News
| 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 |
2012 Data News
13 March 2012
Both the original EASE-Grid and EASE-Grid 2.0 are now fully supported in PROJ 4.8.0. For technical details of EASE-Grid 2.0, including forward and inverse projection mathematics and detailed descriptions of known issues with the original EASE-Grid definition, please refer to Brodzik et al. (2012).
01 March 2012
EASE-Grid 2.0 is now available and is recommended for new data sets. Two major NASA-funded projects have adopted EASE-Grid 2.0 as the standard format for gridded data sets, including the Soil Moisture Active Passive (SMAP) project (data are forthcoming), and the MEaSUREs snow and ice project. Version 2.0 is defined with the WGS 84 ellipsoid rather than the spherical Earth model in the original. Among other enhancements, it also offers GeoTIFF compatibility, an exact azimuthal grid scale, and simplified nested grids. See the EASE-Grid Data Versions page for more information.
2011 Data News
15 August 2011
A new data set is available at NSIDC, the Enhanced-Resolution SSM/I and AMSR-E Daily Polar Brightness Temperatures. Brightness temperatures obtained by the SSM/I and AMSR-E instruments were enhanced using the Scatterometer Image Reconstruction (SIR) algorithm, and are provided in three equal-area spatial coverages: Northern Hemisphere, Southern Hemisphere, and full global. Daily SSM/I images are available from 1995 through 2008, and twice-daily AMSR-E images are available from 2002 through 2009. For documentation and access to the data, please see the product catalog page.
29 July 2011
Updated EASE-Grid SSM/I-SSMIS data are now available at NSIDC. This semi-quarterly update extends the time series of the DMSP SSM/I-SSMIS Pathfinder Daily EASE-Grid Brightness Temperatures data set through 27 April 2011. The SSM/I-SSMIS EASE-Grid brightness temperatures are available in all three EASE-Grid projections: north, south, and global.
25 May 2011
Both the AMSR-E/Aqua Daily EASE-Grid Brightness Temperatures and AMSR-E/Aqua Daily Global Quarter-Degree Gridded Brightness Temperatures data sets have been updated. This quarterly update extends the time series of both data sets through 31 March 2011. AMSR-E brightness temperatures are available in all three EASE-Grid projections (north, south, and global), as well as global, quarter-degree latitude-longitude gridded data.
03 May 2011
NSIDC is pleased to announce that the DMSP SSM/I-SSMIS Pathfinder Daily EASE-Grid Brightness Temperature data for 14 December 2006 through 31 December 2010 are now available.
This update includes many new features, as described in the data set documentation, and new data from the Special Sensor Microwave Imager/Sounder (SSMIS) aboard the Defense Meteorological Satellite Program (DMSP) F-17 satellite. Because the Backus-Gilbert interpolation method is not yet compatible with the SSMIS sensor, NSIDC changed the gridding process to use the Inverse Distance Squared method and completed an intercomparison of F-13 data with F-17 data. To accommodate the sensor and interpolation changes, F-17 data are considered Version 2 (V2), which is reflected in the filenames. Lastly, the data reflect a large overlap time period between the SSM/I and SSMIS sensors from December 2006 to April 2009 so that users may conduct their own analyses on the data differences.
Geolocation and display tools are available for this data set from the EASE-Grid Data Geolocation Tools Web page.
Please also note the new FTP location for this data set. We welcome your questions at NSIDC User Services.
2010 Data News
24 September 2010
Interactive Data Language (IDL) expert, David Fanning, has created a new tool for NSIDC, called the NSIDC DataViewer, that allows data users to conveniently view, display, and manipulate satellite images in a user-defined grid. The tool can be used with a variety of NSIDC passive microwave data sets ranging from brightness temperatures to sea ice motion vectors, and in three different projections, including Polar Stereographic, EASE-Grid, and Quarter-Degree.
Up to 64 images can be displayed simultaneously in the DataViewer resizeable graphics window, allowing data users to page through a series of images. Images can then be scaled and manipulated either individually or as a group. By moving the cursor over an image, a data user can obtain the latitude and longitude coordinates as well as the image value at the cursor location. After an image or series of images is manipulated, the contents of the graphics window(s) can be saved in a variety of image formats, including PostScript, PNG, JPEG, and TIFF.
The NSIDC DataViewer can be run in IDL with an IDL license, via the freely distributed IDL Virtual Machine, or as a run-time application. The NSIDC DataViewer is available via FTP in both Windows- and UNIX-compatible versions: dataviewer.zip and dataviewer.tar.gz, respectively.
2009 Data News
23 April 2009
Both the AMSR-E/Aqua Daily EASE-Grid Brightness Temperatures and AMSR-E/Aqua Daily Global Quarter-Degree Gridded Brightness Temperatures data sets have been updated. This update extends the time series of both data sets to 31 March 2009.
2008 Data News
06 October 2008
NSIDC has released a new data set: Near-Real-Time DMSP SSM/I Pathfinder Daily EASE-Grid Brightness Temperatures. This data set provides daily, near-real-time Special Sensor Microwave/Imager (SSM/I) brightness temperatures in the 25 km Equal-Area Scalable Earth-Grid (EASE-Grid). For more information, please see the data set documentation or contact NSIDC User Services.
