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NSIDC Virtual Globes: Technical experimentsThis page lists some of our experiments with using Google Earth to visualize our data. These files illustrate capabilities we are interested in developing, as technology progresses. Each resulting file proves some capabilities, but also has limitations, as discussed below. These technical notes may be of interest to other Google Earth file developers. Since many of our data sets are time series, and global change is only apparent over time, we are experimenting with the time series capabilities of Google Earth. Google Earth v4, released on January 8, 2007, implements KML v2.1 to enable time series animations on the virtual globe. Time series animations are memory and bandwidth intensive, but users with a substantial amount of memory and good connectivity can install Google Earth 4.0.2722 or better to view some of the time series data sets below. We have animated a variety of time series data to explore the usefulness of the technology. All use the Timeline widget that is new in Google Earth v4. If you are unfamiliar with the Google Earth Timeline widget, see Virtual Globes: Google Earth Timelines. Comments and feedback will be appreciated. |
See alsoQuickTime movie of sea ice extents, 1979-2006 on Google Earth (94 MB) View NSIDC Data on Virtual Globes: Google Earth Related resourcesNSIDC Virtual Globes Help and Documentation Questions, comments or suggestions? Contact us at nsidc@nsidc.org or via the online contact form. |
| Files | Topic | Technical notes | Source data |
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Download Wilkins Ice Shelf imagery of the Spring 2008 break up event.
(KMZ, 20 MB) | Ice Shelves | Technical notes: The Wilkins Ice Shelf imagery for this animation was derived from the MODIS Level 1B Calibrated Radiances product available at Goddard Space Flight Center. The true color images contained in this KMZ file are 250 meter resolution and were processed using the MODIS Swath-to-Grid Toolbox (MS2GT). The Wilkins break up event occurred over the period of a few days in early 2008 and, like the Larsen B break up in 2002, it is an example of how Antarctic ice shelves are becoming increasingly unstable. In an effort to closely monitor ice shelves and outlet glaciers the NSIDC processes and archives MODIS imagery daily of 20 areas along the Antarctic coast. The images in the ice shelf archive are available for download from the Antarctic Glaciological Data Center at NSIDC. | Antarctic Ice Shelf imagery |
| Download AMSR-E Daily
Sea Ice Concentration for the past:
30 days 60 days 90 days (KML, 45 KB) | Sea Ice | Technical notes: The AMSR-E/Aqua Daily L3 12.5 km Tb, Sea Ice Conc., & Snow Depth Polar Grids (AE_SI12) product provides daily, global sea ice concentration for the polar regions. This animation of AE_SI12 shows the sea ice concentration and extent in the Arctic for the most recent 30/60/90 days. The monthly average sea ice extents, derived from the Sea Ice Index, are also shown to give an indication of how current conditions compare with average conditions. Network links are used to keep the imagery updated, so the most recent 30/60/90 days are always shown. | AE_SI12 Product |
| Download IABP buoy data for July 20 - August 18, 2008 (KMZ, 480 KB) | Buoy Data, Sea Ice | Technical notes: The International Arctic Buoy Program maintains a network of drifting buoys in the Arctic Ocean. For this demo we used daily data from a large number of buoys. We have not color coded the buoys as we did in the previous demo - but we have created some different labeling options to see what that might be like. We have also included sea ice concentration and extent as optional background layers. Eventually we'd like the buoy animation to be near real time and updated daily. | IABP Buoy data |
| Download NISE Daily
Sea Ice Concentration for the past:
30 days 60 days 90 days (KML, 45 KB) | Sea Ice | Technical notes: NSIDC has been using the The Near Real-Time SSM/I EASE-Grid Daily Global Ice Concentration and Snow Extent product (Near real-time Ice and Snow Extent, NISE) product to provide daily updates in google earth for over two years. This KML file uses those daily images to animate the sea ice concentration and extent, in the Arctic, during the past 30/60/90 days. The monthly average sea ice extents, derived from the Sea Ice Index, are also shown to give an indication of how current conditions compare with average conditions. Network links are used to keep the imagery updated, so the most recent 30/60/90 days are always shown. | NISE Product |
| Download IABP ARGOS buoy data for 1985-1994 (KMZ, 480 KB) | Buoy data, Sea Ice | Technical notes: The International Arctic Buoy Program maintains a network of drifting buoys in the Arctic Ocean. The buoys in this demo are the 24 ARGOS buoys deployed between 1985 and 1994. To simulate a larger quantity of buoys deployed at one time all 24 buoys have been animated as if they were deployed in 2007. We color coded the buoys to reflect the recorded air temperature and added the monthly average sea ice extents as an additional layer. | IABP ARGOS Buoys |
