Premium
Fine structure of sporadic sodium layer observed with a sodium lidar at Tromsø, Norway
Author(s) -
Tsuda T. T.,
Nozawa S.,
Kawahara T. D.,
Kawabata T.,
Saito N.,
Wada S.,
Hall C. M.,
Oyama S.,
Ogawa Y.,
Suzuki S.,
Ogawa T.,
Takahashi T.,
Fujiwara H.,
Fujii R.,
Matuura N.,
Brekke A.
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl048685
Subject(s) - lidar , sodium , incoherent scatter , atmospheric sciences , spectral density , range (aeronautics) , anomaly (physics) , radar , turbulence , environmental science , geology , meteorology , materials science , remote sensing , physics , ionosphere , geophysics , mathematics , telecommunications , computer science , statistics , condensed matter physics , metallurgy , composite material
We report a sporadic sodium layer (SSL), in particular its fine structure, observed at 92–98 km between 20:00 and 23:30 UT (21:00–24:30 LT) on 11 January 2011 using a sodium lidar, which was installed in the European incoherent scatter (EISCAT) radar site at Tromsø, Norway (69.6°N, 19.2°E) in early 2010. The sodium lidar measurement with 5‐sec time‐resolution reveals the details of dramatic sodium‐density increase as well as short‐period wavelike structure in the SSL. The rate of increase of height‐integrated sodium density at the beginning of the SSL event was 6.4–9.6 × 10 10 m −2 s −1 . Dominant oscillation periods in the wavelike structures were 7–11 min at 95–98 km and 3 min at 92–95 km. The calculated power spectral densities are well represented by power laws, implying the presence of the short‐period waves and turbulence in the frequency range of 10 −4 –10 −1 Hz.