Total sea ice concentration, multiyear ice concentration, first-year ice concentration, thin ice concentration, and shore-fast ice coverage
Source:
Russian Arctic and Antarctic Research Institute's (AARI) digital sea ice charts from aircraft and satellite observations
Projection:
Lambert azimuthal equal-area
Temporal Coverage:
1953 through 1990
Temporal Resolution:
Three times per month
Spatial Coverage:
24°W to 110°E and 105°E to 130°W, 45°N to 90°N
Spatial Resolution:
12.5 km
Data Format:
Binary (721 by 721 bytes) and postscript file formats
NSIDC reformatted digitized ice charts prepared by the Russian Arctic and Antarctic Research Institute from 1953 through 1990 into EASE-Grid to make them easier to use.
Provides information when passive microwave data were not yet available (prior to 1973)
Provides perhaps the most detailed analyses of ice conditions in the eastern Arctic
A useful comparison set for analyses of SMMR- and SSM/I-derived ice concentrations, because passive microwave data were not used to produce the AARI charts
More accurate and useful for studies of coastal polynyas and other relatively fine-scale features along the coast
Disadvantages are that the area covered changes from one chart to the next, and temporal coverage is not consistent in the early years of the record.
A similar version of this data set can be found on the EWG Sea Ice Atlas.
Observations and ice charts from eight meteorology and ice agencies, SSM/I
Projection:
Cylindrical
Temporal Coverage:
Arctic: 1901 through 1995
Southern Ocean: 1973 through 1990
Temporal Resolution:
Monthly
Spatial Coverage:
Arctic Ocean to 40°N, Southern Ocean to about 50°S.
Spatial Resolution:
1 degree grid
Data Format:
ASCII grids
Provides information prior to the availibility of satellite coverage and greater temporal coverage than most ice chart-based data sets
Prior to 1978, data come from early sea ice observations and ice charts.
After 1978, data were obtained from passive microwave-derived concentration and extent using the NASA Team algorithm.
Antarctic data are all from passive microwave using the NASA Team algorithm.
There is a discontinuity in ice concentration (passive microwave derived concentrations are significantly lower than observational data in central Arctic), but no obvious discontinuity in ice extent in 1978.
Useful for studies that require the longest time record possible and do not need the detail and higher resolution offered by satellite data sets
Limitations of the data set:
Prior to 1953, data are primarily climatologies (leading to a discontinuity in extent and concentration in 1953)
Different sources of chart data have imprecise and variable concentration classifications.
Due to the inconsistent coverage of early chart data, concentration has been interpolated in space and time.
Southwest in the broad passage between Svalbard and Franz Josef Land toward Kvitoya Island, a small island east of Svalbard lying between the Arctic Ocean and the Barents Sea (60°N, 30°W to 90°N, 30°E)
Spatial Resolution:
Variable
Data Format:
ASCII text file ASCII text file
Provides a wide range of measurements, including information on ocean, biophysics, meteorology and ice conditions as observed in the Norwegian and Greenland Seas
Sea ice chart data, Russian and U.S. ice centers, individual observations, U.S. and Russian satellite data, ice stations, icebreakers, airborne ice surveys, U.S. submarines, weather stations
Projection:
Polar stereographic,
Lambert azimuthal equal-area
Temporal Coverage:
Russian data: 1950 through 1994
U.S. data: 1977 through 1993
Temporal Resolution:
Varies from weekly to monthly
Spatial Coverage:
Arctic (45°N,180°W to 90°N, 180°E)
Spatial Resolution:
Variable
Data Format:
html, ASCII (SIGRID), ArcInfo, binary (EASE-Grid)
The "EWG Sea Ice Atlas" is our most comprehensive Arctic sea ice data set derived from ice charts and related information.
Offers the most complete collection available of data derived from operational ice centers in the U.S. and Russia
Intended to make operational data more useful for sea ice and climate research
Data are available in EASE-Grid and ArcInfo, as well as the original SIGRID format.
