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FTPS from SPDF (not with most browsers)
HTTPS from SPDF
CDAWeb
WebService:
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Gold Level L2 ratio of the column abundance of thermospheric O relative to N2
var authors='Eastes, Richard; Daniell, Robert E.';
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(2025).
Gold Level L2 ratio of the column abundance of thermospheric O relative to N2.
[Data set].
Space Physics Data Facility.
https://doi.org/10.48322/wjrk-dk56. Accessed on document.write(currentDateStr);.
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ResourceID
spase://NASA/NumericalData/GOLD/L2/ON2/PT8S
Description
GOLD daytime disk scan (DAY) measurements are used to derive the ratio of the column abundance of thermospheric O relative to N2, conventionally referred to as O/N2 or ΣO/N2, but abbreviated to ON2 for the GOLD data product. ON2 is derived from dayside Level 1C data after binning pixels 2x2 for approximately 68 disk scan measurements performed per day by GOLD in nominal operation.
Algorithm heritage
The disk ON2 retrieval algorithm was originally developed by Computational Physics, Inc. (CPI) for use with GUVI and SSUSI radiance images (Strickland et al., 1995). The GOLD implementation of this algorithm takes advantage of GOLD's ability to transmit the full spectrum to maximize the signal-to-noise ratio and eliminate atomic emission lines that contaminate the N2 LBH bands (e.g., N I 149.3 nm). This algorithm has been extensively documented and applied over the past several decades (e.g., Evans et al. [1995]; Christensen et al. [2003]; Strickland et al. [2004]) and Correira et al. [2021] describe the implementation used for the GOLD data.
Algorithm theoretical basis
The geophysical parameter retrieved, O/N2, is the ratio of the vertical column density of O relative to N2, defined at a standard reference N2 depth of 1017 cm-2, which is chosen to minimize uncertainty in the derived O/N2. It is retrieved directly from the ratio of the O I 135.6 nm and N2 LBH band intensities measured by GOLD on the dayside disk (DAY measurement mode). The AURIC atmospheric radiance model (Strickland et al. [1999]) is used to derive this relationship as a function of solar zenith angle and to create the look-up table (LUT) used by the algorithm.
References
Christensen, A. B., et al. (2003), Initial observations with the Global Ultraviolet Imager (GUVI) in the NASA TIMED satellite mission, J. Geophys. Res., vol. 108, NO. A12, 1451, doi:10.1029/2003JA009918.
Correira, J., Evans, J. S., Lumpe, J. D., Krywonos, A., Daniell, R., Veibell, V., et al. (2021). Thermospheric composition and solar EUV flux from the Globalscale Observations of the Limb and Disk (GOLD) mission. Journal of Geophysical Research: Space Physics, 126, e2021JA029517. https://doi.org/10.1029/2021JA029517
Evans, J. S., D. J. Strickland and R. E. Huffman (1995), Satellite remote sensing of thermospheric O/N2 and solar EUV: 2. Data analysis, J. Geophys. Res., vol. 100, NO. A7, pages 12,227-12,233.
Strickland, D. J., R. R. Meier, R. L. Walterscheid, J. D. Craven, A. B. Christensen, L. J. Paxton, D. Morrison, and G. Crowley (2004), Quiet-time seasonal behavior of the thermosphere seen in the far ultraviolet dayglow, J. Geophys. Res., vol. 109, A01302, doi:10.1029/2003JA010220.
Strickland, D.J., J. Bishop, J.S. Evans, T. Majeed, P.M. Shen, R.J. Cox, R. Link, and R.E. Huffman (1999), Atmospheric Ultraviolet Radiance Integrated Code (AURIC): theory, software architecture, inputs and selected results, JQSRT, 62, 689-742.
Strickland, D. J., J. S. Evans, and L. J. Paxton (1995), Satellite remote sensing of thermospheric O/N2 and solar EUV: 1. Theory, J. Geophys. Res., 110, A7, pages 12,217-12,226.
