Skip to main content

Description

Version 9r is the current version of the data set. Older versions will no longer be available and are superseded by Version 9r.
The ACOS Lite files contain bias-corrected XCO2 along with other select fields aggregated as daily files. Orbital granules of the ACOS Level 2 standard product (ACOS_L2S) are used as input.

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.

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.

Version Description

Not provided

Product Summary

Platforms
GOSAT
Instruments
TANSO-FTS
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2009-04-20 to 2020-07-01
Data Partner
Goddard Earth Sciences Data and Information Services Center (formerly Goddard DAAC), Terrestrial Information Systems Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/GESDI
Concept ID
C1720416694-GES_DISC
Data State
COMPLETE
Number of Files/Granules
3958
Processing Level
2
Published
Updated
Science Keywords
Atmospheric Carbon Dioxide

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Science Data Operations System Jet Propulsion Laboratory. (2020). ACOS GOSAT/TANSO-FTS Level 2 bias-corrected XCO2 and other select fields from the full-physics retrieval aggregated as daily files V9r [Data set]. NASA Goddard Earth Sciences Data and Information Services Center. https://doi.org/10.5067/VWSABTO7ZII4 Date Accessed: 2026-05-14

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
Retrieval/offset_o2a_rel Retrieved Band 1 ZLO relative to Band 1 Signal from ACOS_L2_Lite_FP_9r dimensionless float32 N/A N/A N/A N/A
Retrieval/psurf Retrieved Surface Pressure from ACOS_L2_Lite_FP_9r hPa float32 N/A N/A N/A N/A
Retrieval/psurf_apriori Prior Surface Pressure from ACOS_L2_Lite_FP_9r hPa float32 N/A N/A N/A N/A
Retrieval/rms_rel_sco2 relative_rms_strong_co2_band from ACOS_L2_Lite_FP_9r percent float32 N/A N/A N/A N/A
Retrieval/rms_rel_wco2 relative_rms_weak_co2_band from ACOS_L2_Lite_FP_9r percent float32 N/A N/A N/A N/A
Retrieval/s31 Signal_band3/Signal_band1 from ACOS_L2_Lite_FP_9r none float32 N/A N/A N/A N/A
Retrieval/s32 Signal_band3/Signal_band2 from ACOS_L2_Lite_FP_9r none float32 N/A N/A N/A N/A
Retrieval/SigmaB SigmaB_Coefficient from ACOS_L2_Lite_FP_9r dimensionless float32 N/A N/A N/A N/A
Retrieval/surface_type Surface Type from ACOS_L2_Lite_FP_9r 0=ocean;1=land int8 N/A N/A N/A N/A
Retrieval/t700 Temperature_at_700hPa from ACOS_L2_Lite_FP_9r K float32 N/A N/A N/A N/A
Retrieval/tcwv Total Column Water Vapor from ACOS_L2_Lite_FP_9r kg/m^2 float32 N/A N/A N/A N/A
Retrieval/tcwv_apriori Total Column Water Vapor A Priori from ACOS_L2_Lite_FP_9r kg/m^2 float32 N/A N/A N/A N/A
Retrieval/tcwv_uncertainty Total Column Water Vapor Uncertainty from ACOS_L2_Lite_FP_9r kg/m^2 float32 N/A N/A N/A N/A
Retrieval/water_height Water Cloud Height from ACOS_L2_Lite_FP_9r P/Psurf float32 N/A N/A N/A N/A
Retrieval/windspeed Retrieved Surface Wind Speed from ACOS_L2_Lite_FP_9r m/s float32 N/A N/A N/A N/A
Retrieval/windspeed_apriori Prior Surface Wind Speed from ACOS_L2_Lite_FP_9r m/s float32 N/A N/A N/A N/A
Retrieval/xco2_raw Raw value of Retrieved XCO2 from ACOS_L2_Lite_FP_9r ppm float32 N/A N/A N/A N/A
sensor_zenith_angle sounding_zenith from ACOS_L2_Lite_FP_9r degrees float32 N/A N/A N/A N/A
solar_zenith_angle sounding_solar_zenith from ACOS_L2_Lite_FP_9r degrees float32 N/A N/A N/A N/A
Sounding/airmass relative_airmass from ACOS_L2_Lite_FP_9r degrees float32 N/A N/A N/A N/A
Sounding/altitude Altitude from ACOS_L2_Lite_FP_9r meters float32 N/A N/A N/A N/A
Sounding/altitude_stddev Altitude Stddev from ACOS_L2_Lite_FP_9r meters float32 N/A N/A N/A N/A
Sounding/gain Gain from ACOS_L2_Lite_FP_9r none OTHER N/A N/A N/A N/A
Sounding/glint_angle sounding_glint_angle from ACOS_L2_Lite_FP_9r degrees float32 N/A N/A N/A N/A
Sounding/l1b_type JAXA L1B Processing Version from ACOS_L2_Lite_FP_9r none int32 N/A N/A N/A N/A
Sounding/land_fraction Land Fraction from ACOS_L2_Lite_FP_9r percent int8 N/A N/A N/A N/A
Sounding/path GOSAT orbit path number from ACOS_L2_Lite_FP_9r none uint8 N/A N/A N/A N/A
Sounding/sensor_azimuth_angle sounding_azimuth from ACOS_L2_Lite_FP_9r degrees East of North float32 N/A N/A N/A N/A
Sounding/snr_o2a snr_O2_L1b from ACOS_L2_Lite_FP_9r none float32 N/A N/A N/A N/A
Sounding/snr_sco2 snr_strong_CO2_L1b from ACOS_L2_Lite_FP_9r none float32 N/A N/A N/A N/A
Sounding/snr_wco2 snr_weak_CO2_L1b from ACOS_L2_Lite_FP_9r none float32 N/A N/A N/A N/A
Sounding/solar_azimuth_angle sounding_solar_azimuth from ACOS_L2_Lite_FP_9r degrees East of North float32 N/A N/A N/A N/A
sounding_id ACOS Sounding ID from ACOS_L2_Lite_FP_9r YYYYMMDDhhmmss uint64 N/A N/A N/A N/A
source_files L2 Source File from ACOS_L2_Lite_FP_9r none string N/A N/A N/A N/A
time time from ACOS_L2_Lite_FP_9r seconds since 1970-01-01 00:00:00 float64 N/A N/A N/A N/A
xco2 XCO2 from ACOS_L2_Lite_FP_9r ppm float32 N/A N/A N/A N/A
xco2_apriori A priori XCO2 Value from ACOS_L2_Lite_FP_9r ppm float32 N/A N/A N/A N/A
xco2_averaging_kernel XCO2 Column Averaging Kernel from ACOS_L2_Lite_FP_9r none float32 N/A N/A N/A N/A
xco2_qf_bitflag ACOS B9 xco2_quality_flag bitflag from ACOS_L2_Lite_FP_9r none int32 N/A N/A N/A N/A
xco2_quality_flag XCO2_Quality_Flag from ACOS_L2_Lite_FP_9r none int8 N/A N/A N/A N/A
xco2_uncertainty XCO2_Posterior_Error from ACOS_L2_Lite_FP_9r ppm float32 N/A N/A N/A N/A
You're viewing 91 of 91