05 August 2008
Due to an error in an ancillary data file, the following Version 2 AMSR-E Level 3 snow products were removed from NSIDC's archives:
- AMSR-E/Aqua Daily L3 Global Snow Water Equivalent EASE-Grids (AE_DySno)
- AMSR-E/Aqua 5-Day L3 Global Snow Water Equivalent EASE-Grids (AE_5DySno)
- AMSR-E/Aqua Monthly L3 Global Snow Water Equivalent EASE-Grids (AE_MoSno)
The bad ancillary data file creates an incorrect Snow Water Equivalent (SWE) flag. Any AMSR-E Level 3 snowfall data using the Transitional 08 Algorithm (T08) received from NSIDC prior to 23 July 2008 should not be used. The filename has the variable T08 in it.
Beginning 28 July 2008, new Version 2 AMSR-E Level 3 snow products were generated for 21 July 2008 and will continue with forward processing. Reprocessing will beginning with 19 June 2002, the start of the AMSR-E mission, and continue through 20 July 2008. The algorithm will remain at the T08 level.
For more information, contact NSIDC User Services.
04 August 2008
As of 06 July 2008, Version 2 of AMSR-E Level 3 land, rain, ocean, snow, and sea ice products are now available at NSIDC, and are considered Transitional (T) or Validated (V). The following is a listing of the Level 3 products.
Land Product (Algorithm: T05)
Rain Product (Algorithm: V06 - Stage 2)
Ocean Products (Algorithm: V03 - Stage 2)
- AMSR-E/Aqua Daily L3 Global Ascending/Descending .25x.25 deg Ocean Grids (AE_DyOcn)
- AMSR-E/Aqua Weekly L3 Global Ascending/Descending .25x.25 deg Ocean Grids (AE_WkOcn)
- AMSR-E/Aqua Monthly L3 Global Ascending/Descending .25x.25 deg Ocean Grids (AE_MoOcn)
Sea Ice Products (Algorithm: T07)
- AMSR-E/Aqua Daily L3 6.25 km 89 GHz Brightness Temperature Polar Grids (AE_SI6)
- AMSR-E/Aqua Daily L3 12.5 km Brightness Temperature, Sea Ice Concentration, & Snow Depth Polar Grids (AE_SI12)
- AMSR-E/Aqua Daily L3 25 km Brightness Temperature and Sea Ice Concentration Polar Grids (AE_SI25)
Snow Products (Algorithm: T08)
- AMSR-E/Aqua Daily L3 Global Snow Water Equivalent EASE-Grids (AE_DySno)
- AMSR-E/Aqua 5-Day L3 Global Snow Water Equivalent EASE-Grids (AE_5DSno)
- AMSR-E/Aqua Monthly L3 Global Snow Water Equivalent EASE-Grids (AE_MoSno)
Delivered Algorithm Packages (DAPs) are also available for these products. If you are interested in receiving the DAP, or for more information, contact NSIDC User Services.
22 February 2008
NSIDC has released the Global EASE-Grid 8-day Blended SSM/I and MODIS Snow Cover data set suitable for continental- to hemispheric-scale seasonal fluctuations of snow covered area (SCA) and snow water equivalent (SWE). This data set comprises global, 8-day SWE data from 2000 through 2007, enhanced with snow-covered area derived from MODIS visible wavelength bands.
The new data set blends visible and microwave data at higher temporal resolution (8-day) than NSIDC has offered before; and it is our first snow cover product to be released in netCDF format, specifically at the request of modelers.
Produced in the 25-kilometer Equal-Area Scaleable Earth Grid (EASE-Grid), the new product is unique in blending information from both passive microwave and visible sensors on a global scale for the period when both types of sensor data are available.
16 January 2008
The AVHRR Polar Pathfinder Twice-Daily 5 km EASE-Grid Composites data set has been updated. This update extends the time series to 30 June 2005. The data in this update is still considered Version 3. This update includes:
- A change in filename to now include the platform, for example, a14_s005_1996001_1400_albd.v3
where: a14 = NOAA-14.
- Data beginning on day 2001060 are collected by AVHRR on NOAA-16.
- A dual Channel 3 is now included for better cloud detection. Channel
3A collects data during the day at 1.6 microns, and Channel 3B collects
data during the night at 3.7 microns.
- Due to a problem with the NOAA-16 scan motor, all the channel data is shifted sporadically between 2001 and 2005, causing the channels to contain data from another channel; thus, the derived parameters also contain errors during this time-period. See Table 12 in the Error Sources section of the data set documentation for specific dates.
2007 Data News
20 September 2007
The complete times series of Version 2 data for the Near-Real-Time SSM/I EASE-Grid Daily Global Ice Concentration and Snow Extent product is now available from the Data Pool and will remain available indefinitely. The time series extends from 04 May 1995 through present.
2006 Data News
8 December 2006
AMSR-E/Aqua Daily EASE-Grid Brightness Temperatures: NSIDC produces AMSR-E gridded brightness temperature data by interpolating AMSR-E data to the output grids from swath space using an inverse-distance squared method. Data for the Northern Hemisphere and Southern Hemisphere EASE-Grid projections, at 25 km resolution, are now available. Data begin 19 June 2002, and processing is ongoing.
7 February 2006
Arctic EASE-Grid Freeze and Thaw Depths, 1901 - 2002: This FGDC data set contains mean, median, minimum and maximum freeze and thaw depths for each year from 1901 to 2002 on the 25 km EASE-Grid for areas north of 50°. Freeze and thaw depths are estimated using a variant of the Stefan solution that uses an edaphic factor and freezing or thawing indices as inputs.