Metadata Rights
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Version:2.7.1
NumericalData
ResourceID
spase://NASA/NumericalData/GOLD/L2/ON2/PT8S
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
Gold Level L2 ratio of the column abundance of thermospheric O relative to N2
DOI
https://doi.org/10.48322/wjrk-dk56
ReleaseDate
2026-06-26 13:17:03Z
RevisionHistory
RevisionEvent
ReleaseDate
2020-09-14 16:47:17Z
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2023-10-09 12:34:56.789Z
Note
Added complete CDAWeb and HAPI AccessInformation, metadata versioned up to SPASE 2.6.0, LFB 20231009
RevisionEvent
ReleaseDate
2025-11-03 12:34:56.789Z
Note
Contacts and text revised. JMW
RevisionEvent
ReleaseDate
2025-11-14 16:03:02Z
Note
Added PublicationInfo. Added ResourceType and NamingAuthority. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. Matched version number in schemaLocation attribute to updated value in Version tag. ZCB
RevisionEvent
ReleaseDate
2025-12-04 13:29:18Z
Note
Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB
RevisionEvent
ReleaseDate
2026-06-26 13:17:03Z
Note
Add 'Z' to RevisionEvent:ReleaseDate(s), TemporalDescription:TimeSpan:StartDate. ZCB
Description
GOLD daytime disk scan (DAY) measurements are used to derive the ratio of the column abundance of thermospheric O relative to N2, conventionally referred to as O/N2 or ΣO/N2, but abbreviated to ON2 for the GOLD data product. ON2 is derived from dayside Level 1C data after binning pixels 2x2 for approximately 68 disk scan measurements performed per day by GOLD in nominal operation.
Algorithm heritage
The disk ON2 retrieval algorithm was originally developed by Computational Physics, Inc. (CPI) for use with GUVI and SSUSI radiance images (Strickland et al., 1995). The GOLD implementation of this algorithm takes advantage of GOLD's ability to transmit the full spectrum to maximize the signal-to-noise ratio and eliminate atomic emission lines that contaminate the N2 LBH bands (e.g., N I 149.3 nm). This algorithm has been extensively documented and applied over the past several decades (e.g., Evans et al. [1995]; Christensen et al. [2003]; Strickland et al. [2004]) and Correira et al. [2021] describe the implementation used for the GOLD data.
Algorithm theoretical basis
The geophysical parameter retrieved, O/N2, is the ratio of the vertical column density of O relative to N2, defined at a standard reference N2 depth of 1017 cm-2, which is chosen to minimize uncertainty in the derived O/N2. It is retrieved directly from the ratio of the O I 135.6 nm and N2 LBH band intensities measured by GOLD on the dayside disk (DAY measurement mode). The AURIC atmospheric radiance model (Strickland et al. [1999]) is used to derive this relationship as a function of solar zenith angle and to create the look-up table (LUT) used by the algorithm.
References
Christensen, A. B., et al. (2003), Initial observations with the Global Ultraviolet Imager (GUVI) in the NASA TIMED satellite mission, J. Geophys. Res., vol. 108, NO. A12, 1451, doi:10.1029/2003JA009918.
Correira, J., Evans, J. S., Lumpe, J. D., Krywonos, A., Daniell, R., Veibell, V., et al. (2021). Thermospheric composition and solar EUV flux from the Globalscale Observations of the Limb and Disk (GOLD) mission. Journal of Geophysical Research: Space Physics, 126, e2021JA029517. https://doi.org/10.1029/2021JA029517
Evans, J. S., D. J. Strickland and R. E. Huffman (1995), Satellite remote sensing of thermospheric O/N2 and solar EUV: 2. Data analysis, J. Geophys. Res., vol. 100, NO. A7, pages 12,227-12,233.
Strickland, D. J., R. R. Meier, R. L. Walterscheid, J. D. Craven, A. B. Christensen, L. J. Paxton, D. Morrison, and G. Crowley (2004), Quiet-time seasonal behavior of the thermosphere seen in the far ultraviolet dayglow, J. Geophys. Res., vol. 109, A01302, doi:10.1029/2003JA010220.
Strickland, D.J., J. Bishop, J.S. Evans, T. Majeed, P.M. Shen, R.J. Cox, R. Link, and R.E. Huffman (1999), Atmospheric Ultraviolet Radiance Integrated Code (AURIC): theory, software architecture, inputs and selected results, JQSRT, 62, 689-742.
