Characteristics of Mesospheric Na Distribution over Arecibo, Puerto Rico
Abstract
We have analyzed 76 nights of mesospheric Na data that are distributed over a year from a low latitude station (18ο N). A resonance lidar located at the Arecibo observatory was used to obtain this data set. The goal of this study is to evaluate the seasonal variability in the Na distribution at a low latitude station and compare it with a mid latitude site. A preliminary analysis was undertaken that involved determining the nightly averages and fitting a Gaussian to obtain a mean profile. Further monthly average profiles were obtained, which showed annual variation with concentrations peaking during the June month. This peak was close to ~ 8000 atoms cm-3, maximizing around 93 km. A secondary peak is seen in the November months with densities about 2 times weaker than the primary peak. The average Na abundance over Arecibo is ~ 4.2x109 cm-2 with maximum values ~ 6.7 x 109 atoms cm-3 during the summer seasons. The average FWHM of the layer is about 11 km with a strong evidence of modulation with an average periodicity of 4 months. It is interesting to note that this behavior is in contrast to those observed at mid latitudes (40οN). The possible reasons for this variability will be discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMSA11B1927R
- Keywords:
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- 3309 ATMOSPHERIC PROCESSES Climatology;
- 2400 IONOSPHERE