. Its record extends from 1976 to 1996. These soundings have been extracted from the National Center for Atmospheric Research (NCAR) rawinsonde archive of the National Meteorological Center (NMC) (now the National Center for Environmental Prediction, or NCEP). The NCEP/NCAR Arctic Marine Rawinsonde Archive data set complements the Historical Arctic Rawinsonde Archive (HARA) for land stations and the Russian 'North Pole' drifting station archive.
NOAA/NASA Pathfinder Program, Earth Science Information Partners Program, Earth Observing System Data Information System (NOAA/NASA PATHFINDER, ESIP, EOSDIS)
This data set consists of brightness temperatures acquired from the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7 Pathfinder satellite. The brightness temperatures are gridded onto the Equal-Area Scalable Earth Grid (EASE-Grid) and are presented in three different projections: Northern Hemisphere, Southern Hemisphere, and global.
The Tanana river in the Interior of Alaska usually freezes over during October and November. The ice continues to grow throughout the winter accumulating an average maximum thickness of about 110 cm, depending upon winter weather conditions.
The Nenana Ice Classic competition began in 1917 when railroad engineers bet a total of 800 dollars, winner takes all, guessing the exact time (month, day, hour, minute) ice on the Tanana River would break up. Each year since then, Alaska residents have guessed at the timing of the river breakup. A tripod, connected to an on-shore clock with a string, is planted in two feet of river ice during river freeze-up in October or November. The following spring, the clock automatically stops when the tripod moves as the ice breaks up. The time on the clock is used as the river ice breakup time.
Many factors influence the river ice breakup, such as air temperature, ice thickness, snow cover, wind, water temperature, and depth of water below the ice. Generally, the Tanana river ice breaks up in late April or early May (historically, April 20 to May 20). The time series of Tanana river ice breakup dates can be used to indicate climate change in the region.
This data set includes yearly snow melt onset dates over Arctic sea ice derived from Scanning Multichannel Microwave Radiometer (SMMR), Special Sensor Microwave/Imager (SSM/I), and the Special Sensor Microwave Imager/Sounder (SSMIS) brightness temperature measurements. The data are gridded to the 25 km Northern Hemisphere Polar Stereographic projection and available from 1979 through 2022. One browse image is available for each year.
This data set also contains value-added statistics for each grid cell, including: mean melt onset date, latest (maximum) melt onset date, earliest (minimum) melt onset date, range of melt onset dates (the difference between maximum and minimum onset dates), and the standard deviation of melt onset dates. One browse image is also provided for each statistical field.