Strickland, D. J., J. S. Evans, and L. J. Paxton (1995), Satellite remote sensing of thermospheric O/N2 and solar EUV: 1. Theory, J. Geophys. Res., 110, A7, pages 12,217-12,226.
Acknowledgement
National Aeronautics and Space Administration; Dr. Richard Eastes
PublicationInfo
Authors
Eastes, Richard; Daniell, Robert E.
PublicationDate
2025-11-14 16:03:02Z
PublishedBy
Space Physics Data Facility
Contacts
Role
Person
StartDate
StopDate
Note
1.
PrincipalInvestigator
spase://SMWG/Person/Richard.Eastes
2.
CoInvestigator
spase://SMWG/Person/Robert.E.Daniell
3.
ProjectManager
spase://SMWG/Person/Andrey.Krywonos
4.
MetadataContact
spase://SMWG/Person/James.M.Weygand
InformationURL
Name
GOLD Homepage web page
URL
https://gold.cs.ucf.edu/
Description
GOLD web page with news and other information
InformationURL
Name
GOLD Missions Space Science Reviews Article
URL
https://doi.org/10.1007/s11214-017-0392-2
Description
Eastes, R.W., McClintock, W.E., Burns, A.G. et al. Space Sci. Rev. (2017) vol. 212, pp.383.
PriorIDs
spase://VSPO/NumericalData/GOLD/L2/ON2/PT8S
spase://NASA/NumericalData/SES-14/GOLD/L2/ON2/PT8S
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Availability
Online
AccessRights
Open
RightsList
Rights
SchemeURI
https://spdx.org/licenses/
RightsIdentifierScheme
SPDX
RightsIdentifier
CC0-1.0
RightsURI
https://spdx.org/licenses/CC0-1.0.html
RightsName
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
AccessURL
Name
FTPS from SPDF (not with most browsers)
URL
ftps://spdf.gsfc.nasa.gov/pub/data/gold/level2/on2/
ProductKey
GOLD_L2_ON2
Description
In CDF via ftps from SPDF
AccessURL
Name
HTTPS from SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/gold/level2/on2/
ProductKey
GOLD_L2_ON2
Description
In CDF via https from SPDF
AccessURL
Name
CDAWeb
URL
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=GOLD_L2_ON2&index=sp_phys
ProductKey
GOLD_L2_ON2
Description
Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb
Format
CDF
Encoding
None
AccessDirectoryTemplate
https://cdaweb.gsfc.nasa.gov/pub/data/gold/level2/on2/$Y
AccessFilenameTemplate
gold_l2_on2_2018_278_v04_r02_c01.nc
Acknowledgement
Space Physics Data Facility of the NASA Goddard Space Flight Center; Robert M. Candey
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF
Availability
Online
AccessRights
Open
AccessURL
Name
CDAWeb Programmatic Data Access
URL
https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/GOLD_L2_ON2/clientLibraryExample/
Style
WebService
ProductKey
GOLD_L2_ON2
Description
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Format
Binary
Acknowledgement
Space Physics Data Facility of the NASA Goddard Space Flight Center; Robert M. Candey
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Availability
Online
AccessRights
Open
RightsList
Rights
SchemeURI
https://spdx.org/licenses/
RightsIdentifierScheme
SPDX
RightsIdentifier
CC0-1.0
RightsURI
https://spdx.org/licenses/CC0-1.0.html
RightsName
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
AccessURL
Name
CDAWeb HAPI Server
URL
https://cdaweb.gsfc.nasa.gov/hapi
Style
HAPI
ProductKey
GOLD_L2_ON2
Description
Web Service to this product using the HAPI interface
Format
CSV
Acknowledgement
Space Physics Data Facility of the NASA Goddard Space Flight Center; Robert M. Candey
