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)
CEAREX was a multi-platform field program conducted in the Norwegian Seas and Greenland north to Svalbard from September 1988 through May 1989. Canada, Denmark, France, Norway and the United States participated in the experiment.
This data set provides monthly sea ice concentration for the Arctic from 1901 to 1995 and for the Southern Oceans from 1973 to 1990 on a standard 1-degree grid (cylindrical projection) to provide a relatively uniform set of sea ice extent for all longitudes. The data are in ASCII format and are available via FTP.
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.
NSIDC provides this data set to aid investigations of variability and trends in sea ice cover. Ice cover in these data are indicated by sea ice concentration: the percentage of the ocean surface covered by ice. The ice-covered area indicates how much ice is present; it is the total surface area of a pixel multiplied by the ice concentration in that pixel. Ice persistence is the percentage of months over the data set time period that ice existed at a location. The ice extent indicates whether ice is present; here, ice is considered to exist in a pixel if the sea ice concentration exceeds 15 percent. This data set provides users with data about total ice-covered areas, sea ice extent, ice persistence, and monthly climatologies of sea ice concentrations.
NOTE: This data set has been replaced by the <a href="http://nsidc.org/data/g02176.html">Sea Ice Charts of the
Russian Arctic in Gridded Format, 1933-2006</a> data set.
These gridded ice charts represent a reformatting of information contained in another data set, the Russian Arctic and Antarctic Research Institute's (AARI) 10 Day Digital Arctic Sea Ice Charts. AARI digitized Arctic sea ice concentration and stage of development charts as part of an international data exchange program. The AARI source charts, similar to operational charts distributed by the National Ice Center describing ice type and constitution, were developed from aircraft and satellite observations for shipping purposes, and provide extremely detailed information. Such data are particularly valued in process studies tracking the growth and recession of polynyas, or for looking at the preponderance of ice at certain stages of development in a particular area. NSIDC does not maintain the operational charts, but archives the AARI digitized version. However, the Arctic and Antarctic Research Institute (AARI) 10 Day Digital Arctic Sea Ice Charts were encoded in SIGRID (Sea Ice Grid) format, which assigns numerical values to ice parameters and records them at specific lat/lon grid points. But due to the difficulties of visualizing, extracting and working with data in SIGRID, NSIDC is now providing
AARI data in NSIDC's Equal Area SSM/I Earth Grid.
The EASE-Grid format makes it especially easy to compare observed ice concentrations or ice types with the same parameters derived from satellite data (such as ice concentrations from passive microwave sensors).
AARI sea ice data in the EASE-Grid projection are gridded at a 12.5 km resolution, for both Western (24W to 110E) and Eastern (105E to 130W) sectors . Data extend from 1953 through 1990. Postscript (.ps) files depicting coverage per year are also provided with the data.
This archive of daily rawinsonde measurements of wind direction and speed, atmospheric pressure, humidity, air temperature, and geopotential height as well as surface-based observation of cloud cover (amount, type and height) from Soviet North Pole drifting stations was assembled under the direction of Dr. J. Kahl, with funding from the National Oceanic and Atmospheric Administration, the National Science Foundation, and the Electric Power Research Institute. Soundings were recorded from April 19, 1954 to July 31, 1990 at drifting stations located in the Arctic Ocean, north of approximately 70 degrees North. Data were obtained from several different sources. All of these data are ultimately derived from the set of bound volumes of handwritten tables kept at the Arctic and Antarctic Research Institute (AARI) in St. Petersburg, Russia. Data are in 21 ASCII text format files with an average size of under 10 MB.
Earth Observing System Data Information System, Earth Science Information Partners Program (EOSDIS, ESIP)
Last metadata update: 2003-10-13T12:00:00Z
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Abstract:
This data set was distributed by NSIDC until October 2003, when it was withdrawn from distribution because it duplicated, what was then, the NOAA National Climatic Data Center (NCDC) data set DSI-3720. DSI-3720 has been merged into a larger precipitation data set, <a href="http://dx.doi.org/10.3334/ORNLDAAC/220">Global Historical Climatology Network, 1753-1990 (NDP-041)</a>. This merged data set is revised and updated beyond what was originally distributed by NSIDC. The DSI-3720 collection consisted of monthly precipitation measurements from 622 stations located in the Former Soviet Union. Documentation for the original collection can be found at <a href="https://doi.org/10.5065/F2ES-S375">NCDC USSR Monthly Precipitation for 622 Stations 1891-1999</a>. Another closely related data set that may be of use is the <a href="https://doi.org/10.5065/GMFP-N302">Russian Summary of Day, 1881-1989</a>.