Data were manually assimilated from a variety of satellite and in situ sources.
While the data are arguably more accurate than ice edge and concentration derived from satellite passive microwave data, the level of detail and accuracy varies in both time and space.
Also includes sea ice draft statistics from 14 selected submarine cruises between 1977 and 1993. Most of these data are available from the data set Submarine Upward Looking Sonar Ice Draft Profile Data and Statistics, which we recommend you use if you are interested in more than the 14 cruises available on the Atlas.
The World Meteorological Organization (WMO) Commission on Marine
Meteorology (now the Joint WMO/ Intergovernmental Oceanographic
Commission for Oceanography and Marine Meteorology, or JCOMM)
established a Global Sea Ice Data Bank of digital sea ice chart
information from the operational ice forecasting centers of participating
nations in November 1986.
The objective of the GDSIDB project is to preserve ice chart
data for use by researchers, and to encourage its conversion
from paper or graphical form to digital form.
Air pressure and temperature, surface temperature, buoy position
Source:
transmitter-equipped drifting buoys
Projection:
Not applicable
Temporal Coverage:
1995 through 1998
Temporal Resolution:
Raw, instantaneous data values; three-hour averages; daily (24-hour) averages
Spatial Coverage:
Buoys were initially deployed in three study regions within the Antarctic seasonal sea ice zone poleward from 55° S: East Antarctica; the Weddell Sea; and the Bellingshausen, Amundsen, and Ross Seas.
Spatial Resolution:
Not applicable
Data Format:
ASCII text
Data are distributed in near real time for use in operational meteorological analyses.
In addition to the standard parameters, some files also contain total daily ice velocity components and an ice flag to indicate percentage of sea ice concentration.
Processing is ongoing, and data through 2000 will be available in the future.
Ice thickness, ice and snow morphology, floe and runway dimensions
Source:
See note below.
Projection:
N/A
Temporal Coverage:
Late winter to summer, generally March through May. NSIDC holds data from 1928, 1937, 1941, 1948-1952, and 1954-1989.
Temporal Resolution:
A single set of observations was taken at each landing site. The number of landing sites in any one year or month varied.
Spatial Coverage:
Arctic Ocean Basin
Spatial Resolution:
In a given field season, the distance between landings averaged approximately 100 km.
Data Format:
ASCII text (ungridded)
Data sources for the Romanov atlases are described as the AARI Sever expeditions (1940s to 1980s), the AARI North Pole drift stations (1937-1991), the US-USSR joint research Polar Experiment (POLEX) program (1972-1981), ice reconnaissance flight reports, and literature in the public domain ("Executive Summary," Atlas of Ice and Snow of the Arctic Basin and Siberian Shelf Seas, 1995). NSIDC has published the data from aircraft landings only and has not included extensive data from the North Pole program. The source of each year's observations is uncertain.
NSIDC received files that possibly are observations from Sever and North Pole station aircraft landing locations. These files apparently contain snow and ice observations from many but not all Sever stations and possibly from North Pole stations. Note that the Sever data and North Pole data are indistinguishable in the data files.
NSIDC only distributes the raw, ungridded observations from aircraft landings on Arctic pack ice.
NIC weekly or biweekly operational ice chart time
series
Projection:
Not applicable
Temporal Coverage:
1972 through 2004
Temporal Resolution:
Weekly or biweekly
Spatial Coverage:
The Arctic, from 45 degrees N to 90 degrees N
Spatial Resolution:
25 km
Data Format:
EASE-Grid (gridded binary) and GIF
browse files
NIC charts are produced through the analyses of available in
situ, remote sensing, and model data sources. They are generated
primarily for mission planning and safety of navigation.
NIC
charts generally show more ice than do passive microwave derived
sea ice concentrations, particularly in the summer when passive
microwave algorithms tend to underestimate ice concentration.
