| Current auroral 
      activity 
        
      This plot shows the 
      current extent and position of the auroral oval in the northern 
      hemisphere, extrapolated from measurements taken during the most recent 
      polar pass of the NOAA POES satellite.  
      The red arrow 
      in the plot, that looks like a clock hand, points toward the noon 
      meridian.  
      The statistical pattern 
      depicting the auroral oval is appropriate to the auroral activity level 
      determined from the power flux observed during the most recent polar 
      satellite pass. The power fluxes in the statistical pattern are color 
      coded on a scale from 0 to 10 ergs .cm-2.sec-1 
      according to the color bar on the right. The pattern has been oriented 
      with respect to the underlying geographic map using the current universal 
      time, updated every ten minutes.  
      This presentation provides 
      an estimate of the location, extent, and intensity of aurora on a global 
      basis. For example, the presentation gives a guide to the possibility that 
      the aurora is located near a given location in the northern hemisphere 
      under the conditions that existed at the time of the most recent polar 
      satellite pass.  
      Normalization factor 
      (n) 
      A normalization factor of less than 2.0 indicates a reasonable level of 
      confidence in the estimate of power. The more the value of n exceeds 2.0, 
      the less confidence should be placed in the estimate of hemispheric power 
      and the activity level.  
      The process to estimate 
      the hemispheric power, and the level of auroral activity, involves using 
      this normalization factor which takes into account how effective the 
      satellite was in sampling the aurora during its transit over the polar 
      region. A large (> 2.0) normalization factor indicates that the transit 
      through the aurora was not very effective and the resulting estimate of 
      auroral activity has a lower confidence.  
      
        
      This plot shows the 
      current extent and position of the auroral oval in the southern 
      hemisphere, extrapolated from measurements taken during the most recent 
      polar pass of the NOAA POES satellite.  
      The red arrow 
      in the plot, that looks like a clock hand, points toward the noon 
      meridian.  
      The statistical pattern 
      depicting the auroral oval is appropriate to the auroral activity level 
      determined from the power flux observed during the most recent polar 
      satellite pass. The power fluxes in the statistical pattern are color 
      coded on a scale from 0 to 10 ergs .cm-2.sec-1 
      according to the color bar on the right. The pattern has been oriented 
      with respect to the underlying geographic map using the current universal 
      time, updated every ten minutes.  
      This presentation provides 
      an estimate of the location, extent, and intensity of aurora on a global 
      basis. For example, the presentation gives a guide to the possibility that 
      the aurora is located near a given location in the southern hemisphere 
      under the conditions that existed at the time of the most recent polar 
      satellite pass.  
      Normalization factor 
      (n) 
      A normalization factor of less than 2.0 indicates a reasonable level of 
      confidence in the estimate of power. The more the value of n exceeds 2.0, 
      the less confidence should be placed in the estimate of hemispheric power 
      and the activity level.  
      The process to estimate 
      the hemispheric power, and the level of auroral activity, involves using 
      this normalization factor which takes into account how effective the 
      satellite was in sampling the aurora during its transit over the polar 
      region. A large (> 2.0) normalization factor indicates that the transit 
      through the aurora was not very effective and the resulting estimate of 
      auroral activity has a lower confidence.  
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