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In this Issue

NSIDC DAAC
PRODUCTS AND SERVICES
ARCTIC SYSTEM SCIENCE (ARCSS)
MEETINGS

NSIDC Notes

Issue 14, Summer 1995

NSIDC DAAC

EOSDIS Version 0 Status and News

Under the banner of EOSDIS Version 0 (V0), the Distributed Active Archive Centers (DAAC) are actively engaged in providing a full suite of data and information services to the science community. Over the past three months (May, June, and July), the DAACs have served an average of 12,900 distinct users per month, who accounted for an average of 180,000 accesses (which includes a number of casual WWW accesses) to V0 services, including an average of 7,200 data requests that culminated in an average of 1.6 terabytes of data being provided by the DAACs to users each month.

V0 is the complete end-to-end ingest, processing, archiving, cataloging and distribution system used by the DAACs to serve the community. One component of the V0 system is the V0 Information Management System (IMS), which provides the user whose interests cross DAAC or discipline boundaries the capability to obtain, at "one stop", a coherent view of data sets available across the V0 system as a whole. Users may search for data that meet common criteria (e.g., spatial and temporal coverage) and order whatever combination of data from whatever combination of DAACs meets their needs, without advance knowledge of what data sets are available or what their source may be. The V0 IMS, operated now by all of the DAACs, complements DAAC-specific services tailored to the needs of each DAAC's individual user community.

The V0 IMS graphical (GUI) and character-based user interfaces (ChUI) clients are now available for FTP access by any interested user. The V0 IMS Home Page, http://harp.gsfc.nasa.gov:1729/eosdis_documents/eosdis_home.html, now contains instructions for down-loading the client and installation of it on the user's workstation. The V0 IMS GUI and ChUI user interfaces will continue to be accessible from each DAAC, but users will see a significant improvement in performance by obtaining a copy of the client and installing it on their own workstation, and we encourage users to do so.

Also, progress is being made on the WWW interface to the V0 IMS, and an announcement concerning its availability to users as a "working prototype" will be forthcoming shortly. In addition, the DAACs are providing an increasing number of WWW services which will be complemented by the V0 IMS WWW interface.

As before, I invite you to bring to my attention any concerns or problems anyone has with any aspect of the overall V0 system (DAACs, local DAAC services, etc., including the V0 system level IMS). My e-mail is gregh@ulabsgi.gsfc.nasa.gov, or 301-286-0653 (phone). I welcome constructive criticism, I guarantee a reply, and I also don't object to hearing about aspects of V0 or DAAC services that users are pleased with.

Greg Hunolt, ESDIS, DAAC Data Systems/Science Operations Manager.

PRODUCTS AND SERVICES

SSM/I Pathfinder Benchmark Processing Update

NSIDC, through support provided by the NOAA/NASA Pathfinder Program, is pleased to announce the completion, September 1995, of the Northern Hemisphere EASE-Grid Brightness Temperature CD series for the Pathfinder Benchmark Period, including data from August 1987 through November 1988.

The complete EASE-Grid Brightness Temperature Benchmark data set will consist of three series of CDs, one series each for the EASE-Grid Northern Hemisphere (8 CDs), Southern hemisphere (8 CDs) and full global projection, (approx. 16 CDs). Currently available Brightness Temperature CDs, as of September 1995, are:

Through funding provided by the NOAA/NASA Pathfinder Program, NSIDC will continue to process and distribute SSM/I Level 3 Brightness Temperatures and selected geophysical products beyond the Benchmark Period. In addition, NSIDC will process SMMR data in the EASE-Grid format so as to provide a twenty year time series (1978-1998) of passive microwave data in a common grid and projection.

For further information, contact NSIDC User Services.

