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Title: ARM: Disdrometer: measures rain drop size distribution

Abstract

Disdrometer: measures rain drop size distribution

Authors:
Publication Date:
Research Org.:
Atmospheric Radiation Measurement (ARM) Archive, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (US)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
OSTI Identifier:
1025181
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Data
Data Type:
Numeric Data
Country of Publication:
United States
Availability:
Atmospheric Radiation Measurement (ARM) Archive, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (US);
Language:
English
Subject:
54 Environmental Sciences; Horizontal wind; Hydrometeor fall velocity; Hydrometeor size; Hydrometeor Size Distribution; Precipitation; Radar reflectivity

Citation Formats

Mary Jane Bartholomew. ARM: Disdrometer: measures rain drop size distribution. United States: N. p., 2006. Web. doi:10.5439/1025181.
Mary Jane Bartholomew. ARM: Disdrometer: measures rain drop size distribution. United States. doi:10.5439/1025181.
Mary Jane Bartholomew. Wed . "ARM: Disdrometer: measures rain drop size distribution". United States. doi:10.5439/1025181. https://www.osti.gov/servlets/purl/1025181.
@article{osti_1025181,
title = {ARM: Disdrometer: measures rain drop size distribution},
author = {Mary Jane Bartholomew},
abstractNote = {Disdrometer: measures rain drop size distribution},
doi = {10.5439/1025181},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 11 00:00:00 EST 2006},
month = {Wed Jan 11 00:00:00 EST 2006}
}

Dataset:

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  • Video Disdrometer Drop Size Distribution
  • Video Disdrometer Individual Drop Data
  • This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles ofmore » the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.« less
  • Parsivel2 Laser Disdrometer
  • Extended, high-resolution measurements of vertical air motion and median volume drop diameter D0 in widespread precipitation from three diverse Atmospheric Radiation Measurement Program (ARM) locations [Lamont, Oklahoma, Southern Great Plains site (SGP); Niamey, Niger; and Black Forest, Germany] are presented. The analysis indicates a weak (0-10 cm{sup -1}) downward air motion beneath the melting layer for all three regions, a magnitude that is to within the typical uncertainty of the retrieval methods. On average, the hourly estimated standard deviation of the vertical air motion is 0.25 m s{sup -1} with no pronounced vertical structure. Profiles of D0 vary according tomore » region and rainfall rate. The standard deviation of 1-min-averaged D0 profiles for isolated rainfall rate intervals is 0.3-0.4 mm. Additional insights into the form of the raindrop size distribution are provided using available dual-frequency Doppler velocity observations at SGP. The analysis suggests that gamma functions better explain paired velocity observations and radar retrievals for the Oklahoma dataset. This study will be useful in assessing uncertainties introduced in the measurement of precipitation parameters from ground-based and spaceborne remote sensors that are due to small-scale variability.« less