Ion composition in a noctilucent cloud region

摘要: Ion composition at mesospheric altitudes has been measured and compared between high- mid-latitude sites under summer daytime conditions. Both rocket-borne measurements were made with pumped quadrupole ion mass spectrometers (mass range, 15–145 amu). Apogee occurred below 90 km on each flight, subsonic sampling near the mesopause thus being possible. Water cluster dissociation was further minimized by using low attractive bias potentials of —5 V for instrument. The data obtained Wallops Island, Virginia (latitude, 37.8°N; longitude, 75.5°W), June 30, 1973, 1510 LMT (χ = 43°). Large quantities hydronium ions observed through 109+, maximum concentrations 55+ 73+. Also nitric oxide 84+. high-latitude launch Kiruna, Sweden 67.9°N; 21.1°E), August 2, 0700 68.5°), following visual sighting a noctilucent cloud prior evening. show typical mentioned above but also preponderance heavy 145 amu, groupings 18 amu apart unrelated to more ions. One possible set consistent identifications leads iron hydrates. These results may suggest presence metallic particulates which form hydrated within region.