利用1957～2012年南岳高山观测站逐日覆冰资料，对南岳覆冰标准厚度和覆冰日数的时间演变、突变和周期变化进行分析，并推算出南岳各重现期的标准冰厚，结果表明：1）南岳南北向和东西向标准冰厚年代际变化非常相似，呈现偏大—偏小—偏大—偏小—偏大的年代际变化；冰冻日数在20世纪60年代中后期之前，90年代中后期之后冰冻日数偏少，60年代中后期到90年代中后期冰冻日数偏多。2）冰冻在1～4月、10～12月均有发生，其中1月出现天数最多，占全年的31.8%。3）滑动t检验分析发现，南岳东西向和南北向标准冰厚在20世纪60年代末有减小的突变，冰冻日数在近56年没有出现明显突变。4）Morlet小波和小波功率谱分析发现，南北向和东西向标准冰厚存在显著的2～3年、4～6年振荡周期；冰冻日数存在显著的2～4年、5～7年振荡周期。5）基于Pearson III型概率分布统计发现，各重现期东西向标准冰厚均较南北向标准冰厚要大，其中20年一遇南北向和东西向标准冰厚分别为76.33、85.22 mm，10年一遇南北向和东西向标准冰厚分别为60.86、69.57 mm。6）分析气象要素对覆冰的影响发现，覆冰期气温较无覆冰期要低，相对湿地要大，能见度要小，覆冰期风向以偏北风为准，无覆冰期风向以偏南风为主，覆冰期平均风速较无覆冰期风速要小。%Using the icing data measured at Nanyue Mountain Observatory from 1957 to 2012, the temporal variations, n abrupt changes, and period variations of standard ice thicknesses and icing days are analyzed. The standard ice thicknesses of different recurrence periods are also calculated. The results showed that the interdecadal variability of standard ice thicknesses in east−west (EW) and north−south (NS) directions were similar and presented a pattern of large−small−large−small−large. Icing days before the late 1960s and after the late 1990s are less than annual mean icing days and icing days larger than the annual mean icing days were found between the late 1960s and the late 1990s. Icing usually happened from October to April of the next year and the icing days in January accounted for the largest portion of icing days in the whole year with the percentage of 31.8%. The abrupt changes of standard ice thicknesses in NS and EW directions were found in the late 1960s and no abrupt change of icing days was found in recent 56 years. Morlet wavelet and Morlet wavelet power spectrum analyses showed that standard ice thicknesses in EW and NS directions both had significant periods of quasi 2−3 years and 4−6 years and the icing days had significant periods of quasi 2−4 years and 5−7 years. Using Pearson III type extreme value distributions, the calculated standard ice thicknesses for the 10-year recurrence period in NS and EW directions were 60.86 mm and 69.57 mm, respectively. For 20-year recurrence period, calculated standard ice thicknesses increased to 69.57 mm (EW) and 72.33 mm (NS). The authors analyzed meteorological differences between the icing days and non icing days from 1 December 2012 to 4 March 2013. The mean air temperature of non icing days had a reduction of 7.8 °C in comparison to icing days. The mean relative humidity of icing days was larger than that of non-icing days. Both the mean visibility and wind speed of icing days were smaller than those of non-icing days. The dominant wind direction was north when icing happened, and the south wind usually happened in the non icing days. The average wind speed of icing days was less than that of non-icing days.
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