Hourly and other aggregated rainfall amounts reflect unknown proportions of raining and rainless time, arising from the intermittency of rainfall. This causes estimates of intensity derived from aggregated data to be too low, but the extent of this bias is difficult to estimate and remains in need of study.

Rainfall data having high temporal resolution were analysed for sub-daily intermittency. The approach relied on the use of a ‘no-rain’ intensity threshold of 0.2 mm h⁻¹, below which the intensity was regarded as effectively zero. Various aggregation durations (ADs) for rainfall amounts, including day, hour, and 15 min, as well as discrete rainfall events, were analysed for intermittency.

Results show that the use of 1 h AD data results in lower levels of apparent intermittency, typically 42–47%, than does the use of unaggregated inter-tip times (ITTs, which permit higher resolution of intensity estimates) which for both days and events reveal intermittency of 62–67%.

Evidence for both diurnal and annual (seasonal) patterns of intermittency is found. Measures of rainfall intensity extremes, such as extreme hourly rainfall, are affected by this intermittency variation.

For exploring possible ecohydrological consequences of intermittency at sub-daily timescales, new metrics are proposed, based on the number of rainfall interruptions per rain day, the temporal pattern of their occurrence between first and last rainfall, and the distribution of the durations through the sequence of interruptions.

每小时和其他总降雨量反映了降雨的间歇性，导致降雨和无雨时间的比例未知。这导致从汇总数据得出的强度估计值太低，但是这种偏差的程度难以估计，仍需要研究。

分析具有高时间分辨率的降雨数据的次日间歇性。该方法依赖于使用0.2 mm h ^-1的“无雨”强度阈值，在该阈值以下强度被视为有效零。分析了降雨总量（包括日，小时和15分钟）的各种聚合持续时间（AD），以及离散降雨事件的间歇性。

结果表明，使用1 h AD数据所产生的表观间歇性水平要低得多，通常为42–47％，这比使用未汇总的尖端间时间（ITT允许更强的强度估计分辨率）（在白天和晚上）事件表明间歇性为62–67％。

可以找到昼间和昼间（季节性）模式的证据。这种间歇性变化会影响极端降雨强度的度量，例如每小时的极端降雨。

为了探索次日尺度下间歇性的可能的生态水文后果，基于每个雨天降雨中断的数量，第一次和最后一次降雨之间降雨发生的时间模式以及持续时间在整个序列中的分布，提出了新的度量标准的中断。