Showing papers on "Water cluster published in 1969"

Origin of water cluster ions in the D region

Abstract: Laboratory studies of the ions produced by the addition of water vapor into flowing streams of O2+ (or NO+) ions have led to a vapor phase reaction scheme starting with O2+ that seems likely to be responsible for the formation of the observed water cluster ions H3O+, H5O2+, H7O3+, etc. in the D region of the earth's ionosphere. Experimental difficulties have precluded quantitative rate constant measurements so far, and in addition the D-region water vapor concentration is uncertain so that only a qualitative scheme is possible at this time. The O2(¹Δg) photoionization source recently proposed by Hunten and McElroy is presumed to be the necessary precursor O2+ source. The reaction scheme involves O4+ and O2+·H2O as intermediate ions; these ions are possibly present in observable concentrations in the D region. Nitrous acid (HNO2) production is proposed to be an end result of successive hydrations of atmospheric NO+. The hydration of the atmospheric NO+ and O2+ ions and the formation of O4+ are expected to increase somewhat the effective electron recombination coefficient in the ionosphere.

Water vapor ion cluster concentrations in the D region

Abstract: Utilizing some recently obtained laboratory rate constants of Good, Durden, and Kebarle, the qualitative water cluster ion production scheme proposed earlier has been made quantitative, although not precise. Despite large uncertainties involved in the calculations, several interesting conclusions can be drawn and Some useful guidelines for further ionospheric and laboratory investigations established. The calculated concentration of H5O2+ at the concentration maximum near 80 km agrees well with the observed values of Narcisi and Bailey. The values at 65 km do not agree well, which suggests that the reported values are too large due to difficulties in relating observed ion currents to ion concentrations. The calculations suggest the possibility that the water concentration decreases more rapidly above the mesopause than current model atmospheres predict, in order to account for the sharp decrease in observed water cluster ions above 82 km.