New Land Mask for SSM/I Grid

NSIDC has received a new land mask for use with the DMSP SSM/I polar gridded product. The new mask, called GSFC-II, was developed by D. Cavalieri and M. Martino at Goddard Space Flight Center (GSFC). The current SSM/I land mask, developed in the 1980s by Jet Propulsion Laboratory (JPL) for use with the SSM/I polar grids and referred to as the JPL Mask, exhibits known discrepancies with data collected by the high resolution sensors like the ERS-1 Synthetic Aperture Radar. While not perfect, the GSFC-II land mask suggests improvements over the JPL Mask. Two major changes occurred during the production of the GSFC-II land mask:

  1. New source of data. The GSFC-II land mask used data from the most recently published shoreline data, US Geological Survey's Digital Chart of the World (DC). The JPL Mask used data from an earlier source, CIA World Shoreline Data Bank I.
  2. Better classification scheme for coast pixels. A preliminary 6.25 km land mask was created from the DC and used as a basis for both the new 12.5 and 25 km grid SSM/I land masks. A 2 x 2 array of 6.25 km data was examined to determine each 12.5 km pixel's value: land, coast, or ocean. Similarly, when determining a 25 km pixel's value, a 4 x 4 array of 6.25 km data was used.

    NSIDC will distribute both land masks with the next CD-ROM volumes of SSM/I F-11 brightness temperatures and SSM/I ice concentrations. The JPL Mask land mask will allow continuity for researchers doing long term studies. The newer, more precise GSFC-II land mask will become the primary and recommended land mask for new projects. Additional information on the differences between the land masks will be available in a NASA Technical Memorandum,An Improved Land Mask for the SSM/I Gridby Martino and Cavalieri due shortly.

Arctic Water Vapor Characteristics

A gridded climatological monthly-mean data set of Arctic water vapor characteristics has been compiled from existing rawinsonde archives. The data set combines fixed station data with data from soundings taken over the Arctic Ocean from ships and Russian drifting stations.

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 1958 through 1991 for fixed-station data obtained from the Historical Arctic Rawinsonde Archive.

Variables provided include: temperature, specific humidity, zonal vapor flux, meridional vapor flux, zonal wind speed, and meridional wind speed, available for 15 levels extending from the surface and then at every 50 Mb from 950 Mb to 300 Mb; sea level pressure and geopotential height, available at 850 Mb, 700 Mb, 500 Mb and 300 Mb; and precipitable water, vertically-integrated zonal vapor flux and vertically-integrated meridional vapor flux, 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. All variables with the exception of sea level pressure and geopotential height were obtained through interpolation of the raw sounding data.

The file is structured in monthly data arrays over a 17 x 17 subsection of the National Meteorological Center grid (octagonal grid format) centered over the pole, extending to approximately 65 degrees N on each side and about 55 degrees N at the corners.

For information on how to access the data, contact NSIDC User Services.

Reference: Serreze, M.C.; Barry, R.G.; Walsh, J.E. (1995) Atmospheric water vapor characteristics at 70 degrees N.Journal of Climate, 8(4), p.719-731.

Interactive Display Language (IDL) Programs

Two new Interactive Display Language (IDL) programs are being distributed with DMSP F-11 brightness temperatures beginning with Vol. 12. The programs facilitate platform-independent data access to the CDs. That is, since paths and file names must be in the proper case for IDL search, these tools allow for user input to make the appropriate adjustments, whether or not the operating system displays path and file names in uppercase (ISO9660 standard) or lowercase (SUN, SGI). One program opens and displays data as images, the other simply opens and extracts data from files and holds the data in memory for further manipulation.

See the readme file in the tools/idl directory for further information and examples.

Eurasian Glacier Inventory

NSIDC announces the availability of the Eurasian Glacier Inventory. This inventory contains information for over 25,000 glaciers within the Former Soviet Union (FSU) and the People's Republic of China (PRC). Parameters within the inventory include: geographic location, area, length, orientation, elevation, and classification of morphological type and moraines. These data represent the digitized version of thousands of handwritten records. They were digitized at the Institute of Geography, Moscow, and the World Data Center-D for Glaciology in Lanzhou, China. Figure 1 show Eurasian glaciers that are currently in the data base.

Eurasian glaciers in the Eurasian Glacier Inventory

Fig. 1. Thousands of handwritten records were digitized at the Institute of Geography, Moscow, and the World Data Center-D for Glaciology in Lanzhou, China. This figure represents the Eurasian glaciers that are currently in the data base.

The Eurasian Glacier Inventory is available in ASCII files and is distributed both on diskette and electronically.

For further information, please contact NSIDC User Services.

