Location of Chlorophyll data files

By zdufran Date 2010-11-08 17:13 Edited 2010-11-08 17:16

I am not able to access the latest data files linked from the browser at http://oceancolor.gsfc.nasa.gov/cgi/l3. I am specifically interested in the 3-day composite chlorophyll files (HDF bz2) dated 4 Nov - 6 Nov 2010.

Any help would be appreciated-

Zach DuFran

By @norman Date 2010-11-08 17:39

Hi Zach,

Please try your download again. We have fixed a small
problem with our HTTP server.

Regards,
Norman

By zdufran Date 2010-11-09 15:13

Norman-

I was able to download files yesterday afternoon. However, these files were previously formatted with an unsigned integer field called "chlor" and now they are filled with a string field called "l3m_data" I plotted the data and it does not match the preview thumbnails.

Also, I notice the 3-day composite files are not updating as they should. The most recent 3 day period is 4 Nov - 6 Nov 2010.

Zach

By @norman Date 2010-11-09 15:39

Hi Zach,

I suspect that you are getting your level-2 and level-3 products confused.
Our level-2 files contain a data set named "chlor_a" which is in 32-bit
floating-point format. The corresponding level-3 SMI files have always
had the data set named "l3m_data" although the format of those data
has gone from 8-bit integer to 16-bit integer to the current 32-bit
floating-point format. Please see the format descriptions for the
various products that we have provided on our web site.

As to the freshness of our level-3 products, these usually appear
a day or so after all of the orbits for the daily (or 3-day) product
in question have been received and processed. Occasionally,
the lag time is longer if our data source is delayed or if bottle-necks
in our own data system slow processing down. The more recent
3-day products that you seek should be appearing within the next
several hours.

Regards,
Norman

By zdufran Date 2010-11-09 20:33

Thanks, Norman.

I think I've got it all figured out now.

Zach

By zdufran Date 2010-11-10 17:43

Norman-

The aqua 3-day composites are still not updating, while the terra has updated twice over the last day. The latest terra set is for 6 Nov - 9 Nov, while the latest aqua is still 4 Nov - 6 Nov. Are there problems with the aqua data set?

Zach

By @norman Date 2010-11-10 18:18

Zach,

There are no problems that I know of. For some reason the November 7
Aqua-MODIS daily composite did not get generated yet. My first guess
is that this has to do with the increased load on our systems as we reprocess
the Terra-MODIS data.

We will attempt to give the processing a kick in the pants to try to get
the November 7 composite to go through. When that becomes available,
the more recent 3-day products should follow.

Norman

By maulinashella Date 2010-12-12 05:22

hi everyone..

This problem also faced by me.till now (12 Dec 2010), I still can not download aqua MODIS data for the three day composite 2008.For in your information, no data for Chlorophyll concentration for the 3day composite satellite images 2008.data available for 2010 only. well, the data for SSTday and night (3 day composite for 2008 <4km> ) can't be download too.when download, data is only 0kb.I attempt to download data nearly all the time.but it still 0kb.
I need this data to proceed my project.please do something .... :-(

-eja-

By @sean Date 2010-12-12 17:28

The 3D composites are NOT an archived product. See this thread:
http://oceancolor.gsfc.nasa.gov/forum/oceancolor/topic_show.pl?pid=14894

We only produce them as a service for NRT researchers. They cannot be
considered reliable - can disappear at any time, although we try to make
sure the forward stream is available.

Regards,
Sean