<p><font color="#FF0000">Note: This data set is now on HTTPS so references to CD-ROM are historic and no longer applicable.</font></p>
The Ice Altimetry System (IAS) data seet contains surface elevations of the Antarctic and Greenland ice sheets derived from Seasat and GEOSAT radar altimetry data. The Seasat data were collected for a continuous 90 days in 1978, at latitudes between 72 degrees South and 72 degrees North. GEOSAT was launched in 1985 and placed in a nearly identical orbit to Seasat, also at latitudes of between 72 degrees South and 72 degrees North. The orbit was designed to provide high-density measurements over the Earth's surface, at a maximum grid spacing of 2.7 kilometers at the equator and much denser spacing over polar ice sheets. Data were acquired between April 1985 and September 1986.
Initially acquired by the Johns Hopkins APL (Applied Physics Lab) satellite tracking facility, the raw altimetry satellite data from Seasat and GEOSAT were passed on to NASA, via the US Navy. NASA developed slope correction routines for the higher slopes over the ice sheets, relative to ocean surfaces. The data are height profile Level 3 data and gridded height Level 4 data provided by the Oceans and Ice branch of the Laboratory for Hydrospheric Physics of Goddard Space Flight Center. Elevations from the full data rate (i.e., one measurement every 662.5 m) are provided in georeferenced databases. These elevations are relative to the WGS-84 ellipsoid. Gridded elevations at 10-kilometer and 20-kilometer spacing are provided in the gridded data sets created from the GEOSAT and Seasat data, respectively. Software to extract and browse subsets of these data is included. The IAS software also allows the user to view contours created from the gridded data and groundtracks of the full-rate data.
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.
Earth Science Information Partners Program, NOAA/NASA Pathfinder Program (ESIP, NOAA/NASA PATHFINDER)
Last metadata update: 2000-12-01T12:00:00Z
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Abstract:
<h2 class='newsdate'>Please note that the machine on which these AVHRR data are processed has reached its life expectancy and will no longer be available as of 02 June 2008 until further notice.</h2>
The AVHRR Polar Pathfinder Twice-Daily 1.25 km EASE-Grid Composites
are a collection of products for both poles, consisting of twice-daily
gridded and calibrated satellite channel data and derived parameters.
Data include five Advanced Very High Resolution Radiometer (AVHRR)
channels, clear sky surface broadband albedo and skin temperature,
solar zenith angle, satellite elevation angle, sun-satellite relative
azimuth angle, surface type mask, cloud mask, orbit mask, time of
acquisition, and ice motion vectors. Data are composited onto two
grids per day based on common local solar times and scan angle. Reduced-resolution data (25 km) derived from the 1.25 km data are
available to assist users in selecting these data. AVHRR local area coverage (LAC) and High Resolution Picture Transmission (HRPT) level
1b data are used to generate the Polar Pathfinder products at grid
spacings of 1.25 km. AVHRR Polar Pathfinder data extend poleward from
48.4 degrees north and 53.2 degrees south latitudes, from August 1993
through December 1998 for the Northern Hemisphere, and from April 1992
through January 1996 for the Southern Hemisphere. Data are in 1-byte and 2-byte integer grid format. Ice motion vectors are in ASCII text
format. Data are available on 8-mm tape or by ftp. Distribution formats available: North: 104 MB (2-byte), 52 MB
(1-byte), 8 MB (ice motion) South: 82 MB (2-byte), 41 MB (1-byte), 6.3
MB (ice motion).
The total annual freezing and thawing indices are defined as the
cumulative number of degree-days when air temperatures are below and
above zero degrees Celsius. The total annual freezing index has been
widely used to predict permafrost distribution; estimate the
maximum thickness of sea, lake, and river ice, and the maximum depth of
ground-frost penetration; and classify snow types. The annual total
thawing index has been used to predict permafrost distribution and to
estimate the maximum depth of thaw in frozen ground. Both total
freezing and thawing indices are important parameters for engineering
design in cold regions.
Data coverage is global. The data set contains the total annual freezing and thawing indices with a spatial resolution of 0.5 degrees
latitude by 0.5 degrees longitude. Two data files are available, for
the freeze and thaw indices respectively, in flat binary format. Each
file is approximately 1 MB in size. The total annual freezing and
thawing indexes were calculated based upon the monthly mean air
temperature by Legates and Willmott (1990).
This data set contains gridded brightness temperatures and sea ice concentrations for both polar regions. Brightness temperature and sea ice concentration grids have 25 x 25 km grid elements in polar stereographic projection.