Resonant lidar measurements of calcium and sodium atoms and calcium ions have been made from 1982 to 1987 at the Observatoire de Haute Provence. An average value of the column atomic calcium abundance of 2.7×107 cm−2 has been measured, and it is 120 times lower than the corresponding sodium abundance. No systematic seasonal variation of the atomic calcium abundance can be deduced from the measurements. Average density profiles of these two species are also compared for each season. For the calcium ions, two different types of profiles have been identified. Diffuse Ca+ layers are centered around 94 km and constitute the background ionic calcium layer. Denser and narrower layers, presenting strong short time scale variations, are centered in the 95‐ to 115–km altitude range. Comparisons are made between Ca and Ca+ density profiles determined by lidar measurements and through other techniques, such as mass spectrometry. Finally, the relative abundance in the atmosphere and in meteorites of these two metallic species, Ca and Na, are briefly discussed.

Resonant lidar detection of neutral (Ca‐423 nm) and ionized ( Ca+ ‐ 393 nm) calcium altitude distributions has been performed during nighttime at the Observatoire de Haute‐Provence. The emitter is composed of two Nd‐Yag pumped dye lasers, the 393 nm emission being obtained by three waves mixing in a non‐linear crystal. The first detection of Ca has been carried out in December, 1982 and has shown that the integrated abundance of the atomic form is low, with a value of about 1.5 × 107 cm−2, further confirmed by measurement performed in July, 1983. During this same month, the detection of Ca+ has been achieved, proving the lidar ability to follow rapid evolutions of Ca+ layers, which appear between 85 and 115 km altitudes.

Resonant lidar detection of iron atoms have been performed at the Observatoire de Haute Provence (France) during 4 nights in november 1986 and in april 1987. The average iron atoms abundance is 3.6 × 109 cm−2 in november, and 2.6 × 109− cm−2 in april. Iron atoms density profiles are compared to the atomic sodium ones, obtained simultaneously by lidar and indicating an average sodium abundance of 4 × 109 cm−2. The relative abundance of the sum of the atomic and ionic forms is compared for several metallic species with their abundance ratios in the incoming meteorites. Finally, similar comparisons using lidar and mass spectrometer data are made for the ratio of the atomic and the ionic forms in the atmosphere.

The Haute‐Provence Observatory (44° N, 6°E)lidar facility has been extended to study the atmospheric lithium and its isotopic ratio Li7/Li6 in the upper atmosphere. The experimental features have been improved in order to lower the detection limit to 3.105 cm−2 for the total abundance with a resolution of 1.2 km in the altitude profile. The night‐time measurements have been carried out from November 1977 to December 1979 and show some characteristic trends. The seasonal variation of the total abundance is similar to the one observed for sodium. The altitude profile is variable during the night. Total abundance fluctuations and peaks with small scale heights (1.5 km) are observed on numerous occasions. The layer is sensitive to high‐altitude artificial releases, like CAMEO in November 1978, and to impinging meteor showers. It is concluded that study of the behavior of atmospheric lithium and sodium should further our understanding of the alkali‐metals chemistry.

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