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Joachim P. Kuettner
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Joachim P. Kuettner and Joshua Holland

This article, written a few days before the beginning of the field operations, summarizes the scientific and operational plans for BOMEX, the “Barbados Oceanographic Meteorological Experiment.” The basic concept of BOMEX has been described earlier by its former director, Ben Davidson (1968). His untimely death created a temporary crisis in the scientific direction of the project; however, his experiment design and his underlying thoughts have proved sound and no major changes in the layout or scientific objectives have been necessary. In the opinion of the project staff, Ben Davidson remains the man behind BOMEX. Continuity has been preserved throughout the BOMEX preparations by the Project Manager, William Barney, and his multi-agency staff.

At this time, ships, airplanes and scientists are converging on Barbados. Therefore, the plans described here are by necessity final. Only facts of life can change them.

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Joachim P. Kuettner and Stanley D. Soules
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Joachim P. Kuettner, J. Doyne Sartor, and Zev Levin

Abstract

Most of the precipitation related theories on charge generation in thunderstorms fall into one of two categories: the inductive or polarization mechanism initiated by the ambient fair-weather field, and the non-inductive mechanism connected with certain electrochemical or thermoelectric particle characteristics. Our numerical study addresses the question of which mechanism gives more realistic results with regard to charge distribution and hold strength and what effect a combination of the two processes produces. The investigation is a first attempt using a simplified model.

In this model the microphysical processes of particle growth and simultaneous electrification are embedded in a steady state two-dimensional vortex circulation with and without vertical wind shear. The net space charge and potential are obtained everywhere in the cloud and the resulting electric fields are calculated. Computations are made for the collisions of growing solid precipitation (graupel) particles with either supercooled droplets (ice-water case) or with ice crystals (ice-ice case).

The results indicate that the non-inductive mechanism produces a rapid growth of the electric field in the early stages but tends to level out at a stable value considerably below the breakdown field strength. The inductive mechanism in turn shows a slow initial field growth with quickly varying charge distributions of often inverted polarity; however, it will reach breakdown field strength eventually due to its quasi-exponential growth character. Only the combination of the two processes achieves realistic thunderstorm conditions. It appears that the non-inductive mechanism controls the charge distribution and its polarity, and the inductive mechanism the field strength. both ice-water and ice-ice collisions give similar results, the only difference being a higher elevation of the charge dipole. in the ice-ice case. The opposite precipitation and cloud charges are always strongly masked.

The results permit some interesting conclusions on the origin of the fair-weather field.

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Joachim P. Kuettner and Thomas H. R. O'Neill

The problem of airflow over and around mountains, as originally proposed by J. Charney, R. Hide, F. Mesinger, and G. Goetz, was approved in 1978 as a subprogram of the Global Atmospheric Research Program (GARP) by the Joint Organizing Committee (JOC) of the International Council of Scientific Unions (ICSU) and the World Meteorological Organization (WMO). ALPEX will be the field project of this subprogram and, as the name indicates, the general area of the Alps has been selected as its site. The primary observing period will be during March and April 1982. ALPEX will complete the series of large international field projects of GARP (UCAR, 1980; ICSU/WMO, 1980e).

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GATE

final international scientific plans

International and Scientific Management Group for GATE, Joachim P. Kuettner, David E. Parker, David R. Rodenhuis, Heinrich Hoeber, Helmut Kraus, and G. Philander
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Randolph H. Ware, David W. Fulker, Seth A. Stein, David N. Anderson, Susan K. Avery, Richard D. Clark, Kelvin K. Droegemeier, Joachim P. Kuettner, J. Bernard Minster, and Soroosh Sorooshian

“SuomiNet,” a university-based, real-time, national Global Positioning System (GPS) network, is being developed for atmospheric research and education with funding from the National Science Foundation and with cost share from collaborating universities. The network, named to honor meteorological satellite pioneer Verner Suomi, will exploit the recently shown ability of ground-based GPS receivers to make thousands of accurate upper- and lower-atmospheric measurements per day. Phase delays induced in GPS signals by the ionosphere and neutral atmosphere can be measured with high precision simultaneously along a dozen or so GPS ray paths in the field of view. These delays can be converted into integrated water vapor (if surface pressure data or estimates are available) and total electron content (TEC), along each GPS ray path. The resulting continuous, accurate, all-weather, real-time GPS moisture data will help advance university research in mesoscale modeling and data assimilation, severe weather, precipitation, cloud dynamics, regional climate, and hydrology. Similarly, continuous, accurate, all-weather, real-time TEC data have applications in modeling and prediction of severe terrestrial and space weather, detection and forecasting of low-altitude ionospheric scintillation activity and geomagnetic storm effects at ionospheric midlatitudes, and detection of ionospheric effects induced by a variety of geophysical events. SuomiNet data also have potential applications in coastal meteorology, providing ground truth for satellite radiometry, and detection of scintillation associated with atmospheric turbulence in the lower troposphere. The goal of SuomiNet is to make large amounts of spatially and temporally dense GPS-sensed atmospheric data widely available in real time, for academic research and education. Information on participation in SuomiNet is available via www.unidata.ucar.edu/suominet.

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