47 research outputs found
Moving Forward: Refinement of the INTELLIGENT RIVER, A Basin-Scale Monitoring Instrument
2012 S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen
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Measurements of atmospheric electricity aloft
Measurements of the electrical characteristics of the atmosphere above the surface have been made for over 200 years, from a variety of different platforms, including kites, balloons, rockets and aircraft. From these measurements, a great deal of information about the electrical characteristics of the atmosphere has been gained, assisting our understanding of the global atmospheric electric circuit, thunderstorm electrification and lightning generation mechanisms, discovery of transient luminous events above thunderstorms, and many other electrical phenomena. This paper surveys the history of atmospheric electrical measurements aloft, from the earliest manned balloon ascents to current day observations with free balloons and aircraft. Measurements of atmospheric electrical parameters in a range of meteorological conditions are described, including clear air conditions, polluted conditions, non-thunderstorm clouds, and thunderstorm clouds, spanning a range of atmospheric conditions, from fair weather, to the most electrically active
Relationship between level of neutral buoyancy and dual-Doppler observed mass detrainment levels in deep convection
Although it is generally accepted that the level of neutral buoyancy (LNB) is only a coarse estimate of updraft depth, the LNB is still used to understand and predict storm structure in both observations and modeling. This study uses case studies to quantify the variability associated with using environmental soundings to predict detrainment levels. Nine dual-Doppler convective cases were used to determine the observed level of maximum detrainment (LMD) to compare with the LNB. The LNB for each case was calculated with a variety of methods and with a variety of sources (including both observed and simulated soundings). The most representative LNB was chosen as the proximity sounding from NARR using the most unstable parcel and including ice processes. <br><br> The observed cases were a mix of storm morphologies, including both supercell and multicell storms. As expected, the LMD was generally below the LNB, the mean offset for all cases being 2.2 km. However, there was a marked difference between the supercell and non-supercell cases. The two supercell cases had LMDs of 0.3 km and 0.0 km below the LNB. The remaining cases had LMDs that ranged from 4.0 km below to 1.6 km below the LNB, with a mean offset of 2.8 km below. Observations also showed that evolution of the LMD over the lifetime of the storm can be significant (e.g., >2 km altitude change in 30 min), and this time evolution is lacking from models with coarse time steps, missing significant changes in detrainment levels that may strongly impact the amount of boundary layer mass transported to the upper troposphere and lower stratosphere