ARCTIC SYSTEM SCIENCE (ARCSS)

Ice Core Data Available Through World Wide Web

NSIDC's ARCSS Data Coordination Center and National Geophysical Data Center's (NGDC) Paleoclimatology Group have developed a joint World Wide Web page to enhance user access to ice core data. The Web page (URL http://www.ngdc.noaa.gov/paleo/ice-data.html) provides hot keys to download all available ice core data and associated documentation from Greenland Ice Sheet Project II (GISP2), Greenland Icecore Project (GRIP), GISP1, Antarctic sites, and others from which data are already available or may be obtained in the future.

The major benefit of providing data access in this way is that users do not need to be concerned with how or where the data are being maintained. Access to the suite of available ice core data distributed at these two Centers is completely transparent.

As new data are obtained, they will be advertised on the Web page, available for downloading using a Web browser or via ftp. Also, new data can be submitted for archiving to the Centers via ftp, using a hot key on the Web page. See http:/www.ngdc.noaa.gov/paleo/contrib.html for more details.

Data managers at the Centers work collaboratively to ensure a secure, well-documented data ingest process, involving the data owner in developing on-line metadata and documentation for each data set.

Data Access and Visualization Toolkit

PaleoVu, MapPad, and other Windows- and Macintosh-based browse, visualization and access tools provide user-friendly access to paleoclimate data archived and distributed by NGDC. These tools, developed by NGDC, are readily available by downloading from the Web page.

Users can also query on-line databases to select fossil pollen, tree ring, and paleoclimate modeling output data files for downloading from NGDC. The tools will be adapted to the ice core database as part of the ongoing database development process, described below.

Future Plans

NGDC Paleoclimatology Program is developing various relational databases (RDBs) for such parameters as pollen, tree rings, paleoceanographic data. Ice core data are an excellent candidate for a RDB, and the pollen database structure could serve as a starting point for development of an ice core RDB structure. Early 1996 is a target date for beginning the ice core database development work, which will be led by paleoenvironmental database specialists at NGDC. NSIDC's ARCSS Data Coordination Center, will continue cooperation and collaboration with NGDC during this development work, bringing advice and guidance through the established mechanisms of the GISP2 Science Management Office, the ARCSS Data Management Working Group and the ARCSS Advisory Committee.

We anticipate receiving a number of GISP2 and GRIP data sets in the coming months. Science results are being published, and the initial two-year embargo on GISP2 drilling results has elapsed, so data should be flowing into the archive and Web site as a result.

Arctic System Science (ARCSS) Program

GISP2 is a component of the National Science Foundation's Arctic System Science (ARCSS) Program, an ongoing multidisciplinary, integrated effort "...to understand the physical, chemical, biological, and social processes of the arctic system that interact with the total Earth system and thus contribute to or are influenced by global change, in order to advance the scientific basis for predicting environmental change on a decade-to- centuries time scale and for formulating policy options in response to the anticipated impacts of changing climate on humans and social systems." (ARCSS Executive Committee, 1983, p. 3.1)

NSIDC is funded by NSF/ARCSS as the Data Coordination Center for all ARCSS components: Ocean- Atmosphere-Ice Interactions (OAII), Land- Atmosphere-Ice Interactions (LAII), Paleoclimates from Arctic Lakes and Estuaries (PALE), and GISP2. NGDC Paleoclimate Program is the archive and distribution center for data from the PALE component of ARCSS, in collaboration with the PALE Data Manager at the University of Colorado, Institute of Arctic and Alpine Research.

For further information, contact NSIDC User Services.

Bruce Bauer, Data Manager, NOAA/NGDC, Paleoclimatology Program, 325 Broadway, E/GC, Boulder, CO 80303, paleo@ngdc.noaa.gov (Internet), (303) 497-6280 (phone), (303) 497-6513 (fax), (303) 497-6958 (TDD phone).

Reference: ARCSS Executive Committee. (1993)Arctic System Science: A Plan for Integration. Fairbanks, Arctic Research Consortium of the United States.

ARCSS Staff Change

Changes are in store for the ARCSS team at NSIDC. Claire Hanson is leaving her position as project manager for the ARCSS Data Coordination Center to focus on User Services for WDC-A/NSIDC.

