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NSIDC's online data catalog system consists of a database in which we store
information (metadata) about each of the data sets that NSIDC advertises,
as well as a variety of Web pages that interact with that database. These are
Web pages such as the following.
The NSIDC Data Search and Quick
Data Search allow you to search NSIDC's data catalog for data
sets. These data searches only query the catalog database and do not search
our Web site. For a Web site content search,
use the Google Site Search located at the top of our Web pages.
You may enter one or more search criteria. You are not required
to use all of the possible search criteria. For more information, see the
following sections.
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The Advanced Data Search page also provides two other common ways to access
data sets. For more information, see the following sections.
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Enter free-text keyword(s) in the field(s) provided, using the following guidelines.
- Wildcards in search strings are not supported. (A wildcard search substitutes one symbol, such as an asterisk, for a word or string.)
- The search looks for keywords by character string, not by the entire word.
For example, entering "perm" as the keyword returns data sets containing the words
"permafrost", "permanent", "permian", "permeability", etc.
- You may enter keywords in only one keywords field or in both keywords fields.
Select one of the and/or buttons to control how the search
is performed.
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If and is selected, searches for data sets containing contents of both keyword field 1 and keyword field 2 ("Boolean and"); this is the default. |
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If or is selected, searches for data sets containing the
contents of either keyword field 1 or keyword field
2 ("Boolean or"). |
- Keywords are not case-sensitive. Separate searches for "MODIS" and "modis"
return the same results.
- We recommend that when searching for acronyms, spell out the name,
unless it is a valid sensor acronym (see
Valid Sensors/Instruments for a list of
sensor/instrument names). Using an acronym may return data sets whose
descriptions contain the character string for the acronym in another context. For
example, a search for "HARA" also returns data sets containing the word
"characteristics."
- You can narrow the search for a given keyword to some individual fields within
our database, as shown below.
Field Selected |
How Data Search Looks for the Keyword String |
| Parameters/Topics |
Looks for the string in the list of scientific parameter(s) or topic(s) associated with data sets, such as albedo, brightness temperature, or cryosphere. Data search finds all data sets whose parameter(s) field contains the entered string. For example, if you enter "rad", data search returns all data sets whose parameters field contains any word with "rad" in it, such as "radar", "radiance", "degradation", "shortwave radiation", etc.
See Valid Parameters/Topics for
a list of parameters/topics used in our data catalog.
The parameters/topics in our data catalog are specific geophysical
variables or scientific disciplines that correspond to Global Change Master
Directory (GCMD) parameters, which may also be known to data users as science
keywords, categories, topics, or variables. The GCMD organizes these into
a hierarchy, and our catalog uses that hierarchy internally for storing
the parameter information. Our data search looks for the entered string
in all levels of the parameter hierarchy. Visit the GCMD Web site for the
complete hierarchy of GCMD
Science Keywords , and for more information about parameters, visit
the GCMD Parameters
(Science Keywords) Definition. |
| Title or Summary |
Looks for the string in either the title of the data set or in the summary
(abstract) of the data set. Multiple keywords entered in the same field
(sea ice, for example) will be ANDed together (each word searched separately,
not as a single phrase) unless in quotes. Quoted strings (such as "sea
ice")
will be searched for as a single phrase. |
| Source or Sensor |
Looks for the string in the list of sensor(s) or instrument(s) used to collect or measure the data, such as AVHRR, SSM/I, spectrometers, or scanning electron microscopes. You may
use exact sensor acronyms (such as "SSM/I") or spell out the sensor's long name (such as "Special Sensor Microwave/Imager").
See
Valid Sources or Sensors for
a list of sensors/instruments used in our data catalog. |
| Data Contributors |
Looks for the string in the names of principal investigators (PIs), co-PIs, technical contacts, and data
providers responsible for the data product.
See Valid Data Contributors for
the data contributor names in our data catalog. |
Optionally enter the decimal latitude (‑90.0 to 90.0) and longitude (‑180.0
to 180.0) for the southernmost, northernmost, westernmost, and easternmost
coordinates of interest. These coordinates define a bounding box around the
area of interest.
- The default values are for global coverage.
- Longitudes west of the Greenwich Meridian (0°) are negative.
- Latitudes in the Northern Hemisphere have positive values, and latitudes in
the Southern Hemisphere have negative values.
- The search returns a list of data sets that fall within or overlap the
bounding coordinates you enter.
- The spatial extent search does not spatially subset data.
You must enter both a start and stop date; otherwise, no temporal coverage search
is performed. For start and stop dates, select the month from the pull-down menu, and
enter the four-digit year.
Paleoclimate years (for example, 120,000 y.b.p.) are not supported in the temporal
coverage criterion.
By default, all data centers at NSIDC are searched. If you are only interested in data
that are held at a particular data center within NSIDC, select that data center from the list.
You can search only those data sets archived and distributed by NSIDC or include
all data sets that are advertised in the NSIDC online data catalog, which includes
externally-distributed data. The default is to search only the data sets that
are distributed by NSIDC. Such data are either readily available on our FTP
server, or can be ordered from NSIDC.
NSIDC advertises many data sets that are of interest to our users, but we do not
archive and distribute the data, nor do we provide support for such data. For these externally-distributed
data, we provide an e-mail address or Web URL for you to find more information or
access the data.
Results are listed alphabetically by data set title. If too many data sets are returned,
try narrowing your search.
You may view a list of all data sets in the NSIDC online data catalog organized
in one of the following ways.
- by specified parameter/topic; data sets may be sub-grouped by applicable
lower-level terms for the parameter/topic
- alphabetically by data set title
- by name of the data contributor (investigator)
These lists include externally-distributed data. NSIDC advertises many data sets that are of interest to our users, but we do not
archive and distribute the data, nor do we provide support for externally-distributed data. For these data, we provide an e-mail address or Web URL through which you may find more information or
access the data.
Some NSIDC data sets that are related to each other by parameter, sensor (instrument),
project, grid, etc. are grouped together on our Web site as a data collection.
The Quick Links list includes links to some of the most frequently used data collections.
These links go directly to the collection's section on NSIDC's Web site. For descriptions
of these collections, see Data Collections. |
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