JANUARY ANOMALIES IN CIRRIFORM CLOUD COVERAGE OVER AUSTRALIA

Abstract

Records of the occurrence of high-level cloud in the period 1939?1956 are examined for 18 representative Australian stations for the last few days of December, January, and the first few days of February. The mean cover for each calendar date is found to fluctuate by as much as 50 per cent, with conspicuous maxima on 28 December, 12 January, 22 January, and 1 February. The statistical significance of the fluctuations is examined and it is shown, to a high degree of confidence, that they are real. The conclusion is reached that the rainfall anomalies found by Bowen on the same days are related and are also real.