Dr. David L. McGinnis is transitioning into the project, and will be the official project manager as of 1 November. Dave has been at NSIDC for the past year as a Visiting Fellow of CIRES, our home institute. He brings a strong background in climate modeling, a keen interest in Arctic processes, and a Ph.D. from Penn State. Dave has already attended the meeting of the ARCSS Advisory Committee and the ARCSS Modeling Working Group in Boulder last month, and will be getting to know the GISP2 community at the GISP2 Workshop in Wolfeboro, NH, in mid-September.

Matt Cross remains as the ARCSS Data Coordinator on the project, providing continuity and his usual hard work that keeps the data flowing into the archive and back out to the ARCSS community.

From Claire:

"I've enjoyed working with the ARCSS community tremendously, and will miss the challenge of developing a functional data system for ARCSS. The people in the program have been great to work with, and I especially appreciate the support and encouragement NSIDC has received from the NSF/OPP ARCSS, PALE, and GISP2 Program Managers. But I won't miss those weekend meetings!"

She will remain available as a consultant during and after the transition, but she is ready to turn the reins over to Dave and wishes him much success in implementing his ideas and plans.

You can reach Dave at (303) 492-1160 (phone), (303) 492-2468 (fax), mcginnis@nsidc2.colorado.edu (Internet).

ARCSS Data Management Working Group

The first meeting of the ARCSS Data Management Working Group (DMWG) was held in Boulder on 6-8 August 1995, in conjunction with the inaugural meetings of the ARCSS Advisory Committee and ARCSS Modeling Working Group. Members of the DMWG represent each component of ARCSS: Richard Moritz, University of Washington for OAII; D.L. (Skip) Walker, University of Colorado for LAII; Pat Anderson, University of Washington for PALE; Mark Twickler, University of New Hampshire for GISP2; and Thomas McGovern, Hunter College and Nicholas Flanders, Dartmouth College, for Human Dimensions. Jonathan Overpeck represents NOAA's National Geophysical Data Center, the PALE data archive and distribution center. Claire Hanson, project manager of NSIDC's ARCSS Data Coordination Center, chairs the DMWG. Attendees at this first meeting included Patricia Anderson, University of Alaska, and Marilyn Walker, University of Colorado, both representing LAII in the absence of Skip Walker and Mathieu Duvall, University of Colorado, substituting for Pat Anderson. Tom McGovern was unable to attend. At the final plenary session, the DMWG recommended to the ARCSS Advisory Committee that recipients of ARCSS funding need to be held accountable as well as credited for their contributions to the ARCSS data archive. NSIDC, in concert with the ARCSS Component Science Management Offices and NSF/OPP/ARCSS, will continue to develop an ARCSS data policy, and guidelines for citing or acknowledging data in research papers. It is worth noting that the question of scientific credit to investigators for the work involved in preparing data sets for archiving is not trivial, as this type of work is not currently viewed by the research community as a scientific contribution. The ARCSS Program may provide an opportunity to begin changing this view.

A primary purpose of the DMWG is to determine the data needs of ARCSS-funded projects. Each component, and the Modeling Working Group, must be involved in this task, and the ARCSS Advisory Committee should be asked to assist in determining whether the ARCSS science questions can be answered by the available and ARCSS-generated data. There is a general need for "griddable data": spatially and temporally registered; in original spatial and temporal resolutions; in a consistent format per data type, with tools to allow easy subsetting and gridding to various map projections and grid sizes.

The Modeling Working Group (MWG) held a joint session with the DMWG on 6 August. Recommendations regarding data include: 1) The modeling community needs griddable (not gridded) data sets to be made available. The often-discussed "model test kit" is not feasible because each modeling group has different data input and output requirements; 2) The MWG should assist NSIDC in listing parameters missing from their models, and ARCSS- funded research should be leading towards providing these missing data; 3) Model output (i.e., key runs) should be archived and made available to the research community by the modelers, not by the ARCSS Data Coordination Center at NSIDC.

NSIDC should provide World Wide Web and other pointers to sites holding ARCSS-funded models, and perhaps to other key centers of modeling expertise (i.e., NMC, ECMWF, NCAR, etc.) where such model output can also be obtained, thus facilitating access to these important analyses.

