ICON Extreme Ultraviolet Spectrograph Images

EUV Images

https://doi.org/10.48322/hwg4-hw39

2024-05-08 00:00:00Z

This describes the data produce for ICON EUV Daytime O+ (DP 2.6), which is in NetCDF4 format. These files are named ICON_L2-6_EUV_YYYY-MM-DD_vXXrZZ.NC, where YYYY-MM-DD is the year month day and VXX shows the version number and rZZ shows the revision number of this file. Each individual file nominally contains 1 day (24 hours) of data. The L2 EUV Daytime files are produced from the L1 EUV files, and their primary data product is the O+ profile derived from a retrieval that is detailed in a paper: https://doi.org/10.1007/s11214-017-0385-1. In addition, many other parameters and geophysical data products are included in the file. The data are identified in one of 3 var_types: data – which contains the primary data product; support data – which contains parameters used in the retrieval such as geometry etc. that may also be useful in any analysis of this data; and ignore_data – which are recorded for debugging purposes and should not be used for publication without detailed discussion with the ICON team. The dimensions of the data also indicate its type. For example, anything with epoch as a dimension means there is 1 value corresponding to each instrument exposure. Anything with dimension Input_data corresponds to the input data, passed from Level 1. Anything with a dimension of model refers to the forward model parameters used as part of the inversion. Anything with dimension altitude corresponds to the altitude grid used for the inverted parameters.

National Aeronautics and Space Administration; Dr. Andrew W. Stephan; Dr. Thomas Immel

Online

Open

NetCDF

Please acknowledge Dr. Andrew W. Stephan and Dr. Thomas Immel. Please acknowledge the Data Providers and CDAWeb when using these Data.

Online

Open

NetCDF

None

Please acknowledge Dr. Andrew W. Stephan and Dr. Thomas Immel. Please acknowledge the Data Providers and CDAWeb when using these Data.

PT1S

Epoch Time

Epoch

Sample time, midpoint of exposure. Number of msec since Jan 1, 1970.

PT1S

ms

0

6000000000000

-999

Activity Status of the EUV Instrument

ICON_L26_Activity

Flag for activity status of the EUV instrument, as defined in the Ephemeris Definition Document.

PT1S

0

1024

-999

Altitude of the Retrieved Quantities

ICON_L26_Altitude

Altitude corresponding to the retrieved quantities, in WGS84.

PT1S

km

-999

Ap Index

ICON_L26_Ap

Value of the Ap index used in the retrieval, from GPI file.

PT1S

0

400

-999

Local Earth Radius at Retrieval

ICON_L26_Earth_Radius

Local Earth Radius at Retrieval location, from WGS.

PT1S

km

0

7000

-999

F10.7 Values

ICON_L24_F107

F10.7 values used, from GPI file, in solar flux units.

PT1S

sfu

0

999

-999

F10.7a Values

ICON_L24_F107a

F10.7a values used, from GPI file, in solar flux units.

PT1S

sfu

0

999

-999

Retrieval Flags

ICON_L26_Flags

Quality flag associated with the retrieval and L1 data.

PT1S

-999

Height of F2 layer from Retrieval

ICON_L26_HmF2

Height of the peak of the F2 layer from Retrieval, in WGS.

PT1S

km

0

1000

-999

Input Altitude

ICON_L26_Input_Altitude

Diagnostic Tangent altitudes corresponding to the input data, in WGS84.

PT1S

km

0

1000

-999

Input Covariance for 61.7 nm

ICON_L26_Input_Covariance_617

Diagnostic Covariance of the observed Radiance in the 61.7 nm wavelength channel.

PT1S

Rayleighs^2

0

1000000015047466219876688855040

-999

Input Covariance for 83.4 nm

ICON_L26_Input_Covariance_834

Diagnostic Covariance of the observed Radiance in the 83.4 nm wavelength channel.

PT1S

Rayleighs^2

0

1000000015047466219876688855040

-999

Input Filename

ICON_L26_Input_Filename

Name of the L1 file used with the input data.

PT1S

string

Input Radiance 61.7 nm

ICON_L26_Input_Radiance_617

Diagnostic Observed Radiance in the 61.7 nm wavelength channel.

PT1S

Rayleighs

0

1000000015047466219876688855040

-999

Input Radiance 83.4 nm

ICON_L26_Input_Radiance_834

Diagnostic Observed Radiance in the 83.4 nm wavelength channel.

PT1S

Rayleighs

0

1000000015047466219876688855040

-999

Geodetic Latitude

ICON_L26_Latitude

Geodetic Latitude at retrieval location, referenced at 300 km altitude, in WGS.

PT1S

degrees

-90

90

-999

Local Solar Time

ICON_L26_Local_Solar_Time

Local solar time at Retrieval.

PT12S

hours

0

24

-999

Geodetic Longitude

ICON_L26_Longitude

Geodetic Longitude at retrieval location, referenced at 300 km altitude in WGS.

PT1S

degrees

0

360

-999

Magnetic Latitude

ICON_L26_Magnetic_Latitude

Quasi-Dipole Magnetic Latitude at 300 km at Retrieval location, in degrees.

PT1S

degrees

-90

90

-999

Magnetic Longitude

ICON_L26_Magnetic_Longitude

Quasi-Dipole Magnetic Longitude at 300 km at Retrieval location, in degrees.

PT1S

degrees

-180

180

-999

Model Change

ICON_L26_Model_Change

'Diagnostic A value of 1 shows which forward model parameters are set to change during the retrieval, where the parameters are in order, Rz12 multiplier, ig12 multiplier, IRI F107 multiplier, density scalar, and the j0 multiplier'.

