2.7.1 https://spdx.org/licenses/ SPDX CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions spase://NASA/DisplayData/IMAGE/FUV/SI/O_N2_Ratios NASA DisplayData IMAGE FUV SI plots of O/N2 Ratios 2025-12-04T13:27:58Z 2020-07-07T19:48:33Z Only known prior ReleaseDate of the metadata 2025-12-04T13:27:58Z Added MetadataRightsList. Added ResourceType and NamingAuthority. Updated to 2.7.1. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. ZCB This data set consists of images of thermospheric O/N2 column density ratios at 2-min resolution during times of strong geomagnetic storms (Dst.LT.-80nT) of 2000-2005. The ratios are generated from dayside airglow observations of the IMAGE Far Ultraviolet (FUV) Spectrographic Imager (SI). The SI has a peak response at the OI 135.6 nm oxygen emission line and a bandpass of 131.0 to 140.0 nm which includes the LBH band from N2 molecules. For each O/N2 plot, there is a plot of the SI image from which the O/N2 plot was generated, and there is an IDL saveset of the content of the O/N2 maps. The Information URL of this descriptor identifies detailed discussions of the derivations of O/N2 rations from the SI images. spase://SMWG/Person/Yongliang.Zhang DataProducer Data descriptive text at JHU_APL https://image.gsfc.nasa.gov/index.php?documentation spase://VSPO/DisplayData/IMAGE/FUV/SI/O_N2_Ratios spase://SMWG/Repository/JHU_APL Online Open IMAGE O/N2 site at JHU/APL https://image.gsfc.nasa.gov/index.php?data O/N2 and FUV/SI image plots in PNG format PNG spase://SMWG/Instrument/IMAGE/FUV ImageIntensity 2000-05-24T00:00:00 2005-05-18T23:59:59 PT2M Earth.NearSurface.Thermosphere (1) O/N2 values are available only for dayside with solar zenith angle less than 90 degrees. (2) Auroral emissions are not removed. The O/N2 data in the auroral oval should not be used. The original SI-13 images are also provided in the APL web site to identify auroral regions. (3) SI-13 flat field algorithm is provided by the IMAGE FUV team. But it may not work well all the time. This impacts the O/N2 products. (4) Pointing of SI-13 is still subject to some errors even after attitude correction is done. (5) A fixed O/N2 value (assumed) for quiet times may ignore the effects of season and solar EUV flux.