What happened to the tar-on-the-fly functionality for the “Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data” data set?

QandAThis data set resides on an FTP server that was upgraded from WU-FTP to Pure-FTP in November 2015. Unfortunately, Pure-FTP does not support the tar-on-the-fly functionality that was offered by WU-FTP. We are still working to implement the necessary changes to documentation across our Web and FTP site.

Some alternative methods for downloading data in bulk include:

  • Using a web browser add-on, such as DownThemAll! for Firefox
  • Using an FTP client, such as Cyberduck
  • Using the command, “mget *” in a command line interface to copy all files from a specific directory to your host

Note that while this question refers to a specific data set, this upgrade affects all data sets on the sidads.colorado.edu FTP server.

Zoom In: Geolocating IceBridge Data

In 2009, NASA initiated Operation IceBridge, flying airborne missions to pinch hit for the ICESat satellites’ expected gap from 2009 to 2016. The airborne platform and the broad suite of instrumentation allow for the collection of high resolution snow and ice data from targeted areas of scientific interest. The downside is that the total area covered is not nearly as vast as what a satellite typically covers.

The resources listed below allow you to zoom in on the specific areas of the Earth where IceBridge data were collected. Many of these resources also provide a handy way to access the IceBridge data of your choice.

IceBridge Data Portal

IceBridge Data Portal

IceBridge Data Portal

* See flight lines plotted against imagery, DEM or ice velocity layers

* Zoom to your area of interest to find and download data from flights that intersect your target area

ATM Flight Lines in Google Earth

ATM Flight Lines in Google Earth

KML flight lines provided by the ATM instrument team

* Download simplified flight lines and view them in Google Earth or your favorite Earth browser

* Note: While these represent the majority of IceBridge flights, they will not include campaigns flown without the ATM instrument

Earthdata Search

The new Earthdata Search


NASA Reverb or the new Earthdata Search tool

* See the locations of flight segments associated with each data file on a map

* Search for and download just the data files that meet your criteria

* Note: Many but not all IceBridge data sets are available for visualization and download with these tools

IRMCR2 Data Table View

IRMCR2 Data Table View

Geolocation coordinates in the data files

* Those who have already selected and downloaded data files may start analyzing the individual measurements based on the Latitude and Longitude coordinates contained therein

* To the right is an example of a data table taken from the IceBridge MCoRDS L2 Ice Thickness data set


Examples of L0 IceBridge data sets in the NSIDC data search tool

Examples of L0 IceBridge data sets in the NSIDC data search tool

Instrument position data

* Some researchers may need instrument position information, which may include altitude, velocity, roll, and pitch in addition to coordinates

* Separate data sets with this information are available for the DMS Camera and the LVIS Instrument

* For some other instruments, this information is included within the Level 0 data set for the instrument. To easily browse the holdings of IceBridge data sets, see the NSIDC Data Search tool

Flight lines over Greenland

Flight lines over Greenland. Credit: NASA’s Scientific Visualization Studio

How can I avoid having to download files one by one from your FTP site?

QandAIn most Web browsers, you can use the tar-on-the-fly capability by simply appending a .tar extension to the directory name in the FTP address.

For example, to download all of the northern hemisphere files from the following FTP site, append .tar at the appropriate directory level:  ….DATASETS/nsidc0051_gsfc_nasateam_seaice/final-gsfc/north.tar

You can append a .tar anywhere in the file directory structure such as: ….DATASETS/nsidc0051_gsfc_nasateam_seaice/final-gsfc.tar

The previous example would be a much larger file however, as it would include both northern and southern hemisphere data. The browser should prompt for where to save the tar file.

Search and discover NSIDC data sets with our new search tool

How do I differentiate between sea ice data sets? Which ones have file formats that are easy for me to use? How many ice velocity data sets are offered at NSIDC? What are my options for downloading the data? NSIDC has been busily working to develop a Web tool to answer these questions and more. The new Scientific Data Search aims to help you discover the data sets most useful to you.

Scientific Data Search interface

This new tool replaces the previous NSIDC data set search tool. It is recommended for those who would like to explore the breadth of NSIDC’s data holdings.

Using the search tool’s interface, you can find which data sets contain a particular data parameter, such as snow cover, or which data sets were submitted by a specific Principal Investigator. Map and calendar controls also allow you to see which data sets intersect with your custom spatial area or temporal range.

The listing of results is designed to allow for quick scanning. Attributes are clearly displayed to facilitate selection. You can read more about a data set in your results list by clicking on the title, or you can click the ‘Get Data’ button if you are ready to download the data.

The ‘Get Data’ button expands to show you all the various alternatives for downloading or visualizing the data. Those of you who are familiar with the data offerings may appreciate the direct link to the FTP directory. Those who are looking for ways to subset the data will find direct access to tools such as the Reverb and Polaris data order interfaces.

Future enhancements to the search tool will allow for results to be narrowed by custom inputs and will allow for better comparison between similar data sets.

Please give the Scientific Data Search a try. We welcome your comments at nsidc@nsidc.org.

Scientific Data Search listing of results