Physics Commons^™

An Example Of Persistent Microstructure In A Long Rain Event, A. R. Jameson, M. L. Larsen, A. B. Kostinski

Department of Physics Publications

A 2D video disdrometer (2DVD) probe was used to gather detailed drop measurements over a 770-min rain event. Accumulated totals of the rainfall and of the number of drops for each square centimeter showed persistent, significant correlated structures across the approximately 11 cm × 11 cm grid of the 2DVD. This is surprising because larger-scale studies suggest that the values in each square centimeter should be highly correlated with very little variation. Nevertheless, this correlation remains strikingly similar to what is observed at a coarser resolution, suggesting that it somehow scales with spatial resolution. However, because the correlation functions are …

On The Variability Of Drop Size Distributions Over Areas, A. R. Jameson, M. L. Larsen, A. B. Kostinski

Department of Physics Publications

Past studies of the variability of drop size distributions (DSDs) have used moments of the distribution such as the mass-weighted mean drop size as proxies for the entire size distribution. In this study, however, the authors separate the total number of drops N_t from the DSD leaving the probability size distributions (PSDs); that is, DSD = N_t × PSD. The variability of the PSDs are then considered using the frequencies of size [P(D)] values at each different drop diameter P(P_D | D) over an ensemble of observations collected using a …

Evolution And Distribution Of Record-Breaking High And Low Monthly Mean Temperatures, Amalia Anderson, Alexander Kostinski

Department of Physics Publications

The ratio of record highs to record lows is examined with respect to extent of time series for monthly mean temperatures within the continental United States for 1900–2006. In counting the number of records that occur in a single year, the authors find a ratio greater than unity in 2006, increasing nearly monotonically as the time series increases in length via a variable first year over 1900–76. For example, in 2006, the ratio of record highs to record lows ≈ 13:1 with 1950 as the first year and ≈ 25:1 with 1900 as the first year; both ratios are an …

Direct Observations Of Coherent Backscatter Of Radar Waves In Precipitation, A. R. Jameson, A. B. Kostinski

Department of Physics Publications

In previous work, it was argued that a source of radar coherent scatter occurs in the direction perpendicular to the direction of wave propagation because of the presence of grids of enhanced particle concentrations with spatial periodicities in resonance with the radar wavelength. While convincing, the evidence thus far has been indirect. In this work the authors now present direct observations of radar coherent backscattered signals in precipitation in the direction of wave propagation.

The theory is developed for the cross-correlation function of the complex amplitudes in the direction of propagation calculated for nearest neighbor range bins. Data are analyzed …