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Malone, R. C.

Publications and source records attributed to Malone, R. C..

Nuclear winter - Three-dimensional simulations including interactive transport, scavenging, and solar heating of smoke

A reexamination is conducted of the 'nuclear winter' hypothesis with a three-dimensional global model modified to allow for localized injection of smoke, its transport by the simulated winds, its absorption of sunlight, and its removal by model-simulated precipitation. Smoke injected into the troposphere is driven upward by solar heating. The tropopause, initially above the smoke, reforms below the heat smoke layer and separates it from precipitation below. Although much smoke is scavenged while the thermal structure is being altered, the residence time of the remaining smoke is greatly increased. Particularly for July conditions, a longer-lasting 'nuclear winter' effect is observed than was found in earlier modeling studies in which normal tropospheric residence times were assumed. In January the smaller solar flux in the northern hemisphere allows faster removal of smoke than in July. Significant cooling of the northern hemisphere continents is predicted; its dependence on season and injected smoke mass is described.

Malone, R. C.

Influence of solar heating and precipitation scavenging on the simulated lifetime of post-nuclear war smoke

The behavior of smoke injected into the atmosphere by massive fires that might follow a nuclear war was simulated. Studies with a three-dimensional global atmospheric circulation model showed that heating of the smoke by sunlight would be important and might produce several effects that would decrease the efficiency with which precipitation removes smoke from the atmosphere. The heating gives rise to vertical motions that carry smoke well above the original injection height. Heating of the smoke also causes the tropopause, which is initially above the smoke, to reform below the heated smoke layer. Smoke above the tropopause is physically isolated from precipitation below. Consequently, the atmospheric residence time of the remaining smoke is greatly increased over the prescribed residence times used in previous models of nuclear winter.

Malone, R. C.

Rotating-fluid experiments with an atmospheric general circulation model

In order to determine features of rotating fluid flow that are dependent on the geometry, rotating annulus-type experiments are carried out with a numerical model in spherical coordinates. Rather than constructing and testing a model expressly for this purpose, it is found expedient to modify an existing general circulation model of the atmosphere by removing the model physics and replacing the lower boundary with a uniform surface. A regime diagram derived from these model experiments is presented; its major features are interpreted and contrasted with the major features of rotating annulus regime diagrams. Within the wave regime, a narrow region is found where one or two zonal wave numbers are dominant. The results reveal no upper symmetric regime; wave activity at low rotation rates is thought to be maintained by barotropic rather than baroclinic processes.

Geisler, J. E.

Neutron star evolutionary sequences

Detailed numerical calculations which are solutions of the full set of general relativistic equations describing the evolution of a spherical star are presented, for the case of the evolution of neutron stars that are cooling over the central temperatures range of 10 to the 10th to 10 to the 7th K. The effects of nucleon superfluidity in the inner crust and core are included, and models are constructed with and without a pion condensate at high densities. It is found that the localized neutrino cooling which dominates the early evolution of neutron stars is so rapid that heat transport within the star cannot keep pace, and temperature distribution is not isothermal. The residual contraction of the neutron star during the early cooling phase contributes little to the heat budget of the star, and most of the gravitational energy released raises the Fermi energy of the degenerate nucleons. It is concluded that since calculations with and without pion condensate are consistent with the upper limits of current observations, these are not sufficient in distinguishing between the various models of neutron star cooling.

Richardson, M. B.

Preliminary regime diagram on a sphere with a simplified general circulation model

Numerical model studies useful design considerations and which can be accumulated to form the body of basic knowledge necessary for application of the atmospheric general circulation experiment (AGCE) data to understanding of atmospheric problems are reported. The most efficient way to obtain a computer model suitable for this objective is to modify an existing general circulation model (GCM) of the atmosphere rather than to develop such a model from first principles. The GCM and its modification is outlined.

Pitcher, E. J.