ACOS_L2S
7.3
Not provided
ACOS GOSAT/TANSO-FTS Level 2 Full Physics Standard Product V7.3 (ACOS_L2S) at GES DISC
OCO-2 Science Team/Michael Gunson, Annmarie Eldering
ACOS GOSAT/TANSO-FTS Level 2 Full Physics Standard Product V7.3
ACOS_L2S
2016-04-18T00:00:00.000Z
Greenbelt, MD, USA
Goddard Earth Sciences Data and Information Services Center (GES DISC)
7.3
ACOS_L2S_7.3
Digital Science Data
https://disc.gsfc.nasa.gov/datacollection/ACOS_L2S_7.3.html
METADATA AUTHOR
ANDREY
SAVTCHENKO
Distributed Active Archive Center Global Change Data Center
Code 610.2
NASA Goddard Space Flight Center
Greenbelt
MD
20771
USA
301-614-5705
Telephone
301-614-5268
Fax
Andrey.Savtchenko@nasa.gov
EARTH SCIENCE
ATMOSPHERE
ATMOSPHERIC CHEMISTRY
CARBON AND HYDROCARBON COMPOUNDS
ATMOSPHERIC CARBON DIOXIDE
IMAGERY/BASE MAPS/EARTH COVER
EOSDIS
Earth Observation Satellites
GOSAT
Greenhouse Gases Observing Satellite
TANSO-FTS
Thermal And Near Infrared Sensor For Carbon Observation
2009-04-20T00:00:00.000Z
COMPLETE
GEODETIC
GEODETIC
-90
90
-180
180
Not provided
GEOGRAPHIC REGION
GLOBAL
OCO
Orbiting Carbon Observatory
These data are from algorithm build version 7.3
This product have full public access
The Earth Observing System Data and Information System (EOSDIS) data use policy for NASA data can be accessed at https://earthdata.nasa.gov/earth-observation-data/data-use-policy. For information on how to properly cite and acknowledge data from the NASA GES DISC, refer to https://disc.gsfc.nasa.gov/information/documents?title=data-policy.
English
ARCHIVER
NASA/GSFC/SED/ESD/GCDC/GESDISC
Goddard Earth Sciences Data and Information Services Center (formerly Goddard DAAC), Global Change Data Center, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA
https://disc.gsfc.nasa.gov/
DATA CENTER CONTACT
GES DISC HELP DESK SUPPORT GROUP
Goddard Earth Sciences Data and Information Services Center
Code 610.2
NASA Goddard Space Flight Center
Greenbelt
MD
20771
USA
301-614-5224
Telephone
301-614-5268
Fax
gsfc-dl-help-disc@mail.nasa.gov
Online Archive
HDF5
None
Version 7.3 is the current version of the data set. Version 3.5 is no longer available and has been superseded by Version 7.3.
This data set is currently provided by the OCO (Orbiting Carbon Observatory) Project. In expectation of the OCO-2 launch, the algorithm was developed by the Atmospheric CO2 Observations from Space (ACOS) Task as a preparatory project, using GOSAT TANSO-FTS spectra. After the OCO-2 launch, "ACOS" data are still produced and improved, using approaches applied to the OCO-2 spectra.
The "ACOS" data set contains Carbon Dioxide (CO2) column averaged dry air mole fraction for all soundings for which retrieval was attempted. These are the highest-level products made available by the OCO Project, using TANSO-FTS spectral radiances, and algorithm build version 7.3.
The GOSAT team at JAXA produces GOSAT TANSO-FTS Level 1B (L1B) data products for internal use and for distribution to collaborative partners, such as ESA and NASA. These calibrated products are augmented by the OCO Project with additional geolocation information and further corrections. Thus produced Level 1B products (with calibrated radiances and geolocation) are the input to the "ACOS" Level 2 production process.
Even though the GES DISC is not publicly distributing Level 1B ACOS products, it should be known that changes in this version are affecting both Level 1B and Level 2 data. An important enhancement in Level1B will address the degradation in the number of quality-passed soundings.