PT1S

unitless

0

999

-999

Model Covariance

ICON_L26_Model_Covariance

Diagnostic Covariance matrix of the model parameters from the retrieval.

PT1S

unitless

0

1000000015047466219876688855040

-999

Model Lower Limit

ICON_L26_Model_Lower_Limit

Diagnostic Lower limit of the parameters used in the forward model, which are in order, Rz12 multiplier, ig12 multiplier, IRI F107 multiplier, density scalar, and the j0 multiplier.

PT1S

unitless

-1000

1000

-999

Model Parameters

ICON_L26_Model_Parameters

Diagnostic Parameters used in the forwared model, which are in order, Rz12 multiplier, ig12 multiplier, IRI F107 multiplier, density scalar, and the j0 multiplier.

PT1S

unitless

0

999

-999

Model Parameters Initial

ICON_L26_Model_Parameters_Initial

Diagnostic Initial values of the parameters used in the forward model, which are in order, Rz12 multiplier, ig12 multiplier, IRI F107 multiplier, density scalar, and the j0 multiplier.

PT1S

unitless

0

999

-999

Model Upper Limit

ICON_L26_Model_Upper_Limit

Diagnostic Upper limit of the parameters used in the forward model, which are in order, Rz12 multiplier, ig12 multiplier, IRI F107 multiplier, density scalar, and the j0 multiplier.

PT1S

unitless

0

999

-999

O+ density at the peak of the F2 layer from Retrieval

ICON_L26_NmF2

O+ density at the peak of the F2 layer from Retrieval.

PT1S

1/cm^3

0

10000000000

-999

WGS84 Altitude of s/c Position (Geodetic)

ICON_L26_Observatory_Altitude

Altitude of the spacecraft at the time of data collection, in WGS84.

PT1S

km

0

1000

-999

Earth Centered Earth Fixed Spacecraft Position

ICON_L26_Observatory_ECEF

Location of the spacecraft in ECEF coordinates at the time of data collection. Dimension corresponding to the X, Y, Z components of Cartesian vector.

PT1S

km

WGS84 Latitude of Spacecraft Position (Geodetic)

ICON_L26_Observatory_Latitude

Geographic latitude of the spacecraft at the time of data collection, in WGS84.

PT1S

degrees

-90

90

-999

WGS84 Latitude of Spacecraft Position (Geodetic)

ICON_L26_Observatory_Longitude

Geographic longitude of the spacecraft at the time of data collection, in WGS84.

PT1S

degrees

0

360

-999

Number density of O+

ICON_L26_Oplus

Number density of O+ as a function of altitude found in the retrieval.

PT1S

1/cm^3

-999

Orbit Number

ICON_L26_Orbit_Number

Integer orbit number of the ICON spacecraft, incremented throughout the mission.

PT1S

integer

0

105000

-999

Processing Date

ICON_L26_Processing_Date

Date on which this file was generated by the Science Data Center.

PT1S

string

Radiance 61.7 nm

ICON_L26_Radiance_617

Radiance profile of 61.7 nm emission produced by the forward model during the retrieval.

PT1S

Rayleighs

0

1000000015047466219876688855040

-999

Radiance 83.4 nm

ICON_L26_Radiance_834

Radiance profile of 83.4 nm emission produced by the forward model during the retrieval.

PT1S

Rayleighs

0

1000000015047466219876688855040

-999

Retrieval Flags

ICON_L26_SC_Slew_Status

Flag corresponding to slew of the spacecraft during the time of data collection as defined in the ephemeris definition document.

PT1S

0

1024

-999

1 sigma in Height of F2 layer from Retrieval

ICON_L26_Sigma_HmF2

1 sigma in Height of F2 layer peak from retrieval.

PT1S

Rayleighs

0

1000

-999

1 sigma in Density of F2 layer from Retrieval

ICON_L26_Sigma_NmF2

1 sigma in O+ density at the peak of the F2 layer from retrieval.

PT1S

cm-3

0

10000000000

-999

1 Sigma in the Number Density of O+

ICON_L26_Sigma_Oplus

1 sigma in the number density of O+ as a function of altitude found in the retrieval.

PT1S

cm-3

-999

Solar Zenith Angle at Retrieval Location

ICON_L26_Solar_Zenith_Angle

Solar Zenith Angle at retrieval location.

PT12S

degrees

0

180

-999

Space Environment Region Status

ICON_L26_Space_Environment_Region_Status

Flag corresponding to space environment region as defined in the ephemeris definition document during the time of data collection.

PT1S

0

268405455

-999

Binary Coded Integer Describing the View Status of EUV

ICON_L26_Status

Flag for activity status of the spacecraft, as defined in the Ephemeris Definition Document.

PT1S

0

1024

-999

Spacecraft Sun/Shadow Status Code

ICON_L26_Sun_Status

Flag for activity status of the sun on the spacecraft, as defined in the Ephemeris Definition Document. 0=Sun 1=Earth Shadow.

PT1S

0

1

-999

Date and Time in UTC format

ICON_L26_UTC_Time

UTC time corresponding to the retrieval.

PT1S

' '

UT Seconds

ICON_L26_UT_Seconds

UTC time in seconds since midnight corresponding to the time of the retrieval.

PT1S

seconds

-999

Unreduced Chi^2

ICON_L26_Unreduced_Chi2

Unreduced Chi Squared values from the retrieval.

PT1S

unitless

-999

Integer Year DOY

ICON_L26_Year_DOY

Year and Day of Year corresponding to the retrieval, in the format of YYYYDOY.

PT1S

day

2015000

2050000

-999