Until now, climate diagnostic applications, reanalyses, and atmospheric modeling studies that needed a lower boundary condition did not have an arctic-wide gridded ice concentration data set to use based on observations and one that extends back as far as the mid-nineteenth century. Gridded Monthly Sea Ice Extent and Concentration, 1850 Onward addresses this need by improving and extending the Arctic and Southern Ocean Sea Ice Concentrations product. It does this by adding newly available historical sources and by using the NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration for the satellite era.
The NOAA@NSIDC product, Gridded Monthly Sea Ice Extent and Concentration, 1850 Onward, uses the following data sources:
- North Atlantic ice edge positions covering 1850... more
NOAA@NSIDC is pleased to announce the release of Sea Ice Index Version 2. Improvements include using the most recently available version of the Goddard Space Flight Center (GSFC) input sea ice concentration data and revising three computations in the Sea Ice Index processing code. The new GSFC data have undergone additional manual quality control procedures at the GSFC that go farther to remove spurious ice. The GSFC data are available as their own data set from the NSIDC DAAC as Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data. The other three updates adjust calculations present in the old Sea Ice Index processing code that were in need of improvement. Because of these updates, minor changes in some of the ice extent and area numbers can be seen with the average change in the trends over all 12 months being on the order of 0.05 percent/decade (approximately 500 sq. km/year). For a complete... more
An improved version of the Sea Ice Index is coming. On Wednesday, 6 July 2016, Sea Ice Index Version 2 will be released. It will look and act the same as Version 1, but will have updated processing code and will use a new version of the input data. Because of these updates, minor changes in some of the ice extent and area numbers will be seen. These will be clearly described in the documentation, which will also be updated on 6 July.
We are alerting users to this impending update because file names will change. Any scripts that automatically download Sea Ice Index data each day will need to be updated to reflect this file name change. The new file names will have a “_v2” appended to the end of the file name such as N_04_area_v2.txt and N_04_plot_v2.png.
Further, NOAA@NSIDC has received support from the NOAA Big Earth Data Initiative (BEDI) program to create web services built around the Sea Ice Index. This will provide a simple HTTP interface for requesting geo-... more
On 05 April 2016, the vertically polarized 37 GHz (37V) channel of the SSMIS instrument on the DMSP-F17 satellite began yielding compromised brightness temperature data. This channel is one of those used to estimate sea ice concentration shown in the Sea Ice Index, so data processing was temporarily suspended.
NOAA@NSIDC is pleased to announce that, today, Sea Ice Index processing has resumed and the time series now uses the SSMIS instrument on the DMSP-F18 satellite beginning 01 April 2016. These sea ice concentration values come from the NSIDC Near-Real-Time DMSP SSMIS Daily Polar Gridded Sea Ice Concentrations product. Prior to transitioning this near-real-time data set to the F18 SSMIS instrument, NSIDC investigated whether or not algorithm parameters would need to be calibrated to minimize the difference between sea ice extents derived from F17 and F18.
Because each sensor and spacecraft orbit is slightly different,... more
The Sea Ice Index is typically updated every day to display yesterday’s ice extent for both hemispheres. The Index relies on data that come from the DMSP F17 satellite. However, these data have not been reliable since early April; so the NOAA@NSIDC team has not been able to update the Sea Ice Index since 31 March 2016.
Sea Ice Index processing uses an NSIDC NASA DAAC product, Near-Real-Time DMSP SSMIS Daily Polar Gridded Sea Ice Concentrations (NSIDC-0081), as input. The NSIDC DAAC has started the work needed to move to a new source for NSIDC-0081. This involves retrieving F18 and F16 satellite brightness temperatures from our data providers and then implementing parallel processing for ice concentration. The F18 satellite will be the primary replacement for F17, but should that satellite fail, we will be able to switch to F16 without a service interruption.
An interim version of the NSIDC-0081 data stream will be used... more
NOAA@NSIDC is pleased to announce that the International Ice Patrol (IIP) has updated their Iceberg Sightings Database through the 2015 iceberg season. The IIP has been collecting information on iceberg activity in the North Atlantic since 1913, and this database contains data from these sightings starting in 1960. The IIP data files include latitude and longitude of sighted icebergs, coded iceberg size and shape class, and date and time of the sighting. For more information on this data set and to access the data, please visit the International Ice Patrol Iceberg Sightings Database web page.
Data Set DOI: http://dx.doi.org/10.7265/N56Q1V5R
Fifty years ago today, the first satellite in the NOAA Environmental Science Services Administration (ESSA) series of satellites, ESSA-1, acquired its first image. The image was of Antarctica. Now, NSIDC’s Garrett Campbell and David Gallaher are attempting to organize the rescue of data from the satellite. They hope to use the recovered imagery to locate the position of the southern hemisphere’s sea ice edge, as was possible after rescuing infrared imagery from the early NASA NIMBUS series.
It won’t be easy to rescue the ESSA-1 data. According to the book Satellite Remote Sensing of the Polar Regions: Application, Limitations, and Data Availability, limitations of the imagery include “coarse ground resolution obscured by cloud and fog. Inoperative in darkness. Often difficult to distinguish ice from cloud. Imagery from the early meteorological satellites was not coupled to detailed... more
Arctic Matters Day is a free public program that will be held 14 January 2016 at the National Academy of Sciences building in Washington, DC. It will provide an overview of the dramatic environmental changes affecting the Arctic region and the ways that these changes can potentially affect the entire planet. If you are in the Washington D.C. area, consider attending the free public program, Arctic Matters Day. Through exhibits and talks, the program will “explore how many facets of our lives (for instance, our coastlines, our weather, our fish supplies, and our security) are tied to what is happening in that ‘isolated’ part of the world.”
The Glacier Photograph Collection, managed by NOAA@NSIDC, will get a big boost in 2016 from a Council on Library and Information Resources (CLIR) grant. The Glacier Photograph Collection includes over 15,000 digital images available online, as well as an analog collection of photographic prints of glaciers from around the world beginning in the mid-1850s. This grant begins a collaboration between NSIDC and the Digital Library at the University of Colorado at Boulder (CU). The grant will allow for a dedicated archivist and graduate assistants to digitize, describe, and publish the approximately 9,000 remaining photographic prints that have not yet been scanned, described, and entered into the searchable online catalog.
The online portion of the collection now consists of both a relatively small collection of born-digital photos and a large... more
NOAA@NSIDC is pleased to announce that we have updated the Google Earth file for the annual minimum Arctic sea ice extent for 2015. The September 2015 minimum KMZ file has been updated to show the 2015 September Arctic sea ice minimum. To view these, and other, Google Earth files, visit the NSIDC Data on Google Earth web page.