Variation of the Meridional Wind at 95 km with Season and Local Solar Time from Observations of the 11.072 GHz Ozone line and 557.7 nm Oxygen line
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Ground-based spectrometers have been deployed to measure the concentration, velocity, and temperature of ozone in the mesosphere and lower thermosphere (MLT) using low-cost satellite television electronics to observe the 11.072 GHz line of ozone. The ozone line was observed at an altitude near 95 km and latitude of 38 degrees north using three spectrometers located at the MIT Haystack Observatory (Westford, MA), Chelmsford High School (Chelmsford, MA), and Union College (Schenectady, NY) pointed south at 8 degrees. Observations from 2009 through 2014 are used to derive the nightly-averaged seasonal variation in meridional velocity, as well as the seasonally-averaged variation with local solar time. The results indicate a seasonal trend in which the winds at 95 km come from the north at about 10 m/s in the summer of the northern hemisphere, and from the south at about 10 m/s in the winter. Nighttime data from -5 to +5 local solar time show a gradual transition of the meridional wind velocity from about -20 m/s to 20 m/s. These two trends correlate with nighttime wind measurements from the Millstone Hill High-Resolution Fabry-Perot Interferometer (FPI) in Westford, MA. The FPI uses the 557.7 nm green line nightglow from atomic oxygen that occupies the same region of the mesosphere as the ozone centered at 95 km. The results have also been compared with average meridional winds measured with meteor radar.