Earthdata Forum

Looking at the files to download from the Level-3 browser.  For search parameters: MODIS/A, Chlorophyll concentration, monthly climatology, 4km, mission date range. These are the files returned for download:
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20022442018273.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20022742017304.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20023052017334.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20023352017365.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20030012018031.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20030322018059.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20030602018090.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20030912018120.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20031212018151.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20031522018181.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20031822016213.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20032132016244.L3m_MC_CHL_chlor_a_4km.nc

For the exact same search parameters, except using Rrs_412, these are the files:

https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20021822018212.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20022132018243.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20022442018273.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20022742017304.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20023052017334.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20023352017365.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20030012018031.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20030322018059.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20030602018090.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20030912018120.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20031212018151.L3m_MC_RRS_Rrs_412_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20031522018181.L3m_MC_RRS_Rrs_412_4km.nc

The date ranges are different for individual files throughout these lists, but note the July and August files in each list:
A20031822016213.L3m_MC_CHL_chlor_a_4km.nc
A20021822018212.L3m_MC_RRS_Rrs_412_4km.nc

A20032132016244.L3m_MC_CHL_chlor_a_4km.nc
A20022132018243.L3m_MC_RRS_Rrs_412_4km.nc

Why are there no chlor_a data from July/August 2002, 2017, and 2018? I can maybe understand 2002, but especially why no chlor_a data in July/August 2017 - all other months in 2017 are included, and even September 2018 is included.

I don't think this is a cache issue on my end, as I see similar results for chlor_ocx and other Rrs_vvv.

Also, is there a way to tell if there are "missing" years in these mission monthly climatology files that are obscured by the date range in the filename? This would also not be clear in the .nc attributes (time_coverage_start and _end).

Any insight would be helpful. Thanks in advance.
-brian

Brian,

Well, there *are* chlorophyll monthly climatology data for 2002-2018, but there is also a 2003-2016 version which is confusing the logic in place in the browser to present only the most recent version.  Each year a new one is made, but removing the old ones is a manual process, so we wrote something to display just the latest.  A special run for chlorophyll, that skipped the first couple of months of the mission confused the situation.  Should be fixed soon.  Until then, you can grab them manually:

https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20021822018212.L3m_MC_CHL_chlor_a_4km.nc
https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/A20022132018243.L3m_MC_CHL_chlor_a_4km.nc

Sean

Edit:

> Also, is there a way to tell if there are "missing" years in these mission monthly climatology files that are obscured by the date range in the filename? This would also not be clear in the .nc attributes (time_coverage_start and _end).

Not from the mapped data.  The bin file would show the source monthlies:

$ ncdump -h A20022132018243.L3m_MC_CHL_chlor_a_4km.nc|grep source
                :source = "A20022132018243.L3b_MC_CHL.nc" ;
$ ncdump -h A20022132018243.L3b_MC_CHL.nc|grep source
                :source = "A20022132002243.L3b_MO_CHL.nc,A20032132003243.L3b_MO_CHL.nc,A20042142004244.L3b_MO_CHL.nc,A20052132005243.L3b_MO_CHL.nc,A20062132006243.L3b_MO_CHL.nc,A20072132007243.L3b_MO_CHL.nc,A20082142008244.L3b_MO_CHL.nc,A20092132009243.L3b_MO_CHL.nc,A20102132010243.L3b_MO_CHL.nc,A20112132011243.L3b_MO_CHL.nc,A20122142012244.L3b_MO_CHL.nc,A20132132013243.L3b_MO_CHL.nc,A20142132014243.L3b_MO_CHL.nc,A20152132015243.L3b_MO_CHL.nc,A20162142016244.L3b_MO_CHL.nc,A20172132017243.L3b_MO_CHL.nc,A20182132018243.L3b_MO_CHL.nc" ;

I see. Thanks so much, Sean.
-brian