Showing papers on "Disdrometer published in 1993"
TL;DR: In this article, the modification of the drop size spectra of three tropical plantation tree species was measured using a disdrometer and the median volume drop diameters measured were 2.3, 2.8 and 4,2 mm for Pinus caribaea, Eucalyptus camaldulensis, and Tectona grandis, respectively.
Abstract: The modification of the drop size spectra of natural and simulated rainfall by the canopies of three tropical plantation tree species was measured using a disdrometer. Contrary to previously published results, large differences were found between species in the degrees of modification. The median-volume drop diameters measured were 2.3, 2.8, and 4,2 mm for Pinus caribaea, Eucalyptus camaldulensis, and Tectona grandis, respectively. The characteristic drip spectra for the different species are equivalent to the corresponding drop size spectra for rainfall with approximate intensities of 50, 100, and 3000 mm h−1 (essentially infinite) for P. caribaea, E. camaldulensis, and T. grandis, respectively. These results have implications for the choice of the best tree species for areas susceptible to soil erosion.
107 citations
TL;DR: In this article, a linear interpolation between calibration points was applied, and only single peaks were seen in this first, recalibrated dataset. But, field evidence for multiple peak equilibrium distributions obtained in numerical models should be reconsidered.
Abstract: Peaks in number density observed by many authors using Joss-Waldvogel disdrometers are almost certainly due to the manner in which a best-fit curve was chosen to represent the calibration data. The extreme sensitivity to small changes in the calibration curve was demonstrated with extensive observations of Malaysian tropical rain, which for best-fit calibrations showed multiple peaks; however, when a linear interpolation between calibration points was applied, only single peaks were seen in this first, recalibrated dataset. Hence, field evidence for multiple peak equilibrium distributions obtained in numerical models should be reconsidered. On the other hand, the rainfall and radar reflectivity, calculated from best fits, differ by less than 4% from that based on linear interpolation between calibration points.
53 citations
TL;DR: In this paper, the relation between the distribution of equivalent reflectivity, Z(sub e), measured by an airborne C-band radar and that for rain rate, R, measured concurrently by a disdrometer on the same aircraft in the eyewall and outer bands of Hurricane Anita (1977) was investigated using the probability-matching method (PMM).
Abstract: The relation between the distribution of equivalent reflectivity, Z(sub e), measured by an airborne C-band radar and that for rain rate, R, measured concurrently by a disdrometer on the same aircraft in the eyewall and outer bands of Hurricane Anita (1977) was investigated using the probability-matching method (PMM). It was found that the pdf of R is much narrower in the outer rainbands of Hurricane Anita than in the eyewall, and that the mean rain rates are also much smaller. It is shown that the use of PMM provides more realistic relations than the conventional power-law Z-R regression relations based upon scatter-plots of disdrometer measurements, showing higher eyewall reflectivities for the same rain rates at rates in excess of 6.3 mm/h.
20 citations