Earth Sciences Sector Solar X-rays effects on the Ionosphere Donald Danskin Natural Resources Canada European Space Weather Week Oostende, Belgium November 23-27, 2015 Earth Sciences Sector Introduction X-ray flares on the Sun cause absorption of radio waves in the D region (~ km) of the ionosphere. Data from the Canadian riometer network and GOES satellites are used to evaluate how much absorption occurs due to the X-ray bursts. The variation with solar zenith angle is studied. Consideration of the region on the Sun on absorption Earth Sciences Sector How a riometer works Ionosphere (D region) Galactic noise sources Extra Ionization Extra noise Earth Sciences Sector Riometer Equipment Antenna Data sampler Computer and Riometer Earth Sciences Sector Saskatoon Hall Beach Resolute DRAO - Penticton Ottawa Earth Sciences Sector Canadian Riometer Array Earth Sciences Sector Quiet day curve Volt Galactic noise variation over a sidereal day Volt Earth Sciences Sector X-ray induced Absorption (short wave fadeout) NOAA M2 Earth Sciences Sector Ionospheric response time Travel time for X-rays Sun to GOES satellite 150e9/3e8 ~ 500 s GOES to ionosphere 5.6 Re/3e8 ~ 0.12 s Earth Sciences Sector z SQRT (M2) Earth Sciences Sector Q is ion production I 1-8 X-ray intensity q(F,h) - spectral info absorption (h) electron loss K(h) differential absorption Itkina, M. A. (1979), Intensity of X-ray solar radiation and the value of the anomalous absorption of radio waves during periods of sudden ionospheric disturbances, Radiophys. Quantum Electron., 21, 1083. Earth Sciences Sector Peak Flux Earth Sciences Sector Canadian Riometer Array is funded in part by the Canadian Space Agency through CGSM grants. E. Donovan and E. Spanswick are principal investigators for the NORStar part of the array, D. Danskin manages the NRCan riometers. Conclusion The ionospheric response time is ~ s. A linear trend of absorption with cosine of solar zenith angle is prevalent. Absorption is dependent on sqrt(flux 1-8) An upper limit on potential absorption is observed Further parameters must be studied, including other ways that differentiate or classify the X-ray flares effects. Earth Sciences Sector Central meridian Earth Sciences Sector Middle meridians Earth Sciences Sector Limb events