In this Issue



Issue no. 34, December 2000


Arctic Climatology Project - EWG Arctic Meteorology and Climate Atlas CD-ROM Now Available from NSIDC

The Arctic Climatology Project - EWG Arctic Meteorology and Climate Atlas CD-ROM, the final volume in an Environmental Working Group Joint U.S.-Russian Atlas series, is now available from NSIDC. It contains newly available meteorology data from Russian and other sources as well as introductory historical and educational information for newcomers to arctic meteorology.

Meteorological data from Russian and western coastal stations, as well as data from drifting stations and Russian ice patrol ships, are included. Records from some of the coastal stations date back to the beginning of the 20th century. Data from the Russian North Pole drifting station program add records to and correct errors in an earlier release of these data. Selected meteorological records from the historic Norwegian drifting expeditions of the Fram in the late 1800s and the Maud in the early 1900s are included, as are data from drifting stations and experiments supported by the U.S. Air Force and Navy: T-3 (Fletcher's Ice Island), Alpha, Charlie, ARLIS, and AIDJEX. A plotting tool allows easy browsing of data from individual stations. In addition to station data, climatological monthly mean fields of 2 m air temperature, sea level pressure, precipitation, cloud, snow, and global solar radiation are provided in an easy-to-use format. These fields are based on the best available products improved, when possible, with new data. Scientific applications foreseen for the Atlas data include investigation of evidence for climate change; examination of interannual variability of climate in the coastal zone and in the central Arctic; regional study of air mass transformation from open water to ice-covered ocean; and characterization of the spatial variability of meteorological variables.

In addition to providing a great source of meteorology and climate data, the Atlas contains elements that make it an excellent educational tool. The Atlas summarizes the history of arctic exploration from both Russian and U.S. perspectives and includes an article about native Inuit climate knowledge, as well as documents translated from Russian that describe Russian North Pole drifting stations and weather hazards in the Russian Arctic. A photo gallery from early North Pole stations, an arctic weather primer, and an English-Russian glossary of meteorological terms round out the educational and historical information.

The Atlas was developed by specialists from the Arctic and Antarctic Research Institute (AARI), St. Petersburg, Russia; the University of Washington, Seattle; and the National Snow and Ice Data Center, University of Colorado, Boulder; and was funded by the National Oceanic and Atmospheric Administration and the Environmental Working Group (EWG). NSIDC also distributes the other two products in the series: the EWG Joint U.S.-Russian Atlas of the Arctic Ocean (winter and summer periods on two CD-ROMs) and the EWG Joint U.S.-Russian Arctic Sea Ice Atlas.

For further information on the EWG atlases, visit the data catalog summary or contact NSIDC User Services.

A Technician preparing a DARMS instrument before deployment

A technician prepares the electronics of a Russian Drifting Automatic Radiometeorological Station (DARMS) before deployment. DARMS wind, air pressure, and air temperature data are included in the new Atlas.


MODIS Snow Products Now Available

NSIDC is pleased to announce the availability of MODIS snow products. The MODIS snow products, which consist of global snow cover extent at 500-meter resolution, include level 2 daily, level 3 daily, and level 3 eight-day products. Available data include observations made beginning on 13 September 2000. The new MODIS web site at NSIDC includes the new NSIDC catalog pages for the snow products, sample images, information on grids, and an ECS-formatted user's guide. Also included are links to the EOS Data Gateway search and order tool (EDG), user tutorials for the EDG, the MODIS Land Group browse products, the MODIS Instrument Science Team, and other DAACs.

See MODIS snow products at NSIDC.

MODIS sea ice products are expected to be available in early January, 2001. All users of NSIDC's MODIS products will be notified when additional MODIS snow and ice products become available. Comments and questions regarding the MODIS snow products or use of the EOS Data Gateway may be directed to NSIDC User Services.

AVHRR Polar Pathfinder Data Now Available

The AVHRR Polar Pathfinder Twice-Daily 5 km EASE-Grid Composites are now available through NSIDC. This collection of products for both poles consists 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, and Universal Coordinated Time (UTC) of acquisition.

Data are composited onto two grids per day based on common local solar times and scan angle. AVHRR global area coverage (GAC) data are used to generate the AVHRR Polar Pathfinder products at grid spacings of 5 km. AVHRR Polar Pathfinder data extend poleward from 48.4 degrees north and 53.1 degrees south latitudes, from July 1981 through August 1998. Data are in 1-byte and 2-byte integer grid format and are available on 8 mm tape or by ftp. File sizes range from 3.26 MB to 6.52 MB for the Northern Hemisphere, and from 2.58 MB to 5.15 MB for the Southern Hemisphere.

For more information, including links to full documentation and access to data subsetting, visit the data catalog summary.

Regridded IPA Permafrost and Ground Ice Map

The International Permafrost Association's Circum-Arctic Permafrost and Ground Ice Map from the Circumpolar Active-Layer Permafrost System (CAPS) CD-ROM has been regridded to the NSIDC EASE-Grid format and to a 0.5° by 0.5° format. The new digital versions of this data set allow better access to the data for research purposes, since the original versions of this same data set were only available in hard-copy map form or in Geographic Information System (GIS) ArcInfo format. The regridded data set contains a snap-shot of the permafrost boundaries and ground-ice content. Data are gridded at 12.5 km, 25 km, and 0.5° resolution. The data set will be available via ftp from the CAPS data catalog summary.