The record of sea ice concentration from the NIC series is
believed to be more accurate than that from passive microwave
sensors, especially from the mid-1990s on (see references in
the documentation), but it lacks the consistency of some passive
microwave time series.
Weekly operational sea ice charts produced by Navy/NOAA Joint Ice Center (now called the National Ice Center)
Projection:
Not applicable
Temporal Coverage:
January 1973 through August 1990
Temporal Resolution:
Monthly
Spatial Coverage:
Poleward from 50° N and S
Spatial Resolution:
10 degree longitude sectors, 36 for each hemisphere gridded on a 1.0 degree latitude by 2.5 degree longitude grid
Data Format:
ASCII text file (gridded)
Area covered by sea ice in Arctic and Antarctic sectors was computed by digitizing the ice edge from Joint Ice Center (now the U.S. Navy/NOAA/ Coast Guard National Ice Center) weekly charts, and summing the area within the edge for 10° longitude sectors.
The National Ice Center creates ice charts by manually assimilating information from a variety of sources, including satellite and in situ observations (reconnaissance flights, ship reports).
Satellite observations comprise almost 100% of the the Southern Hemisphere data.
Roughly 65% of austral winter data are from passive microwave sensors, and 35% are from visible or infrared band instruments. For austral summer data, the ratio is reversed.
The data set is of interest to those studying variability in sea ice extent by region.
Albedo, pond depth, physical characteristics of melt ponds, characteristics of pond bottoms, reflectance spectra
Source:
Field observations, portable spectrometer
Projection:
Not applicable
Temporal Coverage:
June through July, 1994
Temporal Resolution:
Not applicable
Spatial Coverage:
South of Cornwallis Island in the Barrow Strait in the Canadian Arctic (73°N, 98°W to 75°N, 95°W)
Spatial Resolution:
Not applicable
Data Format:
ASCII text file
Data consist of broadband (400-1000 nm) and narrow band albedos for individual ponds under varying documented cloud conditions, along with other information such as pond depth and bottom characteristics for more than 500 sea ice melt ponds near Cornwallis Island.
The melt ponds were on first-year, multiyear, and land fast ice, although the multiyear data are limited.
While the data set is somewhat limited in time and space, it is exceptional in the number of ponds measured and the detail about the pond and radiative conditions.
Useful for theoretical modeling of melt pond hydrology and radiative processes
The associated technical report fully describes the data set and contains analysis summaries, including the time progression of pond depth and reflectance curves for ponds under different conditions.
Ice extent around Antarctica was digitized from charts produced by the U.S. Navy Fleet Weather Facility.
The charting mission carried out by the U.S. Navy Fleet Weather Facility is now handled by the U.S. Navy/NOAA/ Coast Guard National Ice Center.
Charts were produced using both passive microwave and visible or infrared band satellite data, but it is not known to what extent each data source was used.
U.S. Navy, Royal U.K. Navy, SCICEX, submarines, upward looking sonar
Projection:
Not applicable
Temporal Coverage:
Select cruises from 1976 through 1997
Temporal Resolution:
Not applicable
Spatial Coverage:
Arctic Ocean
Spatial Resolution:
1 m
Data Format:
ASCII text file
This is the largest freely available collection of sea ice draft measurements from submarine upward looking sonar.
This data set is the most extensive collection in time and space of in situ draft measurements from which ice thickness can be inferred.
Data from all contributors have been processed using the same algorithms, making comparisons of draft estimates between cruises more reliable.
Additions will be made to the data set until all releasable U.S. data, including data derived from analog records, has been published.
Data from additional U.K. submarine cruises may be added in the future.
Error estimates for drafts have not been made.
Moored ulS measurements are generally acknowledged to be more accurate than submarine ulS measurements.
The readily available data record from moored ulS instruments begins in the late 1980s. ACSYS distributes moored ulS data and provides a figure showing the distribution of moored ulS positions.
See the bibliography in the online documentation for background on how others have used these and similar data.
Passive Microwave