Satellite Observations of Arctic Change

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NSIDC now offers a new Web site, Satellite Observations of Arctic Change (SOAC) with interactive maps of the Arctic based on NASA satellite and related data. The site allows users to explore how conditions in the Arctic have changed over time. SOAC is available at http://nsidc.org/soac.

This sample image

This sample image from Satellite Observations of Arctic Change shows near-surface air temperature anomalies for October 2012, along with a bar chart of anomalies over time.

Presently, SOAC offers seven data sets:

  • Near-surface air temperature anomalies, from MERRA, 1979 – 2012
  • Total column water vapor anomalies, from MERRA, 1979 – 2012
  • Monthly mean sea ice concentration anomalies, from the NSIDC Sea Ice Index, 1979 – 2012
  • Snow cover duration anomalies, from Rutgers Snow Cover Lab, 1966 – 2012
  • Monthly mean NDVI anomalies, from GIMMS, 1982 – 2010
  • Soil non-frozen period anomalies, from NASA MEaSUREs, 1981 – 2010
  • Annual minimum exposed snow and ice, from MODICE, 2000 – 2013

Users may animate a time series, zoom in or out, and view a bar graph of anomalies over time. Links to the source data and documentation are also included. Additional pages provide brief scientific discussion, and overviews of the scientific importance of these data.

More data types and extended temporal coverage may be added in the future, if interest warrants and funding continues. SOAC was developed with support from NASA Earth Science (http://science.nasa.gov/earth-science/).

NSIDC User Services welcomes your feedback on SOAC. Please contact us at nsidc@nsidc.org.

New life for old data: Nimbus Data Rescue Project publishes first data set

Back in the 1960s, technology to process massive amounts of data and imagery did not exist. Advancements in technology now allow for the processing of film into a digital format. The Nimbus Data Rescue Project set out on a techno-archeological mission to convert data and images from the NASA Nimbus 1 and 2 satellites that were developed on film into a more manageable digital format. These data extend the satellite record back in time providing the earliest satellite data of polar sea ice extent.

The Nimbus Advanced Vidicon Camera System Visible Imagery L1, HDF5 (NmAVCS1H) is the first data set publicly available from the Nimbus Data Rescue Project. NmAVCS1H consists of black-and-white Advanced Vidicon Camera System (AVCS) images that were acquired by the Nimbus 1 satellite during September 1964 and by Nimbus 2 from May to August 1966. NSIDC researchers and staff scanned the images from archival rolls of 35-mm, black-and-white film. Each HDF5-formatted data file contains an array of 8-bit grayscale values, estimates of the latitude and longitude for each pixel, a grayscale calibration map, and a non-data/data quality mask. Browse images are also available.

For a detailed description of the data see the NmAVCS1H documentation.

To obtain the NmAVCS1H data see the Order Data Web page.

The Nimbus Data Rescue Project was a collaboration between the Lunar Orbiter Image Recovery Project (LOIRP) at NASA Ames Research Park, and NSIDC. For more of the project’s history and development see our Monthly Highlights: Glimpses of Sea Ice Past article and the Nimbus Data Rescue Project Web page.

Current and upcoming MEaSUREs data at NSIDC

New data regarding snow, sea ice, Greenland surface melt and more will be coming soon to NSIDC. The NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) program is dedicated to the development of consistent global and continental scale data records related to earth science. NSIDC currently archives six data sets from the MEaSUREs program, and the additional data sets will be available in the near future.

Access to the documentation and data for all MEaSUREs data sets at NSIDC are available from:
http://nsidc.org/data/measures/

The following Principle Investigators have provided data sets that are currently available for download from NSIDC:

NSIDC expects to receive the following data sets in the coming months:

  • From David Robinson, Thomas Estilow, Gina Henderson, Dorothy Hall, and George Riggs
    • MEaSUREs Northern Hemisphere Terrestrial Snow Daily 25km EASE-Grid 2.0
    • MEaSUREs Northern Hemisphere Terrestrial Snow Weekly 100km EASE-Grid 2.0
  • From Mark Anderson, Mark Tschudi, Angela Bliss, Charles Fowler, and James Maslanik
    • MEaSUREs Arctic Sea Ice Characterization Daily 25km EASE-Grid 2.0
  • From Thomas Mote
    • MEaSUREs Greenland Surface Melt Daily 25km EASE-Grid 2.0
  • From David Robinson, Thomas Estilow, Gina Henderson, Dorothy Hall, George Riggs, Mark Anderson, Mark Tschudi, Angela Bliss, Charles Fowler, James Maslanik, and Thomas Mote
    • MEaSUREs Northern Hemisphere State of Cryosphere Daily 25km EASE-Grid 2.0
    • MEaSUREs Northern Hemisphere State of Cryosphere Weekly 100km EASE-Grid 2.0
  • From Ted Scambos, Ian Joughin, Ben Smith, and Ian Howat
    • MEaSUREs Monthly MODIS Mosaic Images of Greenland

In the future, Mary Jo Brodzik and David Long will also provide NSIDC with an improved, enhanced resolution, gridded passive microwave Earth System Data Record (ESDR).

If you would like to receive notifications related to MEaSUREs data updates or when new data sets are published, please contact NSIDC User Services at nsidc@nsidc.org.

 

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Tips for working with NSIDC’s most popular sea ice concentration data

NSIDC’s sea ice concentration data are used by scientists and students, journalists and advisers. The range of possible uses for the data is as varied as the data users themselves. The biggest hurdle encountered by many users is simply learning how to initially read and display the data. Here are some tips on how to get started.

The “Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data” are distributed in gridded binary format. NSIDC provides IDL routines to ingest and read the data. These tools can be found at the Polar Stereographic Tools Web page.

However, if you are unfamiliar with IDL, there are other options that you can use. First of all, you may be interested in downloading the data via the Polaris search and order interface. This Web tool allows you to download the data in GeoTIFF or NetCDF formats. It also allows you to make spatial and temporal constraints on the data as well as change the output projection.

If you are interested in importing the data to ArcGIS, you can either use the GeoTIFF files downloaded from Polaris (see above), or you can perform a few steps to import the native binary files. In order to do this, you will need to rename the files, create a header file for the data, and use ArcToolbox to transform the files to a different format. Instructions detailing how to do this can be found in this Online Support article.

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