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Comment on “Current budget of the atmospheric electric global circuit” by Heinz W. Kasemir

1996; American Geophysical Union; Volume: 101; Issue: D12 Linguagem: Inglês

10.1029/95jd01534

2156-2202

Kevin T. Driscoll, Richard J. Blakeslee,

Plant Water Relations and Carbon Dynamics

Kevin T. DriscollGlobal Hydrology and Climate Center, University of Alabama in HuntsvilleRichard J. BlakesleeGlobal Hydrology and Climate Center, NASA Marshall Space Flight Center, Huntsville, AlabamaThe conventional model of the global electric circuit hasbeen discussed in the literature for many years [Dolezalek,1972; Israel, 1973; Volland, 1984; Roble and Tzur, 1986] andwas conceptualized several decades ago in an effort to describethe electrical connection between the large potential of iono-sphere relative to the Earth, the potential gradient at the sur-face of the Earth in areas of fair weather, and the upward flow ofpositive charge in the vicinity of thunderstorms. Throughoutthe years, measurements [Wilson, 1920; Whipple and Scrase,1936; Gish and Wait, 1950; Stergis et al., 1957; Blakeslee etal., 1986] as well as numerical and analytical simulations[Holzer and Saxon, 1952; Kasemir, 1959; Anderson and Freier,1969; Dejnakarintra and Park, 1974; Hayes and Roble, 1979;Driscoll et al., 1992] have advanced our understanding of theglobal electric circuit. Recently, however, Kasemir [1994]introduced a new model for the global circuit that is claimed tobe an improvement over the conventional model. This claimwas based on calculations made with his new model whichappeared to demonstrate the need for a fundamental change inthe generally accepted model of the global circuit, despite thestriking similarities between the components of his newmodel and the thunderstorm model introduced by Holzer andSaxon [1952]. However, a careful examination of Kasemir'snew model reveals that computational and conceptual errorswere made in its development, resulting in erroneous conclu-sions. It is the purpose of this paper to demonstrate the equiva-lence between the conventional model of the global electriccircuit and Kasemir's model, and to refute Kasemir's sugges-tion that the conventional model of the global circuit containssome physical errors and unwarranted assumptions.In this paper, three major issues relevant to Kasemir's newmodel will be addressed. The first concerns Kasemir's assertionthat there are significant differences between the potentialsassociated with the new model and the conventional model. Arecalculation of these potentials reveals that both models pro-vide equivalent results for the potential difference between theEarth and ionosphere. The second issue to be addressed isKasemix's assertion that discrepancies in the electric poten-tials associated with both models can be attributed to modelingthe Earth as a sphere, instead of as a planar surface. A simpleanalytical comparison will demonstrate that diff_mne, es in theequations for the potentials of the