Application of the detrended fluctuation analysis (DFA) method for describing cloud breaking

A method to sort out correlations and decorrelations in stratus cloud formation, persistence and breakup is introduced. The detrended fluctuation analysis (DFA) statistical method is applied to microwave radiometer data. The existence of long-range power-law correlations in stratus cloud liquid water content fluctuations is demonstrated over a 2-h period. Moreover using a finite size (time) interval window, a change from Brownian to non-Brownian fluctuation regimes is clearly shown to define the cloud structure changes. Such findings are similar to those found in DNA and financial data sequences when mosaics of persistent and antipersistent patches are present. The occurrence of these statistics in stratus cloud liquid water content suggests the usefulness of similar studies on cloud-resolving model output and for better meteorological predictability. (C) 1999 Elsevier Science B.V. All rights reserved.