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 Science Information Partners Program, Earth Observing System Data Information System (ESIP, EOSDIS)
Last metadata update: 2004-03-23T12:00:00Z
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Abstract:
This compilation of recent ice velocity data of the Antarctic ice sheet is intended for use by the polar scientific community. The data are presented in tabular form (ASCII), containing latitude, longitude, speed, bearing, and error ranges. A metadata header describes the source of the data, the time of measurement, and gives details on measurement accuracy and precision. The tables are available for ftp transfer.
Web pages developed specifically for this data set provide detailed information for viewing and selecting the velocity data. These pages contain large satellite image maps (available as jpeg files). The data sets used to create these images were contributed by several investigators, generally from already published work. Both in situ and image-based methods are used.
References for the data sets are included with the data tables. If you have well-characterized Antarctic ice velocity data you would like to contribute to this site, please contact teds@icehouse.colorado.edu. If you have any questions concerning the relevance of these data to your work please contact NSIDC User Services.
A gridded climatological monthly-mean data base of Arctic water vapor characteristics has been assembled by combining fixed station data with data from soundings taken over the Arctic Ocean from ships and Russian drifting stations.
Variables provided include temperature, specific humidity, zonal vapor flux, meridional vapor flux, zonal wind speed, and meridional wind speed, available for 15 pressure levels extending from the surface (1,000 mb) to 300 mb. Sea level pressure and geopotential height are provided for the 850 mb, 700 mb, 500 mb and 300 mb levels. Precipitable water, vertically integrated zonal vapor flux and vertically integrated meridional vapor flux are available for five layers: surface to 850 mb, 850 to 700 mb, 700 to 500 mb, 500 to 400 mb and 400 to 300 mb.
Coverage of the rawinsonde archives extends from 1954 through 1990 for data from the Russian North Pole series of drifting ice stations over the Arctic Ocean; from 1976 through 1991 for fixed-station data obtained from the National Center for Atmospheric Research; and from about 1958 through 1991 for fixed-station data obtained from the Historical Arctic Rawinsonde Archive.
All variables were obtained through interpolation of the raw sounding data, with the exception of sea level pressure and geopotential height. The files are structured in monthly data arrays over a subsection of the National Meteorological Center grid (octagonal grid format) centered over the pole, extending to approximately 65 degrees North on each side and about 55 degrees North at the corners.
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.
NOAA/NASA Pathfinder Program, Earth Science Information Partners Program, Earth Observing System Data Information System (NOAA/NASA PATHFINDER, ESIP, EOSDIS)
The Pathfinder Program, sponsored by the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA), is tasked to produce long-term data sets for global change research. The Special Sensor Microwave/Imager (SSM/I) Pathfinder Level 2 Land Products data set has been generated using the land classification algorithms developed by Neale, and the land surface temperature algorithms developed by McFarland. This data set includes both the land classification and land surface temperature products. The Pathfinder Level 2 Land Products data set is in swath format. Coverage is global land surface, and covers 1 August 1987 through 31 March 1988.
The SSM/I Pathfinder Level 3 Land Products data set has been generated using the Level 2 data described above. The Level 2 data were interpolated to a longitude-latitude grid with a resolution of one degree. For the Benchmark Period, the data were averaged over periods of five days (a pentad) or one month, although, for the land classification product, the most commonly occurring land class (the mode of the distribution within each bin) was chosen as the class for that bin and for the period. The data set, including both pentad and monthly grids, covers 1 August 1987 through 31 December 1988.
As of 26 September 2019, this data set is retired and no longer available for download. This data set was retired because other passive microwave data sets with longer temporal records are available at NSIDC. We recommend <a href="https://nsidc.org/data/amsre">the suite of AMSR-E products available at NSIDC</a> as an alternative.
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.
As of 31 August 2022, this data set is retired and no longer available for download. We recommend using <a href="https://nsidc.org/data/nsidc-0630">MEaSUREs Calibrated Enhanced-Resolution Passive Microwave Daily EASE-Grid 2.0 Brightness Temperature ESDR, Version 1</a> data set as an alternative. This data set provides daily, near-real-time Special Sensor Microwave Imager/Sounder (SSMIS) brightness temperatures in the Equal-Area Scalable Earth-Grid (EASE-Grid). The data set consists of gridded data in two projections: Northern Hemisphere and Southern Hemisphere. The data lag by one day and provide 365 days of near-real-time data. The spatial resolution is 25 km for all channels. Data are contained in flat binary files.
The Comprehensive Ocean - Atmosphere Data Set (COADS) Long Marine Reports Fixed-Length (LMRF) Arctic subset contains marine surface weather reports for regions north of 65 degrees N from ships, drifting ice stations, and buoys. The COADS LMRF Arctic subset contains data collected over the years 1950 to 1995 and includes the following parameters: air and sea temperature, cloudiness, humidity, and winds. The data are in the form of individual marine reports with a given latitude and longitude.
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.
The Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument on the NASA EOS Aqua satellite provides global passive microwave measurements of the Earth. NSIDC produces AMSR-E gridded brightness temperature data by interpolating AMSR-E data (6.9 GHz, 10.7 GHz, 18.7 GHz, 23.8 GHz, 36.5 GHz, and 89.0 GHz) to the output grids from swath space using an inverse-distance squared method. AMSR-E/Aqua L2A Global Swath Spatially-Resampled Brightness Temperatures (AE_L2A) input source data are used to create the gridded brightness temperature data.
Earth Observing System Data Information System, Arctic Leads Experiment, Office of Naval Research Arctic Leads Accelerated Research Initiative, Earth Science Information Partners Program (EOSDIS, LEADEX, LEADS ARI, ESIP)
This data set consists of AVHRR imagery selected from hard copy 'quick look' images to provide the best coverage possible over the Arctic approximately every three days for a three-year period. Level-1B data from NOAA/SDSD have been calibrated and mapped to earth locations, then gridded to 1 km pixels on a basin scale to the polar stereographic projection. The projection is similar to that used by NSIDC to produce DMSP SSM/I polar brightness temperature and sea ice products. Each image was ranked for areal coverage of particular seas and for degree of cloud coverage. Passes covering a large area are generally favored over shorter passes with less cloud cover. The data set was developed in support of the Office Of Naval Research Arctic Leads Accelerated Research Initiative (Arctic Leads ARI). The aim of the Initiative was to develop a more thorough understanding of the oceanography, meteorology, and ice dynamics surrounding formation and evolution of leads in sea ice. The leads ARI field experiment took place from March to April 1992.
A spreadsheet containing the image rankings is available in hard copy (NOARL Tech. Note 118, April 1991); paper copies of the spreadsheet are available on request. Data set information is available on-line. Data are available via FTP.
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).
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.