What are the benefits of registering for data sets at NSIDC?

So, you’ve decided to download some data from NSIDC.  You click on the ‘Get Data’ button, eagerly anticipating getting your data, and you find…a form.  Why do you need to tell us who you are before you download the data?  Well, you don’t need to tell us who you are (you may bypass the form by selecting the ‘Bypass Optional Registration’ link), but you might want to tell us who you are.  Why?  Actually, there are several reasons:


  • Within approximately one business day of registering for the data, we will send you a summary email with information on the data set, including where to access both the data and documentation (remember to bookmark these links for easy future access).
  • If the data are ever reprocessed or updated, we will inform you when the new or revised data are available to download.
  • We will notify you about any major changes to the data documentation.

The good news is that once you have filled out the form for a specific data set, you don’t ever need to fill that form out again.  From then on, you can either go directly to your bookmarked FTP link or you may select the ‘Bypass Optional Registration’ link on the form page and go directly to the data with the confidence that you are already registered to receive any pertinent data-related updates.

In summary, taking a few minutes to fill out the registration forms for your favorite data sets is a great idea.


Is it 1B, 2, or 3? Definitions of data processing levels

If you are a MODIS, AMSR-E or IceBridge data whiz, you may be familiar with the various processing levels for different data sets. Oftentimes the levels will be denoted as L1B or L2, etc. within the data set name. To the uninitiated it can be a challenge to understand what these levels really mean.

Data are processed at varying levels. The NASA Earth Observing System (EOS) define these levels as ranging from Level 0 to Level 4. Level 0 represents raw data, while Level 4 data have had the greatest amount of processing applied. At NSIDC, IceBridge data defined by the EOS system exist from Levels 0 to 3, while MODIS and AMSR-E data sets are offered at Level 2 and Level 3.

Level Definition
0 Unprocessed instrument data
1A Unprocessed instrument data alongside ancillary information
1B Data processed to sensor units, e.g. brightness temperatures
2 Derived geophysical variables, e.g. sea ice concentration
3 Variables that are mapped on a grid, e.g. data using EASE-Grid
4 Modeled output or variables derived from multiple measurements

Many data sets offer a range of data levels, allowing users to choose the processing level that best fits their purposes. For more information, see the Earth Science Reference Handbook published by NASA EOS in 2006.

Stairwell - Photo credit: quapan / Foter / CC BY

Photo credit: quapan / Foter / CC BY