PT  - JOURNAL ARTICLE
AU  - Burnett, C. R.
TI  - Anomalous Abundance of Upper Atmosphere Sodium, 1964
AID  - 10.1126/science.147.3659.736
DP  - 1965 Feb 12
TA  - Science
PG  - 736--737
VI  - 147
IP  - 3659
4099  - http://science.sciencemag.org/content/147/3659/736.short
4100  - http://science.sciencemag.org/content/147/3659/736.full
SO  - Science1965 Feb 12; 147
AB  - Measurements of atomic sodium in the upper atmosphere by absorption spectroscopy with the Pepsios spectrometer on the Fraunhofer D2 line during February to August 1964 at Madison. Wisconsin, have indicated abundances of about 1010/cm2 for the late winter, about twice the values from a similar method in 1961-62. An abrupt decrease in abundance occurred during March in agreement with established seasonal behavior, but the abundance then increased anomalously in the summer to 8 x 109/cm2. The summertime increase may be related to observations of increased turbidity of the upper atmosphere, presumably caused by volcanic dust.