Abstract: The standard deviation of horizontal wind direction is a central quantity in the description of atmospheric turbulence and of great practical use in dispersion models. As horizontal wind direction is a circular variable, ...

Abstract: In earlier works of several authors, wind fields or flow patterns were grouped by means of trajectory calculations or by use of a principal component analysis. A new automated classification method is proposed that makes ...

Abstract: Analysis of vector quantities or directional data, such as the variables characterizing flow, is of significant interest to geophysical fluid dynamicists. For flows with strong channeling, a new simple correlation coefficient ...

Abstract: The method of optimal interpolation, which is widely used in meteorological data assimilation, relies very much on good approximations of spatial correlation functions. Therefore, many models for such functions have been ...

Abstract: The relationship between the surface and synoptic wind direction is examined climatologically in a complex terrain region. Surface winds were observed over a 1-yr period during the MISTRAL project in the Basel, Switzerland, ...

Abstract: A two-stage classification scheme with outlier detection is proposed to find groups of wind fields. A hierarchical cluster analysis according to the complete linkage method is combined with a k-means procedure with detection ...

Abstract: Ten years of global tropospheric data from the European Centre for Medium-Range Weather Forecasts analyses were used to obtain a climatology of quasi-stationary waves and transient normal-mode Rossby waves. The data were ...

Abstract: Optimal averaging is a method to estimate some area mean of datasets with imperfect spatial sampling. The accuracy of the method is tested by application to time series of January temperature fields simulated by the NCAR ...

Abstract: Measurements of the horizontal and vertical wind component by a crosswind scintillometer during foehn, the chinooklike downslope windstorm in the Alps, are presented. Because of the sparsity of vertical velocity measurements ...