Noise with relatively enhanced low frequency power that results simply from serial correlation. The resulting power spectrum will have a negative slope. This is usually a good model for the noise component in a variety of climatic time series including proxy records, historical sea and air surface temperatures, and precipitation records. This type of noise can be explained in terms of the slow-response components of the climate system, such as the thermal inertia of the oceans, providing a memory that effectively integrates the forcing of such fast-reponse and more white noise-like components such as the weather. The produces a temporal persistence that leads to great noise energy at lower frequencies. Contrast with white noise.