Solar extreme ultraviolet irradiance measurements from sounding rockets during solar cycle 22

Our sounding rocket measurements during solar cycle 22 include solar extrem e ultraviolet (EUV) irradiances below 120 nm with 0.2 nm spectral resolutio n, far ultraviolet (FUV) airglow spectra below 160 nm, and solar soft x-ray (XUV) images at 17.5 nm. Compared to the earlier observations, these rocke t experiments provide a more accurate absolute measurement of the solar EUV irradiance because these instruments are calibrated at the National Instit ute of Standards and Technology (NIST) with a radiometric uncertainty of ab out 8%. These more accurate sounding rocket measurements suggest revisions of the previous reference AE-E spectra by as much as a factor of 2 at some wavelengths. Our sounding rocket flights during the past several years (198 8-1994) also provide information about solar EUV variability during solar c ycle 22. (C) 2000 Elsevier Science Ltd. All rights reserved.