SeaWiFS Data Available for Download from

[genecarlfeldman]

good afternoon,

1) seawifs data now available from the ocean color web although it has taken a little longer than we had initially thought, we are happy to announce that it is now possible to download and/or order seawifs data (up to data collected 14 days ago, the required embargo period) directly from the ocean color web browser along with the modis/aqua data that is currently being provided.  this service is provided in addition to the continuing access and user services for seawifs data that are provided by the goddard daac.

2) you still need to be an authorized seawifs user as with data access from the daac, you must be an authorized seawifs data user and have a password.  for those of you who already are authorized users, just request a password directly from a link in the lower right portion on the ocean color web page ( http://oceancolor.gsfc.nasa.gov ) to use this option. if you are not currently an authorized researcher, there is also a link on that web page that you can use to request to become one. upon authorization, new users will be provided with a password. if you are not sure if you are on the authorized list or if you want to verify the e-mail address at which you are listed at (information that we require), you can check at:
https://oceandata.sci.gsfc.nasa.gov/

3) improved seawifs 1 kilometer data product available we are currently producing an improved high resolution seawifs data product (MLAC = Merged Local Area Coverage) derived from the 1 kilometer seawifs hrpt and recorded lac data that reduces geographic overlap from multiple receiving stations and maximizes data quality.  both level-1 and level-2 data are available for this new data set along with the same products derived from the gac (4 kilometer) data.  we are currently processing the entire MLAC archive to create a complete set of level-1 and level-2 products and the entire mission should be available by early next week.  currently, 1997 is online with 1998 and the rest of the mission following close behind.

4) geographic subsetting for seawifs data in addition to being able to order the full level-1 and level-2 files, you can also now request a geographic extract from the full sized file to only get the data for your specific region of interest.  this option only works through the order and ftp option (rather than the direct download from the web browser which provides you with the entire file).  once you've used the browser to find all the potential files for the time frame and general region of interest and hit the <order> button, you'll be given the optionof extracting the data products into a smaller geographic box.  it will be these extracts (all fully supported in seadas) that will be staged for you to download.

5) updated seawifs calibration model the seawifs data that you can get from the ocean color web is slightly different from the data archived at the goddard daac in that we have switched to a revised calibration table which better handles the temporal degradation of the instrument in the very early and later parts of the mission. a comprehensive description of this change in the level-1 calibration can be found under the "validation" section of the ocean color web.  our analyses show that the differences are relatively minor which is why we did not believe it necessary to replace all the data that are currently archive dat the daac based on reprocessing #4 at this time.  as was discussed at the recent science team meeting, we anticipate an official reprocessing of the entire seawifs mission either later this year or early next which will most likely include a number of additional parameters based on the recommendations of the ocean color community.

6) help available for those of you who are not familiar with all the functions of the ocean color web browse and order tool, there is an extensive help function available. we will be keeping our eyes on the ocean color forum for feedback and questions regarding this new feature.

thanks and best regards,
gene