6:15 PM - 7:30 PM
[PEM27-P20] Inter-annual variations of Nitric Oxide in the polar mesosphere observed by a millimeter-wave radiometer at Syowa
Keywords:microwave spectroscopy, Nitric Oxide, MLT region, Energetic Particle Precipitation
To study reliability of millimeter wave spectral radiometer, we compared the NO column amount with the SOFIE sensor on board AIM satellite. We picked observed data in the same magnetic latitude zone as the Syowa Station, and calculate an NO column density. The NO column density observed at Syowa Station and SOFIE shows a same tendency. Further, we compared month averaged NO column density, and found a good correlation. From this, the millimeter-wave spectral radiometer do uniform observations, and decreasing of the NO column density in 2014 winter season is reliably phenomenon.
Next, we study about impact of variations of relativistic electron flux to NO column density in winter. We used the electron flux data observed from POES satellites and calculated monthly integrated amount of the electron flux. The electron flux in the 2014 is less than those of 2012 and 2013. In particular, this tendency is significant in a period between April and August in 2014. From this, a lower amount of NO column density of 2014 winter may be caused by a low amount of relativistic electron flux.