| Download NISE Daily Sea Ice Concentration for July 16 - Sept. 16, 2007 (KMZ, 616 KB) | Sea Ice | Technical notes: NSIDC has been using the The Near Real-Time SSM/I EASE-Grid Daily Global Ice Concentration and Snow Extent product (Near real-time Ice and Snow Extent, NISE) product to provide daily updates in google earth for over a year. This KMZ file uses those daily images to animate the sea ice retreat during the two months leading up the the record shattering Arctic sea ice minimum on September 16, 2007. The monthly average sea ice extents for July, August, and September are also shown to give an indication of how dramatic the retreat was. | NISE Product |
| Download MODIS Daily Snow Cover browse (monthly KML files, 12 KB each) | Snow cover | Technical notes: NSIDC has been generating browse imagery of the gridded MODIS daily snow product for several years, so we already had the images we needed to load into Google Earth. The advantage for the user is the ability to view the browse images quickly, rather than having to click on each daily image. Moreover, users interested in a specific region can zoom in and inspect the browse for only that region, looking for the conditions they want. | MODIS Snow Cover Products |
| Download subsetted SSMI images. (KML, 90 KB) | Brightness temperature | This test is comprised of a few sample
channels (19H, 22V, 37V, 85V, 85H) over a 40 day time period (August
1, 1996 through September 9, 1996). The original data were gridded
on a North Polar Azimuthal projection. The subsetted region covers
the North Pole, Greenland, and Hudson Bay. Technical notes: NISDC's Graphical Interface for Subsetting, Mapping, and Ordering (GISMO) subsetter has been generating subsets of SSM/I and AVHRR gridded data since the turn of the century, but we have not offered quick-look browse in the past. Some minor additions to the processing system that performs the subsetting enabled the creation of Google Earth compatible browse images and a KML file to animate them. As an added bonus, it is possible to animate two parameters simultaneously and adjust the transparency of the top layer to see how they correlate or interact. If that proves useful we may investigate creating false color animations in a similar manner. |
DMSP SSM/I Pathfinder Daily EASE-Grid Brightness Temperatures |
| Download NPEO buoy data file for Google Earth (KML, 3 KB) | Air temperature; atmospheric pressure measurements; infrared radiance; longwave radiation; shortwave radiation; surface winds; wind direction (wind speed, wind vectors); visible radiance | Technical notes: Point data is much easier to animate, as one does not have to generate the imagery, and both network and memory requirements are minimized. This sequence shows an animation of hourly data gathered from a buoy for almost a year. As an added bonus, the animation highlights faulty locations in the data that might be harder to find through simple inspection of the table. Near the end of the animation, the buoy races down the east coast of Greenland and one can get a sense of the current speed. | North Pole Environmental Observatory (NPEO) Weather and Radiation Buoy Data, 2002-2004 |
| Download NSIDC field data file for Google Earth (KML, 3 KB) | Various | This file includes data from anywhere on the globe for which the spatial coverage
is adequately described by
a one-degree bounding box, representing data from a single "point." Technical notes: This approach was a way of exploring how to most easily create a Google Earth file for our field data. We add such data sets to our catalog frequently, so coming up with a rule for identifying these data sets and adding them to the file would make it possible to somewhat automate maintenance of such a file. The resulting file is only a very limited part of our extensive data collection. |
Various data sets; links included with each pushpin |
| Download Screen Overlays example file (KML, 9 KB) | Screen Overlays | This file includes examples of how to use screen overlays in Google Earth. No actual data or imagery is presented Technical notes: Screen overlays are images placed on the screen to display ancillary information that puts the other information in context. Things like logos, titles, and legends are often displayed as screen overlays. See Virtual Globes: KML Screen Overlays for more information. |
None |
| Dowload Antarctic Iceberg tracks file (KMZ, 6.59 MB) | Antarctic Iceberg tracks | This file includes GPS tracks from two drifting icebergs off the Antarctic Peninsula. Associated remotely operated camera views and satellite imagery are also shown. These icebergs were instrumented during the 2006 Antarctic Field season's Ice Trek expedition (see http://nsidc.org/icetrek) by a team of researchers from The University of Colorado, Stanford University, the University of Wisconsin, Madison and the Instituto Antártico Argentino - Dirección Nacional del Antártico, Argentina. GPS data from the drifting stations were converted for use in Google Earth by using the GPS Visualizer, a free, easy-to-use online utility that creates maps and profiles from GPS data (tracks and waypoints). | Ice Trek expedition |
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Supporting Cryospheric Research Since 1976 |
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