ProcessingLevel
Calibrated
ProviderName
GOLD
ProviderResourceName
Gold Level L2 Molecular Oxygen Density Profile
ProviderProcessingLevel
Level 2
ProviderVersion
1
InstrumentIDs
spase://SMWG/Instrument/GOLD
MeasurementType
ImageIntensity
TemporalDescription
TimeSpan
StartDate
2018-10-06 00:00:00Z
RelativeStopDate
P1D
Cadence
PT8S
ObservedRegion
Earth.NearSurface.Ionosphere
Keywords
O relative to N2
GOLD
SES-14
Parameter #1
Name
Mask Defining OI 1356 Bandpass
ParameterKey
mask_oi_1356
Description
Wavelength mask defining OI 1356 bandpass used in retrieval
Cadence
PT8S
ValidMin
0
ValidMax
1
FillValue
-2147483647
Support
SupportQuantity
Other
Parameter #2
Name
Random Uncertainty in N2 LBH
ParameterKey
n2_lbh_unc_ran
Description
Random uncertainty in N2 LBH brightness
Cadence
PT8S
Units
Rayleighs
ValidMin
0
ValidMax
100000
FillValue
9.9692e+36
Wave
WaveType
Photon
Qualifier
Uncertainty
WaveQuantity
Intensity
Parameter #3
Name
Lookup Table
ParameterKey
lookup_table
Description
Lookup table filename
Cadence
PT8S
Support
SupportQuantity
Other
Parameter #4
Name
Mask Wavelength
ParameterKey
mask_wavelength
Description
Wavelength grid for MASK_N2_LBH and MASK_OI_1356
Cadence
PT8S
Units
nm
ValidMin
130
ValidMax
170
FillValue
9.9692e+36
Wave
WaveType
Photon
Qualifier
Scalar
WaveQuantity
Wavelength
Parameter #5
Name
OI 1356 brightness
ParameterKey
radiance_oi_1356
Description
OI 1356 brightness used in retrieval
Cadence
PT8S
Units
nm
ValidMin
0
ValidMax
100000
FillValue
9.9692e+36
Wave
WaveType
Photon
Qualifier
Scalar
WaveQuantity
Intensity
Parameter #6
Name
GOLD channel
ParameterKey
channel
Description
GOLD channel ('A' or 'B')
Cadence
PT8S
Support
Qualifier
Scalar
SupportQuantity
Other
Parameter #7
Name
Latitude
ParameterKey
latitude
Description
Pixel latitude
Cadence
PT8S
Units
degrees
ValidMin
-90
ValidMax
90
FillValue
9.9692e+36
Support
Qualifier
Direction
SupportQuantity
Positional
Parameter #8
Name
Retrieved O/N2 column density ratio
ParameterKey
on2
Description
Retrieved O/N2 column density ratio used in QEUV retrieval
Cadence
PT8S
ValidMin
0
ValidMax
5
FillValue
9.9692e+36
Mixed
MixedQuantity
Other
Qualifier
Ratio
Parameter #9
Name
Random Uncertainty in Oxygen 135.6 nm Brightness
ParameterKey
oi_1356_unc_ran
Description
Random uncertainty in oxygen 135.6 nm brightness
Cadence
PT8S
Units
Rayleighs
ValidMin
0
ValidMax
100000
FillValue
9.9692e+36
Wave
WaveType
Photon
Qualifier
Uncertainty
WaveQuantity
Intensity
Parameter #10
Name
Random Uncertainty in O/N2 Ratio
ParameterKey
on2_unc_ran
Description
Random uncertainty in retrieved O/N2 column density ratio
Cadence
PT8S
ValidMin
0
ValidMax
100000
FillValue
9.9692e+36
Support
Qualifier
Uncertainty
SupportQuantity
Other
Parameter #11
Name
Overall Quality Flag
ParameterKey
dqi
Description
NMAX data quality index (see table below)
Cadence
PT8S
ValidMin
0
ValidMax
2147483647
FillValue
-2147483647
Support
Qualifier
Scalar
SupportQuantity
Other
Parameter #12
Name
Scan Start Time
ParameterKey
scan_start_time
Description
UTC start time of scan, e.g., 2017-06-21T23:46:38.015Z
Cadence
PT8S
Units
date/time
FillValue
' '
Support
Qualifier
Magnitude
SupportQuantity
Temporal
Parameter #13
Name
Solar Zenith Angle at 225 km
ParameterKey
