Multifractal characterization of nonstationarity and intermittency of cloud base height signals

Cloud base profiles measured with laser ceilometer are studied using multifractal approach. The method assesses nonstationarity and intermittency pertinent to such highly fluctuating signals. The irregular structure of the signals is a benchmark for non-linear dynamics processes. The analysis searches for the scaling properties of q-th order singular measures and q-th order structure functions. Therefore, the method seeks for various scales of self-affinity, i.e. searches for multi-affinity. We found that multifractality is the signature of the cloud base height profiles, characterized with a hierarchy of exponems q H(q) and K(q). The value of the roughness parameter H₁ is consistent with the one obtained for the same data using different method of analysis. The multifractal behavior is consistent also with the multi-affine properties of other atmospheric data recorded simultaneously during the same field experimemt ASTEX'92.