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)
NOTE ON GLAS BINARY DATA: Access to all ICESat/GLAS binary data products at NSIDC DAAC was removed 01 August 2017. The Binary Data Subsetter also has been decommissioned. ICESat/GLAS data remain available in <a href="http://nsidc.org/data/glah06/versions/34">HDF5 format</a>.
The Geoscience Laser Altimeter System (GLAS) instrument on the Ice, Cloud, and Land Elevation Satellite (ICESat) provides global measurements of polar ice sheet elevation to discern changes in ice volume (mass balance) over time. Secondary objectives of GLAS are to measure sea ice roughness and thickness, cloud and atmospheric properties, land topography, vegetation canopy heights, ocean surface topography, and surface reflectivity.
GLAS has a 1064 nm laser channel for surface altimetry and dense cloud heights, and a 532 nm lidar channel for the vertical distribution of clouds and aerosols.
Level-1B elevation data (GLA06) include surface elevation, surface roughness assuming no slope, surface slope assuming no roughness, and geodetic and atmospheric corrections for range measurements. GLA06 is used in conjunction with GLA05 to create the Level-2 altimetry products (GLA12-15)
Each data granule has an associated browse product that users can quickly view to determine the general quality of the data in the granule. Browse products consist of image plots of key parameters and statistics. Data are in scaled integer binary format, big-endian (Unix) byte order.
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.
This Level-3 rainfall accumulation product (AE_RnGd) consists of two grids of 28 rows by 72 columns of monthly averaged rainfall accumulation over ocean and land. Both grids are 5 degree by 5 degree resolution.
GLAH08 Level-2 planetary boundary layer (PBL) and elevated aerosol layer heights data contains PBL heights, ground detection heights, and top and bottom heights of elevated aerosols from -1.5 km to 20.5 km (4 sec sampling rate) and from 20.5 km to 41 km (20 sec sampling rate). Each data granule has an associated browse product.
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.
GLAH07 Level-1B global backscatter data are provided at full instrument resolution. The product includes full 532 nm (41.1 to -1.0 km) and 1064 nm (20 to -1 km) calibrated attenuated backscatter profiles at 5 times per second, and from 10 to -1 km, at 40 times per second for both channels. Also included are calibration coefficient values and molecular backscatter profiles at once per second. Data granules contain approximately 190 minutes (2 orbits) of data. Each data granule has an associated browse product.
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).
GLAH06 is used in conjunction with GLAH05 to create the Level-2 altimetry products. Level-2 altimetry data provide surface elevations for ice sheets (GLAH12), sea ice (GLAH13), land (GLAH14), and oceans (GLAH15). Data also include the laser footprint geolocation and reflectance, as well as geodetic, instrument, and atmospheric corrections for range measurements. The Level-2 elevation products, are regional products archived at 14 orbits per granule, starting and stopping at the same demarcation (± 50° latitude) as GLAH05 and GLAH06. Each regional product is processed with algorithms specific to that surface type. Surface type masks define which data are written to each of the products. If any data within a given record fall within a specific mask, the entire record is written to the product. Masks can overlap: for example, non-land data in the sea ice region may be written to the sea ice and ocean products. This means that an algorithm may write the same data to more than one Level-2 product. In this case, different algorithms calculate the elevations in their respective products. The surface type masks are versioned and archived at NSIDC, so users can tell which data to expect in each product. Each data granule has an associated browse product.
NOTE ON GLAS BINARY DATA: Access to all ICESat/GLAS binary data products at NSIDC DAAC was removed 01 August 2017. The Binary Data Subsetter also has been decommissioned. ICESat/GLAS data remain available in <a href="http://nsidc.org/data/glah04/versions/33">HDF5 format</a>.
The Geoscience Laser Altimeter System (GLAS) instrument on the Ice, Cloud, and Land Elevation Satellite (ICESat) provides global measurements of polar ice sheet elevation to discern changes in ice volume (mass balance) over time. Secondary objectives of GLAS are to measure sea ice roughness and thickness, cloud and atmospheric properties, land topography, vegetation canopy heights, ocean surface topography, and surface reflectivity.
GLAS has a 1064 nm laser channel for surface altimetry and dense cloud heights, and a 532 nm lidar channel for the vertical distribution of clouds and aerosols.
Level-1A global laser pointing data (GLA04) contain two orbits of attitude data from the spacecraft star tracker, instrument star tracker, gyro, and laser reference system, and other spacecraft attitude data required to calculate precise laser pointing. Data are in scaled integer binary format, big-endian (Unix) byte order.
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.
NOTE ON GLAS BINARY DATA: Access to all ICESat/GLAS binary data products at NSIDC DAAC was removed 01 August 2017. The Binary Data Subsetter also has been decommissioned. ICESat/GLAS data remain available in <a href="http://nsidc.org/data/glah15/versions/34">HDF5 format</a>.
The Geoscience Laser Altimeter System (GLAS) instrument on the Ice, Cloud, and Land Elevation Satellite (ICESat) provides global measurements of polar ice sheet elevation to discern changes in ice volume (mass balance) over time. Secondary objectives of GLAS are to measure sea ice roughness and thickness, cloud and atmospheric properties, land topography, vegetation canopy heights, ocean surface topography, and surface reflectivity.
GLAS has a 1064 nm laser channel for surface altimetry and dense cloud heights, and a 532 nm lidar channel for the vertical distribution of clouds and aerosols.
This level-2 altimetry product (GLA15) provides surface elevations for oceans. Data also include the laser footprint gelocation and reflectance, as well as geodetic, instrument, and atmospheric corrections for range measurements.
Each data granule has an associated browse product that users can quickly view to determine the general quality of the data in the granule. Browse products consist of image plots of key parameters and statistics. Data are in scaled integer binary format, big-endian (Unix) byte order.
Level-1A global laser pointing data (GLAH04) contain two orbits of attitude data from the spacecraft star tracker, instrument star tracker, gyro, and laser reference system, and other spacecraft attitude data required to calculate precise laser pointing.
The high-resolution Radarsat Antarctic Mapping Project (RAMP) Digital Elevation Model (DEM) combines topographic data from a variety of sources to provide consistent coverage of all of Antarctica.
GLAH02 Level-1A atmospheric data include the normalized relative backscatter for the 532 nm and 1064 nm channels, and low-level instrument corrections such as laser energy (1064 nm and 532 nm), photon coincidence (532 nm), and detector gain correction (1064 nm). Each data granule has an associated browse product.