solar_zenith_angle
Description
Solar zenith angle at 225 km tangent point
Cadence
PT8S
Units
degrees
ValidMin
0
ValidMax
180
FillValue
9.9692e+36
Support
Qualifier
Direction
SupportQuantity
Positional
Parameter #14
Name
Longitude
ParameterKey
longitude
Description
Pixel longitude
Cadence
PT8S
Units
degrees
ValidMin
-180
ValidMax
180
FillValue
9.9692e+36
Support
Qualifier
Direction
SupportQuantity
Positional
Parameter #15
Name
O/N2 Ratio Quality Flag
ParameterKey
on2_dqi
Description
ON2 data quality index per pixel (see table below)
Cadence
PT8S
ValidMin
0
ValidMax
2147483647
FillValue
-2147483647
Support
Qualifier
Scalar
SupportQuantity
Other
Parameter #16
Name
Systematic Uncertainty in O/N2 Ratio
ParameterKey
on2_unc_sys
Description
Systematic uncertainty in retrieved O/N2 column density ratio
Cadence
PT8S
ValidMin
0
ValidMax
5
FillValue
9.9692e+36
Support
Qualifier
Uncertainty
SupportQuantity
Other
Parameter #17
Name
Model Uncertainty in O/N2 Ratio
ParameterKey
on2_unc_mod
Description
Model uncertainty in retrieved O/N2 column density ratio
Cadence
PT8S
ValidMin
0
ValidMax
5
FillValue
9.9692e+36
Support
Qualifier
Uncertainty
SupportQuantity
Other
Parameter #18
Name
Systematic Uncertainty in N2 LBH brightness
ParameterKey
n2_lbh_unc_sys
Description
Systematic uncertainty in N2 LBH brightness
Cadence
PT8S
Units
Rayleighs
ValidMin
0
ValidMax
100000
FillValue
9.9692e+36
Support
Qualifier
Uncertainty
SupportQuantity
Other
Parameter #19
Name
UTC time
ParameterKey
time_utc
Description
UTC date/time string: 2017-06-21T23:46:38.015Z
Cadence
PT8S
Units
date/time
FillValue
' '
Support
Qualifier
Magnitude
SupportQuantity
Temporal
Parameter #20
Name
Mask Defining LBH Bandpass
ParameterKey
mask_n2_lbh
Description
Wavelength mask defining LBH bandpass used in retrieval
Cadence
PT8S
ValidMin
0
ValidMax
1
FillValue
-2147483647
Support
SupportQuantity
Other
Parameter #21
Name
L1C File Name
ParameterKey
input_l1c_file
Description
L1C file name for each occultation
Cadence
PT8S
FillValue
' '
Support
Qualifier
Scalar
SupportQuantity
Other
Parameter #22
Name
N2 LBH brightness
ParameterKey
radiance_n2_lbh
Description
N2 LBH brightness used in retrieval
Cadence
PT8S
Units
nm
ValidMin
0
ValidMax
100000
FillValue
9.9692e+36
Wave
WaveType
Photon
Qualifier
Scalar
WaveQuantity
Intensity
Parameter #23
Name
Pixel Emission Angle
ParameterKey
emission_angle
Description
Pixel emission angle (relative to zenith)
Cadence
PT8S
Units
degrees
ValidMin
0
ValidMax
90
FillValue
9.9692e+36
Support
Qualifier
Direction
SupportQuantity
Positional
Parameter #24
Name
Scan Stop Time
ParameterKey
scan_stop_time
Description
UTC stop time of scan, e.g., 2017-06-21T23:46:38.015Z
Cadence
PT8S
Units
date/time
FillValue
' '
Support
Qualifier
Magnitude
SupportQuantity
Temporal
Parameter #25
Name
Systematic Uncertainty in Oxygen 135.6 nm Brightness
ParameterKey
oi_1356_unc_sys
Description
Systematic uncertainty in oxygen 135.6 nm brightness
Cadence
PT8S
Units
Rayleighs
ValidMin
0
ValidMax
100000
FillValue
9.9692e+36
Wave
WaveType
Photon
Qualifier
Uncertainty
WaveQuantity
Intensity
Parameter #26
Name
Hemisphere Scanned
ParameterKey
hemisphere
Description
Hemisphere scanned ('N' or 'S')
Cadence
PT8S
FillValue
' '
Support
Qualifier
Scalar
SupportQuantity
Other