The sense of the group is that NSIDC should continue to encourage electronic transfer of data both into and out of the archive using the World Wide Web and ftp, while continuing the capability to deliver diskettes, 8 mm tape, and hard copy. It was suggested that we consider charging for hard copy (to cover printing costs) and for large amounts of media. Both NOAA and NASA data policies address these issues; development/enhancement of ARCSS policy and procedures can benefit from ongoing NOAA, NASA, and NSIDC lessons learned.

In order to determine how best to meet the needs of ARCSS projects with specific or general GIS needs, such as the LAII Flux Study which is generating "layered" data that will be mapped, the LAII Science Management Office will survey LAII investigators as to which GIS software packages are in use.

Access to and usability of GIS data for non-GIS users remains an issue; the DMWG will continue discussion of this topic. Feedback from Flux Study recipients of the first LAII CD-ROM will also be sought in this survey.

Also discussed was the additional level of data management that may be required by both small scale studies such as surface soil and vegetation gridded plot data being collected within LAII's Flux Study, and large-scale field experiments such as the planned Surface Heat Budget of the Arctic Ocean (SHEBA) projects. Both demand careful planning for optimal data access, archiving, and utility, but may also need designated data managers for each type of data being gathered to ensure data are fully documented, accurately archived, and available for research use in a timely fashion. Both the Niwot Ridge Long-Term Ecological Research (LTER) site data management project and the UCAR/NCAR Office of Field Project Support are being examined as models.

The Working Group will use the ARCSS listserver to conduct an ongoing dialogue on these and other issues as they arise. Since it is unlikely meetings can be held more than once or twice per year, most of the work will need to be done using e-mail. The Arctic Research Consortium of the U.S. will publish a complete report of the Boulder meetings.

For additional details concerning DMWG and NSIDC's ARCSS activities, contact NSIDC User Services.

MEETINGS

Workshop on Permafrost Data, Potsdam, Germany, August 1995

R.G. Barry, Director, NSIDC, convened and chaired a Workshop on Permafrost Data at the Alfred-Wegener Institute in Potsdam, Germany, 1-3 August 1995. The meeting, sponsored by the International Permafrost Association (IPA) through its Working Group on Permafrost Data and Information, involved 22 participants representing 11 countries. The group reviewed and modified the priorities for permafrost data rescue developed at the 1994 Oslo meeting of the Working Group. A full report of the Oslo Workshop is available in Workshop on Permafrost Data Rescue and Access,Glaciological Data, Report GD-28. The revised priorities are shown in Table 1.

The workshop also heard reports on national contributions to establishing the Global Geocryological Database, and developed related resolutions for the Council of the IPA. The latter, at its tenth meeting, held in Berlin, 4-5 August 1995, approved resolutions to:

  1. encourage national contributions to the Global Geocryological Database and its financial support;
  2. support international science and monitoring programs through IPA working groups; and
  3. implement a strategy for rescue of data orphaned as a result of termination and changes of agency programs and individual careers.
Table 1. Results of priority setting for key permafrost variables as modified at Potsdam
APPLICATIONS
PARAMETERS Process
Understanding
Engineering
Design
OCM
Validation Type
Change
Detection
Impact
Evaluation
GEOMETRY
Permafrost extent M H H H M
Permafrost thickness
(shallow) *
H H H H H
Permafrost thickness
(deep) *
M M L H L
Active layer thickness H H M H H
Ground ice extent H H M M H
Lateral/Vertical displacement H H L H H
THERMAL STATE
Temperature (shallow) * H H H H H
Temperature (deep) * M M M H L
PROPERTIES (SOIL/ROCK)
Moisture content (water/ice) H H M H H
Bulk density H H H L L
Texture H H L M M
Chemistry (water/ice) M M L M M
Trace gases H L H M M
Site description: Location, geology, vegetation, geotechnical properties
Metadata: Techniques, equipment, precision, post-processing, ownership, etc.

NOTES:
H, M, L = High, Moderate and Low Priority
* For permafrost thickness and temperature, the demarcation between 'shallow' and 'deep' is taken as the local depth of amplitude.