Abstract
A 10-day experiment is described in which simultaneous measurements of ice nucleus concentrations have been made in upslope and downslope wind regimes on the island of Hawaii, near sea level at Hilo airport, at Mauna Loa Observatory (MLO) (elevation 3.4 km), and midway at Kulani (elevation 1.5 km). The main results show: (1) at MLO the downslope flows contain the highest concentrations of ice nuclei, (2) the same downslope flows contain the lowest concentrations of large terrestrial particles, (3) the greatest care must be exercised in using the expansion cold chamber technique to collect data on ice nuclei in the humidity extremes at Hilo and MLO, and (4) no evidence was found In favor of a local terrestrial origin of the ice nuclei, and it is suggested that earlier measurements by Kline and Price and Pales were influenced by instrumental errors.