Elimination of many systematic biases, and better agreement with TCCON (Total Carbon Column Observing Network), is expected in Level 2 retrievals. The key changes to the L2 algorithm include scaling the O2-A band spectroscopy (reducing XCO2 bias by 4 or 5 ppm); using interpolation with the instrument lineshape [ ILS ] (reducing XCO2 bias by 1.5 ppm); and fitting a zero level offset to the A-band. Users have to also carefully familiarize themselves with the disclaimer in the new documentation.
An important element to note are the updates on data screening. Although a Master Quality Flag is provided in the data product, further analysis of a larger set of data has allowed the science team to provide an updated set of screening criteria. These are listed in the data user's guide, and are recommended instead of the Master Quality Flag.
Lastly, users should continue to carefully observe and weigh information from three important flags:
"warn_level" - Provides a value that summarizes each sounding's acceptability to a larger set of quality filters. A high warn level predicts that the sounding would fail most data filters applied to it. A low warn level suggests that the sounding would pass most quality filters that might be applied.
"sounding_qual_flag" - quality of input data provided to the retrieval processing
"outcome_flag" - retrieval quality based upon certain internal thresholds (not thoroughly evaluated)
"master_quality_flag" - four possible values: "Good", "Caution" and "Bad", and "Failed", as determined from other flags in the L2 productThe short name for this data type is ACOS_L2S.
GET RELATED VISUALIZATION
https://docserver.gesdisc.eosdis.nasa.gov/public/project/OCO/ACOS.L2S.2015_v7.3.png
Monthly maps of the ACOS v7.3 XCO2 data. Each data point contains the average
value for XCO2 estimates in a 2° x 2° bin for that month that passed all pre- and post-screening
filters; the recommend bias correction has been applied. Reproduced from ACOS v7.3 Data Users Guide.
DATA SET LANDING PAGE
https://disc.gsfc.nasa.gov/datacollection/ACOS_L2S_7.3.html
Access the dataset landing page from the GES DISC website.
GET DATA
DATA TREE
https://oco2.gesdisc.eosdis.nasa.gov/data/GOSAT_TANSO_Level2/ACOS_L2S.7.3/
Access the data via HTTP.
GET DATA
Earthdata Search
https://search.earthdata.nasa.gov/search?q=ACOS_L2S+7.3
Use the Earthdata Search to find and retrieve data sets across multiple data centers.
USE SERVICE API
OPENDAP DATA
https://oco2.gesdisc.eosdis.nasa.gov/opendap/ACOS_L2S.7.3/
Access the data via the OPeNDAP protocol.
VIEW RELATED INFORMATION
http://www.gosat.nies.go.jp/index_e.html
GOSAT site
VIEW RELATED INFORMATION
GENERAL DOCUMENTATION
https://docserver.gesdisc.eosdis.nasa.gov/public/project/OCO/ACOS_v7.3_DataUsersGuide-RevF.pdf
User's Guide
VIEW RELATED INFORMATION
GENERAL DOCUMENTATION
https://ocov2.jpl.nasa.gov/science/publications/
OCO-2 Publications from the Science Team
VIEW RELATED INFORMATION
GENERAL DOCUMENTATION
https://ocov3.jpl.nasa.gov/science/publications/
OCO-3 Publications from the Science Team
VIEW RELATED INFORMATION
GENERAL DOCUMENTATION
https://docserver.gesdisc.eosdis.nasa.gov/public/project/OCO/KnownDataIssues.ACOS.html
ACOS Data Gaps
VIEW RELATED INFORMATION
GENERAL DOCUMENTATION
http://www.gosat.nies.go.jp/en/about_%EF%BC%92_observe.html
Instrument Description
CEOS IDN DIF
VERSION 10.2
2013-03-28
2019-11-21
2020-11-30
2016-01-24T00:00:00.000Z
2016-04-14T00:00:00.000Z
2