To register or for more information, visit the data catalog summary or contact NSIDC User Services.

New Search and Order Tool at NSIDC

NSIDC has a new search and order tool for accessing and subsetting several data sets from our archive. GISMO, the Graphical Interface for Subsetting, Mapping, and Ordering, is a Java-based tool designed to allow users to search for gridded data sets by collection, parameter (channel), and date. Additionally, users can specify an area of interest and spatially subset data to reduce the total volume of delivered data. The GISMO provides access to subsets of AVHRR, SSM/I, SMMR, and TOVS Pathfinder data.

A user registration is required to access the GISMO interface. Most browsers require the Java2 plugin to access GISMO. Instructions and online help are provided. To learn more about the GISMO, visit the GISMO Web site.

SMMR Brightness Temperature Data in EASE-Grid Format

NSIDC has released the Nimbus-7 SMMR Pathfinder Daily EASE-Grid Brightness Temperatures, derived from the recently recalibrated Level 1b SMMR Pathfinder Brightness Temperatures (Njoku, E., B. Rague and K. Fleming, 1998. "The Nimbus-7 SMMR Pathfinder Brightness Temperature Data Set" JPL Publication 98-4.) The format of the new EASE-Grid data set includes three projections: Northern Hemisphere, Southern Hemisphere, and full global. Data are available for 25 October 1978 through 20 August 1987, effectively extending the available time series of global passive microwave data in EASE-Grid format by nine years. Resolution is 25 km for all channels (6.6, 10.7, 18, 21, and 37 GHz).

Users can order temporal or spatial subsets with the web-based Graphical Interface for Subsetting, Mapping, and Ordering (GISMO) at the GISMO Web site. Because data set production of CD-ROMs will not begin until summer of 2001, users are encouraged to use GISMO for subset orders. Prior to the availability of the CDs, we will attempt to fill orders for the complete data set or large time series of the data as resources allow. For further assistance, please contact NSIDC User Services. Documentation is available online at the data catalog summary.

Antarctic 5-km Digital Elevation Model from ERS-1 Altimetry

NSIDC has released a new data set that contains a digital elevation model (DEM) of Antarctica to 81.5 degrees south latitude, at a resolution of 5 km. Data points were derived from ERS-1 radar altimetry during the geodetic phase from March 1994 to May 1995. The improved density in coverage and resolution, compared with past satellite altimetry missions, provides better detection of topographic detail such as surface undulations, ice streams, grounding zones, and interstream ridges. The orthometric heights derived from the ERS-1 data contribute to a more accurate and complete mapping of the Antarctic ice sheets than was previously possible and, therefore, to ongoing studies of ice mass balance studies in Antarctica. The DEM is in ASCII text format in a polar stereographic projection with the origin at the south pole, and is referenced to the OSU91A geoid. The DEM is available by ftp. Documentation is available online at the data catalog summary.

Sea Ice Trends and Climatologies from SMMR and SSM/I

NSIDC has released a collection of value-added products from Nimbus-7 SMMR and DMSP SSM/I data to assist users in investigations of the variability and trends of sea ice cover. Information about sea ice extent, total ice-covered area, and anomalies were calculated from NASA Team and Bootstrap algorithms, and were extracted from NSIDC and Goddard Space Flight Center (GSFC) sea ice data products. These summaries are provided as ASCII text tables and GIF browse images. Ice persistence, monthly climatologies of sea ice concentrations, and ocean masks are provided in flat binary grids. Documentation and data access are available at the Sea Ice Products at NSIDC site.

Browse Images Available for SSM/I Sea Ice Data

Browse images of monthly sea ice concentration for North and South Polar regions are now available for the DMSP SSM/I Daily and Monthly Polar Gridded Sea Ice Concentrations product. Images are in GIF format and are available via ftp through the data catalog summary.

Error Notice

In August 2000, NSIDC was alerted to an error in the GISP2 Visual Stratigraphy references section of the Greenland Summit Ice Cores CD-ROM. The following is a corrected version of the "Spinelli, G. 1996" reference citation:

Spinelli, G. 1996. A statistical analysis of ice-accumulation level and variability in the GISP2 ice core and a reexamination of the age of the termination of the Younger Dryas cooling episode. Earth System Science Center Technical report No. 96-001, Pennsylvania State University, University Park, PA.

This section can be found on the CD-ROM under the GISP2 Data heading, in the Physical Properties and Ice Core Stratigraphy, GISP2 Visual Stratigraphy section. Please contact NSIDC User Services if you have any questions.



In March 2000, the XXI Joint Science Committee for the World Climate Research Programme approved the organization of research into the Climate and Cryosphere (CliC). CliC will provide a globally integrated approach to the study of the role of the cryosphere in the climate system. Visit the CLIC Web site for more information.


NSIDC welcomes Alejandro Machado (User Services Representative), who joined us this fall.

NSIDC bids farewell to Mike Chhor (Operations Technician), John Pyle (Web Administrator), and Derek van Westrum (Scientific Programmer). We wish them well in their future endeavors.

NSIDC also bids farewell to Allan Frei, Research Scientist II. Allan has accepted a position as Assistant Professor in the Department of Geography, Hunter College, at the City University of New York where he will teach introductory climate/weather and environmental courses. We wish Allan the best of luck in his new position.